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A 3.4 DOHC Build then... F40 Turbo by Fierobsessed
Started on: 02-04-2013 03:59 AM
Replies: 560 (36013 views)
Last post by: zkhennings on 11-19-2021 04:35 PM
Fierobsessed
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Report this Post02-17-2016 09:30 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
I ran it up to 18 PSI... and the clutch can't handle it. It slips a little in 3rd and 4th when the power peaks, but then grabs again after a little slippage. So, I'm backing it down to 16 again. Too much power otherwise. Damn shame really. It's monstrous at 18. I can bust the tires free at around 75 mph pretty easily. It's just really nice to not be held back by crap 91 octane.

I definitely hear what you are saying with the different blends, I know they have to cut it with gasoline to de-nature the alcohol right off the bat. I wish it really were E-85. It's really impressive to see what an impact there is just by increasing the ethanol content by 50%. 85% would be really nice.

I'm working on some more code stuff, some refinements. I've found that compensating the BPC vs EGR based on ethanol content isn't doing all that great. BLM's are at 128 in idle cell, but 144 when on throttle. So that means the fueling curves are a little whacked. Could be because of injector non-linearity, as the injectors operate in a happier zone on E-85. Perhaps a little combination of both, give it some love on injector offsets, and feed it some stronger BPC compensations for the ethanol, that might fix it.
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Report this Post02-18-2016 10:33 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
Definitely thinking a lot about the clutch lately. It's really been weighing on my mind. I've looked into twin and triple disc Tiltons which are a little pricey, but have actual torque ratings. And, then again, I was really close to having enough torque capacity with what I have, I just should increase the pressure plate ratio. But to do that I would need to make a custom flywheel.. again. Which is really starting to sound like the only way to go. Perhaps a shift to a 4 or 3 (eek!) button/puck clutch with a higher pressure plate ratio would fix a few issues. I'd get better modulation due to the PP ratio, and lower disc inertia due to less friction material, and far more holding capacity. Only sacrifice would be... clutch life and opposing surface destruction. I would likely move towards using my spec SCC883 pressure plate, as it already has a very high pressure plate ratio. It's higher than my custom one, but requires either a thicker disc, or a stepped flywheel, which means custom flywheel for sure.

As I type this, I realize that my decision is already made. Better get some materials and get to work.
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Report this Post02-19-2016 04:55 PM Click Here to See the Profile for RobertISaarSend a Private Message to RobertISaarEdit/Delete MessageReply w/QuoteDirect Link to This Post
time for a max PSI vs gear table, either temporarily until the new flywheel is done or perhaps a permanent addition in case you find other weak links?
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Report this Post02-20-2016 05:11 AM Click Here to See the Profile for mr_coreanSend a Private Message to mr_coreanEdit/Delete MessageReply w/QuoteDirect Link to This Post
Dave told me you were going to give me your old fuel setup for my birthday. I think that's mighty kind of you.
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Report this Post02-21-2016 05:39 AM Click Here to See the Profile for sardonyx247Click Here to visit sardonyx247's HomePageSend a Private Message to sardonyx247Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by mr_corean:

Dave told me you were going to give me your old fuel setup for my birthday. I think that's mighty kind of you.


Yeah good luck with that, I already tried, and wants to hang on to it "just in case" I don't blame him on that.


I hope you figure out a good high HP clutch setup as I will need one soon too
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Report this Post02-21-2016 09:01 AM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
I'm running a bully stage 6 in my turbo 3500, but I haven't really hammered down on it yet.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
//www.fiero.nl/forum/Forum2/HTML/119122.html

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Report this Post02-22-2016 04:25 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
Clutchnet "4BS9421"

with a Spec SCC883 Pressure plate

Iv'e had this pressure plate kicking around since the original build, I just need to make a flywheel that is stepped to work with the new disc, and the pressure plate.

Metal is starting to show up for making the flywheel... so this will be fun.

Don't you mean a bully stage 4? Looks to me to be almost exactly the same thing I'm putting in anyway. 4 pucks instead of 6, which should add some more grip, and its still sprung. And, with Specs high ratio pressure plate, It's going to feel exactly like a stock clutch, but may be a little tougher to modulate, and won't last as long as it could. But it should easily hold quite a bit more than this clutch has been holding.

Since E-85 is working out so well with my car, My "Old" fuel setup is now destined to end up on my eventual 3800 SC build. It's ideally sized for that application. Sorry guys, I'll definitely be needing it in the future.
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Report this Post02-23-2016 12:55 PM Click Here to See the Profile for zjwesterSend a Private Message to zjwesterEdit/Delete MessageReply w/QuoteDirect Link to This Post
This is an amazing build! i have been watching it for a while and thinking about a turbo...
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Report this Post02-23-2016 01:26 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
I meant stage 4, I don't know where stage 6 came from. it is a 4 puck sprung hub though. I'm happy with it so far, very smooth, but I haven't hit it too hard yet either.
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Report this Post02-25-2016 04:51 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
Looking at my data logs from my quarter mile run, I learned a lot about my driving, and the car, and how the two of us can work together to shave a butt-load of time off the ET.

The breakdown looks like this:
0.0s I launched, no boost at all at and at 100% throttle the moment the wheels started turning
1.6s Boost hits 10 PSI in first gear, I'll consider this the point where the turbo is "Spooled" I was actually pushing 16 PSI solidly when in boost.
2.2s I release the throttle and shift. This also happens to coincide exactly with my 60' time.
2.7s I'm back at full throttle, so my 1-2 shift was 0.5 seconds to complete.
3.1s Turbo is back to 10+ psi. that's 0.4s after the shift was complete.
4.8s I release the throttle and shift
5.4s Full throttle, 2-3 shift was 0.6 seconds long.
5.7s Turbo is back to 10+ psi. that's 0.3s after the shift was complete.
8.7s Shift begins
9.3s Shift complete 3-4 was 0.6s
9.5s Boost is back at 10+ .2 seconds after the shift.
12.85 at 117.

It was a good run, but It really pointed out where improvements could be made.
If I consider anything that is below 10 PSI, to be turbo dead time, then...
I was out of boost for 4.1 seconds of the quarter. In boost for 8.7.
Total time at zero throttle? 1.6 seconds.

Realizing these issues, I wrote some new code, ran a wire between the ECM and the cruise control servo to tap into the brake/clutch input, and added two new features:
No lift to shift, and staging control.
No lift in my code works as follows. When the throttle is at 90%+ and the clutch pedal is not fully released, (basically anytime its pressed at all) a lower rev limiter is set based on current speed. It sets a rev limiter at the predicted RPM that the next gear will shift into.

Staging control is simply a rev limiter that is present when the vehicle speed is below a specified MPH. I have it set for 5 MPH and 3200 RPM.
So I can floor it and the engine will bounce off the rev limiter at 3200. Then as I release the clutch and the car takes off, it will exceed the 5 MPH and allow the rev limiter to jump to 7000.

In testing, I found that although the code works exactly as intended, the driver (me) has to re-learn how to drive stick, as everything I have ever known to be right says to remove the right foot from throttle when using the clutch, and so far, in two attempts, I have failed.

Best part, I found that the turbo remains in boost for a whopping 2 whole seconds when No Lift To Shift kicks in. That's astoundingly long. The engine at high RPM with the throttle blade open, pumps plenty of air to keep the turbo more than happy. Its when you close the throttle blade for a half a second at 16 PSI, you will only have 0-2 PSI when the throttle blade opens fully again. The Blow off valve doesn't do anything to keep the turbo spooled, it merely keeps the turbo from suffering a massive air reversion through the compressor (compressor stall/surge) which can cause catastrophic damage to the turbo.

I'm still struggling with the whole right foot thing, but I can't wait to try it out again when I find a safe place to practice.

Shortening the shift times themselves will have to be a function of a new, lower inertia clutch disc, and I'll have to be more aggressive myself.
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Report this Post02-26-2016 12:07 PM Click Here to See the Profile for 3.1 88FieroGTSend a Private Message to 3.1 88FieroGTEdit/Delete MessageReply w/QuoteDirect Link to This Post
Doesn't look like you have a whole lot of room but a recirculating blow off valve would help with losing boost during shifting. Are you using a maf or just map sensor? Your coding and tuning abilities are very inspiring lol. I'm hoping to have my build up and going before spring. Picked up a 97 monte carlo for obd2 donor harness and 4t65e transmission. Going to be using dhp tuner which seems to have its limits.

[This message has been edited by 3.1 88FieroGT (edited 02-26-2016).]

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Report this Post02-26-2016 08:16 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
MAP only.

Thanks for the compliment, I'm going to release the code and the highly modified definition that has all the patches, and custom stuff when I find a nice way to do so, and I get the definition buttered up for a public release.

Recirculative BOV's are said to be for MAF applications where you don't want to vent already measured air. But even then, it's kind of BS. The compressed air between the turbo and throttle blade still gets measured as it reverts back through the MAF. So even then, it's not really doing as it's advertised.

Either way, when the throttle blade shuts, almost all of the driving energy from the exhaust stops driving the turbine, and the compressor is still pumping a whole lot of air through the BOV, no matter the type. So the turbo has all the reason in the world to slow down as quickly as possible. Keeping the throttle blade wide open, allows the turbo to pump the air into the engine still, and a large amount of exhaust continues to drive the turbine, so the turbo slows down very gracefully. And as soon as the fuel comes back on the boost is already mostly present.

I'm currently working on the flywheel, so far so good , I've got the material machined to shape, I just have a ton of holes to drill, tap and counterbore. I took a bunch of pics, looking forward to seeing how it comes out.
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Report this Post03-05-2016 08:37 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
It's been a fun week. Loads of work was done on the flywheel, So here goes!

Raw materials


I drew a 12" circle on it just to give me an idea where I needed to trim it down


I had to cut the flywheel down to a rough circle, since my lathe can only tolerate a roughly 12.5" diameter stock before I have to pull the gap bed out. Trusty sawsall did the work. It was a lot of cutting!


I needed a hole in the center to even chuck the stock, so I had to break out the hole saw.



Then, I started chipping away at the OD and the ID, working the center out to 5" and the OD down to 11.600" and then surface cuts on both sides.


The disc blank is done!


Next, I had to work on the hub section. I intended this flywheel to be two pieces as it would have been a colossal piece of billet. I could have done that, but it would have been more work really.
Same treatment as before, trim down the outside bore the ID, surface both sides. This time I was able to chuck it from the outside, 7" is right on the edge of what my 3 jaw could take with the external jaws.


Then I did the disc side cuts.


Then the engine side cuts, the two pieces fit together nicely!


With the billet blanks done being machined, It was time to take the take them over to the milling machine and start putting a whole lot of holes in them. The rotary table was as much of an indispensable part of the production as the lathe.


I started my taps with the milling machine right after drilling the holes, so I know they were straight and true, and located exactly in the right place. I then finished off the holes with the hand tap. Much lower risk.



Lotsa holes!


For the off the shelf Fidanza friction plate to bolt to the disc, I had to counterbore all the holes for the length of the screws.


I then made 6 stand-offs for the starter ring, easy work on the lathe again


I figured out what my plate depth needed to be. I wound up having the friction disc be 0.040" above the surface of the flywheel. This way I can use the increased clamp pressure plates with my clutchnet disc.


Bolted on the stand-offs.


Cut a little off the edge off the standoffs till I had them down to 11.092" and then slipped the ring gear over the standoffs.


A little welding


Bolt it all together, and that's pretty much it!



Also, I got my Clutchnet "95-08 Ford Ranger" clutch disc.


It's all coming together... I still have to do some pressure plate soul searching. I need to find a more positive release design, and a ton+ of clamping force. Hopefully I can find a good answer to that issue.
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Report this Post03-08-2016 12:26 AM Click Here to See the Profile for sardonyx247Click Here to visit sardonyx247's HomePageSend a Private Message to sardonyx247Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Fierobsessed:

Looking at my data logs from my quarter mile run, I learned a lot about my driving, and the car, and how the two of us can work together to shave a butt-load of time off the ET.

The breakdown looks like this:
0.0s I launched, no boost at all at and at 100% throttle the moment the wheels started turning
1.6s Boost hits 10 PSI in first gear, I'll consider this the point where the turbo is "Spooled" I was actually pushing 16 PSI solidly when in boost.
2.2s I release the throttle and shift. This also happens to coincide exactly with my 60' time.
2.7s I'm back at full throttle, so my 1-2 shift was 0.5 seconds to complete.
3.1s Turbo is back to 10+ psi. that's 0.4s after the shift was complete.
4.8s I release the throttle and shift
5.4s Full throttle, 2-3 shift was 0.6 seconds long.
5.7s Turbo is back to 10+ psi. that's 0.3s after the shift was complete.
8.7s Shift begins
9.3s Shift complete 3-4 was 0.6s
9.5s Boost is back at 10+ .2 seconds after the shift.
12.85 at 117.

It was a good run, but It really pointed out where improvements could be made.
If I consider anything that is below 10 PSI, to be turbo dead time, then...
I was out of boost for 4.1 seconds of the quarter. In boost for 8.7.
Total time at zero throttle? 1.6 seconds.

Realizing these issues, I wrote some new code, ran a wire between the ECM and the cruise control servo to tap into the brake/clutch input, and added two new features:
No lift to shift, and staging control.
No lift in my code works as follows. When the throttle is at 90%+ and the clutch pedal is not fully released, (basically anytime its pressed at all) a lower rev limiter is set based on current speed. It sets a rev limiter at the predicted RPM that the next gear will shift into.

Staging control is simply a rev limiter that is present when the vehicle speed is below a specified MPH. I have it set for 5 MPH and 3200 RPM.
So I can floor it and the engine will bounce off the rev limiter at 3200. Then as I release the clutch and the car takes off, it will exceed the 5 MPH and allow the rev limiter to jump to 7000.

In testing, I found that although the code works exactly as intended, the driver (me) has to re-learn how to drive stick, as everything I have ever known to be right says to remove the right foot from throttle when using the clutch, and so far, in two attempts, I have failed.

Best part, I found that the turbo remains in boost for a whopping 2 whole seconds when No Lift To Shift kicks in. That's astoundingly long. The engine at high RPM with the throttle blade open, pumps plenty of air to keep the turbo more than happy. Its when you close the throttle blade for a half a second at 16 PSI, you will only have 0-2 PSI when the throttle blade opens fully again. The Blow off valve doesn't do anything to keep the turbo spooled, it merely keeps the turbo from suffering a massive air reversion through the compressor (compressor stall/surge) which can cause catastrophic damage to the turbo.

I'm still struggling with the whole right foot thing, but I can't wait to try it out again when I find a safe place to practice.

Shortening the shift times themselves will have to be a function of a new, lower inertia clutch disc, and I'll have to be more aggressive myself.


You know I came up with the EXACT same idea for launch/staging control at the last track day. and to be done exactly the same way.
RPM limit under certain MPH.

Looking at your last set of pics, you prob spend more time with your lathe than you do you wife

Can't wait to see this next track day Show everyone what a 60deg can do!!!!!
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Will
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Report this Post03-09-2016 09:21 PM Click Here to See the Profile for WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by sardonyx247:

You know I came up with the EXACT same idea for launch/staging control at the last track day. and to be done exactly the same way.
RPM limit under certain MPH.


FYI, DMSLink was doing shift-no-lift since at least the early 2000's (and I'm sure others did it before that).
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Report this Post03-10-2016 04:45 AM Click Here to See the Profile for sardonyx247Click Here to visit sardonyx247's HomePageSend a Private Message to sardonyx247Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Will:


FYI, DMSLink was doing shift-no-lift since at least the early 2000's (and I'm sure others did it before that).


No I was thinking of launch control, and I know others have done it, I was just thinking about how to do it on a Fiero ECM with the knowledge that I have, not saying I am the first, but saying I thought of how to do it myself, with no knowledge of how it is done.
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Report this Post03-20-2016 03:58 PM Click Here to See the Profile for 3.1 88FieroGTSend a Private Message to 3.1 88FieroGTEdit/Delete MessageReply w/QuoteDirect Link to This Post
Bump for update
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Report this Post08-09-2016 08:35 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
any updates?
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Report this Post08-15-2016 08:34 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
None to speak of. Its 110 degrees outside and the car runs too hot in the summer to drive. The old clutch and flywheel are still in the car, and it still slips. The synchros on the transmission are being funky too. So I will have a bit of a go through at some point to address all these issues. But in the meantime, it is parked just mainly due to the heat.

I am working on a 3800 SC build for my other car in the meantime, and that's coming out great so far. But I've been quiet here while I mess around with that.
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Report this Post08-23-2016 02:46 PM Click Here to See the Profile for Joseph UpsonSend a Private Message to Joseph UpsonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Fierobsessed:
None to speak of. Its 110 degrees outside and the car runs too hot in the summer to drive. The old clutch and flywheel are still in the car, and it still slips. The synchros on the transmission are being funky too. So I will have a bit of a go through at some point to address all these issues. But in the meantime, it is parked just mainly due to the heat.

I am working on a 3800 SC build for my other car in the meantime, and that's coming out great so far. But I've been quiet here while I mess around with that.


If you have the means or a local shop near by, have your pressure plate clamping pressure checked as that may be all you need to address to resolve the slip issue. I had mine modified to 2300 lbs as you may recall from a ~1900 lb baseline.

As for the synchro issue, if it's not the common struggle associated with first and second gear on cold start up I'd be concerned. Before my first F40 started to come apart I had trouble shifting into 6th gear without a scrape under light load for about a month. It was a strange, new, seemingly minor issue until it wasn't. Hope that's not the case because if it is that means you probably have to back off the boost. As for your cooling issue, if you can't keep temps around 210-215 deg F under normal driving in 110 deg heat I'd be suspicious of a possible foreign object somewhere on the engine end of the coolant passages.

Is it possible you have a coolant loop somewhere in the system like what's found on the 2.8L where coolant bypasses the engine headed toward the heater core until the thermostat opens?


Just looked at some of your pics earlier in the thread, I see you have some recirculating coolant nipples on the water pump inlet housing. Is it possible recirculating hot coolant is the culprit? The 3900 has a similar arrangement where some coolant coming directly from the cylinder head coolant outlet is recirculated directly to the pump inlet.

[This message has been edited by Joseph Upson (edited 08-23-2016).]

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Report this Post08-29-2016 12:08 AM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
There are two circuits that recirculates the coolant within the engine full time.

One is the oil cooler loop. This one has a fitting with a 1/8 maybe 3/16" hole in the front water jacket drain port as a supply to the oil cooler. It dumps the coolant back into the water pump inlet.
The second is the turbo cooling loop. It taps off the throttle body coolant line coming from the intake. Then it runs through the turbo and wastegate. It also returns to the water pump inlet. It is a 1/2" pipe, but it has some choke points. The coolant likely comes back pretty toasty.

Perhaps you are onto something there. Maybe I can route both of those circuits to dump into the radiator inlet. Proportionally, they probably can flow about 1/4 of the total coolant. Shouldn't be an issue, but I can't shrug it off as not possible.

For the clutch I've built a new pressure plate that seems to have a higher clamping force. I also purchased that 4 puck disc to reduce inertia and increase torque capacity. I'll probably just re-synchro the transmission anyway. Certainly 1-3 or 1-4. I found some metal accumulating on the VSS, which is quite magnetic. So, well, yeah.

Either way, second kid on the way, time is going to be an issue again soon.
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Report this Post09-20-2016 08:06 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
Got a little bit of work done yesterday. Since the transmission was peeing all over the garage floor, I finally changed the drivers side axle seal and put new proper GM fluid in. I also replaced the cracked EGR tube and changed my registration over to Classic Rod. Now that the weather is cooperating, I can drive the car on the weekends again. I really missed taking this thing out and pouncing on the throttle occasionally. I wanted to see if using the factory fluid will help the transmission shift better. If not, I'll have to re-synchro the trans when I finally get around to change the clutch.
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Report this Post03-20-2017 04:19 PM Click Here to See the Profile for 3.1 88FieroGTSend a Private Message to 3.1 88FieroGTEdit/Delete MessageReply w/QuoteDirect Link to This Post
time for an update...
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Report this Post05-03-2017 07:50 AM Click Here to See the Profile for IrrationableSend a Private Message to IrrationableEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 3.1 88FieroGT:

time for an update...


2x
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Fierobsessed
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Report this Post05-21-2017 08:10 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
It's been forever since I've done much of an update. Honestly Its just been sitting. I had another kid in November, a whole 3 months earlier than planned. So, to say the least, things have slowed to a crawl for the last... almost a year.

I did drive the car once and still likes to overheat. It had also decided to break the 3 bar map sensor. I thought it blew the ECM up, but it did turn out to be the MAP.

I replaced the MAP with an expensive GM OEM unit. The car runs and drives great! Still makes much more power than the clutch can handle.

It just gets hot after driving for a while. I'm still pushing around theories as to why it runs hot. I truly don't know why. I'm starting to think its a growing air bubble on the engine side that it cannot purge to the radiator due to the high point being the engine itself. Maybe a simple high inline fill port like the car originally had will fix it, or at least keep air pockets from getting trapped inside the engine itself. That's my latest theory. The turbo is in the engine coolant loop and dumps back into the engine at the inlet. So, if the turbo is boiling water, the expansion can easily get trapped in the engine. My thermostat outlet goes straight down and forward to the radiator, so its probably not flushing any expansion forward as gas. Perhaps this is a critical part of Fiero cooling theory that I just never considered.

You can see what I mean here. The coolant outlet is the stainless 1.25" pipe right near the turbo inlet.


I don't have any intention of doing anything major on the car anytime soon. I really wanted to do the flywheel and clutch thing so I can dyno it and maybe rip off a wicked 11 second 1/4 mile pass.

On the other hand, I did send the tail lights out for the refinishing service, so it's not like nothing has been done at all. I just wish I had time to do it all up.
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ericjon262
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Report this Post05-21-2017 09:59 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
have you pressure tested your cooling system yet? my car was overheating, I saw no signs of a leak, but when I pressure tested it, it leaked down very quickly. turned out, the worm clamps to and from the radiator were not tight enough, I replace several with T-bolt clamps, and put the fear of god in them, and it stopped overheating.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
//www.fiero.nl/forum/Forum2/HTML/119122.html

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Fierobsessed
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Report this Post05-23-2017 09:45 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
Nah, never pressure tested it. Probably wouldn't be a bad idea.
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Neils88
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Report this Post05-27-2017 03:53 PM Click Here to See the Profile for Neils88Send a Private Message to Neils88Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by ericjon262:
"...and put the fear of god in them, and it stopped overheating. "



I never thought of using threats of violence as a maintenance tool.... I'll have to add that one to my tool box.
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ericjon262
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Report this Post05-27-2017 05:26 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Neils88:


I never thought of using threats of violence as a maintenance tool.... I'll have to add that one to my tool box.



lol, it works, I promise.
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mr_corean
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Report this Post05-29-2017 05:46 PM Click Here to See the Profile for mr_coreanSend a Private Message to mr_coreanEdit/Delete MessageReply w/QuoteDirect Link to This Post
I might be talking out my ass here, but could you put some sort of a purge valve like our fuel pressure valve? Then you could just run a hose to that into a bucket and purge it until only liquid and no gases were coming from the line. I'm guessing that's the high point in the lines right?
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Report this Post07-11-2017 07:46 PM Click Here to See the Profile for elitoprClick Here to visit elitopr's HomePageSend a Private Message to elitoprEdit/Delete MessageReply w/QuoteDirect Link to This Post
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ericjon262
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Report this Post07-12-2017 10:57 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by mr_corean:

I might be talking out my ass here, but could you put some sort of a purge valve like our fuel pressure valve? Then you could just run a hose to that into a bucket and purge it until only liquid and no gases were coming from the line. I'm guessing that's the high point in the lines right?



kind of already exists, the radiator cap should provide this function for gasses in the radiator, and *most* engines made past the late 80's/early 90's have bleed valves installed at the high points in the system. with my car, I went a step further, and installed a small tank in the recirculation line that goes from the thermostat housing, back to the water pump. the tank provides for a high point fill in the engine compartment, and has enough volume to allow the velocity of coolant in the tank to lower, and allow gas bubbles to collect there instead of going back into the engine where heat transfer would be effected. I also installed a bleed valve on the tank to allow the gasses to be vented when the system has pressure.


there's pictures of my setup on RFT, and until I find a suitable replacement for photobucket, I won't have them posted elsewhere.

http://phpbb.realfierotech....4510f5475412#p153537

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
//www.fiero.nl/forum/Forum2/HTML/119122.html

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Fierobsessed
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Report this Post12-04-2017 11:42 PM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
Apologies for the radio silence as of late. Just haven't been working on it or for that matter fixing the little issues till now.

I finally got around to doing some work on my car.

I pulled the cradle, pulled the transmission and replaced the synchros. Which as it turns out, they don't appear to be bad. The clutch may have been causing all of my issues with shifting. So... I'll keep the old synchros in a safe place in case they are needed in the future. I got a different brand pressure plate that seems like its a MUCH better donor than the sachs/Spec. style setup. Its a Exedy GMC502. These have positive release clips that physically PULL the pressure plate off the clutch disk when disengaged as opposed to relying on weak spring pressure to do the retention. I took this pressure plate and moved its pressure angle significantly. I had to add new metal to the plate to machine down. I also modified my press to become a pressure plate dyno by adding a pressure gage. It was fascinating to see how changing the pressure angles effected the clamping force.

Second and even more important task was to work on the cooling system again. I popped out the water pump to make sure it wasn't having any issues. That checked out perfect. So I ordered some fittings and pipe and what not and started changing the layout of the fuel lines and coolant lines near the the turbo. It all needs to change. I'll come back and update this with more pics and details later. But I'm feeling good about this project again.
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Rickady88GT
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Report this Post12-06-2017 12:07 AM Click Here to See the Profile for Rickady88GTSend a Private Message to Rickady88GTEdit/Delete MessageReply w/QuoteDirect Link to This Post
That is cool stuff. I would love to have my own mill and lathe.
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Fierobsessed
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Report this Post12-09-2017 07:51 AM Click Here to See the Profile for FierobsessedSend a Private Message to FierobsessedEdit/Delete MessageReply w/QuoteDirect Link to This Post
Ok, back at it. Engine out! It's a bit dirty. Mostly Dusty, but I found a small oil leak from the breather fitting too. Seems like things stayed in order for the most part.


Started taking it apart. I removed the turbo, and there it is. I believe the coolant drain is the design mistake I made that is causing the overheating. More on that later.



The first items on the list of tasks, Clutch and flywheel replacement, pressure plate modifications (Round 2!) and replacing the synchro's. (Which in hindsight, didn't seem to be bad.)

Pulled the transmission and clutch. Honestly, for it slipping at well over 400 HP (I assume) It actually doesn't look too bad. Just a little bit of heat checking on the flywheel and pressure plate, Some material was worn off of both surfaces. Sintered clutch disks are known to wear the opposing surfaces. The disk is flawless, no material lost there.




I had a lot of trouble shifting with the F40. So I cracked open the F40 transmission. I changed the synchro's on gears 1-4. It was actually surprisingly easy to work on this transmission. Splitting the case was just as easy as pulling the shift shaft assembly and removing all the case bolts. INCLUDING THE ONE IN THE BELLHOUSING. This was almost a tragedy story.

Once the case was split, all I had to do was use a gear puller on the outer most gears on the mid shafts, and that forced the bearings off, then it was just a matter of removing the parts, and a couple of snap rings and change the synchros.

Part numbers for the synchros, in case you ever need them
55351580 3rd, 4th, Reverse
55351579 1st, 2nd.
24451752 5th, 6th.

Oddly enough, you can use the 1st and 2nd synchros in 3rd and 4th. Just omit the inner friction, and reuse the original cone. The outer two rings are the same. I suppose with a little creativity with a welder and a lathe, you could possibly convert the 3-4 synchros to triple cone.

I only took one pic of the parts out of the transmission because I was busy doing the work.


New clutch stuff!

I modified my Horrible Freight shop press to add a pressure gage. Now, I have the ability to measure clamping force on pressure plates.
I bought a new donor pressure plate, A Exedy GMC502. I really REALLY like this pressure plate. The positive release clips though change the game for me. It was a design weakness in the other pressure plates I've messed with. Including the Spec SCC883.

Pressure plate tests. I used my press to apply pressure to the pressure plate. I used a dial indicator to measure the distance that the pressure plate was being moved by the press. I recorded the pressure at 0.010" increments, starting at first contact.



The first one I tested is the unmodified Exedy GMC502. You can see that peak clamp pressure was achieved at 0.120" of compression. Peak clamp pressure was 2094 lbs. The pressure curve is really wide, still producing 1076 lbs at 0.250" of compression, Probably could have traveled a little more, but I didn't see the point in doing that.

The second one I tested was the one I just removed from the car. It's the one I modified here: //www.fiero.nl/forum/F...L/000143-7.html#p253
I really didn't make as much of a clamping improvement as I thought that I did. It peaked at 2459 between 0.120" and 0.130" compression. Not bad. The useful range of compression was shortened up slightly. In testing though, I hit a point right at 0.190" where the spring plate actually inverted and nearly all clamping force is lost completely. The spring's fingers were pointing considerably downward. They would have contacted the clutch disk if there was one installed.

Third test was the newly modified Exedy pressure plate. It had an astounding 3285 lbs of clamp between 0.110" and 0.120" of compression. But, the spring inverted after 0.140" So there is very little range on this plate. Obviously, this plate will be very sensitive to the thickness of the disk, or to wear.

The fourth test was the Spec SCC883. Which also has a very high clamp load, peaking at 3074 between 0.100" and 0.110". It appears based on the data that I may have mis measured the compression distance by about 0.010". This pressure plate actually still has a decent usable range before it inverted after 0.170".

One thing I noted, was that all of these pressure plates peaked clamp load when the spring fingers are about flush or just proud of the surface of the cover plate. This is how I now figure out exactly how to modify the pressure plates now. I also try to slightly overshoot the compression point that peak pressure is produced so that it wears into the peak pressure before it starts to slowly lose clamp load.

Heres a stock pressure plate, and the new one that is about half way through its modification. You can see that I machined a groove into the disk so that I could insert new metal.


I used a "Ring roller" from Harbor Freight to roll a piece of 3/16" steel to about the diameter of the grove I machined.


I used my press to force the ring into the groove. Its a press fit. You can also see my pressure gage that I used to measure the pressure plates.


Machining the metal into the correct angle and height.


Final result. Original vs modded.


Once I had that all sorted out, I put the new flywheel and clutch in, gave the transmission paint a once over, and installed it. It was also time to give the cradle and engine a quick bath. Simple green and a soft brush goes a long way.



I also cleaned up the turbo. The cast iron CHRA rusted up pretty bad. Looks nice now.



Now, I have to deal with the coolant return pipe debacle. I screwed up when I routed it downward, which at the time seemed like the obvious choice for routing. But while what I did was mostly functional, It did however drain from a point that wasn't absolutely the highest point in the coolant system. I believe that this caused any vapor that would invariably be produced in the engine to go to the high point, and not migrate to the radiator like its supposed to. So as I drove more and more, the water level in the engine would continue to be pushed down by the growing bubble, causing a progressive overheating situation that took almost 30-40 minutes to occur. The solution to this problem would be to route the return pipe upwards, then migrate it down to where it needs to go. I also want to add a bleed/fill port.

Having the pipe going up first would ensure that any coolant leaving the engine must flood the engine all the way to the top before trickling down the return pipe. This is how it works on the original Fiero's cooling system. I also blocked off the throttle body coolant line. I was using it to feed the turbo, but now Iv'e teed off the heater core feed line to feed the turbo, and that returns to the inlet of the water pump. If any bubbles show up here, they will flush back to the engine, then up to the return pipe. This change was done to have the turbo receive its water from a point that is guaranteed to be flooded. The throttle body coolant feed is a high point not guaranteed to be flooded at all.

So, before:


And, after:




Added the fill/bleed port.


So I had another problem to deal with, The water pump inlet (discontinued part) had a bit of a corrosion problem where the hoses meet it. I previously smeared RTV over the pitting and got away with it.


But I decided to fix this issue and also add a better turbo water return.
Cut off the old, destroyed barbs


Made a new barb on the lathe, and recycled an AN fitting I used to have on the turbo.


Welded them on.


Honestly, It's the first time I've had any luck attempting to weld cast aluminum. I cooked it with a torch before attempting to TIG weld it and I didn't run into too much porosity as I had previously when welding cast aluminum. It's certainly not my prettiest work, but its effective.

That's all for now, but I still have a few things to do before I shove this engine back in. One thing I am doing next is sound proofing the engine bay. It's just too damn loud in the car. I also want to try to make some changes that will help with shifting. I think the bend at the firewall was too aggressive.

[This message has been edited by Fierobsessed (edited 12-09-2017).]

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yamahasrx700
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Report this Post12-09-2017 10:33 AM Click Here to See the Profile for yamahasrx700Send a Private Message to yamahasrx700Edit/Delete MessageReply w/QuoteDirect Link to This Post
Your work is awesome and the way you attack issues is inspirational. Great job.
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Irrationable
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Report this Post04-11-2019 11:56 AM Click Here to See the Profile for IrrationableSend a Private Message to IrrationableEdit/Delete MessageReply w/QuoteDirect Link to This Post
Bump for an update!
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robymon
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Report this Post07-05-2019 03:57 AM Click Here to See the Profile for robymonSend a Private Message to robymonEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm also curious. What happened to your project?
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ericjon262
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Report this Post10-29-2019 01:18 AM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
you ever put this through it's paces?

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
//www.fiero.nl/forum/Forum2/HTML/119122.html

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La fiera
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Report this Post12-05-2020 01:00 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just got rading this thread and man, you are a very talented individual, very Impressive!! Can't wait to see more!!!

Best wishes!

Rei
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