Improving the skirting and new radiator is going to help for sure. Make sure your coolant mixture is set to 65% anti-freeze, 35% water as that is typically the best ratio for most anti-freeze heat transfer. Going further than that Water Wetter added to system drops temps about 10 to 15 more degrees.

Not sure where you're getting that info, but pure water (plus anti-corrosion additives) is the best coolant, as long as you can keep it under enough pressure not to boil.

quote Originally posted by Will: Not sure where you're getting that info, but pure water (plus anti-corrosion additives) is the best coolant, as long as you can keep it under enough pressure not to boil.

Yep, that's true, It's just that I'm old and forget that some people don't live in the cold north like I do.

Link attached for OP that should be useful, didn't occur to me the he lives near Las Vegas:

http://www.torcavettes.com/.../CorvetteCooling.htm

What a nice radiator!




I'm anxious to install and test it, but I'm going on a short vacation in the meantime.

The Champion is a tight fit, review thread by Archie on how to trip rubber isolater's at the bottom mount area, otherwise it will sit too high. On mine, I also had to grid hole out just a little on upper mount plate were it fits around the fill neck. Be sure to plug input for automatic transmission lines if you have manual trans.

Installing the radiator went very well. I did some trimming of the rubber mounts, plugged off the holes for the transmission cooler, slipped the radiator in and connected it all up. While I was at it, I sand blasted and painted the upper radiator support, and put a new rubber upper air dam in place. It looks so much better!



I wanted to also knock out another issue that has been driving me mad for a long time. The back of the fuel tank was leaking whenever it was full and I am parked on an incline. I noticed just how bad the leak was when I was making the new front air dams, the fuel was just dribbling out of the tank!

I noticed that the smaller vent return hose that goes to the fill neck appeared to be pretty dry rotted.

So I bought some new Fill neck - Tank hoses from the Fiero store.

But, that didn't make any sense to me. Why would a fuel impervious (not submersible) hose dry rot, unless the gas was soaking the outside?
Turns out, that the small fill nipple's weld to the tank had been broken. Probably when I was struggling to remove the hose from the back of the tank to change the fuel pump.

I used some JB weld, to help re-adhere the nipple to the tank, and put some on the large nipple for a little added insurance.


I also used a tank repair material to build up the spot where the weld was, just to add some additional anchor. I put the hoses on and that problem is likely fixed. I'll have to fill the tank up to find out.

Another quick project was attacking the drivers side door. Last year I tested a new window motor alternative to the crappy ones the Fiero's have always had.
Thread about that... Faster windows

I had some problems with the window channel striking the motor, but I did some grinding to the channel and now it slides right past the motor without clunking against it.


I also had the door latch assembly out for a little cleaning and lubrication. It's nice to have the power door lock working as it should again. Believe it or not, I found one of the biggest obstruction to the power door lock motor working properly is the arm on the back of the door lock cylinder. It has to pivot whenever the door lock is being used, and without a little bit of good grease it provided too much resistance. It has a spring clip that adds a bunch of friction to the tumbler arm. It's a good one to know. Next I'll have to attack the passengers side door.

As far as the engine goes, I haven't drove it yet with the new radiator, and it's looking like the end of the Las Vegas summer is coming near. So unless I drive it on a 100+ degree day, it might be hard to tell if the new radiator was a silver bullet or not.

Either way, I'll also need to pop the FMHE (Intercooler) back in sometime soon. 'Cause boost season is coming, and I think a trip to the dyno sometime in the near future. I want to see 400+ horsepower, which it certainly registers in that range on the butt dyno, even at only 11 PSI. Perhaps I can top 500 if I go for ~20 PSI. That will be exciting.

I also have been having some knock sensor issues to sort out. I keep getting code 43's even though I do see some knock sensor feedback. I'm sure I'll figure that out easily. Could even just be a needed ground strap.

I'm having a hard time wrapping my head around the fact that it's still running hot. The radiator made no difference at all. It was only 90 degrees out this morning, and I was still two notches above 220 towards the end of my drive to work.

It's so strange, there just isn't any reason for it to be running so hot. The only thing I can do now is check or change the water pump. And I still can't see that even being possibly the cause, unless somehow the impeller is loose on the shaft when it's up to temperature. It's an OEM water pump from what I remember, so its got that nice cast impeller.

Drive up to Mt Charleston and see if it cools off some at the top?

Have you sprayed the radiator with a garden hose to see if it cools it off when running? If that helps it may need another fan.

*edit* Just remembered that one day I forgot the hood was unlatched while driving to work, couldn't help but notice how much hot air was pouring out from underneath driving down the 215. It usually ran about 200* with the AC on full when it was 100* out, that instance it stayed right around 190*. Food for thought?

[This message has been edited by sleevePAPA (edited 09-27-2015).]

I actually did try driving with the hood not only unlatched, but propped up a few inches. That didn't make any difference. But I haven't really tried driving into much lower temperatures yet. Mt Charleston is a bit of a climb which will up the heat load a bit. I'd like to have this issue solved before I try that trip. So I've got a week till that little cruise that's been put together.

I think the garden hose on the radiator isn't a bad idea, just to see if the system can cool the engine once it has achieved a high temperature.

At this point I feel like I could rule out anything concerning the front section of the coolant system. The radiator that was in there was fine when it was just a N/A 3.4 DOHC, and now I have really good air control with the custom air dams and that monster of a radiator. The fan is factory, but it has a relatively new motor and is in good working order. There's nothing that could be bad, and certainly not undersized, it's just a 3.4L engine!

My coolant pipes and hoses are in good condition, that really just leaves the water pump, or the thermostat. The thermostat has proven to work exactly as intended. I can see it opening on my Logger, the temperature goes flat at 180 degrees for a little while then starts a slow and mostly steady climb up towards the red.

It behaves as a system where the engine puts just a little more heat into the coolant than the radiator can remove, so it slowly loses the battle to control the temperature. But I just can't believe that this is what is going on. The front half is so overkill now for a 3.4L engine. I'll have to do some more digging.

I used to have a 4 cylinder Jeep wrangler and when its water pump failed, I went to an auto parts store and got a replacement. I got it to temperature and then the car started bucking and overheating. Turns out that the water pump was spinning the wrong way; my year jeep sold counterclockwise and clockwise spinning pumps. What was on the belt drive determined what type of pump you needed.
Could, by chance this be the same for your motor?

That isn't an option on the 3.4 DOHC, they all use the smooth side of the belt to drive the water pump. That being said, the 3.4 PR engines come with a water pump that is driven off the smooth side of the belt, while in the Fiero, the 2.8 is driven off the V side of the belt. So when swapping in a 3.4 PR engine, you have to put on a different timing cover and waterpump, or you'll have a bacwards spinning waterpump and the same issues you described. So there are some motors where you will run across that.

I tried driving in to work with the A/C on for a while untill it was running close to the 220 mark, then turned the A/C off while on the highway. This was helpful as it was hotter today than yesterday, and for the first time in a long time, I watched it go from running hot, to cooling down to the 1/4 mark (halfway between 100 and 220, whatever that value is) which is exactly what is supposed to happen when the system works properly. It wasn't a fast drop at all, but it was noticible.

I rinsed off a bunch of dust that had somehow accumulated on the back of my decklid and got the engine wet a bit. The belt squeeked the whole drive in and that got me thinking, perhaps the belt is slipping, that could slow down the waterpump. So I think a new belt is in order, just to check off that box while I'm at it. Perhaps its not a bad idea still to inspect the water pump if I have the belt off.

Guess I'll need to replace a wheel bearing. It only had a few thousand miles on it, they weren't easy miles though. Maybe there wasn't proper torque on the axle nut or the alignment took a toll on it. But at least it was easy to notice and diagnose. I had some on - off throttle yaw, and a rear end twitch on braking, as well as some instability on the highway. I was expecting to see some loseness in the suspension linkage or something, but it was a little more obvious when I took a closer look.

Compare fins per inch and number of rows per inch between the stock and Champion radiator. Although the Champion cools better, in my experience it wasn't by an exceptional amount during a period where I installed a brand new stock radiator while the leaking Champion was out to be replaced.

I performed a head gasket replacement on a Nissan Versa recently after an Ebay special said to be an equivalent replacement turned out to be just the opposite. The car ran fine for months because it was installed in late Fall in cool weather. By the time Summer approached the first unexplained overheat occurred. The thermostat was removed and with a scan tool connected as the car has no temp gauge, it was test driven at night on the hwy where coolant temps settled at ~220ish which was a high normal with a stat and unacceptable without. Long story short, Nissan info on normal temp range could not be found until a youngster finished it off. With the gasket job completed the temps continued to run too high and that drew my attention to the radiator. I sourced an OE replacement and compared the two and noted the Nissan stocker had more fins (~25 vs. 17) and tubes per inch and the difference on the car under the same conditions was ~20 degrees plus cooler difference in favor of the OE plus quicker cool down time.

The V6 stock radiator should be 1.25" thick tube width and the Champion 1.5" with 3 half inch tubes which equates to only 25% more cooling volume if and only if they both have the exact same number of tubes. Then it's down to the number of fins per inch. If the Champion has less in any of those two areas you have to adjust its theoretical advantage over the stock radiator accordingly.

Many aftermarket providers are jumping on the "made in China discount". You really have to check your "old original" part against the new "?" to make sure you're not setting yourself up for failure. Also keep in mind there is at least one row of coolant tubes that are not functional (plugged) in the Champion, at least I was able to see that in my radiator through the filler neck and it's possible another row like it exists at the bottom so you can't count those if so.

You're not losing coolant and have no restrictions yet the car runs hot on hot days and behaves on cool days I say it's still your radiator. If you had a pressure problem you would also have a coolant level problem unless the problem is the cap which would allow the coolant to be pulled back in the radiator after cooling down masking the situation.

Here is a link to what I described about the radiator differences in my old thread about midway down, my first Champion shows one more coolant tube than the one you pictured;

//www.fiero.nl/forum/F...2/HTML/127904-2.html


Those who have had successes and failures with the stock radiator behind a V8 could possibly be dealing with the 1" vs. 1.25" radiator that came in the Fiero at least during the first year.

Not taking a shot at "Made in China" as the retailer makes the decision on quality.

[This message has been edited by Joseph Upson (edited 10-19-2015).]

Time for a dual pass radiator?

I did a bit of research, and yes, read your thread on champion radiators.

Some of the things that I have had to consider:

This engine has been in this car for 5 years without any overheating issues, before I turbocharged it. The radiator that was in the car was a replacement V6 unit, not sure of the brand.

The radiator that was in the car had 15 fins per inch, a single core approximately 1" width to the inside of the tube. and 34 rows of tubes.
The champion radiator had 19 fins per inch and 3X approximately 1/2" width to the inside of the tube. and 38 rows of tubes.

So the Champion radiator should have far outcooled the radiator that I had, yet it made very little difference at all.

Since the weather had cooled off, the temperature has been rock solid, running even a bit cool with the 180f thermostat

I honestly think that with ambient temperatures at 110f, and the A/C pre-heating the air going into the radiator I may have been trying to cool the radiator with 140-150f air. At that temperature, there really isn't much left to cool with. But I still think that my engine is producing excessive heat anyway, or it could still be the water pump. For now, it will remain a mystery unless it suddenly has problems again.

This was a fun morning

Ever since I got my 08' Trailblazer SS, and changed out the shocks for some nice adjustable height Belltechs and lowered it an inch, Replaced all the bushings in the front end and had it aligned, I've been very impressed with how well it handles. This hulking 5,000 lb. SUV undoubtedly handles BETTER than my 88 Fiero. Not just by a little, but by a lot.

Once I got this swap done and riding, I quickly noticed why this was. The suspension in my Fiero is FAR softer than in the Trailblazer. It feels like it floats over every hump in the road. Clearly this "Sporty Commuter" has grandma's suspension. Well, at least as far as springs and shocks go.

I decided to install new springs and shocks in the front end.

After much deliberation, looking at spring rates, sizes, motion ratio... All that stuff. I concluded that I needed to up the front suspensions spring rate, not just a little. But a whole lot. I actually had slightly shortened 84 Fiero "WS6" springs in the front already. But I don't think that it made any real difference from stock.

So I started with these.
MOOG:
Part Number 639
Inside Dia. 3.22
Bar Dia.0.593
Spring Rate 344
Load 1625
Install Height 9.5
Free Height 14.22
End Type 1 SQ (Squared Cut)
End Type 2 TG (Tapered flat)

New springs, vs one of the old ones.


Obviously, they're too long.
One side has a nice flat tapered finished edge, So I left that intact for the top hat. I cut the other end.

Originally, I cut it at 10.25" (exactly 3 coils off) and did a test fit. The car came up an inch from what it was before. And since the motion ratio is 0.53 I knew I could take off a whole inch safely, since my goal was to lower the car 1" from what it was before. Another test fit revealed that 9.25" of free coil was infact right at stock ride height. So I took off another .75" of coil. That lowered the car exactly 1" So my final coil length was 8.5". This cut just so happened to line up perfectly with the tail end of the spring, so I had a good reference for where the cut was made to ensure I duplicated it on the other side.


I went from this


To this


Anyone who knows anything about springs knows that shortening a spring raises the spring rate proportionally. 344 Lb/in X 14.22" = ~4900 lb/in/in. So having just 8.5" means that the spring rate is now ~575 lb/in. Which is nearly 3 times stiffer than stock.

So now, My spring specs are:
Inside Dia. 3.22
Bar Dia.0.593
Spring Rate 575
Load 950
Install Height 6.8
Free Height 8.5
End Type 1 Open
End Type 2 TG (tapered off)

Why so stiff? It's got a hefty motion ratio of .53. This means that with 575 lb/in springs, the wheel spring rate is .53^2 X 575, which is only 162 lb/in at the wheel. That's actually not bad at all. The front end is pretty light on a Fiero, so this rate is very appropriate. That's a heck of a jump from the factory 58lb/in wheel rate that the 88's front end comes with.

But, having a spring that stiff does mean you need a strong shock absorber to control it. There aren't many options here. But Koni Red's, if you can find them for the front of an 88 Fiero are a decent answer. I adjusted them to full stiff rebound.


It's just a little bit bouncy. The red's weren't quite intended for this high of a spring rate. But, I can and likely will have them re-valved in the future specifically for these hefty springs. That's one advantage of the Koni reds, they can be rebuilt, re-valved, whatever you need. Bilstein's are also an option for this.

I still have the stock Fiero springs and KYB's in the back, and it still feels floaty back there. but I do have Koni's for the rear, and I plan on converting them to coilovers, and putting in 425 lb/in springs on them. I'll Keep the ride height I currently have. Which is actually pretty low with the heavy engine, transmission, Turbo, Intercooler... all that good stuff brought the back end down a bit with 28 year old springs.

Driving Impressions?
Backing out of the drive way, the back wheels going down the apron dip was just so sloppy. Then the front wheels went down the dip, with a little kiss of the air dam on the way down. I was expecting it to be super stiff, but it really isn't.

Hitting man hole covers and the usual road bumps; the things that really only make noise and shake the car, feels exactly the same. It's when I run over certain dips, where I would normally expect the suspension to compress and rebound is where I can really feel the difference. There is a little bit of a bounce in the front end like I said before, the shocks are a bit weak for these springs. I weaved a bit to see how the car leans on turns. It' doesn't, It's so flat and so confident. But it really highlighted for me just how badly this car needs a faster ratio rack.

Another big difference was that there isn't any front end lift on heavy accel, and very little dive on braking. I got used to the feeling of the front suspension unloading almost completely when boosting hard in second gear, and snapping off the throttle transitioning to a nose down dive. All of that is gone now. I suspect that I've lost some rear wheel traction in accel, now that the weight transfer is likely just not there like it used to be.

I'm anxious to do the rears now.

quote Originally posted by Fierobsessed: now that the weight transfer is likely just not there like it used to be.

The weight transfer is definitely exactly the same... the front end just doesn't rise as far now.

Would any of you guys happen to have a G6 F40 intermediate shaft assembly you're not going to use?

I have never had one. I'd suggest archie or the DIY F40 thread, but I see you've already done that.

On another note, I decided it was time to remove the catalytic converter and do some testing without it. I quickly whipped up a "Test" pipe, and bolted it in place of the cat. It's like its a different car. It spools faster and knock has been reduced greatly. Feels really good, I start lighting the tires up pretty good in third right around 65mph, usually grabs the ground again when the car hits about 75.

I'm trying to get this car ready for some potential track time soon.

Finally got the car to the track, unfortunately it was very busy, so I only got two runs in. The first run wasn't good at all. It was cold outside and I overestimated what kind of traction I would encounter at the track. That and the light turned green much quicker than I expected, I wasn't even in gear, nor up to RPM. So I spun the wheels pretty hard in first for what felt like forever. I had some wheel chatter towards the end of first, still spun second a little, and ran it out the rest of the run.


Second run was much better, Since it was 2.5 hours of waiting in the staging lanes I knew it was going to be my last run. So I was overly cautious. I let air out of the tires, down to 22 PSI, did a light little burnout to heat the tires. Then I launched really softly, and had to wait for the RPM's to come up and the turbo to spool, so it was a bit sluggish out of the hole. I should have been more aggressive. Still it hooked very well, and was a clean run from that point forth.



Car #364


Overall, It was a fun night. I should have been doing low 12's according to my trap speeds, but I'd need a driver mod and a set of tires that aren't made of rocks for It to run a good time.

[This message has been edited by Fierobsessed (edited 12-05-2015).]

Good fun!

What was ambient temp and altitude?

I can tell you from experience that a 112 mph trap is about 315 RWHP in a Fiero. A 116 trap should be about 355-360 RWHP.

You can drop 0.3 off your 60' time just with driver mod. Fieros are capable of 1.8 sixties on street tires. Dropping that 0.3 will compound to 0.4-0.5 total ET difference by the end of the quarter.

That being said, launching a big-turbo car can be tricky. The Northstar has enough low end torque to be fairly linear in its launch behavior at different launch RPM's, it's been fairly easy for me to dial in with some practice. Speaking of which, practice makes perfect. Find yourself some sparsely traveled road or a little used parking lot and get some practice in. With a few runs under your belt you'll get a feel for how hard the engine pulls, how much you can abuse the clutch and how hard you can hit the tires. Good Luck

Edit to add: if you can find a track that prints the 660' and 1000' times, you end up with about 1 shift per interval (60, 330, 660, 1000) and you can use your interval time splits to gauge how well you did at each shift at each run. With the triple and double cone synchros in the 6 speed, you should have no problem at all ripping off outstanding shifts... That should be *MUCH* easier than nailing every shift in a 282.

[This message has been edited by Will (edited 12-06-2015).]

I agree, I didn't practice much and 2 runs wasn't enough to get the learning curve down. Especially because track conditions vary heavily based on temperature, weight distribution, tires. We are at 2000' of elevation, and it was right around 40f. Fortunately, I had my laptop hooked up and logged the runs, I counted my shifts to be the gaps between 100% throttle, those were 1-2 0.5s, 2-3 0.6s, 3-4 0.5s. Not the fastest, I'm not used to ragging on it that hard and banging through gears. I probably would have hit that 1.9 60' if I had some rpm when the light changed. But I didn't want to risk lighting the tires up on my last pass. I'm hardly a big turbo though. It's a good fast spool, but it does require about 2800-3000 RPM's to make it spool nicely.

I kept the boost down at 15.5, because in testing at 18 I actually made the clutch slip when I was in 4th. So I found its hard limit. I had no clutch issues at all on the track fortunately.

One thing I noticed on the quarter mile list was Matthawkins 3.4 DOHC turbo 282 getrag, he ran an 11.92 @ 118. almost the same trap speed I have. Clearly I need to drive better to get a good time. His turbo is slightly smaller though.

Figured something out the other day... Gm's flex fuel composition sensors output signal is compatible with the unused MAF signal input on the 1227730 ECM. So...

quote Originally posted by Fierobsessed: Figured something out the other day... Gm's flex fuel composition sensors output signal is compatible with the unused MAF signal input on the 1227730 ECM. So...

you need to start working with robert...

http://60degreev6.com/forum...-and-Concepts-Thread

------------------
"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

ha, we've touched base before.... Matt certainly knows what he's doing without too much input from me.

^ Awwe thanks! I'll take that as a compliment.

Speaking of code, I'm still on TGP $8F, but boy has it gone through quite a number of evolutions. Been adding and refining the code more than just the tune. Long story short...

1. I've condensed the 3 VE table components into a single N/A VE table - 400-1200 RPM in increments of 200, 1200-4000 X 400, 4000-6375 X 600. Boost is still a 2D multiplier, but It's stupid easy to tune that.

2. 3 BAR conversion - Works great! but It is limited to 22.5 PSI or 255kPa due to the fact that it calculates BPW on a 8 bit byte that figures out actual kPa. So I'd have to overhaul a few more things to enable even higher boost levels. I just don't need to go there yet.

3. Manual / Shift light logic - Imported from $6D, and I used it to replace the old TCC control section. I had to also specify the N/V ratios for the gears, so that it can figure out what gear its in. Which consequently led to...

4. Decel Fuel Cut Off for manual conversion - Pushing in the clutch caused stalling in DFCO, but now I have a bit that is set when the N/V ratios fall outside the known ratios for any gear. If that bit goes high, DFCO is instantly disabled. This solved the problem beautifully. I've actually retained 100% of 8F's DFCO settings with this little trick.

5. Added sensors - I have 3 IAT's for pre-turbo, post turbo, and post intercooler. The pre and post turbo sensors report to the ALDL only, but the info is useful.

6. A/C pressure transducer - Originally, the code was meant to turn on and off the A/C clutch with 1 input. (A/C requested) I added the transducer, its value reports to the ALDL, but it also has a high and low acceptable setting that can turn off the A/C request if the pressure gets too high or too low.

7. Waste gate control improvement - The original control method left a lot to be desired. It wasn't quick enough to adjust to the correct pressure, nor could it adapt to different boost settings. So I added a small section of code that now looks at the desired boost level based on throttle, then looks up an appropriate waste gate duty cycle, then when the waste gate spring pressure is achieved, the solenoid goes into closed loop control. It re-evaluates the WG DC on throttle/RPM change too, so it will instantly and accurately respond to changes in the amount of boost requested.

8. WBo2 support - No control off of the wide band, but it does report to the ALDL. I haven't found any real reason to actually implement wide band fuel control. Maybe some day I will.

That's about it for now.

I switched back to "Premium" as they call it here, which is an abysmal 91 octane, still $2.89/Gal here. It sucks. I have to back the boost down to wastegate spring settings to keep it from detonating. Or, I could pull back the timing. This has really disappointed me. I'm feeling the pinch of the limits of pump gas. And the pain of $8.00/Gal for 100 octane.

This has really set my mind in motion looking at going with E-85. Currently $2.47/Gal here. I'm not sure if my injectors and pump are large enough at my power level for E-85, but I might be just enough. Price wise, the fuel is a wash against "Premium" when mileage is factored in, but it offers relative octanes that usually exceed 100. So, it makes good sense at this point to go that direction. Thankfully, my injectors, pump, and fuel lines are all ok for use with E-85. The regulator? I have no idea. So I think I only need to add the sensor and wiring, and a bit of code to put it to work, and hope that my injectors and pump are good for the additional flow they will have to handle. Sounds like a fun challenge to me.

quote Originally posted by Fierobsessed: I switched back to "Premium" as they call it here, which is an abysmal 91 octane, still $2.89/Gal here. It sucks. I have to back the boost down to wastegate spring settings to keep it from detonating. Or, I could pull back the timing. This has really disappointed me. I'm feeling the pinch of the limits of pump gas. And the pain of $8.00/Gal for 100 octane. This has really set my mind in motion looking at going with E-85. Currently $2.47/Gal here. I'm not sure if my injectors and pump are large enough at my power level for E-85, but I might be just enough. Price wise, the fuel is a wash against "Premium" when mileage is factored in, but it offers relative octanes that usually exceed 100. So, it makes good sense at this point to go that direction. Thankfully, my injectors, pump, and fuel lines are all ok for use with E-85. The regulator? I have no idea. So I think I only need to add the sensor and wiring, and a bit of code to put it to work, and hope that my injectors and pump are good for the additional flow they will have to handle. Sounds like a fun challenge to me.

You can spray methanol to keep it simple and still use 91. Ive tuned with the 100 octane(rebel?) over there and switching back to weaksauce 91 was a pain. What injectors do you have now? Pump? Wont take much to max 80lb injectors and a 320lph pump with E85.

fringe benefit of E85 is that you'll have a noticeably higher idle PW, should you get to the range of the injectors being difficult to control.

also, for the flex fuel sensor, do you know what frequency it outputs? when I was measuring stuff on the VATS/MAF circuit, I seem to remember the low-pass filter not liking much above the ~160Hz that the old low-frequency digital MAFs on early MPFI 60V6s output. you can change a single resistor or cap to up the limit obviously, but just something to keep in mind should nothing be seen by the ECM. I discovered this after hooking a simulated "modern" MAF up to that circuit and got no results in the pulse accumulator, started digging around and in the late 90s/early 00s, someone else on the diy-efi boards determined the low-pass frequency being fairly low. they wanted to run a "modern" MAF as well, it was determined that the ECM used by the MPFI Buick 3.0(or maybe 3.3?) is essentially a 1227730 with a different RC low-pass filter, I want to say it was setup for something like a 20-30KHz cutoff though.

Flex fuel sensor is 50 hz to 150 hz. It expects 5V to be present at the signal pin, which it switches to ground for signal. The PW indicates fuel temperature, 1ms (-40f) to 5ms (304f, sound familiar?), but that's not important to us really.
50 hz is 0% ethanol, 150 hz is 100% ethanol. There is also a 180 hz signal that it will throw out when in sensor error.

I only know that the MAF which was intended for the 7730 was a ~30 to 150 hz signal. Not entirely sure of the voltage, signal form or if its a pulsed ground like the flex fuel sensor. According to the ECM schematic, it is held high, appears to be to 12V, (I haven't measured it) which likely means it needs to be pulsed to ground. There is a capacitor, between the signal and ground, but that is typical for any ECM input, not so much a filtering circuit. From there the signal runs through the injection I/C (U13) which does something (? but it is shown as an amplifier) to the signal before the signal is handed off to the P4 timer chip, which then pushes that signal to address L3FF8. That's about how much I know about it at the moment. I've only begun connecting the dots.

I'd need to hit U13 with an oscilloscope (that I don't have) to see what it does to the signal, perhaps its a pulse divisor of some form? Or maybe it is just a signal amplifier or filter. I don't know.

sleevePAPA, im running 60's and a HFP-343 pump (255 LPH) I think switching to E-85 will run both near their capacities, hopefully not beyond. But really 80's and a 340 pump aren't all that expensive. I just worry that I may exceed my fuel rail, fuel lines, or regulator's capacity. That's where it becomes expensive in a hurry.

I bought Deka 60's off a friend that was using them in his T Type, hot air(no intercooler). His car was running low 12's at 110 and the 60's were static after the 1000' mark, and engine was lean. He has since switched to 80's, and sprays meth, running low 11's at 120 with a 6262 turbo, 23psi. He also switched to the aero 340 and gave me his 255. If you switch to E85 I think your fuel system will not be able to keep up.

https://web.archive.org/web..._num_12/threads.html

diy-efi seems to be down(gone?), this had the thread in it, but I can't find a way to get to it. I did copy some stuff out of it and save it to txt format since I was referencing it often. the resistor and cap after the pullup is a low-pass.


Ludis Langens wrote:

> To see if the signal is getting through, hook your scope to pin 16 of
> the '34984/'79435. That's the output of an inverter. Pin 17 is the
> input. The counting is done in a different chip.

Yes, I did not explain exactly when/where I connected the probe very
well. I was at both the counter and the fuel chip. No pulses at all on
the counter. The input conditioning expained the problem when probed at
pin 17 of the 9435 chip.


> The frequency MAF in the 727/730/749 has an RC filter on the input of
> the inverter mentioned above. R is 100K. The C looks like many of
> the other surface mount capacitors.

The C is .01 micro farad.


> The 8253 ECM (used with the 3800) has a different RC filter. The R is
> 48.7K (1%). The capacitor looks different from any other cap on the
> circuit board.

The C is 120 pF (measured in-circuit).


> Hmmm, is the high frequency MAF also used on the Buick 3300 V6?

Yes. The 3300 is just a "batch" version of the 1228253 code.
The 1228706 also uses the 48.7k resistor, but the C would not
read right in-circuit.


> This would explain why it uses an ECM (1228706) that doesn't
> interchange yet looks just like the 1227730.

Exactly. I did not understand the difference either, but now
it is clear. So if one wants to use the high freq MAF in
a 1227730 app, you have to find the 1228706 ECM. This
might turn out to be the easiest way to get the high freq
MAF in an earlier application, changing chip caps is not
for the timid. ;-)

Scot Sealander
going off of their values, a 100K+.01uF combo is a 159Hz cutoff, which makes sense for the 150Hz max signal of the old MAF. plugging in their numbers from the high frequency version(48.7K+120pF), there's a 27.2KHz cutoff, which is quite a bit higher than the ~10KHz the MAF hooked up to it would have produced, maybe some meter error due to being measured in-circuit or the signal was getting too rounded when getting near the upper limit(one of them mentions this in a previous post that with the 160Hz filter in place, even a 30Hz VATS square wave gets extremely rounded already), I'm fairly certain that is why U13 is being used as a buffer as well, to get nice, crisp square waves to the timer chip. the 1.2K pullup should be to 5V as well.


but since you're dealing with something that is already more or less within the frequency range of the old MAF setup, you probably don't need to worry to much about it unless you want to open it up some more to track the possibility of the 180Hz signal occurring.

[This message has been edited by RobertISaar (edited 12-20-2015).]

I've tied a micro controller to the input for the MAF sensor (or VATS) pin F10. I sent the raw input at L3ff8 to the ALDL. I've figured out that it is some sort of rollover pulse counter.

Only thing is, that it appears that the pulse width changes what shows up in the accumulator just as much as the frequency. I tried sending it different frequencies and pulse widths, and the results were all over the place.

I'm not sure if it's actually reading frequency, or just reading "on" duration time or what. I'm honestly pretty confused about what its reading. I have to translate 3FF8 into a delta value to further investigate.

The changes in pulse width that accompany the signal from the Fuel composition sensor will likely skew what the computer reads. Not sure how I'm going to work this just yet. Lots more testing is needed.

quote Originally posted by Fierobsessed: I've tied a micro controller to the input for the MAF sensor (or VATS) pin F10. I sent the raw input at L3ff8 to the ALDL. I've figured out that it is some sort of rollover pulse counter. Only thing is, that it appears that the pulse width changes what shows up in the accumulator just as much as the frequency. I tried sending it different frequencies and pulse widths, and the results were all over the place. I'm not sure if it's actually reading frequency, or just reading "on" duration time or what. I'm honestly pretty confused about what its reading. I have to translate 3FF8 into a delta value to further investigate. The changes in pulse width that accompany the signal from the Fuel composition sensor will likely skew what the computer reads. Not sure how I'm going to work this just yet. Lots more testing is needed.

3FF8 may be similar to the knock sensor input in that it only is meant for measuring time that the signal is high. take a look at 3FC6 when you can... I believe it is the actual pulse counter for that circuit as opposed to the "on-time accumulator" that 3FF8 may be.

You make me glad I know you.

It looks like that pulse only counter is perfect for the task, I made heavy changes to the pulse width on the microcontroller, keeping the frequency, no changes occurred to the input, which is exactly what I need it to do.

Heck, technically I could now pull fuel temperature from the fuel composition sensor, if I were to do a delta of both 3FF8 and 3FC6 and factor the frequency related changes out of 3FF8. But, I don't really care to do that. I just want to make this car fully "Flex Fuel" compatible.

Got my heavy ECM testing equipment out:


The main part of my equipment is the "test box". I built it 10 years ago when I was studying ECMs. It has some output lights, digital input switches, and some potentiometers, (MAP, TPS, A/C Press, CTS, IAT). Most importantly for this test, an ALDL connector, and power inputs for the ECM. I built this box to actually function as a pass through, So It can be put inline in the car itself, and you can interrupt some of the sensors with the switches and pots. I learned a ton about how the ECM's work with this tool.

Also shown in the pic, other items needed for this project,
Power Supply
Emulator
ECM
Custom Chip Adaptor
ALDL to USB adaptor
Microcontroller (Basic Stamp B.O.E.)
Laptop

I also got my E-85 upgrade hardware too. The fuel composition sensor, a pigtail for the connector, and I'll have to step up to even bigger 80# injectors. I was running 60's and had plenty of breathing room with them. But E-85 will require 42% more fuel, so I had to go big.


So far, I have written some code for handling what compensations I may make for whatever the fuel composition sensor gives me.
The first one takes the ethanol content 50-150 hz = 0-255 = 0-100% Ethanol, then goes to a 2D table that will kick out a number that will get added to the BPC vs EGR result, Basically it will scale the injectors. The resolution is a bit course though, I figured on about 11 counts of BPC vs EGR change going from Gas to Ethanol, but I have to do that in the 16 increments of the table. So it's a bit course for sure. I'll have to rely on BLM to work out the details. I also worked out a sensor default mode, signal under 40 Hz, or over 160 Hz which will default to E-85 and send a CE light error, and default to a value that will be slightly lean on ethanol. It'll still run stupid rich with gas, but that's better than REALLY lean on ethanol. I'll also open up the BLM window a bunch so it can still handle trying to correct for a sensor default condition.

I worked out a second compensation for spark advance. I made a relatively small table, half the resolution of the Main Spark table, (1/4 the size) that adds to the spark advance what it would be if the fuel were 100% ethanol. Then, that number is multiplied by the ethanol content factor then added to the spark advance. It's skipped if the sensor is in default. This correction method seems ideal.

I've also been working on my rear suspension a bit in the meantime. I made some coil overs out of the rear Koni struts.
First, I cut the perches off carefully using a sawsall.


Next, I trimmed the weld where the perch was fixed on, down to match the diameter of the sleeve (2.170")


I had some "Spacers" leftover from my drop strut kit from my trailblazer. They happened to be just the right size to modify to make sleeve seats.


I think you can see where I'm going with this.


It's actually a fairly tight fit, I had to push the sleeve onto them with a little bit of force.


I decided to make my own "Pillow ball" top hats, So I machined out a couple of holders that I could install the spherical bearings onto. I also made them 2.5" on the outside, so they function as the center part of the seat for the top of the springs


Machined a 1/4" thick disc to fix the bearing holders to


Coming together a bit


Looking pretty good I think!


I was a bit less than impressed with the quality of the spherical bearings that I got. They are the only 14mm ID ones that you can buy in the world, yet the quality leaves a lot to be desired. The seats on both sides appear to be pressed in. So, I'm going to have to machine some washers to go on either side of the bearing in case they are so bad that the ball pulls or pushes right out of the spherical. They claimed they are rated at 3000 lbs axial thrust load, which should be sufficient, but I think they may fail anyway. I may come up with something better down the road if they do indeed turn out to be insufficient.

Well, went ahead and tore the intake off



60# coming out, 80# going in



I adjusted my BPW vs EGR and took it for a test spin. Accel enrich has become a problem. It was becoming a problem with the 60's but now with the 80's its barely drivable. I can't find a happy spot in the Async/AE settings that gets the engine to have good, snappy throttle response.

My theory is that It can not do any asynchronous injection between synchronous injections without completely overwhelming the engine with fuel.

So I'm going to test a little theory, and see if just adding the async pulse width to the BPW and get rid of Async all together. That way it will just introduce AE with the normal course of firing the injectors.

Only thing is that I have no idea what the execution order is on the ECM, so It's going to be fun trying to find the correct spot in the code where I can add the two together and it actually not just throw the math out on the next pass. We'll see.

I think the 80's have a slightly different dead time, so you may have to tweak the offsets

quote Originally posted by ericjon262: you need to start working with robert...

quote Originally posted by Fierobsessed: You make me glad I know you.

LOL!

car is looking good. good luck with getting the injectors right.

------------------
"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

Spent the last week working on the E-85 Flex Fuel conversion.

First things first, I made a little bracket to hold the fuel composition sensor, and the fuel filter. I also welded some quick connects to a U shaped 3/8" pipe. Conveniently, I found a tiny bit of space next to the oil separator and the cruise module. Officially, I have no space left in my engine bay for anything.


The other side for reference...

Yep, no room any more.

I decided that the 255 LPH pump I was running wasn't going to hack it with E-85. So I dropped the tank and wanted to fix a few things while I was at it.

I attempted to "fix" my gas tank with JB weld last year, It wound up peeling up and leaking anyway. So this time I got serious about fixing it.
It was leaking badly from the vent nipple at the back of the tank. I had intended to TIG weld the tank, so I had drained every drop, cleared out the vapors, and filled the tank with argon. But first I had to clean the joint. In the process I found that the nipple was actually soldered in. So I wound up re-soldering it using a torch. I know gas tank work is scary, but you just have to be smart about it.



Heres the old fuel pump, vs the new.



The new pump also has an inlet screen, good feature.


I spent a little coin, and got some Teflon 3/8" stainless braided hose, and -6AN fittings to make it all happen, I also had to use some quick connect to 6AN fittings to adapt to all the existing lines.



There was one thing that was difficult. I had to run new wires through the firewall bulkhead, from the computer to the composition sensor. I wired the signal into F10, and put in my chunk of custom code, and bam! I've gone Flex Fuel. I also have it reporting to the ALDL, so I can see the amount of alcohol easily. Immediately, I started the car up and found that the alcohol content in 91 here is in fact 10% ethanol. I ran the tank nearly empty and then filled it up with E-85. The content immediately went up to 60%. Not exactly the 85% that is advertised. I think when I dilute the last of the gasoline out with the ethanol, my final percentage will likely approach 70%.

Detonation resistance has skyrocketed. It's really happy at 15 PSI. I think I may turn up the boost a little more, see if the clutch can handle 18-20 PSI. The car is fast now, but I'm excited to push it a little further.

The car's exhaust smells a bit like moonshine, I'll have some esplainin' to do when I get pulled over.

i know in this area, actual ethanol content varies wildly depending on the anticipated weather, but that's to be expected when negatives are reached somewhat regularly during the winter. I kind of expect you're seeing that for the same reason, though not nearly as extreme(we've seen below 30% before).