A 3.4 DOHC Build then... F40 Turbo (Page 55/57)
Fierobsessed AUG 29, 12:08 AM
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.
Fierobsessed SEP 20, 08:06 PM
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.
3.1 88FieroGT MAR 20, 04:19 PM
time for an update...
Irrationable MAY 03, 07:50 AM

quote
Originally posted by 3.1 88FieroGT:

time for an update...



2x
Fierobsessed MAY 21, 08:10 PM
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.
ericjon262 MAY 21, 09:59 PM
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."
http://www.fiero.nl/forum/Forum2/HTML/119122.html

Fierobsessed MAY 23, 09:45 PM
Nah, never pressure tested it. Probably wouldn't be a bad idea.
Neils88 MAY 27, 03:53 PM

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.
ericjon262 MAY 27, 05:26 PM

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.
mr_corean MAY 29, 05:46 PM
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?