Real Fiero Tech

http://www.youtube.com/watch?v=a32aqEoR ... r_embedded

370 whp and 330 torque on 13 lbs

Turbo is a 62-1 and 67# injectors

Seems a little light on torque for a turbo car...

The way I feel about this: It's sad the same amount of effort wasn't invested in a better engine venue. Great number for the LQ1, very low numbers for a boosted 3800.

I agree on the torque, but would a 3800 really make 370 HP to the ground on 13 psi?

The Dark Side of Will wrote:I agree on the torque, but would a 3800 really make 370 HP to the ground on 13 psi?

You are thinking the same as me. I doubt it would.

Paul, you got some dyno graphs to back that up? If I recall correctly, the 3800 doesn't suck up boost quite like the 3.4 DOHC...

There was another guy on pedoland that had a dohc 3.4 on a ferrari type rebody that made 430 whp on 12 psi. Here is his setup.

page 2 has some pics. page 4 has engine bay pic
http://www.madmechanics.com/forum/build ... whp-2.html

Garrett 32-76R turbo and intercooler
Spec stage 3 clutch
Fidenza aluminum flywheel
custom short runner intake
LS1 throttle body
GM 7727 PCM with $8f
Greddy Profec boost controller
Tial wastegate
Greddy blowoff valve
Innovate wideband
42lb injectors
walbro fuel pump
powersteering delete pulley
undersized pulley



video
http://www.youtube.com/watch?v=LsaPtDyFud8

the E85 could be hurting performance at only 13psi. The only reason to run it is to use big boost. At 13psi the engine is at little danger of detonation running regular premium.

He would be better off with gasoline with a small amount of water/meth injection.

The 3.4TDC is absolutly more volumetric efficient than the 3800. At any given boost, even being down on displacement the 3.4 should make more power than the 3800.

I wish we had E85 in Alberta

I was thinking the numbers sound low at 13psi, even on a stock motor/bolt-on kit. I've run up to 14psi without any KR on the stock timing tables 91 octane. Even at my altitude that would be close to his in terms of actual air mass. But with e85 can't he advance his timing?

As for the torque, that definitely seems low, most 3.4s dyno about equal. Not to start another flame war on my numbers, but they were only 10 apart at peaks. But my build is also night and day different.

Series8217 wrote:Paul, you got some dyno graphs to back that up? If I recall correctly, the 3800 doesn't suck up boost quite like the 3.4 DOHC...

First of all, to unscramble things a bit (as they have become), I was addressing Shaun, not Will.

In light of this, I will answer your question. Yes, I have a ton of data to stand behind the 3800 being the better engine venue. I was not eluding that boost for boost, the 3800 would win - I could care less about volumetric efficiency in Fiero related discussions, I only care about track records. Turbos cost relatively the same. Injectors (in this range) cost relatively the same. One utilizes a single cam shaft and the other four. Cost would have been equal if not less, effort to bolt a larger compressor onto the crossover and install larger injectors would have been the same, and output would no doubt have been easily higher (with a larger compressor). This is a battle that has been waged in the Grand Prix arena for a decade and some change. One engine is inferior to the other in terms of longevity, maximum power output, and ease of mining output. I'm answering you because I respect you, otherwise, I think Fiero's are junk, GM engines are cheap underdogs, and would opt out of such a silly conversation.

Why did I post at all then? I jumped in here originally because I feel sorry for Jeff, because I know he spent a lot of money, sweat and blood, to put that car together. There are bums at ClubGP who have churned 410 whp with the measly M90 behind the 4t65. So, relatively speaking, I'm sad to see all of the effort put in with a realized output less than 400 whp. /pity

I agree that for the effort of building a turbo swap, a 3800 running 25 psi would make a lot more power than a 3.4 running 13 psi.

Which Jeff is this?

Maybe he's not done tuning it, maybe he did it because he wanted that engine...

Jeff, the original owner of the car. He sold it to buy a house. The new owner is some DSM wannabe fag who wanted to install 90lb injectors - because that's what 4g62's run. The dyno run above is with the new owner. Jeff's out of the picture. I feel bad for him.

I am pretty sure Jeff dynoed close to the same amount without E85.

Its just a single walbro 255 so it might be running out of flow volume with that pump to support much more than that. Hell the 255's from walbro when they first came out were only rated at 450-500 hp N/A.

That turbo tech is pretty old too. The 62-2 comp wheel is a good 20 years old now.

Shaun41178(2) wrote:I am pretty sure Jeff dynoed close to the same amount without E85.

Its just a single walbro 255 so it might be running out of flow volume with that pump to support much more than that. Hell the 255's from walbro when they first came out were only rated at 450-500 hp N/A.

That turbo tech is pretty old too. The 62-2 comp wheel is a good 20 years old now.

He's got the turbo up for sale now.

I agree about the fuel pump too. The first thing I would be testing after that dyno would be my fuel pressure under boost to see if I'm outflowing the pump.

He doesn't even need to go that far. Since he has a Haltech all he has to do is open up the IPW and if the car still leans out up top then its obviously the pump. The stock lines are 3/8 id so they should be able to flow enough volume using e85 so it probably is the pump. He probably has to step up to the 340 or the 400lph.

When I first put my turbo setup on, I was running a stock pump. I hit 210 whp, and the car was leaning out on the dyno. No matter what I did tuning it to increase fuel flow, I kept running lean. I knew the stock pump wasn't going to flow enough for the hp I wanted, I just wasnt sure how far they could go. Evidently 210 whp through a boosted application at aprrox 52 psi fuel rail pressure is the limit of a factory fiero v6 pump. After I put the 255 in, I was fine.