turboing 86 fiero gt

[kikinz24]

I'm already going to deal with lag if I run that much pipin its going to add a bit more. Look at acura nsx's and toyota mr2s running a rear mount with a diffuser catches plenty of air to cool also remember I have an alky injection setup for it as well

[robertisaar]

lag is not the same as boost threshold. more piping will increase the threshold. lag is entirely dependant on engine tune and the turbo. retarding the spark 15* will spool the shit out of a turbo to get it up to speed. that's reducing lag.

[Joseph Upson]

I'm already going to deal with lag if I run that much pipin its going to add a bit more. Look at acura nsx's and toyota mr2s running a rear mount with a diffuser catches plenty of air to cool also remember I have an alky injection setup for it as well

robertisaar is correct and that's the point I was trying to get across that side by side a long distance intercooler system compared to a long distance turbo system all else the same will build boost quicker in part because of how far the energy that spools the turbo has to travel and the loss of effective spooling due to the cooling of the exhaust gases along the way causing them to contract. This phenomena has the opposite and positive effect on intake charge air over the same distance.

I didn't notice any increased lag with my front mount intercooler and I made it a point to do the math before conducting the experiment, I believe my results are in my build thread but the time to throttle body increase was such a small amount compared to what I stood to gain it was not a problem. My inlet air temps are now about 100 deg farenheit at ~8 psi on mid grade fuel down from 212 deg without an IC, that's good for about a 10% increase in power.

I'm going to convert it to rear IC because I don't have room for the proper pipe diameter to run the intended 15 psi over that distance and because I want to simplify the entire system for dependability, so I'll be moving away from the twin turbo setup also to a T72 or T76 single turbo with a .96 or more if necessary turbine housing. I also have a water/meth kit that hasn't been installed yet as well as 60 lb/hr injectors which is another area I forgot to mention to you may be a problem on a 2.8L if you can't pulse them low enough to avoid flooding the motor at idle since they are more than 3 times the flow ability of the stock injectors.
Although you mentioned other engines using the setup or similar to your plans, I believe all of them were more powerful and efficient than the 2.8L which means you are more likely to have too much supply for your engines demand which can be a problem.


Here is my car now with the front mount intercooler and cripplingly advanced camshaft that is likely cutting output by as much as 100 hp if CNCguy's estimate of 20 deg advance and my Dyno simulators estimate is correct. I'm going to degree it in to fix that.

Hope you succeed at what you have planned.

http://videos.streetfire.net/video/Testing-with-without_680592.htm

Proof of the front mount intercooler

http://www.fiero.nl/forum/Forum2/HTML/084972-5.html

[robertisaar]

buy, borrow or steal it... cost me $35, but goddamn, i learned a lot.

[kikinz24]

I am running a 7730 ecm which from talking to a few people on v6z24 and fiero forums that comp can be chiiped propperly to change my fuel maps to run such large injectors. And if I'm wrong then someone tell me now buecause I will spend the time upgrading to a obd2 setup and using my hptuners. If I fail in the end ill know why. And then I will sell my turbo and get a smaller one its all about trial and error. This isn't a car I will ever drive but a few nice days s year and to car shows around town so Its a learning experience. I kno of guys who ran the tgp setups on z24 s with a larger turbo obviously not as large as mine but pushing amazing numbers. To me it is just a hobby, just like twin charging a sunfire it is absolutly under powered compared to just a turbo but the guy did it just to do it. It runs 13s but is a 1 of a kind. I'm pretty confident I can get this thing up n running propperly.

[RedZMonte]

the turbo is entirly too big... I understand you got a great deal... but sell it and buy a T3/T4 and pocket the rest of the $$$$... i don't care how much you port the heads, bore the engine, and rev the piss out of it you will not make boost untill near redline... if its a show car thats fine..... (well that would be kinda gay actuall) but if you actuall want someting driveable this turbo is not it... I don't care what the magazines and articalls all say i know from 1st hand experience that turbo will be very dissappointing on that engine!

Hell my 3.4L DOHC 24V engine barly spools a standard T4 in time to make it much fun... if anything its a little to big, should have went with a T3/T4 hybrid, letalone on a iron head 2.8 MPFI with a fraction of flow from out of the heads. The TGP ran a Large T25 and it spooled about perfect on that old boat anchor 3.1MPFI...

[kikinz24]

I'm using a 3.1 for the car not the 2.8 that's in it. anyhow it is overkill and want to see if I can push it. Wats it guna hurt to try it if it don't work how I like I can sell it and go smaller with no problem. I originally bought the turbo oh hell about 5 months before I even found the fiero at the time I was going to turbo my grand cherokee 5.2 but the deal on the fiero came qwick so I bought it. And figured wth let's try it.

[Joseph Upson]

I am running a 7730 ecm which from talking to a few people on v6z24 and fiero forums that comp can be chiiped propperly to change my fuel maps to run such large injectors. And if I'm wrong then someone tell me now buecause I will spend the time upgrading to a obd2 setup and using my hptuners. If I fail in the end ill know why. And then I will sell my turbo and get a smaller one its all about trial and error. This isn't a car I will ever drive but a few nice days s year and to car shows around town so Its a learning experience. I kno of guys who ran the tgp setups on z24 s with a larger turbo obviously not as large as mine but pushing amazing numbers. To me it is just a hobby, just like twin charging a sunfire it is absolutly under powered compared to just a turbo but the guy did it just to do it. It runs 13s but is a 1 of a kind. I'm pretty confident I can get this thing up n running propperly.

The same principle for the turbo applies to the injectors, the parts ability is not in question, the engines need is. Injectors have an effective range at which they can deliver fuel efficiently, even at the minimum pulse rate sustainable for the injector (not the ECM) you may still flow more fuel than is needed by the 2.8L at idle. The injectors have a minimum fuel pressure at which they are still able to atomize the fuel effectively, in some cases people have had to lower their fuel pressure in addition to the chip settings to get idle fuel flow within limits. There is no need to purchase injectors that are probably capable of supplying fuel for as much as 700 hp on an engine that based on its long history probably will not see 400 hp due to its design limitations.

I have never heard of more than 300 + hp being produced by a built 2.8L or 3.1 and given that Ford 302 small blocks crack at around 500 hp I don't expect to. Again not trying to discourage you, just drawing on experience and observation to help you avoid wasting good time, money and effort.

[Joseph Upson]

I know we keep refering to your planned engine as a 2.8L but 3.1L is not that much more as the Fiero guys are already finding out from the wall they are slamming into when they put the Fiero intake manifold on a Camaro 3.4L and choke it down from its stock 180 hp.


This is the last thing I'll mention about the turbo you have, think about the movie Driving Miss Daisy, except instead of Miss Daisy you're driving a turbo around town in the back seat :-).

[kikinz24]

Yes I completly understand the injectors I've already taken this into consideration. And yes there is a 412 hp camaro with a 2.8 in it on the f body forums running a turbo that is honestly just shy of what I have fuel pressure will be lower and idle is set at 1k instead of 800 to kinda keep it up a bit. I understand ur not tryin to discourage me but I have the stuff at hand sitting in my basement so y not. If in fact I build it and need to downgrade turbo I will until then I'm goin for it. I considered swapping engine to a 3800 bc I've built a grand prix already and know how they run but that's about what everyone else does to these cars

[kikinz24]

Well I'm just going to be stubborn about it I guess bc I am going to put it on either way. And yes its is like driving a turbo around in the back seat . The damn thing weighs more than my son!!

[robertisaar]

I considered swapping engine to a 3800

please. do this. join clubGP for all i fucking care. i'm tired of trying to explain why this is a horrible fucking idea. i'm sure joseph is as well.

[pocket-rocket]

If I fail in the end ill know why.

Proper planning can give you a much more enjoyable car when this is all said and done- without the fail. I eventually want to turbo my 92, and when I do, I am going to do tons of research before I buy anything just to make sure it will work as I intended it too. I agree with Shane. Sell the big turbo and buy the right one. Let the profit pay for the rest of the build.

[kikinz24]

I've done a ton of research in the past I know what I'm lookin to get and only way to do so is try it. Guys can bash all they want on how stupid I am for even wasting my time but I relle don't care because it all comes down to personal opinion. No offense but I wouldn't waste my time on a lumina to me its just a car. But that's my opinion. And obviously you feel differently about it. I was just originally posting to ask the simple question of should I brace my crossover. And this is what it turned into

[RedZMonte]

YES, brace your turbo anywhere and any how you can... you have the T6 in hand, you see how big it is.. it will crack your welds with the heat....

i also understand you have what you have and want to make it work.... again my point is you can sell the T6 and have money left over on a turbo that will actually spool. find a compressor map for that turbo and plot your motor, it will be way off of the charts for what your motor will be capable of... I am one that understands doing something just for something to do as a hobby or what not... at the same time if it doesnt make sence it doesnt make sence... i applaud you for doing the project but just wanted to make sure you know what you should expect... what you do from there is your choice. Not bashing you but i am definatly discouraging you from doing something that doesnt make a damn bit of sence... (but doesn't effect me either way, just sharing my $.02 of turbo knowledge) map it out on the compressor map and show us how it will work.... that should end the conversation....

Compressor map should look simmilar to this:


S