2.8/3.4 turbo selection. please help

[ericjon262]

ya I'm reading that... decisions decisions.... well I'm pretty sure I'm going to stick with the motor i just picked up. been reading a lot of threads over on pennocks and 180hp to 190hp 3.4's that people are claiming with basic mods and no turbos sound like they scoot pretty good compared to 2.8 in these fieros. i'll keep reading on which route to take.

don't believe everything you read over there.

[Guest]

So will swapping in a '7730 so you can tune your turbo 3.4 properly... you can run the 3400 off a '7730 just as easily. They are both DIS ignition motors...

you don't need a 7730 computer to tune your 3.4 turbo properly. You post on pennocks Carbon?

OP listen to Eric. Don't take advice from people on that fiero board. Sign up on a different fiero board if you want good turbo advice. They don't know what they are talking about on pennocks. A stock fiero computer with a modified chip can allow you to tune the turbo setup just fine. Two questions for the OP. What is your hp goal and what is your budget?

[ericjon262]

personally, I would go ahead and swap to a 7730 instead of one of the stock fiero computer. mainly because it opens so many options.

here's a prime example of why I typically avoid PFF.

http://www.fiero.nl/forum/Forum2/HTML/131477.html

[TTT123]

don't believe everything you read over there.

well i think doing all the mods i can to the motor minus turbo since i just don't want to have to deal with tuning it etc. it will be enough for what i'm looking for out of this car.

question... i read in a thread that its not a good idea to port/gasket match etc. the intake side of these heads... is this true?

[caffeine]

The stock Fiero ECM with boost is more of a hack job IMO. Having a knock sensor is also very important for a turbo car and the Fiero ECM does not use one.

The main issue though is you need to run a 2 bar map sensor on a code that is only designed for 1 bar. That means if you hack it to work you lose half the resolution in the VE and spark tables. Unacceptable IMO.

For an EASY ECM conversion, use a 7165. Only about 6 wires need to be changed (uses same connectors as Fiero ECM) and you can run $12P which supports 2 or 3 bar map sensors.

[ericjon262]

well i think doing all the mods i can to the motor minus turbo since i just don't want to have to deal with tuning it etc. it will be enough for what i'm looking for out of this car.

question... i read in a thread that its not a good idea to port/gasket match etc. the intake side of these heads... is this true?

I'm real hesitant to do a true gasket "match", because when the gasket compresses, if the match is too good, the gasket will squish into the port. and create more restriction then if left a little bigger. honestly, if you don't have a good eye, and good hands, porting heads is a crapshoot, doesn't matter what you're trying to port.

there's another one of the myths spread on PFF too, "oh that mod won't require a tune..." every mod requires a tune, esp with a speed density ECM.

[caffeine]

Also you want to leave the intake tract surface rough post-injectors I think to help swirl the fuel in with the air.

[TTT123]

you don't need a 7730 computer to tune your 3.4 turbo properly. You post on pennocks Carbon?

OP listen to Eric. Don't take advice from people on that fiero board. Sign up on a different fiero board if you want good turbo advice. They don't know what they are talking about on pennocks. A stock fiero computer with a modified chip can allow you to tune the turbo setup just fine. Two questions for the OP. What is your hp goal and what is your budget?

hey bigcheese. my goals was just to have a pretty quick fiero for having a little fun with while driving to work. i just sold a twin turbo camaro that was pushing around 800hp i built and I'm planning on getting a 930 slantnose turbo this spring... i honestly don't say that to sound arrogant or be a show off just saying money or it being super fast isn't really the concern. its more of a have a little fun with it over the winter and have kind of a nice poor mans sports car lol

i am interested in that 7730 swap i'm just not that great at that stuff so i'm hoping to find someone who can help me with that. i heard gmtuners does a lot of that stuff so maybe i'll contact them.

[caffeine]

The 7730 guide on the gm tuners website is foolproof. Very very easy to follow.

[TTT123]

great info guys, i really appreciate it.

caffien can you elaborate on the the codes, ecm stuff you were talking about or point me in a direction so i can read about it. that stuff just honestly goes over my head. the camaros i've built have all been old school carburetor and well i just got into hotrodding a little late in life lol

[ericjon262]

The 7730 guide on the gm tuners website is foolproof. Very very easy to follow.

very very easy, practically idiot proof.

[TTT123]

just seen your last post.... i'll go read up on gmtuners web page.

thanks

[TTT123]

very very easy, practically idiot proof.

umm well that idiot part might be a catagory i fit into sometimes lol i've tried and tried and that stuff just doesnt stick in my brain... and i'm a programmer for over 17yrs now lolol

[caffeine]

Codes I'm talking about are the overall program that runs the engine. Certain codes can run on certain ECMs. Some are modified programs based on other codes (like $12P, $59, nAst1), while others are factory.

The common code used to run a 3x00 is $A1, which is the factory J-body 3.1 code. TPI V8s usually use $8D IIRC.

The ones that support boost natively (not requiring a 'hack' job) that I know of are $58 (Sy/Ty, 2-bar), $59 (modified Sy/Ty 3-bar), $8F (Turbo Grand Prix, 2-bar), nAst1 (modified $A1, 1, 2, or 3-bar) and $12P (I think this one is based on a Holden code, 1, 2, or 3-bar).

$58, $59, $8F and nAst1 all will run on 7747, 7730, 7727, and 9396 ECMs, code $12p needs a 7165 or equivalent.

[caffeine]

umm well that idiot part might be a catagory i fit into sometimes lol i've tried and tried and that stuff just doesnt stick in my brain... and i'm a programmer for over 17yrs now lolol

The guide basically just tells you remove pin X on Y connector and move it to pin Z on Q connector etc... There are a handful of splices required as well and then in the engine bay there are a few wires to move around and if you're doing a 3x00 you will also need to change a few pigtails (i.e. wiring is the same but a newer sensor uses a different connector).