Is tuning important for a hybrid?

[TazMan]

Hello. I have a 3.1l 92 GP that I am going to make a hybrid. I have a set of heads from a 03 3400 Grand Am, and set of ported large port 3400 intakes from a 2000 GA. The upper plenum is ported for a 62mm TB and I have a 65mm TCE TB. Now when I put all these parts on will the car run alright with the computer the way it is or does it have to be tuned?

[SappySE107]

You should port the upper for the 65mm TB. You will will have to run stock 3.1 injectors to use the stock ECM, severely limiting you power because of the small injectors. Tuning and 3400 injectors/rail from the 03 would be a better idea.

[Alxsmt]

wont he run into issues with the 3400 injectors not being compadable with the obd1 ecu? i know they will work but i thought it would run way too rich (even with a complete 3400)

[sharkey]

it will, because the ecm isnt tuned for the large injectors. but if he uses the 3400 injectors AND tunes, that would be the best thing to do.

[TazMan]

If I put the 3400 injectors in, do I have the car tuned at any mechanic or do I have to go to a dealer or something? Any idea's what something like that should cost? Also, I already have a set of injectors from a 95 3100 Century. Would those be the same or as good as the 3400 injectors?

[Superdave]

If you run the pre-2000 3400 injectors OR the older 3100 injectors and the older FPR you should be able to run the stock chip. More of a band-aid than tuning it for sure..


what computer is in it?

Us Jbody guys have a chip avaliable by a member that allows you to run the multech 2 injectors and the newer FPR on the stock computer...

[TazMan]

I don't know what computer, I just know it's obd1. How do I check? What am I looking for?

[Alxsmt]

hmmm, are 3500 injectores the same??? i threw out my 3400 ones lol, i was planning on gettin some 3100 injectores

[SappySE107]

Its compatible.

[TazMan]

So the injectors from the older 3100 are big enough to give me better performance than my stock 3.1 injectors, but not so big that my computer will run the engine rich. Is this correct? If so can I leave this set up like this? I mean, are the gains really big enough that it's worth going back and changing the injectors again before having it tuned?

Thanks again everyone for all the help and ideas

[Z2_4cams]

yes, using 94-98 3100 injectors will get you the best performance from the stock ECM with the stock tune. but it won't give you the best overall performance.

note: my hybrid went 14.13 @96.69 MPH with a stock tune and those 3100 injectors.

[MY91GT(Z)]

if 3500 injectors help ill sell u a set cheap

[Superdave]

if 3500 injectors help ill sell u a set cheap

they won't fit.. too short.