matthewpims

Im building an 88 core to fit into the 84 se glove. I was planning on porting the engine (with limitations) to get a few extra hp ftlbs out of it. If I perform mild port work to the engine where will it put my power band? Will I be able to port the engine and still run the factory injector system? I dont want to put all this time into porting the engine and find out the efi cant keep up, or have the power band waay above 7grand. Preferably id like to keep it under 8000, any imput would help thx guyz
matt w

LongDuck

Stock SE injectors (680cc nominal at 40psi) flow pretty good, but you're still limited to only have 2 of them. There's a reason why the 2nd Gen cars have 4 staged injectors in the intake path, and that's due to the need for greater fuel flow at specific airflow velocities.

The engine itself would probably need more work to get beyond what the stock SE EFI system can provide, but you're probably getting near the upper end of the duty cycle on the 2 stock injectors. You may have to go with an aftermarket FI system if you have other modifications that will increase fuel and air flow - such as headers, or a turbo later on. That will definitely require some custom work.

I have made header/exhaust/intake mods to my stock SE and have never felt that it's leaning out at either top speed or during acceleration. For that reason, I would tend to think that you can probably streetport the 6-port engine and not have to worry about it. Get into a bridgeport or something more radical in design and you're likely going to need to make some more modifications just to get good performance out of it. Things like increasing the airflow plenum diameter to allow better flow characteristics.

I'll let some of the intake guys talk to that. HTH,

MarkPerez

If it's the 88 engine your putting in your -SE, you should be okay with the stock EFI. Everything is bigger as far as air flow. Larger injectors, and a programable 'CPU'
( plug in the laptop) would be 'my' thinking before any porting. car should go good with the 88 engine. IMO

LongDuck

Maybe I misunderstood his post, but I was thinking he was taking the 88 13b short block and installing his 6-port SE induction system and EFI, after his port job.

That would give the poster some of the rotor and seal improvements of the later years, but on rebuild, he'll need to remember that the water jacket seals are located in a different place for 86+ 13b housings. The 84/85 13b housings had the water jacket O-rings located in the rotor housings, IIRC; whereas the 86+ engines have them in the end and center housings. Someone correct me if wrong.

If you try to put the 88 EFI system in the SE, you're going to have to transplant the wiring harness and ECU as well, as your SE ECU is only designed to fire 2 injectors, not the 4 on the 88 EFI system. HTH,

j9fd3s

iTrader: (3)

my gsl-se ran for 13years with an s4 short block and the gsl-se efi. here are the problems

1. IT WILL NEVER EVER PASS SMOG, the s4 motor and gsl-se have different air injection ports, and they dont line up (gsl-se and s5 do though)

2. i have always had a leaning out problem in the upper gears. especially with the bigger exhaust. in fact i have actually gotten it to ping. i have a bigger fuel pump, and the afm is opening more than stock, and i still need more fuel up top. the afm is 100% open at 4500rpms btw. my peak power is in the 6800-7200rpm range.

MarkPerez

I had to re-read the post too, long duck.