I'm probably going with the fp big t28 or the agp t28 , I'm assuming I need the smaller fuel pump, I have a afc on order, do I need bigger injectors and a afpr. Or could I get away with it.

Originally posted by 95talontsi
I'm probably going with the fp big t28 or the agp t28 , I'm assuming I need the smaller fuel pump, I have a afc on order, do I need bigger injectors and a afpr. Or could I get away with it.

Click to expand...

I was running 16psi on my Big28 before I installed my 550's. Now I'm running about 19psi with egt temps around 875c at the top of third. I also run the walbro 255lph fuel pump without an afpr. Mine seems to be ok with the bigger pump. But... I'm sure the fpr is getting over-run. If I had to do it over again I would probably just go with the 190lph pump, that should be suffice for the Big28. I wouldn't run anymore than 16psi on the Big28 without bigger injectors to be on the safe side. Everybody's car is different though, so you could possibly be able to run more boost with stock injectors, especially since the outside temps are geting cooler.

yeah.. id have to say optimal mods for the Big28 or AGP28 would be a Denso 190lph pump and 550 injectors

If the big28 is all you're ever gonna use for a turbo, you can find really good deals on JDM 510 injectors.. I'm sure they'd suffice for the big28

there's a really cheap group buy on RC 550's at:

http://www.importevolution.com/store/rc_fuel_injectors.php

i've also heard that if u stick the 510cc injectors in that you do not need to get an air/fuel controller like you would if you got 550's. Is this true? I am eventually going to need new injectors, but I also am only making my car so fast to a point. And i'd rather not spend a few hundred on a fuel controller. And if u can run 510's w/out the controller than that's what i think im going to be getting.

i dont see that.. I think your always going to need a fuel controller of some sort.

You will need the AFC, no real need for an afpr at this level.

Mike

Originally posted by larryd
i dont see that.. I think your always going to need a fuel controller of some sort.

Click to expand...

I agree 100%

I was in the same boat a 2 months ago and I decided to go with 650cc so not to max my injectory duty cycle at high boosts and and I could decerease my air flow signal more on S-AFC and that yields better timing for 2G cars. If you worry about idling, they idle great too.

Originally posted by cagri
I was in the same boat a 2 months ago and I decided to go with 650cc so not to max my injectory duty cycle at high boosts and and I could decerease my air flow signal more on S-AFC and that yields better timing for 2G cars. If you worry about idling, they idle great too.

Click to expand...

I agree with this statement.

I recently installed an AGP T-28 on my 98 GSX and I am waiting for my AFPR to arrive to install my fuel system, but for explaination purposes here's the fuel system I will be running.

Walbro 255 fuel pump (rewired)
Spoolinup AFPR
Apexi S-AFC
Denso 660cc injectors
Autometer EGT gauge
OBDII pocketlogger
Apexi Autotimer (estimates A/F ratio but easier to read than blinky lights on an A/F guage)
New o2 Sensors

I guess I will see how that works out for fuel and tuning and I will post results when it is complete.

Joe