is there somthing i can do to give my car alittle more gas... without getting a custom eprom... i just wanna bump it up like 1-2 psi or so.... any suggestions

 

Send ur TBI to this guy Camaroracer1992@yahoo.com He will shave all the restrictive stuff off ur throttle body, add an injector spacer, do the ultimate tbi mods and do the adjustable fuel pressure regulator so u can boost ur fuel pressure to how ever u see fit, plus give it a nice cleaning and makes it look brand new. All for 40 bucks, pretty good deal. I did it and I love it.

 

Did it make a SOTP difference? How about a quantitative difference?

 

If you don't want to spend the money, and are pretty handy with tools like a dremel and drill, then I'd recommend doing it yourself. It's about a half day's worth of work (from start to finish), and you'll end up with a slightly higher-flowing throttle body, and a manually adjustable fuel pressure regulator. Buy a guage for the fuel pressure, and you're ready to tune.
For a step by step breakdown of what needs to be done, check the tech articles on the home page of the site. It'll be under "ultimate tbi".
Try searching the archives for this kind of stuff, too.

 

Yep...buy yourself a Dremel/grinder. You will find alot of uses for it

 

Well I've got one...what bits/wheels, etc. do I need?

 

First and easiest step to increase pressure is to put a washer(s) under the regulator spring. The engine may run a little rich at idle, but ask yourself what kind of driving you do. If it's rarely at idle, go for it. You'll have more power at the other end.

 

What collet size do you have 1/4" or 1/8"?

You just need a general grinding bit . Carbide or even a sanding roll will work. Just try it on another part before starting on your tb if you don't have much grinding experience.

 

I already tried the quarter mod and it made the car fall on its face on the top end....I suspected the fuel pump was weak and couldn't support the required volume of fuel at that pressure. Maybe what I should do is put the quarter back in and see how it runs...now that I have a guage I can see how the car responds at high rpms. This could be interesting. Thanks for reminding me.

 

What kind of gains could I see with this? Also, what happened to your milage? I know that might sound a little weak, but mine is a daily driver and I can't take a big hit.

 

Kev,
Go down to the ME lab (I know that'll hurt, but gotta be done) and have them turn you some shims to put on the end of the spring not against the diaphragm. Tell them 1 1/16" OD (that's outside diameter for you EEs) and .83 ID. Make .03 thick, .06 thick. If you want more, add both.
The mod should definitely not make top end fall down. If it's your pump, the car should fall due to lack of volume, not pressure.


Gunny,
Shouldn't affect mileage at all. Small gains.

 

I will have the numbers when I run the car at the track in May but most people gain a good hp/tq amount and great throttle response. E-mail Camaroracer1992@yahoo.com

 

Oh, so they're ring shims...these go on the other end of the spring? I guess that's why they need to be rings instead of chips, like a quarter. I think I will put the quarter back in anyway, temporarily, and check my fuel pressure idle (should be ~2psi higher, or 15psi) then check it during a long WOT run...if it falls on its face at 4000+ rpm like it has previously with the quarter mod and the pressure does NOT go down, do you have any ideas?
Obviously if the pressure goes down I should start looking for a new fuel pump.

 

Are you saying the engine doesn't fall off after 4000 without the quarter mod? only with the higher pressure?
If that is true I don't have any ideas without seeing what else is happening. Maybe see you on the 27th at NED.

 

Yup, that's what happened last time I used the mod.

 

That is odd, Kev. Have you tried putting jumper wires on the ALDL so you can observe feedback from the O2 sensors? If not we can talk about it on the 27th. Mine runs a little rich at idle but leans out later than without the higher pressure. If I ever get the vAFPR tuned, I'll share that with you.

 

Well I have a scanner, XP240. Dunno if you knew that or not. I am fairly familiar with the sensor-operation of my car during many running conditions, due to my constantly checking things over during random times (cruising on the highway, stuck in traffic, etc.).
I am still thinking that the 15psi the regulator is demanding from the pump PLUS the volume requirement at WOT/high rpm is causing something to mess up, and make my power COMPLETELY fall off (it's a push-pull type thing, but no audible knocking).

I just need to get outside and do the $0.25 mod again to sort of "force" the pump to fall off at the top end...I'm just secretly afraid that the power will fall off at 4000+, like last time, but fuel pressure WON'T drop...that would make no sense whatsoever.

 

I dunno, Kev. Even if the pump couldn't make more pressure, it shouldn't make less. Raising the pressure through the regulator is very similiar to sqeezing the return line. Pressure at the injectors rises and less fuel returns to the tank. I can't yet imagine a mechanical scenario that would cause what you experienced. Still, check your O2 sensors when the engine drops off. Pressure may drop off, but fuel volume is increasing by only the tiniest amount.(square root of the pressure diff) Maybe Ken R has some ideas.