So, I retract the statement that the exhaust made huge power, and replace it with this: The exhaust made huge power in the mid-range, but now, boost creep makes me run out of fuel on the top-end. I had to turn my MBC from 19-20 down to 12 just so I can run all the way through second gear without boosting past 20 psi and detonating. If I leave the boost turned up, I have HUGE midrange, ripping tires clear through 2nd, but I can't stay in it past 5500. Setup is: 14b, Walbro 255 with factory wiring, freemods, 3" dp and side exit, MBC. Would a fuel pump rewire flow enough to compensate, or are my injectors maxed? Also, is it the fact that I am running a factory o2 housing that is causing the boost creep? I'm pissed. If I turn the boost down enough to actually get to 7000, my car is slower than it was with a stock dp and 2.5 pressbent. Help!?

I would have to say that you need to get a different O2 housing. I run a 3" (goes to 2.5" right before rear axle) turbo back exhaust, an EVO III O2 housing stock manifold, and get 0 boost creep. Also, my exhaust housing was port matched to the O2 housing and a larger wastegate flapper was installed. I say was because I have a new setup, but the car has yet to start with the new setup on it. Good luck!

Dude your pissed?!?!...you took a ride in Natedoggs car...didn't you!!!

Check out these O2 housings. They are inexpensive and looks pretty decent!

http://www.punishmentracing.com/frameset.html

Most likely. Just port the shit out of the factory O2 housing...they're good for 12's ported out. Not saying that by just porting it out you'll be running 12's , but a ported 1G O2 housing will allow you to get there.

12's? Nice. I already run 9's (1/8mi ). Anyway, I have an o2 I'm currently porting, but it takes time. I just wanted some back-up input to reaffirm my suspicions. About the fuel, I'm inclined to think that my injectors (450's) are too small, they have to be close to their limit. Thoughts?


BTW: If my FWD ever sees the 12's, I will more than likely pass gold bricks from my...nevermind.

Well, having the 255lph pump surely helps. However, you don't really know what your fuel pressure actually is. If you did know, and could bump it up a bit, that would allow you piece of mind, at least. I doubt that you need larger injectors, though. It IS only a 14b, after all . Anyway, if you port out your O2 housing, and possibly upgrade the wastegate flapper to a 34mm (and port out the wastegate hole some), you "should" be able to run around 17psi (maybe even a l'il more) on that turbo, with those injectors, efficiently.

RRE says u need new injectors if ur running any higher then 16-18 psi....

http://www.roadraceengineering.com/eclfuel.htm

check the chart half way down the page

umm....no. That chart says you need a fuel pump upgrade (which he has) for anything up to 18psi on a 14b (which he has). Looks like you need to "tune" your researching skillz

I think you need a pocketlogger, but that's just me talking.

NC, you may have a point... So, when are you available?

Also, re-reading through your original post, it struck me that you might be trying to wind it out too much. Higher RPMs don't necessarily always equate to more HP. For example, I get max HP at ~5500, but that's w/the crappy '90 cams. Yours is probably a bit higher (see if anyone on here w/a '92 has a dyno sheet) but there's really no need to go above 7000 rpms (unless, of course, you've got upgraded springs and retainers).

2g my friend, you need a 1g logger

oh wow, MY BAD, anything above 17-18 PSI!!!!!!! I assumed since the chart said "fuel pump upgrade" is good to 16psi, anything above that would require injectors! Even if it says 14b @ 18 psi = new injectors...

Enless it is totally impossible to run 17 psi on a 14b lol.... Then i would have to say 17 psi is just a little sketchy

That's why a logger is necessary. There are to many factors(IC pipes, IC, turbo condition, A/F....) That's why every car at that level just needs to be logged and taken care of individually.

you live close enough to me... wanna split one?? I dont think we both need it all the time.

my thoughts exactly, just tryin to help out

yeah, it says 550cc injectors WITH 91 OCTANE

Many people have run 17psi or higher on 14b turbos. But, as NC suggested, a logger is a must at that point.

Spy, what is the comparison between the denso vr4 and the walbro 255?


This whole problem seems to stem from the fact that I have the worst case of boost creep imagineable. Just for fun, I turned boost to factory 12ish psi and made a run in 3rd. 22psi by 5800. No matter the rev range, I never seem to run lean until 19+psi. I am becoming more convinced that a seriously ported o2 would help immensely. I think if I can get the boost under control, I should be ok @ 17-18psi. I guess I may have taken this glitch a bit too seriously, but this is frustrating to say the least. I appreciate all your input.

Spy, you're right, that information was worthless. But interesting nonetheless.