Some enlightenment would be sweet

[Nibbib]

So I went to Cobb surgeline in Oregon and I'm sorta happy with my numbers 168hp and 188 torque but my air/fuel mix is bad full boost its at 14.3 or so and they say I need to be running 12.1 and I was told a easy way to make it happen was to buy a rising rate fpr and I've read on here a little but not sure the ratio I want I know the stock on is 1:1 but I found one on eBay that says its a 1:3 not a 3:1 typo maybe? But I was wondering if I went with a walbro 255 pump (gss342-400-whatever lol) is just the pump able it improve the mixture and I don't plan on running the rising rate fpr for very long just so nothing horrible happens I want to run stand alone at some point

And thoughts would be very nice thanks

[macipusy]

The pump is just a supply line, upgrading it only increases the amount of fuel available and it won't change fuel pressure...that's controlled with the FPR. I have only heard of n/a guys tuning with adjustable FPRs and personally would not recommend to try to tune using this method.

You probably need a piggyback unit, at least, to control fuel delivery.

Get a wideband O2 installed and verify what your AFRs are.

[SILINC3R]

Those are pretty good numbers for a 20+ year old car. Stock numbers but good none the less.

[Nibbib]

Car does have a wideband that's how I know my mixture... And Cobb even recommended that solution to me as a temporary fix not permanent fix and I wouldn't mind finding another pp6 but I would rather run a full stand alone personally since a piggy back sorta just masks problems if there are some

And car isn't stock has 16g ported turbo and 3in downpipe and 2.5 cat back

[mike-tracy]

That should be where a stock 02-05 WRX dynos, but with more torque. One of the past members here datalogged his SS, also with a td05, exhaust and mostly stock otherwise. He quickly came to the conclusion that the td05 was too big a turbo for the stock injectors (Subaru ran 440cc injectors with td05's in the 90s). I believe the guy was bsod2000 if you wanted to read his conclusions.

So until you get some method of controlling your mixture, perhaps bigger injectors would be a stopgap to prevent holes in your valves and pistons?

[Nibbib]

I asked Cobb about that and they said pretty much doing that just allows more gas biting boost and I don't need more gas

[mike-tracy]

Would you agree that a 14.x AFR is bad under boost? Adding bigger injectors on an otherwise stock system would cause it to run richer everywhere, and hopefully lower the AFR on boost.

This isn't ideal at all because of how big your turbo is, but I would wager that my idea would add a small layer of safety.

[dscoobydoo]

If you are running those mods on a stock ECU, then you need to do something about the fuel control and delivery.
What about the intercooler? List your full mods. The TD05 went with 440's and a decent intercooler on the JDM wrx's and normally only 12-14 lbs of boost. Since you are probably only 440's away from a 20G setup, you might consider a Robtune.

The 12:1 AFR is pretty much standard for boost situations. You might want to consider dropping boost back to low single digits until you fix the issue.

[Nibbib]

So mods are 16g port and polished 3in down pipe 2.5 cat back subaru air water inter cooler and that would be it and car is running stock boost which hits from 8-10lbs

[randomiam]

What AFR do you see at idle Nibbib? They are right, 14.3 is more like what you should be seeing at idle/out of boost

I'd back the boost off and get some injectors as a start-- 440s can be run by the stock ecu for a measure of safety or you can begin collecting the bits needed for the TD05 robtune route.

[Nibbib]

idle is 14.8-15.2

if i go the way of a robtune which i wouldn't mind

what is exactly do i need i've read a lot about it and i have also read that if you dont run coil packs you need to do something for the spark plugs

[cj91legss]

All that information is on the RobTune thread. What size injectors do you have currently? Are you SOHC or DOHC?

[Nibbib]

Stock injectors and sohc heads

[Legacy777]

I'm going to chime in here because I think there's some misinformation. If you are running stock boost pressure with stock fuel injectors and a TD05-16G you should be absolutely OK. I ran this way for quite some time. Despite the TD05 flowing more than the VF11, it will not flow enough to cause those AFR's.

My suggestion would be to start with your fuel pump and see if that corrects the issue. It may be worn and not flowing enough to maintain proper AFR's under boost. If that doesn't fix the problem, you've got some sort of other issue.

[Nibbib]

Okay would a walbro 255 be a better option then stock?

[SILINC3R]

Yes this is the standard upgrade and cost about 100 bucks.

[Nibbib]

Okay sweet hopefully that will help me cause if it does I still rather run a standalone like mega squirt cause a guy I know is working on making a full plug n' play and then it's just removing the maf and running anything I want lol

[robertpaige]

A full plug and play would be SWEET.

[Nibbib]

Yeah I'm going to talk to the guy today and see where he's at with it