LUDELVR

Right now I have a t3/t4 and the turbine housing is a .48. I have an h22a1 and basically the engine flattens out just as vtec hits. I am looking at getting the .63 housing but I need to know if by changing the turbine housing I will need to also add more fuel. I am currently using a 5:1 fmu and my fuel seems to be pretty good but I've been searching for an answer to this question but to no avial. Any help would be great!

Rolla1990

I think a 5:1 fmu isn't enough fuel.. If you're gonna go FMU, get a 12:1 and adjust it down.

red91sit

a bigger turbine will cause you to need more fuel for the amount of boost your running due to the more concentrated ness of the air. Everythought about investing in a S-afc? i think it'd be a better plan than using a FMU

drag0n

actually, the big question is, will you turn up the boost with the new housing? With a larger housing, you can get more air moving at a lower boost setting than before. If that is the case, then you should be fine with your current fuel setup. Running the same amount of boost with the new housing could result in the engine running a bit lean. Best bet is to stick it on a dyno with a wideband O2 and find out what it is doing.

LUDELVR

well, first of all, 12:1 would be super overkill and I would completely foul my plugs and be way to rich! I had an 8:1 in there and I was constantly cleaning my back bumper because of all the black soot on it. I swapped to a 5:1 from jrsc and it was a hell of a lot better. Anyway, I will not be going any higher than what I am at right now which is 8-9 psi. I am planning on taking it to the dyno but I just couldn't come up with an answer as to whether or not the bigger turbine will require more fuel. I'm gonna keep the same compressor and I was really wondering how a bigger turbine will create more compressed air. I can see how it can choke a turbo by restricting the exhaust gas from passing but I really want to know how it will create more cfm. Thanks again for all the replies.

HMT-Admin

Since the bigger turbine does flow more cfm at the top end, yes you will probably need a bit more fuel. Best way to make sure you are within safe levels is dyno tuning with wideband o2 support, to get your air/fuels dead on.


Jeff

shortyz

thats a new way to judge if your cars running rich "loookit the rear bumper, depending on soot buildup"

lol

LUDELVR

yah, I actually have a little glass plate at the back where I can see just how black it gets!! hahaha, yah, it sounds kinda funny but when I had the 8:1 it bogged quite a bit and there was a lot of unburnt fuel coming out so it was a few things that pointed me in the direction that my a/f was way too rich. I will hopefully be taking it to the dyno soon, just depends if I can locate a .63 housing.

Hey jeff, I remember that you were looking for one before, how big of a difference will it make on your ride jumping up from the .48? I know that you'll be able to spool throughout the entire rev band but how much of a change will you have to do on your setup?

shortyz

mabey this does prove that lude injectors are 350cc's...