Will A Turboback Exhaust Make My Car Run Rich?

[RBwhatever]

Ok, so I was thinking of upgrading my stock exhaust to a 3" turboback. I was looking into getting one of those xforce mild steel ones.

I've still got the stock ecu and i'm trying to stay away from upgrading it.

My car is a R33 S1.

Mods are:

K&N Hi Flow Panel Filter

Boosted to 10 psi

Sports muffler (yes thats right, the muffler only.....hence the upgrade.)

Current economy: 500kms from 50-56L

Will it make my car run rich and have bad fuel economy?

Thanks guys...

[mad082]

it shouldn't affect it too much. although it will be letting more air through the motor at 10psi so it may use a bit more.

also you shouldn't be running 10spi through the stock exhaust. it isn't good for the turbo. you are adding more heat into the system as it is working harder to get to 10psi.

[RBwhatever]

yeah it very rarely sees the 10psi, only on odd occasions.

[RBwhatever]

does anyone else have any opinions?

[Munkyb0y]

i've been told 2 opposing stories on this.

1. any mod incl. exhaust (which is highly recommended for better flow) will cause the ecu to run things a bit richer/use more fuel.

2. the bigger exhaust will allow the motor to run less restricted, using less effort, better economy. this one i heard for the first time the other day from a tuner. i have my doubts.

[mad082]

having a bigger exhaust should give you better economy at cruise, because it has more power (due to less restriction). so you should be able to use less throttle % for a given speed.

at WOT it lets a bit more air into the motor, so the ecu has to add in more fuel to keep the afr's right.

so both of munky's answers are right.

[Munkyb0y]

wooohooo, cant lose.

but if you're getting 500kms to a tank now, you're doing pretty well. so lets say you start seeing 480 or even 450 a tank, that's nothing to complain about.

get the exhaust, it's a very worthwhile mod. from the turbo back is the way to go.

[mad082]

i only get that sort of economy on the highway. round town i get around 250kms to about 45L. but i have some issues that i think are being caused by the o2 sensor. that and my tune is rather fat.

[ctjet]

Joises... i used to only get like 300 to a tank!!! Maybe driving style plays more of a role in fuel ecconomy that i was told

But i was also under the impression that exhaust would help fuel ecconomy

[mad082]

my economy is definately affect by driving style.

[Munkyb0y]

my economy is crappy too. ~15L/100kms.

but then i just found a unichip connected to my ecu. didnt know it was there.

maybe a tune may help. but the car runs farken great, and sometimes you mess with stuff and then regret it.

sorry for cross-threading again. goober lookie here http://www.skylinesaustralia.com/forums/in...t&p=2595890

Edited October 19, 2006 by Munkyb0y

[ctjet]

whats a matter, afraid to send a PM?

why take up my intraweb with unnecessary cross-threading

[RBwhatever]

Just about 85% of my kms are around town.

I had the impression also that with a bigger exhaust it would actually make the engine run more efficiently, but as said before at WOT it would run richer than stock.

Hmm thanks guys, I just wanted to make sure that I wouldn't be seeing it drop to 300 - 400 kms per 50-55L.

And yes, driving style has a lot to do with fuel economy. When I bought my car it was dead stock, the first I week I had it, I did 300kms to 55L

Edited October 19, 2006 by KeyMakeR33

[Munkyb0y]

whats a matter, afraid to send a PM?

why take up my intraweb with unnecessary cross-threading

shut up !!!

[Black_Widow34]

i think it depends largely on the way u drive it, if u mainly cruse then ur car should have the same or even better fuel economy with the turbo back because as it will require less throtle to keep the car moving but if u give it a bit then it will have better flow in which case it will require more fuel to match the afr. but a turbo back exhaust is the very first mod u should do. u should never boost ur car higher with a stock exhaust and/or stock intake as you are working the turbo harder and creating extra heat.

[_8OO5TED_]

the R33s run quite rich standard, i found fitting a full exhaust and pod only confuses the sh*t stock ecu even more and runs the car even richer. SAFC or Power FC or some other type of fuel/air management would be ideal if your worried about fuel economy and richness.