petesmith

Hi, thinking of fitting a stainless steel manifold to my classic turbo my00 at some point in the future and was wondering if it's worth it or not. Have read that it is supposed to increase power and torque. There are also two types out there, unequal length - keeps the subaru noise and equal lenth which is supposed to give you more power. Just wondering what experience and power increase people have had by fitting one.Cheers

VWscooby

I have an un-equal length HKS manifold fitted.

It was on the car when I bought it but the previous owner said it made a noticable increase in torque and turbo spool-up.

Whether thats true or not, it certianly hasn't caused me any problems!

petesmith

Cheers for the response. There must be some more people out there who have changed it!

neilswrx

just got the car back from the garage new unequal headers fitted
sounds good seems to have a better pick up
and i would def get a garage to fit them as the bhoys said it was not as easy as people would think(mucho cursin) ,engine mount disconnected turbo disconnected and bolts stuck as car is 10 years old no surprise there
not found out if fuel ecomony is affected but i didnae buy the car for that anyway

FASTER MIKE!!

s.steal headers will be lighter than the std cast ones, prob need a remap for the full benifit, but you should gain something

mike

Engineer@Uni

Equal length headers will give you a better power curve, both low down and ligh up. You will, as you said, loose the burble. If you've already gone ahead and developed the car past the 1st stage and are now looking towards the 350+ hp figures, an equal length manif will deffinitely net you some power and torque. The good thing about exhaust mods is that they give you more to play with without needing more fuel! although I wouldn't bet you'd see any difference in mpg. Stainless headers are a good deal lighter so they should improve turn-in and they also make a slightly different noise to the stock cast ones.
Go for equal ones, I say. If you're ditching the stock ones you might aswell go for the best spec out there.

Tone Loc

iTrader: (1)

Wouldn't agree with that... or much else that was said to be honest. The highest power spec cars in the UK are mostly running unequal length and they seem to do the job fine. True equal length are hard to find and more expensive, personally i'd stick to the proven unequal length designs from HKS, Gruppe-S etc.

You don't need more fuel.... you sure. Ask the people that have mapped cars running tubular headers on MAP based ecu.... a few have had to add a fair bit more fuel. More air=more fuel. MAF based ecu's will 'see' this additional air and so should access a part of the map which should already be a tad richer.

Tony.

petesmith

Cheers for all the response. One of the comments goes to say that fuel consumption does not go up and some say it will. When i fitted a full decat system on the car, mpg dropped by 4-7mpg i thinks. I don't think i am drivin the car any different to before the decat, but i might be drivin it harder due to it soundin so good without realising.

Tone Loc

iTrader: (1)

I'd say you're driving it harder due to the sound . If you're on the oem ecu while cruising, idling the AFR is under closed loop controol and aims for 14.7:1, so really should be any different. But when on boost the engine does breath easier so more air, so it will be in a new section of the map compared to pre decat... probably a little bit richer. That could be the difference but i wouldn't expect 7mpg difference

Tony.

neilswrx

unequal rocks
mpg not bothered(too much)
fitted by garage =super job(saved my knuckles and fingers)