jurassicreps

what is the bhp gain from tubular headers? are they worth the money? also un-equal or equal? do equal reduce torque and remove the scooby burble?

wrighty338

iTrader: (33)

do a search its been covered quite a lot. depends on your mods too. worth the money - well not if you buy cheap ones with flexi up-pipes etc.

General rule is you free up quite a few ponies and quite a lot of torque for the money.

Equal gain you more power (iirc) and yes you lose the burble but gain more of superbike style sound at higher revs

scoobiewrx555

Up to 350bhp the standard headers are fine if you get them ported. Scooby owners don't take into account that buying a decent set of headers like GT Spec Gen II with uppipe can have quite a detrimental affect on turbo spool up by reducing exhaust gas velocity bigtime. You can in effect experience Turbo lag. They don't come into their own until you're hitting higher mid range + rpm's, then you're motoring but we don't drive at 10/10ths all the time therefore a more driveable car with good torque low down is more desirable and it gets you out of corners a lot quicker.

Unless you are making big power stick with the standard headers and uppipe, just port the headers where they bolt on to the heads, maybe port your exhaust ports so they are concentric (round) and stick with a standard diameter decat uppipe. That way you keep exhaust velocity nice and high which will in turn reap the benefits of early turbo spoolup, even with some of the bigger turbo's.

P.S. With std headers you get to keep that lovely deep warble, it's all but gone with GT Spec type headers.

HTH

Aztec Performance Ltd

iTrader: (234)

The flat 4 beat is far from gone with GT Spec headers as they are unequal

For anything low to mid 300s upwards, decent tubular headers are recommended.

scoobiewrx555

I dissagree with you. I have a set of GT Specs on mine with the 3-bolt flange and the burble has all but gone. They aren't equal length but they are not far off. Compare the difference in unequal lengths between the GT Specs and the std headers and the difference is night and day. If you want a proper deep burble while still making some decent power ported std headers will do the job well.

Aztec Performance Ltd

iTrader: (234)

Maybe you have the unequal ones in that case.

GT Spec headers fitted to my own car and not short on burble.

petedotuk

I have GT spec headers also, unequal and it has lots of burble.
Didnt effect spool up, torque was increased and the driveability was great.

Anders_WR1

iTrader: (8)

I ported my headers but found them to be a restriction when I bolted on an MD321H, so I ended up spending more upgrading to GT Spec headers.

Go for tubular and one of Harvey's GT Spec up-pipes. I fitted his up-pipe and a couple of other mods last week and spool to 1 BAR was improved by 300rpm

Anders

"Taylor"

iTrader: (2)

Another thumbs up for GT Spec headers. Just fitted a set to mine and was worried about everything i read on here about increased lag. Well all that worry for nothing, they seem to have improved turbo response if anything. I'm only running my engine in at the mo, so haven't had the turbo on anywhere near high boost so can't comment on performance at that level, but the turbo seems to be spooling nice and early. They still have the burble too, just sound a little raspier. All in all, money well spent i think. As for my spec, its a forged 2 litre running a 20g, last rolling roaded at 330 bhp.