Decat my 5?

[93 Mk1]

I noticed a drop in torque at low rev's in my wee beastie until the stainless exhaust manifold went in. THat freed up more torque and high end power than before but I;ve no dyno results before or after cos they ain't free to do!

When you say you noticed a drop in torque at low revs, what it after fitting
the decat pipe ?
From past experience, the more you help an engine breath the more power gain
you will have at the top end of the rev range but low end response can suffer
slightly.

[Steve]

Think I remember reading something about naturally aspirated engines creating more torque with some backpressure...

[93 Mk1]

Think I remember reading something about naturally aspirated engines creating more torque with some backpressure...

A trick some people used to do with the Mk2 Golf GTI 16v was to fit a smaller
bore exhaust to beef up the torque under 4000 rpm as normally it felt a little
dead until after 4k rpm. But fitting the smaller bore exhaust probably took a few
bhp off the top end.
That's why alot of multivalve engines need to be revved hard to get into their
powerband. 8 valve engines seem to feel a bit stronger in the lower rev range.
My last Mk2 GTI was an 8 valver which are known to be torquier than the 16v
model. After the head gasket failed, I had the head gasflowed and I fitted a
Piper 268 cam, free flow exhaust and a K&N induction kit. The result ? Well I
gained a fair bit of power from mid to top end but the low end torque suffered
slightly !
I'm going to shut up now because I'm probably ranting.........