Small turbo and exhaust bore

Small turbo and exhaust bore

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Discussion

steve-V8s

Original Poster:

2,675 posts

216 months

Wednesday 9th June
quotequote all
Was encouraged to change the exhaust downpipe and cat on a small engine turbo car for something with a larger diameter to reduce any restrictions. It feels as if the car has lost some low end torque. I was speculating that perhaps with a larger bore pipe the exhaust gas speed will be less resulting in a reduced turbo speed at lower RPM. Is that a valid thought or nonsense ?

Boosted LS1

20,068 posts

228 months

Wednesday 9th June
quotequote all
I'd have thought that with less exhaust pipe back pressure the turbo/turbine speed would be higher.

Max_Torque

16,927 posts

185 months

Wednesday 9th June
quotequote all
Nonsense, sorry!


steve-V8s

Original Poster:

2,675 posts

216 months

Thursday 10th June
quotequote all
Ok I will dismiss that idea then.

My thinking was with a larger bore pipe immediately after the turbo the same amount of gas flow would have a lower speed and presumably a higher pressure.

Will look elsewhere for the disappointing loss of torque.

GreenV8S

28,871 posts

252 months

Thursday 10th June
quotequote all
Maybe wishfull thinking, but is it possible the car has picked up torque at higher revs and this is why it feels a bit flat lower down?