Exhaust wrap??
Exhaust wrap??
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Discussion

dwgriffith

Original Poster:

436 posts

251 months

Tuesday 10th July 2007
quotequote all
The griff I purchased last month has heat wrap applied to the branch manifolds from the heads to the lower part of the front Y pipe where it goes backwards. The question is this, could it be causing power loss due to the pipes being too hot? Starting the car from cold, letting it warm up to a decent temperature the thing has a surprising amount of power available, however, after say 30 minutes driving or a re-start the car has less power. It does not get worse after 50, 100 or 150 miles but oviously something is changing? Anybody seen a similar issue.

GreenV8S

31,020 posts

314 months

Tuesday 10th July 2007
quotequote all
dwgriffith said:
The question is this, could it be causing power loss due to the pipes being too hot?
No. If anything, probably more power due to reduced heat soak within the engine bay.

V8 GRF

7,299 posts

240 months

Wednesday 11th July 2007
quotequote all
GreenV8S said:
dwgriffith said:
The question is this, could it be causing power loss due to the pipes being too hot?
No. If anything, probably more power due to reduced heat soak within the engine bay.
yes

350Matt

3,902 posts

309 months

Wednesday 11th July 2007
quotequote all
Things do get damn hot under the lid

Typically the plenum temps can rise to about 80-85°C if all is left standard the air running through it doesn't quite reach these sorts of levels but it will be in the 55-60°C region at idle, under full load the air rushing through cools things down to 35° ish

But its still worth insulating everything that you can as the cooler you can run the advance the thing will tolerate which is more power. Also 20° hotter air will cost about 3.5% power loss so about 8-10Bhp on most Trevs

Matt

GreenV8S

31,020 posts

314 months

Wednesday 11th July 2007
quotequote all
350Matt said:
Also 20° hotter air will cost about 3.5% power loss so about 8-10Bhp on most Trevs

Matt
If you're talking degrees Celcius I think it's even more than that. Just the density change works out to about 1 BHP per degree C, if you're optimising the timing too you get further gains/losses on top of that. It's well well worth cooling the incoming air flow.