Rolling road test for sports exhaust

[kev north]

The big question! Does the straight through sports exhaust loose you power.
I have been advised to go on the rolling road before and after fitting, so i went on the rolling road today at Sanspeed Bexleyheath.
The test, i thought they would bolt the car down! But no i had to sit on the boot instead! Does this sound normal to you?
The outcome.
The car is a TVR Chimaera 5.0ltr V8 1997, which should be around 320bhp, Sanspped mearsured it at 217bhp at the wheels and 270bhp at the fly wheel! Does this sound right? When i questioned them about the read out they said check the car because it may have something wrong with it.
The exhaust is being fitted on the weekend and then rolling roaded again, i will be back with the read out.
Has anybody else had similar problems with their read outs?

[smifffy]

There are *loads* of posts about this.. have a quick scan through the archives using the search facility.

To give you a brief potted history:

TVR lie when they state 320/340 bhp for the Chim/Griff. They lie when they say 420 Bhp for the 4.5 Cerbie.

They tell the truth with the 4.0/4.2 Cerbies.

270 for yours sounds about right.

A little simplified maybe, but if you want the full history have a look at the archives

[trackdemon]

And as usual, the conclusion is simple: does the car go F@#KIN fast? Don't know of anyone who's said no so far....

[smifffy]

Exactomundo, but if you'd just been on a rolling road and expected 320 bhp and got 50 less, I think you'd be justified in being a little concerned.

But yes, they are still fcuking fast and give you -->

[joospeed]

quote:The big question! Does the straight through sports exhaust loose you power.
I have been advised to go on the rolling road before and after fitting, so i went on the rolling road today at Sanspeed Bexleyheath.
The test, i thought they would bolt the car down! But no i had to sit on the boot instead! Does this sound normal to you?
The outcome.
The car is a TVR Chimaera 5.0ltr V8 1997, which should be around 320bhp, Sanspped mearsured it at 217bhp at the wheels and 270bhp at the fly wheel! Does this sound right? When i questioned them about the read out they said check the car because it may have something wrong with it.
The exhaust is being fitted on the weekend and then rolling roaded again, i will be back with the read out.
Has anybody else had similar problems with their read outs?

I sit on the boot when doing the tests at John Nobles so yep it's normal. quite scary though when you're on a cerbie doing 7k revs and the exhaust extractor pipe blows off and twats the roller shutter door! yikes
your power sounds spot on.

[2 Sheds]

217 at the wheels & 270 @ flywheel spot on, you can't do a definitive comparison test unless its done the same day. there are so many factors such as atmospherics and operator technique.

[joospeed]

just noticed I seem to have lost my logo .. Ted??

[nubbin]

Jools, can you e-mqil me with the details of the rolling road you use, please?. I fency getting some power outputs for the Tamora. Also, can you do this sports exhaust cut 'n' shut stuff. I'd like my car to be a bit noisier!!

[joospeed]

quote:
Jools, can you e-mqil me with the details of the rolling road you use, please?. I fency getting some power outputs for the Tamora. Also, can you do this sports exhaust cut 'n' shut stuff. I'd like my car to be a bit noisier!!

no need to e-mail you, I'll tell the whole world .. it's John Noble on Chatsworth Road in Chesterfield. they're excellent .. did the engine install for the Noble M12, often lots of engines being built at their workshop.
Louder exhaust .. can have a go at the Tamora .. aren't yuo worried about warranty though? .. the factory could get quite picky about it not being std anymore.
call in for a chat if you're passing or join us on a chesterfield bevvy one day?