Results from the Dyno

[Stewart H]

I was up at Weltmeister yesterday with a mixed bunch of cars from 911UK.com and had a chance to run with both the standard exhaust tip and one of Will Norman's "silenced" tips. An interesting comparrison.

Standard tip 291.4 bhp @ 6,300 rpm
Will's tip 290.6 bhp @ 6,300 rpm

The average runs were about 2 bhp different but the peak runs were as above.

The car is running a Cargraphic hot film kit, a cat by-pass and a cup pipe.

Interestingly, a 964 C2 with nothing more than a RUF chip and (I think) a cat by-pass made 273 bhp on an engine with 235,000 km on it.

 

[ChrisW]

9M's magic dyno put the Clubbie (with Motec + 1/2) at 335 bhp and 420Nm.

As I become used to it it's as fast as a GT3RS .... more torquey, but less at the top (of course).

 

[Jamie Summers]

ORIGINAL: Stewart H

I was up at Weltmeister yesterday with a mixed bunch of cars from 911UK.com and had a chance to run with both the standard exhaust tip and one of Will Norman's "silenced" tips. An interesting comparrison.

Standard tip 291.4 bhp @ 6,300 rpm
Will's tip 290.6 bhp @ 6,300 rpm

The average runs were about 2 bhp different but the peak runs were as above.

Stewart,
That sounds about right. Will's done various tests on different cars and with different exhaust configurations, and overall the biggest drop in power by running with the "silenced" tip was c. 2bhp ie. practically undetectable in the real world. I leave mine in place full time now - can't be bothered to switch it over just for trackdays. Will's still working on a "stage 2" option which should get a 964 RS down to the 98db level for static tests (but to be removed for actual track driving). Just needs to work out an easy fit / remove procedure and the pricing ........... watch this space ..........

Jamie

 

[Jamie Summers]

ORIGINAL: ChrisW

9M's magic dyno put the Clubbie (with Motec + 1/2) at 335 bhp and 420Nm.

As I become used to it it's as fast as a GT3RS .... more torquey, but less at the top (of course).

Chris,
My Motec + 1/2 came out at almost exactly the same figures on Colin's dyno - so at least there is consistency. I've not verified the figures on anyone else's dyno, but Colin's dyno is, perhaps a little "optimistic" ??? I'd like to think it isn't, but it has always seemed a little bit too good to be true ???

Jamie

 

[Melv]

ORIGINAL: Jamie Summers
but Colin's dyno is, perhaps a little "optimistic" ??? I'd like to think it isn't, but it has always seemed a little bit too good to be true ???
Jamie

Thing is, if you take Colin's argument, the rolling road is only for proving before and after readings, so the final reading, to some extent is almost irrelevant......

 

[Jamie Summers]

ORIGINAL: Melv

ORIGINAL: Jamie Summers
but Colin's dyno is, perhaps a little "optimistic" ??? I'd like to think it isn't, but it has always seemed a little bit too good to be true ???
Jamie

Thing is, if you take Colin's argument, the rolling road is only for proving before and after readings, so the final reading, to some extent is almost irrelevant......

Mel,
Agreed, absolutely. However, that doesn't stop people wanting to know "definitive" numbers (which may prove ultimately to be a complete waste of time). What is interesting to me in this instance is that two pretty much identically specced engines produced almost identical results on Colin's dyno, which I think proves the integrity and consistency / repeatability of his work. What would be even more interesting is to see how my car reads 12 months on, to see whether one can add longevity to the list of attributes !

Jamie

 

[Stewart H]

Jamie. If you want a "more pure" reading, book it in with Parr and put it on their hub dyno. That will take any friction losses out of the equation. IIRC, they charge about £100/hour.

 

[ChrisW]

Agreed on all counts --- the driver of my car is it's greatest limitation.

But it sounds and feels wonderfuel --- and only 105.8dB at Oulton --- hey ho.