RR results

Author
Discussion

mrpbailey

Original Poster:

992 posts

193 months

Thursday 19th March 2015
quotequote all
Having had a fair bit of work done in 2013 my car was then mapped to 491bhp & 427lbft by Trevor at Track n Road.
Here's the RR graph:



Last year I had a new exhaust (BCS powervalve) and fitted the pro-alloy hardpipe kit. On the previous mapping the car was already fitted with a dual stainless system.
I recently had a power run on another well known RR in the Noble community (that apparently has a reputation of sometimes rather optimistic figures...) and found I'd lost 23bhp & 15 lbft. Also, the power drops off rapidly at the top end. Graph here:



Is it likely the mapping just needs tweaking to take into account the changes or does it point to an issue?

anonymous-user

61 months

Thursday 19th March 2015
quotequote all
23bhp out of 491 is just 4.6%.


I work with an engine dyno system that cost £10M to build, and controls everything to 0.1degC 0.2kPa, and i quote +- 1% full scale error in flywheel power as the absolute best possible

You have run on two different rolling roads, on different days, and are measuring power at the wheels. frankly, ime +-10% is typical!


(and the power drops off at the top end probably because the operator lifted the throttle once they had seen power peak)

Gadgeroonie

5,362 posts

243 months

Thursday 19th March 2015
quotequote all
the boost, and shape of the torque / power looks the same

could it be the first Dyno is more optimistic than the second one ?

Adrian W

14,414 posts

235 months

Thursday 19th March 2015
quotequote all
argue

131 mph V 163, they were running in different gears, probably the reason for the difference, something to do with inertia and mass.



Edited by Adrian W on Thursday 19th March 15:35

mrpbailey

Original Poster:

992 posts

193 months

Thursday 19th March 2015
quotequote all
Apparently the way it dropped off around 6.5k is typical of a car with standard valve springs, but mine has the upgraded ones. No mention of lifting off, as the operator was a bit concerned at the tailing off?

Will probably look at getting the map tweaked to take into account the now slightly different setup

F.C.

3,897 posts

215 months

Friday 20th March 2015
quotequote all
They look identical given different days and set up.
tailing off is present on both graphs at the same point, it is exaggerated on the last one as it was pulling a lower gear and everything happened a bit quicker.

rich83

14,711 posts

145 months

Friday 20th March 2015
quotequote all
Nothing to add apart from say that BCS systems are fantastic :-)