RS246 Rolling Road Meet Sat 17th Nov Thorney Motorsport

[MarkB]

From 120mph upwards (on de-restricted autobahns of course) a 5500bhp car pulls like a train...

Yep 5500bhp would pull like a train! literally!

[spen]

Mihnea,

My power and torque were corrected by 25.1%. You're suggesting that power should be around 30% loss and torque around 13% loss? Should we all be quoting power and torque at wheels instead?

FWIW I'm just going to use the same dyno, assuming I can get booked in by myself after the next batch of mods. That way I'll just be looking at the increases (hopefully) rather than absolutes.

[dace]

From 120mph upwards (on de-restricted autobahns of course) a 5500bhp car pulls like a train...

Yep 5500bhp would pull like a train! literally!

Yep, sorry should have been 550bhp. Well spotted....

[Jarv]

Jarv - I think you took yours away on a memory stick?

Yes Clive, you're right, I did. Do you need it back for collation purposes or did you keep a copy? I'm a bit confused about what format the collated data is going to be shown as. As a suggestion to the mods, how about an RS246 FATS database page similar to MRC's? It might encourage non-MRC tuned car data to be uploaded.

Mike

I kept a copy thanks Mike

I thought the collated data would be presented as a table (like the MRC FATs database)?

In view of Mihnea's comments, we need a view on whether the data is worth presenting at all. My view, for what it's worth, is lets collate the data and post it up - at least we're comparing apples with apples (even if they are bad).

I agree Clive, it is worth presenting as we can compare from one car to another, and if any of us want to see the benefits of further mods, we can go back to Thorneys. Given what has been said by those that know, is it worth gathering the wheel torque at wheel values from everyone as well? Mine was 430 Ft Lb's.

Just had a quick look through a few of my photos of the day, this is one of my favourites.

[DavidT]

The idea of going was to get a comparison of lots of different cars on the same RR. It does not matter if the bhp is doubled and the torque halved, the comparisions between different cars will be valid, right ?

Plus there will be lots of FATS runs to compare as well.

[CliveH]

Yes, that was my point about the apples, David.

Nice photo Mike

[GrahamS4]

The idea of going was to get a comparison of lots of different cars on the same RR. It does not matter if the bhp is doubled and the torque halved, the comparisions between different cars will be valid, right ?

Yes, but!

I'd say yes other than I really need a better laymans explanation of how two like cars, tuned similarly can have wheel BHP within a single digit of each other (mine and Daybar for example) but the flywheel figures be 10BHP apart. I think Julian and Clive's example is greater. Surely to have a higher flywheel figure it must mean the losses were greater to read the same at the wheels? How can two S4's have this much variation and on what parameters does it calaculate as we know it is not a set %?

On a DD is the difference a loss estimation or is the engine power an estimate that takes into account other variations that you dont see on the dyno? If so that could make more sense, just.

I am intrigued by this I have to say.

I think we have already missed a trick by not measuing boost on the all the B5 cars (I think this is the biggest variation especially the K04 cars) so we need to get this clear.

I agree we all used the same dyno on the same day. Great. But use one set of numbers and two cars are equal and another and they are not.

I'd like to know my torque figure at the wheels but my plot of wheel BHP has my torque at the flywheel the same as my BHP at teh flywheel plot. Daybar's BHP at the wheels plot had his torque at the wheels.

I am not sure we have left with a full set a figures.

What with my plots being a really bad scale (small graph at the bottom of a big page) do we think there is any chance of Thorney printing out all the data from all cars, wheel plots together, flywheel plots together and scaled nicely (can be done) and sending them all to one of us for distribution?

20 x 2 two plots is only 40 sheets of paper and ok a little time.

[s4woody]

well im happy with my figures..the torque figure is bang on..

[spen]

GrahamS4 - the MAP sensor Thorney plugged in to my manifold popped off mid run! I dunno if TMS attached it to anyone else's car after that?

Did the FATS loggers take block 115? If so you already have boost figures for the B5s.

[Jarv]

I got 003, 115 & 118 on the day Spen.

[S4TAN]

Ok - my @wheels figures are 313.6hp and 400ft-lb torque from the dyno - best FATS time was 3.65sec.

[CliveH]

Did the FATS loggers take block 115?

Yes we did, but David didn't log everyone's car.

[CliveH]

I think we have already missed a trick by not measuing boost on the all the B5 cars (I think this is the biggest variation especially the K04 cars) so we need to get this clear.

What boost data do you want to gather here Graham?

Peak boost? redline?

[daybar]

Interesting wheel/crank figures issue - can't contribute to that discussion, I'm afraid but here are my car/figures details.

Engine - standard exhaust cats and everything else except MRC custom remap (I take it that N710Ns and N249 delete aren't relevant) and no leaks (thanks Dave!)

Wheel bhp - 248
"crank" bhp - 322
Wheel torque ft/lbs - 298 ish (have to estimate it off graph as absolute number not quoted on the print out and memory of the number stated at the event now fallible)
"crank" torque ft/lbs - 390 (again based on the printout graph)

FATS - TBC as I have not done one yet

[Jarv]

Who's was the silver S4 saloon, registration starting V3? I have a minute of footage of their car on the rollers, if you want me to upload to You Tube and post the link on here, let me know. The V3 is the only part of the reg that shows on the clip due to the fan being in the way, so car won't be fully identifiable. PM me if you'd prefer.