RS246 Rolling Road Meet Sat 17th Nov Thorney Motorsport

[DavidT]

Right, thanks Clive.

I have my file, David's (DHT's) laptop ran out of juice at the worst time I'll email it to you now.

Are there more ?

[CliveH]

If there's anyone we promised to email VAG-COM logs/scan to and you haven't received it, please drop me a PM.

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

[saf]

Spec: B5 S4, RS4 airbox, RS4 y pipe, Thick headgaskets, MRC intake pipes, Tubular Manifolds, MRC Hybrid Turbos, Phenolics, FMIC, 600cc injectors, 3" downpipes, dual 2.75" exhaust no cats one box, 23 psi flat (will make more low down boost/torque but limited to keep S4 rods in block)

dyno: 503.8bhp 525 ft-lb
fats: 2.8 on a dodgy rs4 box

MAF peak: 450

Thats pretty good. Whats the max torque you reckon the car can safetly handle on stock S4 rods pistons etc.

Are your turbos running 23psi all throught the whole range once spooled up. I presume thats what you mean by flat.

Thanks.

[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

[spen]

Rolskii

Thanks.

Tubular manifolds are not all plain sailing. Maybe some lovely MRC ones are, but mine aren't. I'd recommend seeking advice before going for it.

For example, mine get hot. Hot enough to cause problems for things nearby. Especially plastic things! If you directly lag them you'll destroy the welds. Mine expand and stretch the threads on nuts and bolts over the months. Retorquing them in situ is a 'fraught' experience. And so on....

Edited just to make plain: My manifolds are not the ceramic coated MRC exhaust manifolds.

[s4woody]

here goes nothing..
M5 391.6 bhp,408ft/lbs
best fats run was to the toilet..boy did i need a

[S4TAN]

Edit on FATS: just found a 3.65 in the log .... nice!

[rolskii]

Spencer are they MRC un-coated manifolds ... ? if not which make are they ..?
retorquing in situ cannot be fun - how long you run them in yr car..

cheers - david

[S2tuner]

One word about the crankshaft torque figures: they are wrong on all dynodynamics dyno sheets unfortunately. Sorry to disappoint you people, I know some of you loved your torque figures, and so did I (managed 520ft/lbs on my RS4 engine on a dyno dynamics too), but unfortunately they aren't accurate.

I used to think that DD overreads crank TQ and Paz's car is the one that proved it. It produced (from memory) 262ft/lbs at the wheels (356Nm), which is about right for a standard S4 (factory rated at 400Nm at the crank). At the revs and engine speeds where torque happens at, the losses for torque are more likely to be in the region of 13% rather than 30%, which sounds surprisingly high to me.

Sorry for the disappointment, but I'm just not buying a 30% drivetrain loss for torque. Power, yes, but not torque. 198wHP is about right for a standard S4, especially judging by how lean the car runs standard, but 340ft/lbs (462Nm) is just wrong.

This of course has nothing to do with Thorney Motorsport who did a great job throughout the day!

Cheers all,

Mihnea

[GrahamS4]

@ Mihnea - I still can't quite get my head around the correction from wheel BHP to engine power works. I know you don't like they way it doesn't measure the losses but do you know what criteria it uses to make it's calculation? It's not a set % we know that. I listened to John Thorne's explanation and he mentioned it takes fulling into consideration as one factor.

My peak torque was 380ftlb which I think is 515NM. Is that unlikely? Your site quotes 500NM for remap, I think generic so with a custom map and an exhaust, I thought 515 sounded reasonable. Odd that Paz's stock car could overread so much and also the much higher powered cars, but mine doesn't seem so unlikely.

Also the power figures. We had two examples where we know the wheel to engine correction is not a set % - mine and daybar had same wheel power but different flywheel and as Julian said his and Clive's had same power @ wheels but different flywheel numbers.

[dace]

the correction temperature on the dyno is the air temperature - not the intake temperature.

I did a test with 2 similar tuned S4s - one with FMIC and one with stock s4 SMIC - running the same file - the differnece was 370bhp to 440bhp and intakes were 100+ deg c and 30 deg c (IIRC - there is a post on here) Side By side on teh road there was hardly anything - and intake temps on the car with stock ics wera round 50 deg c max)

It just goes to show that bhp is not the "be all and end all"...

Let's face it it is real world figures that count. I think we all crave for big bhp/torque numbers, however on the track or the road is where it counts (driver dependent of course).

[Doug_S2]

dave - i expected that s4 on stock ICs to do 400 to 410 - not 370. the on the road shows it is not a 70bhp differnece - but a lot less. But then a 550bhp car against a 440bhp car - there is a difference but not huge (you and rich compared to my car on the way to the ring)

[dace]

dave - i expected that s4 on stock ICs to do 400 to 410 - not 370. the on the road shows it is not a 70bhp differnece - but a lot less. But then a 550bhp car against a 440bhp car - there is a difference but not huge (you and rich compared to my car on the way to the ring)

You are bang on there Doug. There was not much difference at all and when you look at the weight difference, very very similar.

However I do believe that the real power difference is at the higher end.

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

[CliveH]

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).

[Thorney]

Thanks to everyone for being patient. We were sort of expecting to run all the S4/RS4's first and leave anything different to the end as it means we get through the cars faster that way but we didn't have that opportunity so sorry for the slow start. Its true we don't do much 4wd stuff (not many awd BMW's and Vauxhalls) but the dyno is used frequently for awd cars and was used this week for a couple, but perhaps this did affect the B7 so I'm happy to run that again FOC to be sure.

Nice to catch up with some old friends, sorry about the butty van not showing up (although I think we dealt with it pretty well by going out and getting food) and sorry it was a long day for some but we at least made sure we did all the cars.