The Triumph Dolomite Club - Discussion Forum

What are the losses on a rolling road?
I'm not expecting any definative answers, just curious as Caroline's car is being tweaked at the mo and we've been told to forget rolling road tuning as it's difficult to get the cooling and intake temps consistent on a rolling road - good for initial setup but not for final mapping.

In Richard's post about cams viewtopic.php?f=3&t=23228 I was thinking 135/9 at the wheels would work out to be 158/165 at the flywheel (as a guess).

Jeroen (with much greater rolling road knowledge than me) confirms this would actually be about 150 at the flywheel. Between 11 and 15 bhp loss.

One reason I've always thought of a %age loss is the amount of friction, resistance and other stuff(*)

But - is that so - once in top gear (or whatever the direct gear is, say 4th) are all losses pretty minimal (less than 20bhp).

My 1300 Toledo has (well, maybe had when new) 58bhp - does that have a 15bhp transmission loss (or would have if I put it on a rolling road)?
At the other end of the scale, Caroline's 911 Turbo has 560bhp at the wheels - does that have a 15bhp loss?

Is Caroline's car likely to be 575bhp at the flywheel?

(*) Stuff - POE, my Sprint, runs on 175 section tyres, the Toledo on 155 - do these have the same loss as the 911 driving four wheels on 245 and 295's. Do all props, diffs and wheel bearings have the same resistance, as in a Sprint prop, diff, wheel bearing, are these the same as Darren's HiLux diff and the same as the Porsche 4wd setup and diff. Or if not the same, just 1 or 2 bhp different. Also the harder the engine is pushing I'd assumed that there would be more of this resistance and other stuff - meaning it's not a constant between a 58bhp engine and a 560bhp engine.

Caroline's car has been into Parr who use a hub dyno, take the wheels off and bolt the dyno direct to all four wheels but the hub dyno is not good at measuring losses, as there is no friction on the rollers and very little inertia (no wheels spinning). Off the power the engine spins down much faster.
And for the big power stuff Nine Excellence don't use a dyno - (for whatever reasons) preferring to do the final maps at Bruntingthorpe, using a VBox and the engine ECU for 0-300kph, 100-200, 200-300 runs.

Just curious about rolling roads, the last Triumph I had on one was a TR7 8 valve with 125bhp at the wheels.

If you have for instance 50hp loss trough the transmission your oil would be boiling. The real DYNOJET can measure neg. power. When the car is at max rev in 4 let it roll out in neutral. The dyno can measure how much power is needed to go to zero. That is about the Nm what is the loss in transmission and tires. This is not the actual but almost. You can ask if he can do this for you. This is why i know the Landrover had 25hp loss. But it had 130hp at the wheels. I did fit a eaton compressor

Jeroen

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Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

I'm sure you could also do some clever sums with fuel demand...

cos then you know the energy required to do certain things........

Point measure the mpg required to sustain given engine revs in neutral and then in gear....at least then you get the same intake conditions...

Then you can work out for CDA and speed on wind resistance, Rolling resitance at a given speed you can find from rate of deceleration when you take the power off, so dip the clutch for a sec and see how much you slow down...

Its only physics... the sums are quite tough but nothing beyond a few equations of motion...

Jonnners

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Note from Admin: sadly Jon passed away in February 2018 but his humour and wealth of knowledge will be fondly remembered by all. RIP Jonners.

Rolling roads are ok for inital set up
Final Mapping MUST be done on the road ,
A car mapped on rollers will run weak on the road due to loadings
Also rolling road operators can make your car more powerfull than it really is,
Just by touching the brakes on run down can have a dramatic affect !!
Here is a print out of my old dolomite at 1.6 bar
Dyno dynamics are the best rolling roads but get a bad operator !!!!!
spot the mistake

PS Carolins car may have 560 hp at the wheels for a nano second
Power dimminishes as intake temps rise (turbo /supercharged engines) as the ign is backed right off to compensate
A car may start its run at brunters with 100000 hp half way down it may be down to 500 ,
I have been to brunters with many high powerd cars only for them to be dissapointed at the outcome mph wise
rolling road figures are GOOD pub talk
This is where it counts
These runs were all done with datron timing gear.
http://www.youtube.com/watch?v=feNrQd8K ... r_embedded#!

I had my sprint ran on a "dynometer" not a rolling road as I was told - it was at a old school garage that specialises in Mogs and lagondas and have raced Mogs for an eternity. They did exactly what Jereon said - adjusted everything to get the car running well, then maxed it in 4th and then put it in neutral and let it run down on the rollers. Result just under 15hp transmission losses 152hp at the back wheels.

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1976 Taihiti Sprint
2020 Jaguar iPace ev400
2011 Landrover Defender pickup - twisted
2023 Porsche 911 Carrera T Manual!!
2021 Toyota Yaris GR-Four
2011 Super Skoda Fabia 1.2 S HTP

Gone but not forgotten 2008 BMW M5 (E61) Touring (George, as in Best, as it likes a Drink) to be replaced soon...... Epic epic car

I've always thought of Rolling Road losses as a percentage - but that really does not make sense.
Apparently you can't do that on a hub dyno. Probably bollocks.
Now that starts to sound sensible - a Dolly has 15hp loss and a Landy 25 - that definately better than a %age of the engines power.
How, say, Darren's Dolly could loose 50hp in the transmission\tyres does sound daft - the entire power of a 1300 dolly lost, it has to go somewhere and some of it would be heat!
Car's also booked in for a VMax event on the 1st - should see how well it performs against some other cars, as it's a relatively low powered Porky I doubt it'll get anywhere near those 800+ hp monsters. On a test session last week a 9e20 car did 209 then 213 - which is not too bad. Caroline's is a 9e30 (and is less powerful). Caroline will be chuffed just to get near to 300kph.
Which is exactly what Ken said - hence taking the car for mapping on a test day before VMax. He needs the 0-300kph, 100-200 and 200-300 for his sales blurb and the data logs.
So fit the most efficient Intercoolers you can get, which will delay the effect of loosing power from halfway down Brunters to two thirds of the way down - another thing Ken said - the more boost the more cooling is required. When speaking to Caroline about how a standard 911 Turbo's power backs off at the end of a track session and how she can feel the difference from the first couple of laps - hence the need for more cooling. In fact cooling has been more important in this car than the amount of boost.

One of Ken's other customer cars (he'll no doubt add Caroline's car to his youtube stuff once the logging is done)
http://www.youtube.com/watch?v=VkXwxqTm ... =coext-cha

Anway - long winded, but I can see where Ken, Jeroen and Darren all come from - stuff the rolling road figures and get a proper datalog.
A standard 996 GT2 should do 0-300 in 40.9
A 9e25 is 26 seconds
A 9e20 is 19 seconds
Caroline's 9e30 should be around 30 seconds (I've just realised what the 9e Package numbers are - they are the 0-300 times!!!)

We'll know in a couple of weeks, and it's no wonder people find it hard to do the final mapping on these cars. Where the heck is long enough to give it some beans.

Any updates ??

Caroline has got the car back - but has a slipped disc and will get that sorted in the next week or two (she's had an epidural to ease the pain but unfortunately that didn't work), so fuse the bones.

9E will take Caroline along for a private day if she misses another VMax or 9E test day.

All I can say is xuck me, that thing is fast. They turned the boost down to 1.2 bar to save the gearbox, but it'll light up all four beefy tyres on a dry slip road in 2nd and 3rd. I have never been in anything so bloody fast. It's currently running (according to 9E) at 560 at the wheels.
It's not superbike fast (as the monkey found when he tried to run a GT2RS against a Panigale) - but bloody quick.

Once Caroline is fit and well she's looking at a little holiday to Spa, I may take the 1UZFE Scim (not that it'll touch the Porky) and our mate will bring his super charged XKR, (which is slow compared to both). Good girl.

In the mean time I'll just have to give the car an occasional run out whilst Caroline is on the mend

Sorry - no fun update. Caroline is on the mend from a spinal decompression and has been out having a little bit of fun. No driving for six weeks equates to no full 600hp blasts for a few weeks. So she's scared me, my dad and most of the family who show the remotest interest.
Winter tyres are on and Ken at Nine Excellence has a new map, I've had to say no to PSS10's as Caroline's back really won't like too hard a ride. Speaking to Ken 600hp is 80% of what the hybrids will give, but till the missus gets better I'll have to sit tight.
A brunters run is hopefully on between 23rd Feb and 9th March (the front diff may be removed - who cares - it's stupid quick already).
Anyway - the missus is getting better, the porky lot want the Akrapovic videos and the classic lot want their faces back (it is rather quick)
9E's latest map update is for low down grunt - but, who gives a stuff when you're over 600 hp.
As a little aside - my brother is full on with a Broadspeed XJ12 coupe, the only Fezzer 712, a 512, a 312 a Lola T70 a couple of Lister Storms and a few other weird F1 things - Caroline scared him as well!
The car is in for a few more mods at the end of Feb then, hopefully, a full on Brunters run. Should see 150 at least
I've driven the car a bit whilst Caroline is on the mend - and don't take this the wrong way, but why have over 420hp (standard) It really is no fun, touch the throttle and you're likely to be loosing your license. 60-130 is 5 seconds, suddenly the digital speedo says 140 leptons, that's just a quick overtake. My old Dolly is just fine for me, once Caroline has done some high speed runs, I'll let you know!
It won't be ALG1K quick - well not with me or the missus in the driving seat, but it'll be nearly as powerful. Here's to a good 180+ run at brunters.

Quick update, most importantly Caroline is back to work.

Her car has had some minor changes, it's now two wheel drive rather than four, with 2wd geo done - drives lovely. The suspension has been updated with top mounts, B6's and a few other things. Not lowered at all and standard springs, Caroline is not keen on more back surgery. Good job Caroline is a damn site better driver than I am!

It was VMax today for German cars, but she didn't run as Ken said the gearbox may not take the max speed event and survive for Spa in two weeks, his comment was 'I know how expensive a few days at Spa is - and I'd rather you upgraded the gearbox before doing Spa and a VMax day!' Ken has a couple of upgraded boxes for his car, but the bugga would not sell me one!

That said, another 9E car won the day with a 215 run. It literally ran out of gearing. Strangely the R8's (even "twin turbo" V10's, wow) struggled to top 200, only one did (the R8's must have more power than the 911's). A Ruf Porsche was second with 205. The 9E car was doing 210+ on all runs, then hitting the rev limit which is 7400.

We have a few track days and a driving holiday then the gearbox can be uprated and lower the final drive (after August - unless I buy a second transmission/final drive and get the work done and swap it - but it all costs).

And to keep the Dolly theme - POE is going to Spa with the Porky (I'll get some GoPro footage of the 911 flying past POE), I'm really looking forward to taking a Sprint around Spa
We decided against taking the Scim, I thought stuff it, I don't get much chance to take the Sprint anywhere.

Wasn't expecting to find Vmaxers on a dolomite forum!!

I concur with some of the comments above. Cracking 200mph at Vmax is no easy task. Have done/built it for a customer (got to drive it too). Definitely an eye opener!!

Problem is, now i need to build a car to do it. No wonder the dolly is relegated to the queue!

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1970 Triumph 2000 Estate w/ RV8
1980 Triumph Dolomite Sprint
2003 Holden Ss Ute
1969 Dodge Charger
1973 Triumph Stag
1961 Standard Atlas

Ahhh, you'll find us Dolomite people are into lots of things.

VMax - a 9E40 did 190 which is not bad for a very mild tune, not even uprated IC's.

The 9E17, now that's something else

https://www.facebook.com/photo.php?v=10 ... =2&theater

With a 9E40 doing that Caroline is really looking forward to getting her gearbox uprated, the turbo's turned up a bit, and seeing what she can get out of her car.
In the mean time - Kemmel straight - whoosh....

Well, my health stuffed all our opportunities at Brunters, Caroline was raring to go and I let the side down yet again!!

At least another 9e30 did 201 on a wet and windy day Saturday 19th, but a big power 9e car broke the Porsche record at 229.

http://www.youtube.com/user/Nineexcelle ... ture=watch

We've had a few great track days with the Sprint, LexScim and Porsche at Spa and Goodwood, a real mixture of old fun and newer power. POE the Sprint has kept in front of lots of seriously quick cars, if only Rob (SprintSpeed) would put the vids up!!

Ken at 9e will await our turn for a fast run

POE is getting some pretty serious mods next year, engine, bodywork and smile inducing stuff.

It's been a long time since a 9e30 did 201 at Brunters (not Caroline's).
But - the Vmax guys did a Dunsfold day on 7th March, Dunsfold - the home of Top Gear, has a 1 mile runway, which isn't very long, and when the service road cuts a bit off and you have a load of cars parked at the end, the usable distance is well below one mile.

Oh, and it's a standing start, whereas at Brunters you can have a run on for two miles.

Still, Caroline and her 9e30 held their own against some well tuned cars, the 9eXX cars are well over 1400bhp.

It was interesting to see a new 911 GT3 and GTR using launch control with Caroline's car idling, yes they are faster, but they start at some silly revs, Caroline's is at idle. Then press the throttle. The Ferrari F12 was quite fun, shot ahead up to 150 then Caroline's car blasts past. The Lexus LFA - not a hope in hell. There were a few McLarens 12C's there, funny how no times are listed.

And the fastest girl there

How well did the car do in 0.70 miles....

Vmax Nine Eleven:
Gary Hewstone 9EXX 205
Matthew Gibbard 997 9exx 201
Thomas - Nine Excellence 997 - 9E 198
Asim Allan Porsche 918 192
Toby Baxendell Porsche 997 GT2 Rs Tuning 185
Mark Hughes Porsche 997 GT2 183
David Kibbler 991 Turbo S 176
Chris Hunter 997.2 Turbo S 175
Peter Gledhill GTR satin matte blue, 700hp 172
Scott Parker 2015 911 GT3 170
Caroline Tomkins (Ben) 2001 Porsche 996 Turbo, blue, 167 <== Pretty good for sitting in D at idle, then floor it. It's an old school auto, no brake boost. Car at idle, mash the throttle.
Imran Arshad 997 Turbo 166
Andrew Barraclough 996 Turbo 165
David Willis Panamera Turbo, Black 165
Paul Goddard 997 GT2 165
Lee Frost Car 996 turbo s 162
Tom Brooks 996tt 2001 silver 570bhp 163
Marek Soroka Porsche 996 Turbo 162
Steve Messenger Black Porsche 997 Turbo, 2006 162
Ashley Alinia 997 turbo, red 161
Jon Hayward 2014 991 Turbo Black 161
Richard Smith 911 gen 2 turbo 2010,black 161
Alan Taylor 2011 997.2 turbo convertible, white 160
Kevin Lynch 2005 Porsche 996 turbo X50 Polar silver 160
Larry Annan 2014 911 GT3 991, Red, 160
Steve Pick 996 Turbo '03. Arctic Silver, 160
Jay Lexus LFA 161
Nuri Bodur 2006 997 turbo 159
964- grey 159
Andrew T 996 turbo 159
Asim Ferrari F12 159
Mat Finch Porsche 911 997 CSR, black and gold 157
Mel Rockett 997 CSR Atlas Grey 156
Mark Holroyd White 2008 Cayman S. 145
Shaun Moreland Porsche 911(997) C2 146
Peter Harrison Porsche 911 2004 996 C4S 140


Things have moved on a lot in a few years, now the 9eXX cars are aiming for 270+

Long time and no update.

Last year Caroline managed a 188,




then sprung a leak on the gearbox which we always knew was the weak link.

So, a new gearbox to cope with 1000 lbft of torque was installed, and, as you do, we turned up the boost and blew the head gaskets, bent the rods, cracked the block, ooops.

New block, rods, crank, turbo's, intake, injectors etc.

At TV6 (last weekend) with a 25mph head wind manged 192 - but run out of fuel, new fuel system needed (pumps not pumping enough).

Intake temp at the end was 45deg C, injectors running 62% duty cycle, turbos at 72% - so with a new fuel system finally should crack the double ton, without the 25mph head wind 200 would have been cracked, at VMAX even F1's, LaF's and a Veyron 'S' failed to crack 200 with a 25mph head wind.

Caroline uses the car for work, it easily does 60-130 in 7.5 seconds (vbox) just flooring it in 'D' and carries the dogs very nicely

I may get around to doing some work on POE this year, but maybe not.