RE: Rolling road day deemed success
Discussion
drunknfuctup said:
Nothing wrong with those figs at all..
The E34 M5 is what i would expect, as are the TVR's and Lotus.
Only one that looks disapointing is the 355, I would expect about 350 out of one of those.
Vixpy - Are these power figures adjusted to estimate what the engine makes at the flywheel or just horsepower at the drive wheels?
Rob
estimated flywheel figs, but we give a whp sheet to all our customers as well. Most RR's dont, and if you add in the loss correction (which can be anything) it can be confusing to compare figs on different RR's
snuffy said:Probably an overoptimistic rolling road then. Customers are always happier with bigger numbers! Seriously though, it's hard to make fair comparisons though unless you've got lots of evidence with the same cars.
Looks like all the Esprits on the rolling road on the Wirral on Saturday knocked you boys in to a cocked hat then !! 399, 401 and 423 ( for me, obviously ! ).
dannylt said:
Looks like all the Esprits on the rolling road on the Wirral on Saturday knocked you boys in to a cocked hat then !! 399, 401 and 423 ( for me, obviously ! ).
I agree. I'm vert sceptical with those figures as well.
dannylt said:
Looks like all the Esprits on the rolling road on the Wirral on Saturday knocked you boys in to a cocked hat then !! 399, 401 and 423 ( for me, obviously ! ).
Well Lane maybe
joust said:
Hmm.. Do they pull timing if they get hot i wonder
J
I have no idea, not my rolling road and i was'nt there.
Mid engined cars are a nightmare to keep cool, add in turbos and intercoolers and it would be hard to keep the manifold intake temp below 34 degrees too be honest without a fan directly ontop of the intercooler.
I've never done a noble, so would be interesting to experiment with one.
Hey Snuffy - your figures definitely a bit optimistic I think. Happy that our road produced results such as a bog standard V8 producing EXACTLY what Lotus said it would. All credit to the road and the engines they produce.
Road only had one fan (which was a huge affair) but at the front of the cars. This is fine for the Esprits as all the rads (including chargecooler (intercooler)) are at the front. I don't know where the rad for the intercooler is on a Noble.
Road only had one fan (which was a huge affair) but at the front of the cars. This is fine for the Esprits as all the rads (including chargecooler (intercooler)) are at the front. I don't know where the rad for the intercooler is on a Noble.
JEsprit said:
Hey Snuffy - your figures definitely a bit optimistic I think. Happy that our road produced results such as a bog standard V8 producing EXACTLY what Lotus said it would. All credit to the road and the engines they produce.
All 3 Esprits had been modified around the exhaust. Unfortunatley, we did not have a standard one to use for a comparison. Mine has straight pipes, racing cats, ITG filters and dump-valves ( no extra power for those I know ). Mine's a Sport 350 but the differences are weight etc, not maximum power. I can't see that my mods would increase power by 73bhp, which is 21%. So either the RR is a tad out or my car has been 'fiddled with' as it were. It was owned by a former CEO of Lotus cars so that could be a possibility.
Snuffy
Are rolling roads terribly unreliable due to the factors pointed out (suitable cooling, transmission correction factors, BP corrections) are these number PS, DIN, ISO ?
the only reliable way to test the power at flywheel is get the engine out on a calibrated dyno and do a proper job.
the only reliable way to test the power at flywheel is get the engine out on a calibrated dyno and do a proper job.
At first I was pretty disappointed with the result for the Griff and was going to post on here as soon as I got back, to find out how I could get the power back up. The people running the road looked at the dyno curves and couldn't locate a problem. The curves were nice and smooth and the engine was putting out loads of torque (just shy of the cerbie in fact). So I started to panic even more.
However a quick dip into the Steve Heath 'Bible' when I got home confirmed what vixpy posted earlier. The figure of 260bhp is what you can expect from the factory quoted 320bhp version of the 500.
As mongoose says, I didn't do my homework before I took the car and I scared myself by expecting to see the factory figure.
That helped explain why the car doesn't struggle when it’s out hooning against the Loti gang (and it stopped my high blood pressure) but it doesn't help explain why or how TVR overstate their figures in the first place.
I also need to add a big thank you to the organisers (Jason and Martyn) and Marlin Motor Engineering, who provided excellent facilities, free tea and coffee all day and bbq'd burgers that tasted superb - with not a hint of food poisoning.
>> Edited by fleshlightfreddy on Wednesday 12th April 14:59
>> Edited by fleshlightfreddy on Wednesday 12th April 15:16
However a quick dip into the Steve Heath 'Bible' when I got home confirmed what vixpy posted earlier. The figure of 260bhp is what you can expect from the factory quoted 320bhp version of the 500.
As mongoose says, I didn't do my homework before I took the car and I scared myself by expecting to see the factory figure.
That helped explain why the car doesn't struggle when it’s out hooning against the Loti gang (and it stopped my high blood pressure) but it doesn't help explain why or how TVR overstate their figures in the first place.
I also need to add a big thank you to the organisers (Jason and Martyn) and Marlin Motor Engineering, who provided excellent facilities, free tea and coffee all day and bbq'd burgers that tasted superb - with not a hint of food poisoning.
>> Edited by fleshlightfreddy on Wednesday 12th April 14:59
>> Edited by fleshlightfreddy on Wednesday 12th April 15:16
JEsprit said:At the back. That would explain a lot - all that is at the front is the water rad on a Noble (oh, and the air-con rad).
Road only had one fan (which was a huge affair) but at the front of the cars. This is fine for the Esprits as all the rads (including chargecooler (intercooler)) are at the front. I don't know where the rad for the intercooler is on a Noble.
J
I think the figures at MK were pretty accurate.
My wheel bhp was 311, and they put the engine bhp at 384. That's a 19% loss which isn't unreasonable for a heavy transaxle and 285 section rears. Plus the ambient temperature was 19'C so nothing there.
But the most interesting part was comparing a large number of cars at the same time since obviously the RR isn't going to favour a particular make/model!
>> Edited by neal_mcdonnell on Wednesday 12th April 20:58
My wheel bhp was 311, and they put the engine bhp at 384. That's a 19% loss which isn't unreasonable for a heavy transaxle and 285 section rears. Plus the ambient temperature was 19'C so nothing there.
But the most interesting part was comparing a large number of cars at the same time since obviously the RR isn't going to favour a particular make/model!
>> Edited by neal_mcdonnell on Wednesday 12th April 20:58
joust said:
Road only had one fan (which was a huge affair) but at the front of the cars. This is fine for the Esprits as all the rads (including chargecooler (intercooler)) are at the front. I don't know where the rad for the intercooler is on a Noble.
J
Try owning a V8 TT Esprit. Lotus simply didn't bother with intercoolers!
>> Edited by neal_mcdonnell on Wednesday 12th April 21:04
Bit bizarre some of these performance machines are way wide of the mark.
My 20 year old Scirocco was tested last year. 125k miles, no mechanical mods, 20 years old. Should be 112bhp. Put out 115bhp. Tester said K&N aif filter element, Bosch Super 4 plugs and Optimax were worth 1bhp each to make up the extra 3.
For what some of these cars cost, I'd be mighty pissed off it they were more than 10-12bhp down.
My 20 year old Scirocco was tested last year. 125k miles, no mechanical mods, 20 years old. Should be 112bhp. Put out 115bhp. Tester said K&N aif filter element, Bosch Super 4 plugs and Optimax were worth 1bhp each to make up the extra 3.
For what some of these cars cost, I'd be mighty pissed off it they were more than 10-12bhp down.
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