Fifth Gear 200mph car
Discussion
bayliss said:
I work for Fifth Gear.
One of our current projects is to attempt 200mph in a modified Esprit.
Has anyone out there achieved a genuine 200mph in a car that cost them under £50k, or knows someone that has?
If so we'd like to hear from you.
Ian Bayliss (0121 697 1904)
I cant help with the car, but can i have VBH's phone number
You need around 550-600 horsepower to shove a (pretty darn aerodynamic, actually) Esprit past 220 MPH - the top end you need to hit 200 in 2 miles.
No way in hell is this going through a Renault 25 gearbox. Go to Quaife or Xtrac and get a decent one. It'll cost a third of the project budget and it'll be worth every penny.
600 horsepower from an Esprit V8 engine isn't gonna be hard at all. Nice strong block, good heads, and good turbo location.
No way in hell is this going through a Renault 25 gearbox. Go to Quaife or Xtrac and get a decent one. It'll cost a third of the project budget and it'll be worth every penny.
600 horsepower from an Esprit V8 engine isn't gonna be hard at all. Nice strong block, good heads, and good turbo location.
Plotloss said:
Derestrict an SL55 AMG and it will do over 200mph. Private sale prices now starting to nudge towards £50k.
The SL65 we have had at VMax twice now is derestricted and that hasnt done 200mph on the runway yet...
You've been done. Check out your back issues of Autocar for a derestricted SL55 AMG test. Could just be a distance issue. I suggest taking out the carpets.
Plotloss said:
Davey S1 said:
A CTR went for just over £60K not too long ago IIRC.
For teh performance that is an absolute bargain.
Stateside they are going for less - 1990 RUF CTR Yellowbird for £31k anyone?
[url]<a href="http://www.fast-autos.net/features/04barrettjackson/">www.fast-autos.net/features/04barrettjackson/</a>[/url]
"Serious car collectors had a fantastic opportunity to purchase some of the finest cars in the world, and buyers with a smaller budget could still find a lot of car for the money. For example, a 1990 RUF CTR Yellowbird sold for just $58,500,"
Its black though and it doesnt look like a Yellowbird and the wheels dont look right.
Its got lots of stickers though.
Cant believe the bargain factor here though, thats madness.
Fancy going halves on one for the next VMAX Mat?
Thanks for all the comments.
To answer some of your points.
1)We always knew the Lotus had a dodgy box and have been in discussion with various gearbox specialists from the word go. However the idea has always been to keep costs down where possible and if this occasionally results in failure then it's all part of the story.
2)We've not run out of ideas for the Esprit and as well as the gearbox and turbos have been looking at various stages of development to the engine and aerodynamics.
3)Bruntingthorpe was to be the venue for the first test run but will not necessarily be the location for the final run - it could be somewhere much longer.
4)Finally, we're not looking to ditch the Esprit for another car. We simply want to know if anyone has taken theory through to practice and achieved 200mph without spending a fortune.
To answer some of your points.
1)We always knew the Lotus had a dodgy box and have been in discussion with various gearbox specialists from the word go. However the idea has always been to keep costs down where possible and if this occasionally results in failure then it's all part of the story.
2)We've not run out of ideas for the Esprit and as well as the gearbox and turbos have been looking at various stages of development to the engine and aerodynamics.
3)Bruntingthorpe was to be the venue for the first test run but will not necessarily be the location for the final run - it could be somewhere much longer.
4)Finally, we're not looking to ditch the Esprit for another car. We simply want to know if anyone has taken theory through to practice and achieved 200mph without spending a fortune.
A bit of simple engineering maths is always useful before you start any project (as an engineer I would say that I suppose).
Right - assume that you're leaving the aerodynamics of the Esprit alone - the 350 bhp of the standard car pushes it to 170 mph (IIRC). Power required to overcome aero drag increases with the cube of speed. Therefore to achieve 210 mph (to give you a shot of hitting a true 200 mph at Bruntingthorpe) you need.... 660 bhp.
I'm afraid that messing about with 450-odd bhp just will not do. Ya canna deny the laws of physics Jim...
>> Edited by toys on Thursday 14th April 17:15
Right - assume that you're leaving the aerodynamics of the Esprit alone - the 350 bhp of the standard car pushes it to 170 mph (IIRC). Power required to overcome aero drag increases with the cube of speed. Therefore to achieve 210 mph (to give you a shot of hitting a true 200 mph at Bruntingthorpe) you need.... 660 bhp.
I'm afraid that messing about with 450-odd bhp just will not do. Ya canna deny the laws of physics Jim...
>> Edited by toys on Thursday 14th April 17:15
I think the Phoenix Cerbera is looking at that figure with some attention (Indeed it's looking at Maclaren's speed record too - no fear those chaps!)
www.projectphoenix.xt7.net/
Not sure on cost though!
Phil
www.projectphoenix.xt7.net/
Not sure on cost though!
Phil
bayliss said:
I work for Fifth Gear.
One of our current projects is to attempt 200mph in a modified Esprit.
Has anyone out there achieved a genuine 200mph in a car that cost them under £50k, or knows someone that has?
If so we'd like to hear from you.
Ian Bayliss (0121 697 1904)
I work in the automotive industry in performance development.
Before one starts hacking and modifying ones car they should know what they're aiming for.
Therefore I usually use some sophisticated vehicle simulation calculations to work out what I'm aiming for first.
In a good sim package you enter fairly fundamental stuff, such as CD, frontal area, rolling resistance estimation, tyre size, gear ratios, rotational inertias etc etc, torque curves. About the hardest figure to get hold of are rotational inertias and transmission efficiencies ( i have different rotational inertias and loss defaults I use for 4WD, FWD and RWD cars) .
I have correlated my package to MANY vehicles with great sucess (usually to Autocar or Car magazine figures)- in terms of both flexibility , standing start acceleration and Max speed. The Max speed is the easier of the figures to calculate.
For instance - for my 408 Bhp Porsche 993 TT, I've entered it's Cd figure of 0.34, it's frontal area of 1.93m^2 etc etc. I found it predicted a 0-60 mph of 4 seconds and a top speed of about 184 mph. If anything these figures are slightly conservative- compared to the 3.7 secs and 180 plus Autocar got. I then put in the figures for the official Porsche 450 Bhp/590Nm upgrade ( which uses twin K24s Turbos from the usual K16s I believe) and to my suprise - was shown that although the acceleration was only slightly effected, the top speed was very similar.
When I upped this to 470Bhp (with a peak 610 Nm torque figure-and the lower speed torque further reduced) I found that the top speed still stayed the same. My sim showed that the car, even in Sixth is under geared. It also showed that theoretically a genuine 470 Bhp plus figure in the 993 Porsche could achieve above 200 mph if the car had ideal gearing. This would involve either swapping out the 3.44 final drive ratio for a 3.00 one (if it exists?) or chaging the top gear from 0.75:1 to 0.65. This sim stuff has proven really succesful time after time and if anything-slightly conservative.
The moral of the story is that - you could modify the Lotus and find that you hit the rev limiter in top gear. Seeing as the gearbox needs to be upgraded- it would be ideal to calculate the ratios for an upgraded box! The Lotus Esprit figures wouldn't be too hard to enter into the sim for calculations.
BTW I worked with some Ex Lotus engineers and have ribbed them about the TG episode where the gearbox failed
I suspect the majority of people who have done a 200mph run have essentially done it via handing over a large amount of cash and let professional engineers deliver a finished product.
So... assuming ditching The Lotus for another car isn't on the cards (can't have the stars appearing to have made a wrong decision there), that the engine is duly NOs'ed, overboosted (I do think you should use a proper custom ECU rather than just chipping) and that the transmission can cope (you have actually calculated the ratio top speeds with respect to the power curves?):
That leaves us with drag and weight, which are important at any time, but absolutely vital on a short course (that is to say, any thing other than US or Aus dried lake beds). I assume losing the spoiler, removing the obvious trim panels, noise insulation and so on have been done.
How about calling in some assistance from a University, or perhaps one of the "big boys" (i.e. F1 teams) and blagging some wind tunnel and autoclave time? A short time in a wind tunnel can tell you a lot about where the drag is created, how the downforce (or lift) reacts and will give you the figures to calculate the power needed for a particular run length.
Whilst I presume the car will have to remain road legal (a 200mph non road legal car isn't rocket science) that doesn't mean it has to be road practical. The Esprit will have an undertray, designed for maintainability, downforce, stability and practicality on normal roads (can you say traffic calming?) this could probably be replaced by a custom 1-piece carbon fibre unit which would smooth the airflow somewhat.
Alternatively, does anyone have a spare Rolls-Royce Gnome or a JATO pack going cheap?
Mike
P.S. Lotus people: Does the V8 have a dry sump?
So... assuming ditching The Lotus for another car isn't on the cards (can't have the stars appearing to have made a wrong decision there), that the engine is duly NOs'ed, overboosted (I do think you should use a proper custom ECU rather than just chipping) and that the transmission can cope (you have actually calculated the ratio top speeds with respect to the power curves?):
That leaves us with drag and weight, which are important at any time, but absolutely vital on a short course (that is to say, any thing other than US or Aus dried lake beds). I assume losing the spoiler, removing the obvious trim panels, noise insulation and so on have been done.
How about calling in some assistance from a University, or perhaps one of the "big boys" (i.e. F1 teams) and blagging some wind tunnel and autoclave time? A short time in a wind tunnel can tell you a lot about where the drag is created, how the downforce (or lift) reacts and will give you the figures to calculate the power needed for a particular run length.
Whilst I presume the car will have to remain road legal (a 200mph non road legal car isn't rocket science) that doesn't mean it has to be road practical. The Esprit will have an undertray, designed for maintainability, downforce, stability and practicality on normal roads (can you say traffic calming?) this could probably be replaced by a custom 1-piece carbon fibre unit which would smooth the airflow somewhat.
Alternatively, does anyone have a spare Rolls-Royce Gnome or a JATO pack going cheap?
Mike
P.S. Lotus people: Does the V8 have a dry sump?
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