Swiss_Tony Posted July 29, 2008 Share Posted July 29, 2008 Bit of a silly question, following a conversation over a few beers 😳, but what would it take to get a 7 over 200mph? Obviously a lot of horsepower 😬 but how much roughly? The aerodynamics are allegedly not the best compared to modern production cars but what can be done to improve matters apart from making it look like something else The easy solution in my mind is the gearing but am more than willing to be proven wrong 😬 James Su77on Se7ens Link to comment Share on other sites More sharing options...
henry21p Posted July 29, 2008 Share Posted July 29, 2008 I'd imagine you'd need an aero body, an RST v-8 engine, a big track and the right gearing/diff combination.  Oh. That's what they've done in the US with the GTO car. 😬 Link to comment Share on other sites More sharing options...
Swiss_Tony Posted July 29, 2008 Author Share Posted July 29, 2008 I must have missed that 😳 Any pics/info? James Su77on Se7ens Link to comment Share on other sites More sharing options...
myothercarsa2cv Posted July 29, 2008 Share Posted July 29, 2008 You could strap a jet engine on to it? According to my Darwin Awards book some chap tried that with his car and they found the smoldering remains about 50 ft UP a cliff  Looking at 200mph cars (off the top of my head, F1 car, Veyron, Batmobile...) all have ridiculous amounts of power and a fair amount of aero aids. Give it a go. I'll help you rob a bank to fund the 200mph Seven. _________________________ Paint weighs too much... Link to comment Share on other sites More sharing options...
Miltec Posted July 29, 2008 Share Posted July 29, 2008 😬We could just put The Stig in a R500 and see what happens  VX 1600 Live Axle T440LKK Link to comment Share on other sites More sharing options...
Slipper man Posted July 29, 2008 Share Posted July 29, 2008 On the basis that power requirement varies with the cube of speed (for some reason - aero drag is only a square relationship) you need 550 bhp. And big balls... Link to comment Share on other sites More sharing options...
henry21p Posted July 29, 2008 Share Posted July 29, 2008 I would imagine that they haven't taken it to 200mph, though it looks quite capable of that, especially with the sweep hardtop fitted and the low front etc. With the RST engine, it's certainly got the power/weight combination and some good downforce to keep it glued to the road.  Link to comment Share on other sites More sharing options...
myothercarsa2cv Posted July 29, 2008 Share Posted July 29, 2008 How fast does the RST V8 levitation wotsit go top whack? Anyone been brave enough to try? Because that must have getting on to 550 bhp... John _________________________ Paint weighs too much... Link to comment Share on other sites More sharing options...
henry21p Posted July 29, 2008 Share Posted July 29, 2008 Mike Biddle's done a VMax run in his - with different diff/gearing to the GTO21. Link to comment Share on other sites More sharing options...
henry21p Posted July 29, 2008 Share Posted July 29, 2008 Sneaky pictures of the GT 21 without it's hardtop (topless, one might say) and the bigger engine fitted.... Link to comment Share on other sites More sharing options...
Irrelevant Posted July 29, 2008 Share Posted July 29, 2008 With the RST engine, it's certainly got the power/weight combination Doubt it . . .. any anyway, top speed is all about power to drag not power to weight. Plus the 'GTO car' is a 21 not a 7 . . . which would help with it's speed, but the original question was about a 7 not a Caterham.  Link to comment Share on other sites More sharing options...
henry21p Posted July 29, 2008 Share Posted July 29, 2008 Silly me. Then the answer is NO, not without using an aero body. Link to comment Share on other sites More sharing options...
Swiss_Tony Posted July 29, 2008 Author Share Posted July 29, 2008 Dave Is that an MX5? 😳 Any idea what the vmax was for the rst v8 in a 7? James Su77on Se7ens Link to comment Share on other sites More sharing options...
Irrelevant Posted July 29, 2008 Share Posted July 29, 2008 I dunno . .. Caterhams have a similar drag coefficient to an F1 car don't they - about 0.7 to 0.8? So if you stuck an F1 engine and box in one, it would have a fair chance of getting 200mph . . . some bits might fall off mind - the wings for starters, but what's left should be OK.  Link to comment Share on other sites More sharing options...
weeman Posted July 29, 2008 Share Posted July 29, 2008 200mph 🤔 drive it off of a cliff 🤔.......... not you, Cliff C. _________________________ Be Lucky!! Martin Link to comment Share on other sites More sharing options...
neil.cavanagh Posted July 30, 2008 Share Posted July 30, 2008 seeing as I don't think anyone has officially cracked 150mph in a 7, then 200 mph is a LONG way off. Link to comment Share on other sites More sharing options...
peterg Posted July 30, 2008 Share Posted July 30, 2008 Neil this did 0-154mph in a quarter mile OK, it's not a Caterham but it is a 7 😬 Link to comment Share on other sites More sharing options...
Peter Carmichael Posted July 30, 2008 Share Posted July 30, 2008 I've seen 145mph out of 250bhp limited by gearing - suspect 150 would be vMax. That makes the power requirement for 200mph around about 570bhp. On the basis that power requirement varies with the cube of speed (for some reason - aero drag is only a square relationship) you need 550 bhp. And big balls... Just to explain this: drag force is proportional to speed squared. drag power = drag force x the distance per second the force acts through i.e. drag power = drag force x speed ... drag power is proportional to speed^3. Strong neck muscles. Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted July 30, 2008 Share Posted July 30, 2008 I've seen an indicated 155MPH but have no idea what it was really. 8000rpm (rev limiter) - in 5th using an SPC Quaife semi helical box on 20 inch diam slicks and a 3.92 diff. Must work it out one day. It lasted about 5 minutes before the engine went pop when held foot flat to the floor. ----- VDU 7X Pics More VDU 7X Pics Link to comment Share on other sites More sharing options...
rgrigsby Posted July 30, 2008 Share Posted July 30, 2008 Mike Biddle's RST has definetly seen over 150mph, my 260bhp Duratec is gearing limited to 137mph on CR500's which it hits without really trying at all. I can lift of and still maintain top speed, I suspect 150mph would be achievable if the gearing was changed.   Rob G www.SpeedySeven.com Link to comment Share on other sites More sharing options...
fatcat Posted July 30, 2008 Share Posted July 30, 2008 seeing as I don't think anyone has officially cracked 150mph in a 7, then 200 mph is a LONG way off.  race CSR's are geared to pull 154mph in 6th and that's without taking account of tyre fling. I think pretty much the whole field hit the rev limiter in 6th on the main straight at Monza at some point during the races there. So that's at least 16 sevens that have exceeded 150mph. To be fair we were all taking advantage of the tow to do it - and yes it was fun unless you misjudged your braking point for the 2nd gear chicane at the end of the straight 😳 Link to comment Share on other sites More sharing options...
Swiss_Tony Posted July 30, 2008 Author Share Posted July 30, 2008 Thanks for all the replies  That Westie is an awesome bit of kit 😬 So all I need to do is find 570bhp and I am there 😬 I will have a good look under the bonnet tonight and see if there are any spare horses lurking  One of the things which was making me think that it would need more is the Sierra Cosworth which cracked 200 mph. That has some awesome amount of bhp as well as some nitrous to help things along! and I assumed that a 7 was going to have worse aero than a Sierra 😳 James Su77on Se7ens Link to comment Share on other sites More sharing options...
Support Team Shaun_E Posted July 30, 2008 Support Team Share Posted July 30, 2008 The 200mph Sierra packs about 900bhp - see here. Yellow SL #32 - member of Drowned Rat Racing Link to comment Share on other sites More sharing options...
Swiss_Tony Posted July 30, 2008 Author Share Posted July 30, 2008 Thats the one I was not sure how bad my memory was but I seemed to think it was fairly powerful 😳 James Su77on Se7ens Link to comment Share on other sites More sharing options...
Anthony Posted July 30, 2008 Share Posted July 30, 2008 Ok, this is part of project X, but what about one of those lovely 7's with an 11 type ali body on it - may get past the 150 mark... Link to comment Share on other sites More sharing options...
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