FAO: Mike Rainbird..
13 March 2003, 06:20 PM
#1
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Join Date: Nov 2001
Location: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
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Mike,
Seem to remember your cossie did 186 odd mph..
What revs do you get peak power
What size wheels and tyres do you use.
What is your final drive and what is the ratio of 5th gear...
Why??
http://bbs.22b.com/ubb/Forum25/HTML/000101-4.html
Cheers
David
Seem to remember your cossie did 186 odd mph..
What revs do you get peak power
What size wheels and tyres do you use.
What is your final drive and what is the ratio of 5th gear...
Why??
http://bbs.22b.com/ubb/Forum25/HTML/000101-4.html
Cheers
David
17 March 2003, 09:32 AM
#4
My car was overgeared for 1.25 miles (TOTB distance), to get that speed you mention, I needed a lot longer distance with the set up I had in testing at that time (1.4+miles). Final drive was 3.36 and fifth was 0.80 and rear tyres were 235/40x17. Peak power was made at 7000 (515.4bhp), but it only dropped by 1.5bhp at 7500. It would actually do the same speed in a shorter distance if you used the standard gearing (3.64 final drive), but obviously rev a lot higher. The 3.36 gearing had a "theoretical" top speed of in excess of 200mph at 7500 rpm. However, I never had enough runway to get there, as once it hits 170mph, each few mph after that is hard to come by. It gets to 170 (in the words of Tommy Cooper 
) - "jush like that", but then hits an aerodynamic brick wall and as you may or may not know, aerodynamic resistance increases expotentially. I had two timed goes at this, one was into a massive headwind (but perfect ambients - 12°C) and one was on a completely still day (but with 30°C ambients 
). The first time the car did 180.6mph (indicated 183mph), the second time it did 180.9mph (indicated 183mph). I have seen an indicated 186mph (Stack ST500SR) on a "private" road and it was still climbing (would have seen over 190 as I was just about to hit a slight down-hill stretch 
), but discression got to me...
To do 180+mph, you either HAVE to have 500+bhp and reasonable aerodynamics OR superb aerodynamices (latest Mercedes 500s) and still well over 400bhp. Removing your rear spoiler and wing mirrors, running the narrow tyres (205s) and sorting an undertray for the whole bottom of the car will increase your chances of hitting a genuine 170+mph (NOT speedo indicated ).
Hope this helps.
) - "jush like that", but then hits an aerodynamic brick wall and as you may or may not know, aerodynamic resistance increases expotentially. I had two timed goes at this, one was into a massive headwind (but perfect ambients - 12°C) and one was on a completely still day (but with 30°C ambients ). The first time the car did 180.6mph (indicated 183mph), the second time it did 180.9mph (indicated 183mph). I have seen an indicated 186mph (Stack ST500SR) on a "private" road and it was still climbing (would have seen over 190 as I was just about to hit a slight down-hill stretch ), but discression got to me... To do 180+mph, you either HAVE to have 500+bhp and reasonable aerodynamics OR superb aerodynamices (latest Mercedes 500s) and still well over 400bhp. Removing your rear spoiler and wing mirrors, running the narrow tyres (205s) and sorting an undertray for the whole bottom of the car will increase your chances of hitting a genuine 170+mph (NOT speedo indicated
).Hope this helps.
17 March 2003, 09:45 AM
#5
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Join Date: Nov 2001
Location: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
Posts: 15,239
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Received 1 Like
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cheers...
Not going for indicated speed.. going for one by timing gear
Not going for indicated speed.. going for one by timing gear
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