I've tried searching and haven't found a conclusive answer. I got that I wonder how fast my car can actually go thought earlier. So I found an old run way and gave it a blast. My car is a classic with a uk 6 speed running around 400bhp. I got to 165ish and bottled it as I haven't fitted the front brembo's yet and it still had plenty left.

Assuming it will rev out to say 7k in top gear with 17" wheels what do you recon top speed will be.

I'd love to find out on a motorway but I don't think "I was curious" would stand up in court.

 

im not to sure on this 1 but i have found the rev limiter/ fuel cut on mine is quite abit off where it is on the clocks, red line is at 7400rpm but it doesnt hit the limiter till past 8k on mine :/ i know its a different car but still a 2.0l uk spec car

 

If your rev limit is 7K drive at 3.5K and see what the speed is then double it.

 

mine uk300 with 6spd box hit limiter in 6 at 177 on sat nav, my mate has picture of the speedo

 

This website assumes a ratio that equates to 24.5mph per 1,000rpm in 6th.

IF that is correct multiply 0.245 x your rev limiter

It suggests 176 mph

Perhaps slightly less than this after an adjustment for error, but in theory if your car has the power to pull to the limiter in 6th you'll be near enough at 170 mph.



http://webcache.googleusercontent.co...&ct=clnk&gl=uk

 

Cheers everyone one

 

Iv done a top speed run in my blob and had 177 out of it

 

Not on a a public highway I hope

 

A little while ago we did the maths with 18" wheels at 7000rpm in 6th gave a theoretical speed of 183.4 mph. Don't ask me how we worked it out as i can't remember lol

 

No this was done at a airfield where I was asked to attend to help bikes as a wind break to get up to there top speed and to help so they didn't get blown off the runway by side winds lol,,,,at the end of the day they let me do a few runs on my own and I got 177 ,,might of got a tad more but my bum hole starting twitching so I backed off

 

My type r has recently had a forged 2.5 build with a td05 20g running 380bhp but I have found when doing speed runs on my private grounds that It hits fuel cut at about 123?? Its mapped on an alkatec by andy forrest. I am going to ask him obviously but just wondered if anyone had any ideas? Still running tmic and 5 speed box.

 

Has it still got a restrictor on it? I think jap cars are restricted to that. IIRC its something to do with the speedo.

 

Do aerodynamics ever come into these gear ratio calculations? You're on diminishing returns with aero, it becomes increasingly difficult to go faster due to the drag generated by our cars.

 

Yes the aero does have a big effect at higher speeds, from memory and I can't remember where I seem to think the UK 6speed tops out at 184mph but it's a different story if you think you will actually hit it, In theory with no drag it's possible but you would probably need over 600bhp to actually hit it and a very long straight stretch of road......I think

 

No, thats why it's a theoretical speed based entirely on max rpm and gear ratios . Theoretical and real world speed are 2 totally different things. Bit like the manufactures claimed mpg. They test on a rolling road so don't take into account wind resistance, road surface ect.

 

Mine wasn't calculated I actuly done 177mph in mine but its 450bhp and lightened a lot so makes getting up to speed a lot easier but at that speed it was my aerodynamics that let me down as the car went very very light and felt like far to much air was going under the car rather than holding it on the run way