i am nowhere near going for the sva yet, but i am thinking about buying wheels and tyres.

I am sure that the calculated top speed assuming the engine runs to 6500revs and i use 195/50/15 tyres, 3.62 diff is 173!! no my sums are correct and yes i now it will not do this speed.

the question is what speed rating do the tyres need to be???

Going by the guide I have here....

149mph - V
168mph - w
186mph - y

There are some other quirks about loading on each tyre at different speeds that I will try to post up if you need it, but I would say go for Y or Z rated tyres

Try calculated top speed in 4th at peak power RPM -- it will be more realistic

Remember a Locost has the aerodynamics of brick privy.

BUUUUtttt i thought you had to put the top speed you thought it would be on the sva form..... ie locost,s are brick shaped and don't go through the air very well so i would say the top speed will be 140 mister sva man honest

brick shaped? i geared mine to do 121mph and it does 121mph so....mmmmm

[Edited on 29/7/08 by r1 locost]

Big RON suggests:

1100 cc = 90 mph
1300 cc = 110 mph
1600 cc = 130 mph

(or thereabouts - I need to check the book).

as long as you put something reasonable down you'll be fine for SVA and you tyre rating is correct.

I just put the engine donor's top speed on the SVA form, which was 129mph for a 2l zetec.
My tyres were h rated (130mph).

also remember your tyres are a continuous rating, sitting on the boards on the limiter is not.

dont know about sva specifically, but for the mot you can buy a modern tin top and fit poo tyres to it and so long as they all match its fine? surely seeing as its illegal to exceed 70..........

I put 125mph down as the max speed, and have H-rated tyres.

As for the max speed - what happens if you take it over to Germany on the ferry? Nothing like 100km at max speed for knackering the tyres!

quote:

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Originally posted by 02GF74
Big RON suggests:

1100 cc = 90 mph
1300 cc = 110 mph
1600 cc = 130 mph

(or thereabouts - I need to check the book).

as long as you put something reasonable down you'll be fine for SVA and you tyre rating is correct.

---

All very good but does the sva man look at the gearing, and then check your tyre rating.... I don't want to spend loads of money on the wrong tyres........

i will have no windscreen and hopfully get in the region of 325-350bhp

SVA bloke will not know power of motor (unless you tell him) he doesn't know what it's geared for either. Just tell him it's geared for 120 (or whatever you decide) at max revs and buy tyres accordingly.

[Edited on 31/7/08 by Marcus]

so you don't enter the gearing on the sva form

seems like a very good idea not to tell the sva man the whole truth

thank you

The theoretical speed in top gear at max revs irrelevant. The SVA wants to know the highest speed the car can achieve and make sure the tyres are rated above that speed.

My Peugeot is geared to reach 143 in top gear at max revs but it won't even to 100 because the power is too low.

That said, 350 BHP might be enough to reach your 174 MPH, so start saving up for your expensive tyres.

BTW, the life expectancy of tyres at the quoted speed is a matter of a minute or two

cheers

i think that will just about what i needed to know