985cc Turbocharged Nova Sprint Car

[MK999]

Lee are you still running a small block box on yours? I was under the impression you switched to an F20 after finding the bearings on a small block box spit themselves out at 7500+ RPM, or did I make that up/dream it?

[lee303]

Definitely I need 5 gears. I need about 110mph, and I can only hit that with a 5th gear (on Quaife ratios anyway).

I have a hydraulic clutch on mine, but it actuates as a slave cylinder pushing directly onto the clutch release lever arm.

ah right ok, wonder if you could get a 4 speed to suit ratio wise, could be a good weight saving, but i digress, the clutch, yes, thats like the daewoo setup, often think of switching to that as its a pain having to remove the box if anything goes wrong with the hydraulic side, which is more common than the mechanical going wrong for sure!

[lee303]

Lee are you still running a small block box on yours? I was under the impression you switched to an F20 after finding the bearings on a small block box spit themselves out at 7500+ RPM, or did I make that up/dream it?

no you didn’t dream it, i run a hewland F18 cased 6 speed dog now, i would have stayed small block but with a dog kit to get over the revs issue, with the synchros rather than the bearings being the things that couldn’t keep up, but when i built the 1800 it also started to twist the input shaft splines round on the f13 synchro, was lucky to make it home from germany!, so a stronger option was needed, the big block input shaft being a fair bit beefier and the hewland having the added bonus of a stronger tooth pattern than the small block

but i have run both boxes with a 7.5 clutch, hence my input to this thread

[MK999]

Nice one, your box is probably worth more than my build so it might have to be an F20 for me Nice to know there's options out there though, I guess from the rallying world mainly. Bit of sequential action would be awesome, DTA handling the flatshifting aspect

[novarally]

Nice one, your box is probably worth more than my build so it might have to be an F20 for me Nice to know there's options out there though, I guess from the rallying world mainly. Bit of sequential action would be awesome, DTA handling the flatshifting aspect

I'd imagine Lee has sourced his gearbox from a Vectra Challenge car. They've always been a good source of tricky bits.

[lee303]

yup, luckily the guy who i got it from didn’t know what it was really, so i got it for a very good price, seen a few complete cars go but haven’t seen just a 'box for sale for a while

[OllieKing]

Have you thought about using a smaller alloy steering rack?
http://www.mambamotorsport.co.uk/com.../racerack.html

[novarally]

Have you thought about using a smaller alloy steering rack?
http://www.mambamotorsport.co.uk/com.../racerack.html

No, I had never considered it, and I've never seen that particular rack before.

I shall need to do more research!

Thanks.

[novarally]

A few photos of the flywheel and clutch which have been in the car for the last 2.5 years of my ownership (and I suspect since the car was built in 1998);







On closer inspection the flywheel is showing signs of excessive heating, and there are a couple of hairline cracks showing, so it's definitely time for a replacement. The clutch plate is breaking up as well.

I'm going to have TTV make me up a billet flywheel, and Superclutch are going to make me a clutch, the only thing I need to decide now is whether to go for a 7.25" or a 5.5" clutch.

[novarally]

At the moment I have an F10 gearbox, with Quaife straight cut close ratio gear cluster and Quaife ATB. This still used the standard helical type CWP.

The F10 has always been on the margins of the torque it can handle, although it's survived very well considering. But I've been starting to think that traction could be improved with a plate type LSD instead of the Quaife one.

A few weeks back I bought a Corsa rally car, which has an F15 gearbox in it, with the stronger Quaife SCCR gear cluster fitted, and the straight cut final drive. But even better it has a Tran-X LSD in it on 55/90 ramp angles.

So that is going to get fitted ready for the new racing season;











I was worried that the F15 would be heavier, but in fact they weigh precisely the same, which is great news. There are some interesting differences between the casings when you compare them............the F10 'box is the one which has been painted black.