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Minimum sump to ground clearance??
bitsilly - 21/10/10 at 09:10 AM

Is there any tried and tested minimum height from the ground for the sumo of a track dedicated car?
Not worried about speed bumps and road hazards, just concrete corners at a track.
I suspect my engine is too low.

bitsilly - 21/10/10 at 09:18 AM

Just found this on RGB:

"5. Ground Clearance: Minimum ground clearance with the driver normally seated is 3" (75mm) excluding exhaust system and sump. Minimum ground clearance under the sump is 50mm. It is permitted to add shims to or modify the engine mountings in order to comply with these minimum heights.

"

TimC - 21/10/10 at 09:44 AM

Where did you find that? I can't see it in the regs. It says 75mm for all suspended parts except for the exhaust.

How low is yours?

ETA: Draft 2011 Regs

[Edited on 21/10/10 by TimC]

matt_gsxr - 21/10/10 at 09:49 AM

Ed,

I think the RGB number of 75mm is based on the fact that the series was for "Road-going". It wouldn't be fair for some people to trailer their cars to the track and run 25mm, and others to drive there and so have to be higher (to avoid the speed humps). In practice they alll trailer their cars now, but changing 75mm to something smaller would stuff up the geometry on some of the older cars.

How low is your sump?

dhutch - 21/10/10 at 09:50 AM

I only use mine for roads, occational clubleval autotesting and non-comp trackdays.

Chassis Hieght circa 4inchs.
Height to sump circa 2inchs.

I do hit the odd speed bump on the way off, the sump being just behind the front wheels. But not issues on track. Been like that for the two years ive had it, more before no doubt, looking at the sump! I have a chopped sump lined up however.

Daniel

bitsilly - 21/10/10 at 10:16 AM

http://www.locost-racing.com/racingregs2.htm

Just came up on a search, 2002 though.

Mine is about 63mm, but thats without me in it.

AB just rang and he sets his racers up at 75mm.

Tyres are old.

bitsilly - 21/10/10 at 10:18 AM

And while I was on phone everyone responded!
Thanks all, I wont worry too much for now (at least until I sit in it!!).

TimC - 21/10/10 at 10:21 AM

quote:
Originally posted by bitsilly
http://www.locost-racing.com/racingregs2.htm

Just came up on a search, 2002 though.

Mine is about 63mm, but thats without me in it.

AB just rang and he sets his racers up at 75mm.

Tyres are old.


I reckon you'll be ok at 63mm. AB can't set his any lower for RGB. I did once clatter my exhaust which was at 60mm but that's because I ran out of tarmac at Snetterton and there is a massive drop to what was probably the original runway.

procomp - 21/10/10 at 02:51 PM

Hi

Which championship are you building for. Locost or RGB.

In Locost we have a MIN height for chassis and a lower height for sump bellhousing and exhaust.

5. Ground Clearance: Under no circumstance can any part of the bodywork, or of the suspended part of the car with the exception of the exhaust system, the sump and the bellhousing, be below a horizontal plane passing 75mm (50mm for the exhaust system, the sump and the bellhousing) above the ground, the car being in normal racing trim with the driver aboard. A gauge of 75mm or 50mm may be used by Scrutineers before or after races or practice to check the ground clearance. It is permitted to add shims to or modify the engine mountings in order to comply with these minimum heights. There is no minus tolerance to these measurements.

And for the RGB championship it's exhaust only. Sump remains at 75mm.

5. Ground Clearance: Under no circumstance can any part of the bodywork, or of the suspended part of the car with the exception of the exhaust system, be below a horizontal plane passing 75mm (50mm for exhaust systems) above the ground, the car being in normal racing trim with the driver aboard. A gauge of 75mm or 50mm may be used by Scrutineers before or after races or practice to check the ground clearance. There is no minus tolerance to these measurements.

Cheers Matt


Edit for. Or is this just a trackday car. ?

[Edited on 21/10/10 by procomp]

TimC - 21/10/10 at 03:00 PM

quote:
Originally posted by procomp
Hi

Which championship are you building for. Locost or RGB.

In Locost we have a MIN height for chassis and a lower height for sump bellhousing and exhaust.

5. Ground Clearance: Under no circumstance can any part of the bodywork, or of the suspended part of the car with the exception of the exhaust system, the sump and the bellhousing, be below a horizontal plane passing 75mm (50mm for the exhaust system, the sump and the bellhousing) above the ground, the car being in normal racing trim with the driver aboard. A gauge of 75mm or 50mm may be used by Scrutineers before or after races or practice to check the ground clearance. It is permitted to add shims to or modify the engine mountings in order to comply with these minimum heights. There is no minus tolerance to these measurements.

And for the RGB championship it's exhaust only. Sump remains at 75mm.

5. Ground Clearance: Under no circumstance can any part of the bodywork, or of the suspended part of the car with the exception of the exhaust system, be below a horizontal plane passing 75mm (50mm for exhaust systems) above the ground, the car being in normal racing trim with the driver aboard. A gauge of 75mm or 50mm may be used by Scrutineers before or after races or practice to check the ground clearance. There is no minus tolerance to these measurements.

Cheers Matt


Edit for. Or is this just a trackday car. ?

[Edited on 21/10/10 by procomp]


Its Josh Smith's old RGB car Matt, but Bitsilly (despite my attempts to convince him otherwise) is only using it on trackdays at present. He's removed the heavy/unnecessary/failed/obsolete dry sump system and hence has lost some clearance.

[Edited on 21/10/10 by TimC]