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Ride Hight/Sump ground clearance

Flying kiwi

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What is the correct ride hight for a k/1.8 S/S?


The reason i ask is that my sump, all the fins at the front have worn away, and I`m afraid that the sump will split next time out blatting.


maybe new adjustable shocks could be the answer? What do these cost?, and does anyone know what a new sump would cost.


Any help would be appreciated. [obvoiusly i could slow down when out blatting, but whats the point in owning a seven if i drive in a sedate manner].



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sump ~£220 +vat.


Rideheight under the sump on my car AFTER flat floor was 75mm. This was far too low for day to day road use (I removed a fin from the front of the sump). I have now raised the suspension all round to give 85mm clearance (all other fins still intact.)





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I had the Adj. Platforms fitted at Dartford, during the service, followed by the flat floor set up. I purchased them cheaply from a fellow sevener last year. There was a marked difference in the cars handling charecteristics. With the lower settings (Factory set up) the turn in was better, at the expese of a very bumpy twichy ride. This setup worked fatastically well at Anglesey over the Easter break. Following the Fin / Sump episode, I raised the ride height all round by 6mm on the dampers (10mm overall extra height - don't ask me how this works) and the on road ride is now softer and less twichy. The turn in etc is still extremely sharp, but not as sharp as previously.


During the club trackday at Cadwell, I could tell the difference, with the car feeling slightly less responsive than previously. For the next sprint (MIRA) I will be lowering the ride height once again, in an effort to improve the handling for the track.


Hope this helps.


Let me know if you want more info.






P.S PC will talk to you at length about Suspension / car set up if you ask him nicely.

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If you change the ride height at the front you change camber and toe too, so it takes a bit of resetting. If you are not careful, you end up with random settings.


A slightly stiffer than standard front spring rate is a good idea all round. 250 lb/in is a good bet to use with standard dampers - Miraz has just followed my lead with these - and will keep the sump off the deck a bit more.


I run ~50mm under the sump (parallel lower wishbones, small wheels) and it doesn't ground that often. Worst culprit are very abrupt speed bumps. I lost my first wet sump to a compression with standard springing. I try to confine my suspension changes to the rear where fine adjustments affect the handling greatly, sticking to the principle of adjusting one variable at a time.



253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red>


Edited by - Peter Carmichael on 4 Jun 2002 10:35:37

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If you remember that you sump will not clear a coke can laid on its side, you will be OK. Some of those centre stops for gates can be a bit nasty. Feeling for the sump touching speed bumbs slows the traffic as well.
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As Peter said I'm now running on 250lb fronts and have not grounded the car at all in the last 3000 miles. I put a few dabs of paint on the sump during the upgrade and they have remained intact.


I was previously running on 200lb front springs, these became completely coil bound when used on track and still allowed the shallow dry sump pan to ground occasionally (the 'C' in caterham on the sump has been ground away completely)


I have about 50mm of clearance under the sump on 13" wheels, but I tend to use 15" wheels on the road to increase the clearance without affecting the geometry too much.


Very happy with the handling at the moment....




Edited by - Miraz on 5 Jun 2002 16:06:10

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