Suspension & Exhaust

Suspension & Exhaust

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Discussion

paceracing

Original Poster:

729 posts

273 months

Friday 22nd February 2002
quotequote all
Johno and S3bob,

Thought i'd open a new thread for suspension and exhaust so that discussions on Superchips can carry on.
The exhaust on my S2, being straight through stainless pipes has a silencer box built around it which is purely cosmetic for that nice MOT man to pass. My S2 has been noise tested many times and the avarage seems to be 105dB. To silence down for Castle Coombe, which if memory serves correctly is 98dB, requires large lumps of wire wool shoved down the pipes which is prevented from blowing back out by fastening chicken wire over the ends of each pipe with a jubilee clip to hold it in place. To get the wire wool back out, remove the chicken wire and blip the throttle. Hey presto! It's a bit heath robinson but because the pipes are so close together on V6's you can't really get supertraps on both pipes. Plus supertraps are bl@@dy expensive when you need two of 'em!
By the way although the exhaust smacks the floor occasionally, it doesn't happen as often as you would think because the suspension is that much stiffer, you get less travel. Overtaking is an art though because under hard acceleration the rear mounting on the exhaust hits cats eyes, so you need to time it but you soon learn!
Hopefully, I should be able to measure spring lengths and damper body / rod lengths this weekend and post it on this thread.

Jas.

johno

8,520 posts

289 months

Friday 22nd February 2002
quotequote all
Jas,

Cheers for the suggestion. Yours must sound very simialr to mine with lots of pops and bangs etc etc etc.

I will have to play with the wire wool idea as I don't want to have to change the exhaust for Zolder if I don't have too.

Would ove to see this 'Heath Robinson' set for real though.

As for suspension I have changed the original dampers for the Gaz dampers and uprated springs. I feel I could ahve done better and have blown 2 pairs of dampers apart at the rear and now have Peter's originals all round which seem a lot more sorted.

What kind of ride quality are you getting as my car is my everyday transport. I know Pete's is to but he is running the Nitrons which I imagine make a significant difference is comparison to the Gaz dampers. The reason I ask is that I don't think I could live with uprating the spring much more but would like to be convinced otherwise

paceracing

Original Poster:

729 posts

273 months

Saturday 23rd February 2002
quotequote all
johno,

Ride quality isn't too bad. Mine is mainly used for normal road driving with the odd track day now and it's quite easy to live with.
I travel to Cornwall in it with the wife 3 or 4 times a year (going down there again on wednesday actually) which is approx 330 miles each way and even she doesn't mind it, infact by the time we get to Reading, she's fast asleep even with the noise of the exhaust!
With the damper rates matching the spring rates you should be ok anyway. (during the development phase I tried 825 LBs front springs with standard valves in the new dampers and that loosend the fillings in my teeth!)
My old man who is 63 and suffers back trouble doesn't mind it either (except when I start to scare the sh!t out of him by nailing the launch pedal).
My suggestion is that if you really want to transform the handling then go for it.
If you use Leda, then you should be OK anyway. They do all sorts of conversions from full on race stuff to boyracer upgrades for the Nova brigade. They really know their stuff and can often recommend a setup if you tell 'em what you are after. Even after you have bought the springs / dampers you can chop and change. As I have already mentioned springs are fairly cheap, but you can also have the dampers re-valved at a later date or use different spec damper oils if you want. If the car just doesn't feel right or is nervous, there is plenty of info to help you out. If you want to investigate further you could try reading a book called 'Suspension Tuning' or 'competition car suspension', something like that, can't quite remember, but it is written by Alan Staniforth. I got a copy from my local library. It explains suspension pretty much in laymans terms and is generally a good read.

Jas.