raising ride hieght

[clive f]

Probably a well discussed subject but here goes, have new avos, with 300lb springs on front and 250lb on rear and ground clearance is about 5 1/2" , and the springs are all set at the same hieght. the back end still likes to squat down when accelerating causing the exhaust at the rear to grind out, this normaly happens when going uphill, with a few lumps in the road.
what I`d like to know is , do all the springs have to be the same , ie. can I raise the rear making the back springs more compressed to give me a greater ground clearance, and less likely to squat down so much, or should I buy 350lb springs and put them on the front and the 300lbs on to the back??

[GreenV8S]

Standard ride height is with the rear dampers roughly 5mm longer than the front, so wind the rear up a little and see how you get on with it. Changing the front ride height changes the rest of the front geometry way out, but changing the rear has relatively little effect.

[bugsy]

I was grounding out at even higher on anything and everything and found that the back was 190mm outrigger to ground and the front was 160mm outrigger to ground.

I lifted the front to 190mm and had no problem, I know this is higher than recomended but speed bumps are getting bigger.

If you want to compromise, how about 175mm all round, thats what, 7" in the old money, with the AVO's set to 8 clicks on the front and 7 clicks on the back

By the way, I was told that the height should be 150mm to 175mm ie 6 to 7"all the way round, so you are a bit below the minimum anyway

>> Edited by bugsy on Saturday 19th March 19:09

>> Edited by bugsy on Saturday 19th March 19:11

[clive f]

thanks chaps, its out with the old c spanner in the morning and I`ll tweak the back up a little as suggested, I`ve had the dampers set at 10 all round while I`ve been trying to get a feel for the best set up, some roads it`s good, on others its back breaking stuff, as soon as I can sort this hieght and grounding problem out I`ll really be able to enjoy driving the car properly.

[19560]

clive f said:

ie. can I raise the rear making the back springs more compressed to give me a greater ground clearance, and less likely to squat down so much, or should I buy 350lb springs and put them on the front and the 300lbs on to the back??

Raising the ride ht does not compress the springs at all and as Peter says can be done independantly of the front so why not raise the rear by an inch. Spring rates for TVRs appear to be a black art but the rear are usually 67 to 75% (2/3 or 3/4) of the rate at the front so if you put 350 on the front without changing the rear that would give you a comfortable 73% ratio. Food for thought?

[joospeed]

19560 said:

Raising the ride ht does not compress the springs at all

You've no idea how difficult it is explaining that point to people! Assuming all mechnical ratios remain constant then rasing the ride height doesn't compress the spring any more than before as it's still carrying the same load. It will increase the pre-load on the spring with the damper fully extended, and compressed length of the spring on the fully extended damper will be less, but it's load-carrying length will be unaffected.

[Hoover33]

still
by more luck then judgement i have sorted mine out.....
Bought my set up.... had it put on ..... was totally unhappy with it...
Took it Austec..... Gid knows what they did to it, but along with lazer aligning the wheels YES YES YES