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that will tell you if they have hit the bump stops, but the best way to tell if they ARE hitting the bump stops on the track is a smear of grease on either the chassis rail or the bump stop. if its on the other part when you come back into the pits - bingo!

it is likely the problem if the bump stops are the stock length. you can pull them out and cut them down with a hacksaw or similar. just keep them tapered rather than cutting it off flat if you know what I mean.

But other than that - as someone said before - stiffening the front is the only way to increase weight over the inside rear! You can do that with spring, bar or roll centre adjustment depending on the current situation.

what poundage front springs dow you have and what front bar?

Bob the easy way to see if it's on the bump stop is to simply check the top of the stop/chassis..........likely have a 10-20mm shiny spot.


See if this sounds familiar:

My Showroom Stock class 1990 Miata (MX-5) would in a banked right hander , Turn 2 LVMS outside road course, corner on the bump stop. If I progressively unwound the wheel off the apex, the car would jibe to the left and get the back weaving around like the wheels bearings were loose but only for about 30-40ft. After that it would exit the corner normally. For this corner I'd wind the wheel in just past a 90 degrees. When unwinding the wheel if I paused at about 45 degrees for a split second then kept unwinding, no problem. I finally figured it out my third race with the car: I was being greedy and did a slide job on 3 spec RX7's from a 100ft back (oops). Well needless to say as the car slid up the baking I heard a light bonk, even though I'd already unwound the opposite lock the rear end snapped round to the left...........after being plucked out of the gravel trap I looked at the bump stop and sure enough the left one was slightly polished. Being a Stock class car I had to live with it.

Basically the bump stops have a much greater spring rate and as soon as the load came off the rubber, it would shove the back end up 1/4 inch or more.......creating a sort of crack induced weight jacker making the car weavy in one section of one corner. Also becuase of instructing at track days I end up in a lot of cars, some with goofy set ups.........usualy the rebound cranked way stiff (car jacks down in long sweepers with pavement undulations) so your plight sounded familiar.

I know I trimed the stops in the coupe when we lowered it.

Tom

Just trying to build a better mousetrap Bert.

Geez Bob,it can't be too much of a nail,i just checked the nat soft site and notice you to be second in class!!!
Not too shabby given the competition and almost the smallest capacity

Hi Guys
Thanks for your input and ideas.This problem of mine sounds unique so maybe I haven't descrbed it properly so I'll try again.
On the slower corners and coming out of corners the ute fells great.The two quicker corners 110k's or thereabouts which also create the most G's the inside rear feels like it is coming off the deck (I have no evidence of it off the ground though)and the body roll is more pronounced.
I have just measured that my front struts had 80mm travel on the day (the old rubber band around the shaft trick) and I have 50mm travel till the bumpstops bottoms out. I think I am starting to answer my own question .
It sounds like the bump stops are bottoming and doing strange things to the rear end.
Tell me if I am wrong and if I am right tell me what you think will make it right.
I am thinking a rear sway would help and also some quality rear shocks.Also taking a little off the bump stops for more travel.
Rear end consists of standard springs reset so wheel lip is 590mm off the ground.Overload spring has been removed.
The shocks are of unknown parentage.
Once again thanks to all for their input especially Bert (I will give you a call to have a gasbag).
Cheers
Bob

I'll chime in: If the inside rear wheel is actually leaving the ground, as said check and make sure the rear suspension is moving freely. Insufficient drop would lift the rear wheel. Are the rear dampers adjustable and if so do you have the rebound set uber stiff? Per Carroll Smith's books work on the end that is a problem first. It sounds as you may have someone to help you check it out, I would recommend that. Also can you tell us if the car has snap oversteer etc. Basically something is reeeeeally out of whack, I've seen/experienced a few 1200's lifting the front and even both inside wheels at once (I found it sort of entertaining) but never the rear only.

Tom

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If the inside rear is unloading or three wheeling, how can traction out of corners be better?

maybe try describing what the car did that made it un-nerve you, eg the back end would sudenly let go.
or why you say it felt like it was three wheeling? ie was there more bodyroll?

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maybe it's your dose valve bro?

Good call and well done Bert.

Bob,there are several questions to be answered before a solution can be arrived at,and every action causes a reaction in chassis handling.On the assumption theres no one in Albury that can advise you without ripping you off and selling you stuff you may not need,i am sending you a PM with my number to do with what you like.

A satisfactory end result will,using this forum take months of tooing and frowing