And if it still handles like a bag if sht, give me my car back

Nah Tyres is important too and that can affect these characteristics too.

Benny beat me to it, but basically when I read this the first thing I noticed was "stiffer rear springs" which will make it over steer more.

The one big question I have is if you have snap oversteer (as it would appear) under exactly what circumstance does it occur? corner with big bump in the middle, is the driver slapping the throttle to the floor etc? With any handling issue always sit down and think about exactly what is going on with the driver and car.

In this case it sounds like a car cornering on the bump stops.

Tom

Quote:

And when this happens, intended verticle travel quickly translates to lateral movement. Manitain sufficient suspension travel is the key to roadholding performance. Lowered cars look visually pleasing, but if suspension travel if compromised, road holding will be far from optimum.

seems simple to me,

he listed what he has changed and never mentioned shock absorbers

well when i was at powercruise i came to turn 2 the hairpin left and i was doing about 40kmph and as soon as it came on boost it spun me around before i could even correct it, while it was spinning around it felt like the car was on its side thats how much body roll it had. all i want to ute to do is to be able to be handled sideways, im not gonna pro drift it or anything but i still want it to handle alright.

ill put some new shocks in the rear in the next week or so and i was thinking about going a stiffer spring in the front with a stiffer sway bar any suggestions??

thanks for all the help too guys

I do have one more question; When the motor comes on boost, what sort of horsepower jump are we talking..............if you are already cornering near the limit and the motor jumps 20 or 30 horsepower then even after upgrading the suspension you would still have this issue.

As for suspension upgrades, I don't know utes but the basics are same as for any car. Believe it or not err on the soft side, the car won't have that snappy feel but will corner much better with a slightly soft set-up versus the urban myth oxcart springs.

As for actual set-up I'd say the rear springs are very likely more than stiff enough since Utes are designed to carry a load. For sway bars on the coupe I'm using 7/8 inch front and 5/8 rear. ( I think this equates to 21mm and 15mm) With a ute I would try adjusting the ride height so that the back is slightly lower, shifting the weight to the rear. While on the subject of rear suspension you need to see if you are cornering on the bump stops, if the car is doing it alot the spot where the stop his the chassis rail will be polished clean or you can put a dab of white grease on top of the stop do a skid pad test (if you can find a deserted parking lot) and see if the grease ends up on the chassis. You need to see what the car does in steady state cornering. As for Dampers any good quality brand will work.

The Carroll Smith "Tune/Prepare/Engineer to win" Books will help a lot, Tune To Win in particular. The reason I bring up the Smith books is in it he says fix the end that isn't working. In you case address the rear of the car first. First you need to do two things determine is this a "boost" induced problem or is your car cornering on the bump stops? If it's a boost issue that can be cured by you pretty easily with you're right foot, if it's cornering on the bump stops as Benny pointed out you need more travel. The cure could be changing the ride height if it's way to low or using a shorter bump stop. Next as you don't like the amount of body roll the car fit a set of sway bars. Finally how do you like the ride? If you're OK with the ride then the one issue you have mentioned will be cured by the sway bars.

Finally read up and make adjustments one at a time; A car has three phases you need to isolate, Transient (Turn In), Steady State (mid corner) and Power-On Exit. You may have to compromise on one phase to get better overall performance for a particular car. For example on my coupe with 73HP at the wheels turn in and mid corner speed are more important then exit as there isn't enough power to have issues on exit. Compare that against a 400HP 3500lb car, which isn't going to obtain the same corner speed, and the exit will be most important.

Tom

Solid info there Tom!!
Makes we wanna go play with my suspension just for the hell of it!

Tom,
It's interesting you talk about adding a rear sway bar.
I would have thought that with the Hotchkiss rear end, where ride and roll rates are coupled you would have more then enough anti roll from the leaf alone?
And given how light the 1200s are, the height of CoG, surely it wouldn't require a high spring rate in the rear.
Whats the thought behind going a rear bar?
Cheers

Bryan

i fitted a 14mm rear sway bar to my ute, and found that initial turn in felt better (at road speeds)
but on the circuit it did nothing for body roll and just helped to unload the inside rear wheel in corners

i also believe that the overload leaf in the standard spring pack does horrible things to handling
(much the same as hitting the bump stops) and if your doing ciruit racing you'll need to add at least one
full leaf as the rate of the remaining 3 leaves is too soft.

good shocks make a world of difference but again too stiff on the rebound and they'll unload the inside rear
(i run koni reds on full soft)

these mods will reduce body roll (if the fronts sorted) but will not stop power oversteer obviously

heres how mine handles
youtube link

ANGE,
Thanks for the reply.
I understand (could be wrong) that unloading the inside rear could also be a front end problem. (i.e opposite corners are coupled). So too much anti roll in the front, too high front spring rate, or on front bumps??
with a 14mm rear bar did you notice the front inside wheel lifting?

Bryan