H&R lowering springs on ROW S

[jimk04]

Ive fitted these springs to my car and they have lowered it approx 30mm.

I am experiencing rear bump steer, although to be fair it did a bit before hand.

So I need to have an alignment done and make the rear toe more parallel to stop the bump steer, but then I understand that the camber goes more negative.

So my Q is do you think I will be ablt to get parallel toe and reasonable camber with the standard suspension links?

I want to get rid of the bump steer, but dont want to end up with masses of camber that will wear my tyres out!

Any input appreciated

[woodsman]

I installed ROW M030 and slotted the hole in the mounting flange thereby allowing me to lower the strut .75" in the hub. I had massive toe-in (and bump steer) and after much investigation, ended up buying Top Speed's adj. toe links ($275). This allowed me to get the toe in spec and the camber is at -1.5 at the min. setting and have driven it 6000 mi. with no signs of a bad wear pattern. The eccentrics have a narrow range of adjustment. I have a thread in this section with Brad Roberts ( pro race car builder including many Boxster builds) helping diagnose the problem.

[edc]

It depends on your definition of reasonable and what you are trying to achieve. I can tell you that brand new tip M030 was basically the same height as 70k mile standard suspension. With equal front to rear lowering you are never going to be able to achieve parallel toe all round and more negative camber at the front than rear. You might just get there if you widen the top mount nut slot.

[Topless]

Toe-in is what really kills tires, not so much neg camber. One of the problems with lowering springs is it gets the rear of the car too low and this screws with suspension geometry and alignment. Adjustable toe links will help, and if you can get the car lower in the front than the rear with a slight forward rake, it will handle much better. Stock ROW suspension is factory-tuned to the car pretty well so it is difficult to "improve" on it without going to adjustable coilovers.

[edc]

You can get a good rake with the tip kit. It has slightly stiffer and higher rear springs and allowed me an extra half degree of rake over the standard old suspension that was already on the car.

[jimk04]

Think I might try to raise the strut out of the hub 10/15mm to raise the rear; give me more scope for getting the geo right, and also give me more rake!

[woodsman]

Originally Posted by edc

You can get a good rake with the tip kit. It has slightly stiffer and higher rear springs and allowed me an extra half degree of rake over the standard old suspension that was already on the car.

What are the specs you're running EDC and do you track your car or is it strictly street?

[woodsman]

For the record: NA suspensions are built without rake in order to meet the front bumper height restrictions- What we call ROW M030 suspension has rake as it's designed for outside of NA.

[edc]

Sadly I no longer have that car but now have a 550 Anniversary instead. It handles crap in comparison as I have not done anything to the suspension.

My S had new arms all round, new tip M030, new top mounts. It's a manual UK car. Top mounts slots drilled. Old suspension was ~65k and M030 gave approx -5mm front axle and +5mm rear axle. I am not a track day person but over 10 days the car was amazing when driven hard for 3k miles across the Alps, Dolomites and gorge of Austria, Italy and France. Parallel 0 toe all round, just less than -1.5 degree neg camber rear and just over -1.5 deg neg camber front. Accurate to within 1 min across the axle and set up with full tank and my weight for front seat ballast. 30 psi front 36 psi rear.

[woodsman]

Thanks for the stats- Damn, does the guy who bought it know what he's got??!