430 Coilover Removal Procedure

Its a bit of a pain. Remove shock. I made my own spring compressor. Measure installed spring height-record data, compress spring, loosen the two lower nuts, remove spring.

do not attempt to remove top of shock.

H&R progressives should be 7"-7.5" installed depending on wheel & tire combo - on a 430

most likely no alignment needed, measure fender to ground before and after spring change, .5"-1" drop will increase camber but should not be dramatic.

 

Why would you change to H&R? They won't provide spring rate, and my experienced told me if that's the case it doesn't differ much than stock. Which is no reason to run them other than to just lower the stock one. That is if all your care is look. Otherwise you should change the spring with higher spring rate. Stock front spring rate is about 323 lb/in. Scuderia is about 437 lb/in. I changed mine to 560 lb/in. It is getting stiff on the street but I think it is just barely sufficient for the track. I'll find out for sure in November when it hit the track.

 

What is the rear rate, Andrie?

 

596 on the F430
620 on the Scuderia

 

Andrie,

I used the H&R to lower a street car for ascetics (f430) not to setup for the track.

I don't think even 560 is enough to use a slick tire. My CH car is running Hypercoils 1100# front and 1300# rear on Penske coilovers @ race weight of 2865. The hard part is finding a good combination of spring vs weight vs grip. @560 if you avoid slicks, you may be ok, but a grippy tire will most likely bottom out those shocks. And of course as spring rate rises so must dampening. I will test my Scud with the stock setup but am planning to replace the entire suspension with the penske's as they did an amazing job - higher rate springs VS 360 challenge and much more pliable suspension. Totally useless on the street, it is not a setup that I can live with on street. I was hoping on the Scud that maybe 800-900 front would be enough to allow Pzero slicks and not bottom the shock and not rattle my fillings out. But I would not move to such a high rate spring on the stock strut.

 

Hi rmachjr

Penske makes great products. Which Penske do you run and which valving and how do you come up with valving? They don't really offer off the shelf item if you don't already find out. Usually you have to work with a race team to develop a good valving for the car. I developed one of the S2000 choice, and it's my car they have featured on their website. I'm also a dealer for Penske products and do all rebuild in house.

As you have experienced, good shock is much more compliance over bumps, which is what penske excel in. Especially if you start playing with their digressive valving, although it can be finicky.

I'm also surprise that you have to run 1300# on the rear. Looking at the motion ratio and my experience in mid engine car, I would think 1100# in the front is about the right window, but I'm expecting a lot lower in the rear, maybe around 800#. Of course all of this will have to be verified on track.

I don't plan to race my F430, just for occasional track day. However, I do drive my cars harder than most people. The stock shock is not as good as some of the penske offerings, but IMO, it is pretty decent. I'm going to try to work with it with just spring change first and go from there. I'm an engineer by trade, so I love doing all these stuff. I also race in IMSA Continental series with BimmerWorld this year.

BTW, I'm following your repair on the scud, which I must say you've been doing a good job.

 

Andrie,

Not sure about my valving(part#), the setup was developed on a 430GTC car that my mechanic worked on and I was the beneficiary. It is just awesome vs the Ferrari Challenge setup. Soooooo much smoother - I thought the springs were softer but in fact they were harder and smoother. Great products - I am a believer.

I may be wrong about the current setup, I am missing the rear spring info. On the CH setup it was 987#F & 1278#R and on the Penske 1100#F & not sure but think 1300#R.

What number are you, I watch that series, I'll route for you.

Thanks for kind words, hope the Scud will be on track in early Oct.

 

I'm on #81 BimmerWorld car.

Do let me know what do you think of the scud on the track.