Help me pick spring rates R3V!

[Wishno87]

Alright guys the car is my DD but I would also like to do some autoX and track days when the car is finished. I have IE3s right now which don't bother me at all and I would be comfortable with going considerably stiffer. Here is where it gets tough though. I carry rear seat passengers often and also pull around a small single axle trailer a couple of times a month. This would mean I would need to get stiffer than average rear springs no? How would that affect handling? Thanks for any help. You guys are the best


Cliffs: DD/Track setup. Often times carry a lot of wright in the arse.

[CorvallisBMW]

I'd say something along the lines of 475/600

[nando]

I think you'll get a million opinions on this. But for a RWD car I'd give the rear a bit more bias than 475/600, remember the effective rear spring rate is about 1/2x the front.

[nrubenstein]

You don't need to run high rates in the back. You just need to run higher. Given where you are, I'd suggest 550/750ish if you're running real shocks. And if you aren't *at least* running something at the GC Koni level, you need to be.

[jlevie]

Unless you go to coil overs the only stiffer OE sized springs that I know of would be Turner J-Stock springs (680/1026). That's almost double the spring rate of the IE S3's (315/570) and is going to be awfully stiff on a DD.

[KennyT]

Just remember stiffer is not always better.

[nando]

not always, but it often is. :)

[Wishno87]

I guess I should have clarified I'm getting coils. Going from progressive rates to linear would also make a difference huh?

[reelizmpro]

I guess I should have clarified I'm getting coils. Going from progressive rates to linear would also make a difference huh?

absolutely. I switched from 477/650 on my vert to H&R Races (progressive 310/580) and it's more comfortable on the street and rides great. It's a good compromise between street/track. The M3 will be getting the 477/650 GC's.

[Wishno87]

I'm going to be using billstien sports for now but does 500/700 sound like a good compromise then?

[UDelaware30]

450-650 on mine. perfect with the m20, may pop it up to 550 in the front now with the m52.

[Wishno87]

Ya I already have an M50 in mine but plan to install AC as well in about 2 months. Anyone else DD a car in the 500/700 range?

[CorvallisBMW]

How soon are you looking to order them? I'm hoping to have my 475/600 on in 2-3 weeks, you can test it out.

[2002maniac]

I'm going to be using billstien sports for now but does 500/700 sound like a good compromise then?

Yeah, that's about as high as you'll want to go without revalving the shocks. IMO bilstein sports don't have enough rebound damping to handle super stiff setups.

[Wishno87]

500/700 purchased. Thanks guys!