Track Car Suspension

#1

OK, I need some advice. Helping a friend set up his e30 Track Car, it is not going to be a Spec e30 race car. So with that in mind, what would you guys do to your e30 325i, if you did not have to meet the Spec requirements? We would like to do this right the first time.

#2

Everyone has different ideas re. ideal suspensions. If my heart was set on a really good suspension I’d contact Jim Pantas and buy his JStock suspension out of his E30. I don’t think it’s made anymore so it might not be available new.

What I’d really do tho is just buy the SpecE30 suspension. 1) It’s cheap. 2) It will make it more fun to play with other tracked e30’s because it’s the most common e30 suspension being tracked. Nothing makes playing on the track more fun then have equal tools.

#3

I agree about the Spec e30 suspension, except that I have heard some say that we don’t need a 19mm rear sway bar.
Coil-over would give the ability lower the car and corner weight it, any advantage to using those?

#4

I would set up the rear suspension for se30 including adjustable sway bar and put coilovers on the front. I have some of you need them that came on my car. The sway bar is needed and can always be disconnected. If you are dropping the rear subframe go on and put better subframe bushings and adjustable trailing arm bushings, otherwise don’t worry about them. You do need to check the condition of the diff mount bushing and all of the bushings in front and rear and engine and tranny mounts. Camber plates up front would be nice too.

#5

We are planning Camber Plates and Sub Frame Bushing. I have been trying to decide if we are going to use adjustable trailing arm bushings, I have read all the problems people have with them.
What sway bar do you guys like? I know some are more difficult than others.

#6

I have driven track E30’s with full coil over suspensions, forget about the SpecE30 stuff unless you want to go racing with the group. It is night and day in handling.

#7

Yeah, I love the SE30’s but because it’s about cost-effective racing with a bunch of like-prepared cars. The cars are pretty forgiving, too, so I can screw up all over the place and still make the corner. If I were trying to get the absolute peak in suspension performance, I’d look at what the Pro3 guys are doing. Pretty sure they have an open suspension rule.

#8

This car is going to be an all out Track Car, we can build it without restrictions. That is why am asking for ideas on what you guys think would be the ultimate e30 for the track. I will have to look into the Pro3 stuff, I’m not familiar with there set-up. I know that IE sell some parts for ITS race cars, I think that could be adjustable.

#9

Full build: 400# coilover front, 600 rear. Largest bars you can find. Rod end links for adjustment. Aluminum subframe bushings and diff. Hard trailing arm bushings and camber toe adjustment. Note … trouble with camber and toe adjusters is easily fixed by tack welding the eccentrics after the alignment is done. When its right, you’ll never change it. Camber plates in front. Front ride height 5.5" beside pinch weld, rear 6". Camber 3.2 all the way around (Hoosiers), 1/16" toe OUT in front, 1/16" toe IN in rear. Front control arms M3 offset, delrin. Shorten front struts to accept Koni 8211 13.3" shock. Use DA both ends. Most everyone makes camber plates for front. Never needed a strut bar for the front but some like the bling.

This is a very good starting point but since every chassis is different, you will probably play with rear springs. When the car is strippen and the cage installed, it should weigh in the neighbor hood of 2200# without gas.

#10

Now that looks more like the direction we are planning to go, we are building an all out Track Rod. I like the IE hollow 25mm front sway bar, but I have never liked the fat sway on the rear, seems to make the car to loose for me.

“Use DA both ends”??? I’m not sure what this means.

I know the people on this forum are real racers, that is why I came hear for ideas.

#11

DA = double adjustable. Rear bar gives you another adjustment to fine tune the suspension. Its a balancing act between rear springs and sway bar.