Spring Options for Budget Rallycross Build? (6 cyl swap)
 

Hello All,

Trying to piece together my budget rallycross "build" and I'm fumbling through the suspension setup for my mismatched swap. The car is a stripped down '95 TI with an M50 swap. Most of the interior is removed, but the dash (and wiring behind) is still in place, leaving the rear very light, and the front still the full weight (+bracing) of an E36 with an M50.

The car is currently equipped with what I believe are 318ti H&R sport springs (purple) with Bilstein Sport shocks/struts. It drives well (even offroad), but already this is too low for a normal TI, and with the added weight of the M50 I'm probably an inch lower which turns the car into a bit of a plow.

I just picked up some springs from a 325 that I believe to be the "sport" springs which I understand are about 1" lower than OEM and a good bit stiffer. I plan on running these 325 "sport" springs in the front, but I'm not sure if I want to leave the H&R sport springs in the back, find OEM TI rear springs, or run the 325 sport rear springs, as I've heard they will fit.

Has anyone tackled a similar issue? My end goal is increased stiffness with OEM ride height, or minimal lowering.

P4C, which is my favorite photo of my car:
https://i.imgur.com/33kUTjV.jpg?1

Not much help
 

I'm working on the same type of a build, a good way behind you though.

I don't have any spring recommendations, but would suggest you look elsewhere, this forum is pretty quiet.
Try researching under "BMW compact rally" since there is a ti class in the UK.

Your best resource, if you have the budget, would be to call a few suspension companies or specialist vendors and get their recommendations. They are probably going to want the weight at each wheel since your car has a non-stock engine and your trying to balance height. I'm probably going with coil-overs since I'd like to autocross & rallycross.

I'd like to cage it for hillclimbs, and if I do I'll get some proper coils. In the meantime I'll throw in the front 325 sport springs and update this thread when I do in case anyone comes across it in a search. I'll toy with the rears as well depending on how it sits with the fronts.

These cars are old and cheap. This forum is the best place to look for any information on the Ti! No offense meant Motts, but 8 comments since July '17 ain't exactly stressing the server...

OP, you are looking for "JerseyTim" posts. Should give you ideas. Here is one so you know his username:

http://www.318ti.org/forum/showthrea...t=43109&page=2

There was another member that did some more serious rally and I know they ran Bilstein HD. They were shot after every season. You could shove a stiffer e30 rear spring with adjuster for height. I liked my stock 328i springs for Detroit
Streets, which might as well be rally.


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Thanks for the comments all. Not doing real rally, so the Bilsteins will have to do. The springs that were supposedly from an E36 325 sport were nowhere close to fitting which is a bit of a bummer, and not sure if I just need different perches and top hats, or if they are hopeless. I'm beginning to doubt they are even from a BMW. This means I have to rallycross on the super low H&Rs again...I hope it's not muddy again!

There should be plenty of cheap or free stock options near you from 6 cyl cars. Any of the non M front springs should fit. I've seen rears fit as well.

Dude if you’re serious about really competing or pushing the cars limits in rally or autox, stop looking for whatevers cheapest and buy some coilovers. Im using BC racing br series coilovers. They are by no means cheap but worth every penny.


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While I agree that he should not go for the cheapest option, in this scenerio OP would destroy BC's quickly as well. Coilovers with external valving would be ideal. The rears could probably be sourced by offroad community in trial and error to see what would fit. There is someone on here or FB that has external valved setup because they kept destroying their Billy HD setup

Destroy BC’s how? These are built very very well. Ive had mine for a good 2 years now with not 1 issue. And i have the ISC coilover covers too, to protect the threads lock rings and tubes from grime and debris.


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Rallycross is entirely different on a shock than extreme street/track driving. That's why serious offroad shocks almost all have external valving and/or built for that application. Think of what the shock would be going through on a track and then over dirt/stone terrain. Completely different environments. BC's are good for the money, but they are not designed for this.

I see. With these BC’s ive done some nasty canyon climbs, but it was entirely paved. And then brutal street use evry time I drive the car.


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Exactly what BC designed them for and they work great, as they should. Your BC's and almost any off the shelf coilover option will have stiff springs in which is not always good for rally. Here is decent read on suspension if you're curious: https://www.offroadxtreme.com/engine...ock-absorbers/

Not necessarily looking for whatever is cheapest, but I'm looking for something that work that I won't be upset about destroying as I get the hang of this sport. My investment into this car is fairly low. If I cage the car for "real" rally stages and hill climbs, I'll get some real suspension. Until then there's no reason I can't have decent results with cheaper stuff at the expense of replacing it sooner.

The springs need to be stiff, but not lower the car much, or at all. I'm thinking stiffer lowering springs for a 325 with strut spacers would work well in the front. I need to get the car weighed to see what I need in the rear, but OEM 325 springs would probably be fine given how light the 318ti is in the rear.

If you want stiff springs and they do lower the car a bit, you can counter that with spacers. I know condor makes a spring perch spacer kit and its pretty damn cheap too.

https://www.condorspeedshop.com/coll...spring-pad-set


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