Suspension recommendations for mild track build- SCCA TT Sport 5

[roninsoldier83]

I'm thinking about building my E82 128i for SCCA Time Trails Sport 5. It's a very restrictive ruleset. I had a few questions:

1. Sway bars are limited to essentially whatever you can find at Tirerack (Eibach, H&R, etc) or factory options. What sway bars would you recommend? For reference, the car will NOT be allowed to run a LSD, so I'm hesitant to run too much rear bar.

2. The springs and shocks are also very limited, mostly to what is available at TR, with a few exceptions. I was planning on running Koni yellows with a set of Swift R springs (for a 135i, which I'm assuming should be just fine?) unless anyone has any alternate recommendations?

3. Camber plates are allowed on MacPherson strut cars, but have to be used in conjunction with commonly found springs/shocks (NO threaded coilovers). What camber plates would you folks recommend? I would like to try and shoot for -3 camber if possible, to help with grip as well as to help fit the class limit width for 200tw tires (245 wide).

Thanks in advance!

[HP Autosport]

You can experiment with from bar size depending on your particular setup. E90/92 bar is slightly larger than the E82. The E93 bar is the largest of the OEM bars. You are on the right track for no rear bar. You might even find it helpful on an autocross course with it remove altogether.

Koni Yellow is likely the best damper with rebound adjustment. Swift is no longer making the Spec-R spring for the 135i, so you are left to find them on the used market.

We like Vorshlag plates with OEM top hats. -3 is possible on a lowered vehicle.

PM us if you have any other questions regarding setup or parts.

[roninsoldier83]

Originally Posted by HP Autosport

You can experiment with from bar size depending on your particular setup. E90/92 bar is slightly larger than the E82. The E93 bar is the largest of the OEM bars. You are on the right track for no rear bar. You might even find it helpful on an autocross course with it remove altogether.

Koni Yellow is likely the best damper with rebound adjustment. Swift is no longer making the Spec-R spring for the 135i, so you are left to find them on the used market.

We like Vorshlag plates with OEM top hats. -3 is possible on a lowered vehicle.

PM us if you have any other questions regarding setup or parts.

Thanks for the feedback, I appreciate it!

After further research, I don't believe the 128i will be terribly competitive in SCCA Sport 6, so I'm either going to shoot to build it for SCCA Tuner 4 or NASA TT5 (more likely).

Thanks for taking the time either way, though!

[spidertri]

Yeah, I was trying to come up with a response to your original question but I just kept thinking how frustrating that ruleset would be for the 128, glad you came to that realization as well!

[HP Autosport]

Originally Posted by roninsoldier83

Thanks for the feedback, I appreciate it!

After further research, I don't believe the 128i will be terribly competitive in SCCA Sport 6, so I'm either going to shoot to build it for SCCA Tuner 4 or NASA TT5 (more likely).

Thanks for taking the time either way, though!

Let us know if you have any other questions or need help setting up your suspension.

[sibanez]

Originally Posted by spidertri

Yeah, I was trying to come up with a response to your original question but I just kept thinking how frustrating that ruleset would be for the 128, glad you came to that realization as well!

Curious what you see is holding back the 128i in Sport 5. The rules allow for a pretty solid car on the track:

OBD-based ECU reflashes
Most wheels
Single-adjustable fixed-perched shocks
Lowering spring kits
Some camber allowances for Strut-type suspension
Direct-replacement sway bars
Cold-air intakes
Cat-back exhausts
Radiator and fluid coolers
Brake option packages and some cosmetic modifications from a different trim model of the vehicle—like swapping spoilers

Koni Yellows, plus Swift R springs (can find them used), front and rear sway bars, a tune and camber plates get you a pretty solid track car. Throw on some 17x8.5s with 245/40R17 RE71RS, and it's going to move.

You have to deal with NDs and first-gen Twins, but the 128i is going to have better gearing and should be faster on any tracks with long straights.

It's not going to be a walk in the park, but it's not an underdog, either.