135i Race Car Project Thread - 1Addicts.com riding on board

[scottn2retro]

Originally Posted by UdubBadger

nice, hows that borla sound?

Definitely gives a deeper rumble to the power of the 135, but not obnoxiously loud.

[UdubBadger]

I'll bet its hard not wanting to mod the crap outta this car though.

[scottn2retro]

Originally Posted by UdubBadger

I'll bet its hard not wanting to mod the crap outta this car though.

The rules are the only thing that keep us from going nuts with it

[scottn2retro]

Originally Posted by maxnix

Which radiator sis you use, Scott?

The 335is and 1M solution of adding an auxiliary radiator is just so stupid and unnecessarily complicated.

It's the ones that HP Autowerks are having fabricated.

[scottn2retro]

Originally Posted by AntonioMiceli

Looks like a great project very interesting.

Thanks. We had our first BMW Club Race at the new Chuckwalla Valley Raceway this past weekend. Here is driver Rolando Saldana driving the 135i sans sunroof.

[wildcat767676]

Did the larger radiator make a difference? I am torn whether to do oil or water cooling upgrade first. I keep running into the dynamic rev limiter after 3-4 laps, and sometimes full on check engine light limp modes...

[scottn2retro]

Originally Posted by wildcat767676

Did the larger radiator make a difference? I am torn whether to do oil or water cooling upgrade first. I keep running into the dynamic rev limiter after 3-4 laps, and sometimes full on check engine light limp modes...

I would do both, but if you want to try one first, then I believe the software is keyed off of the water temp.

[wildcat767676]

Thanks! Off to dealer today to see why I have ABS warning lights like crazy after coilovers installed...............arrrrrrrrrrggggggg........ ......

[scottn2retro]

Originally Posted by wildcat767676

Thanks! Off to dealer today to see why I have ABS warning lights like crazy after coilovers installed...............arrrrrrrrrrggggggg........ ......

Maybe broke one of the ABS sensor wires on one of the corners (or maybe one of the connectors not re-connected?)

[wildcat767676]

I hope not, but the shop checked everything over twice and didn't see any issues.

[Biasasaja]

that radiator, will it fit to an n55?

[scottn2retro]

Originally Posted by Biasasaja

that radiator, will it fit to an n55?

Not sure - have to check with HP Autowerks

Well, we finally got to try some coilovers per the new rules, so we're trying the Eibach set. Made a huge difference on the car with some real spring rates as Ralph was out there trying to chase I-prepared cars at Willow Springs

[wildcat767676]

Do you think the coilovers on the 135i really are necessary for track days? I like mine but the rear is so stiff and clunky. It seems to oversteer like crazy too. What did you set your camber at front and rear? The shop set my rears to -1.8 and fronts to -1.0. I think you had said the front needs to be more than the rear. Taking it to another place to get set up again...see how that goes.

What size tires are you running?

[Kcyrusm]

Originally Posted by wildcat767676

Do you think the coilovers on the 135i really are necessary for track days? I like mine but the rear is so stiff and clunky. It seems to oversteer like crazy too. What did you set your camber at front and rear? The shop set my rears to -1.8 and fronts to -1.0. I think you had said the front needs to be more than the rear. Taking it to another place to get set up again...see how that goes.

What size tires are you running?

If you have oversteer issues like you say, making your front have a more aggressive camber than your rear will only exacerbate your oversteer issues. In general, 135i's understeer, which is why people go more aggressive with the camber in the front so you have more grip up front and reduce understeer. This doesn't seem to be your case. Try softening your rebound settings on your shocks in the rear?

[wildcat767676]

Makes sense. With the stock suspension it did understeer pretty badly. This last time I stiffened up the front coilovers all the way and there was no understeer. However, I could induce oversteer very easily. The tires I had weren't that great(Contisport Extreme Contact) so I just switched to Nitto Invos(however FYI Nittos run large and they rub, so having to get fender rolled Friday). Interested to see how it handles with an extreme performance tire this time. I will pull apart the rear trunk and soften the rebound, see if that helps.

Since the rear shocks are adjustable in length, does anyone know how to properly adjust them? I'm thinking the clunking sounds could be due to too much preload on the rear shocks since its pretty low?

Sorry, not trying to thread jack.........just interested in what you have experienced with your race car.....

[scottn2retro]

We are running springs that are a few hundred lbs. higher in the rear than in the front. That is quite different from the e46 M3.

The shocks are set at about the same stiffness front and back and a slightly lower ride height in the front. That is like the e46 M3.

We run a square setup with the same tires front and rear. That is like the e46 M3.

We run a large front sway and little or no sway bar in the rear. That is like the e46 M3.

[scottn2retro]

With the new Sport Class rules, we weighed the car at Willow Springs and we were still over 200 lbs. overweight. Time for the 135i to continue it's diet. It's amazing how many non-essential things you can find to take out of a car.

[scottn2retro]

We continue the diet plan for the 135i (here at Sear's Point)

[BimmerJim]

Time to bring this car to the Ring for a little fun!!!!!!

[scottn2retro]

Originally Posted by BimmerJim

Time to bring this car to the Ring for a little fun!!!!!!

Ah, if only we had budget for that!

But in the mean time, we're a little busy with a rear subframe bushing project

We're going with the Turner bushings


They are aluminum and delrin


So what do you need to do first? Drop the rear Sub-Frame. Which means drop the rear everything. It's not often we have the whole back end of the rear drivetrain on the garage floor.


Now to remove the old bushings. You'll need a bushing removal/install kit. HP Autowerks rents one.


Putting the bushing catcher underneath, the long bolt thru with the pushing and stopping washers and go at it with the impact gun. It takes a while and it vibrates like crazy.


Old Bushings out.


Now install the new ones. Be sure to have the flatter sides of the aluminum part aligned right with the rear subframe (perpendicular to the travel direction of the car). Delrin from up top, Aluminum from the bottom, bolt thru with the squeeze washers and hit with imapct gun.


Now to figure out how to get the rear subframe back in.

[EDSA.aguas]

Great Thread!! Thanks for posting

[BimmerJim]

Originally Posted by scottn2retro

Ah, if only we had budget for that!

But in the mean time, we're a little busy with a rear subframe bushing project

We're going with the Turner bushings


They are aluminum and delrin


So what do you need to do first? Drop the rear Sub-Frame. Which means drop the rear everything. It's not often we have the whole back end of the rear drivetrain on the garage floor.


Now to remove the old bushings. You'll need a bushing removal/install kit. HP Autowerks rents one.


Putting the bushing catcher underneath, the long bolt thru with the pushing and stopping washers and go at it with the impact gun. It takes a while and it vibrates like crazy.


Old Bushings out.


Now install the new ones. Be sure to have the flatter sides of the aluminum part aligned right with the rear subframe (perpendicular to the travel direction of the car). Delrin from up top, Aluminum from the bottom, bolt thru with the squeeze washers and hit with imapct gun.


Now to figure out how to get the rear subframe back in.

Good luck with the project