[Rotary Rocket]

I am new to this forum and wanted to share my build with the E90 community.

I just picked up an E90 race car in need of TLC, and motor/tranny.

This will be a build for the United States Touring Car Championship, they are a power to weight ratio series of late model sedans. www.ustcc.com

The car has moton shocks, some heim joints in suspension arms, 135i brakes, TC design cage, sparco seat and steering wheel.

I am thinking of putting in a S52 motor/tranny. This power plant is cheap, reliable, will provide enough power, lots of aftermarket support, and I have some experience with it (have the same power plant in my current E36 race car).

Very excited to get going on it.

[mike-y]

very nice. keep us updated with the build!

[Rotary Rocket]

Started to take things apart, getting it ready for a paint job first.

Have to do something about this hole.... hehehe....

[TSM330i]

Sweet! Can't wait to see the completed project.

Why do paint? Why not just wrap it? You can get great graphics on it too.

Good-luck.

[Rotary Rocket]

One of my sponsers is Universal Technical Institute (UTI) in Sacramento. The students are our crew when we race, and the students are the ones painting this car. I will post pictures of their handy work.

[yakev724]

Why 135 brakes? Pretty sure 335 brakes have more stopping power and probably run cooler since they've got larger rotors.

[mike-y]

Originally Posted by yakev724

Why 135 brakes? Pretty sure 335 brakes have more stopping power and probably run cooler since they've got larger rotors.

Maybe the car started out as a 328i, so the 135 brakes were an easier upgrade? With a lot of weight removed, he might not need much more than that with race pads.

[Rotary Rocket]

mike-y, you are correct sir. It was a 328i. The car came with the 135 brake set up, I might upgrade to Stop-Techs at some point.

The car should be in the 2800-2900 range and Project U pads will be going in.

The current E36 work horse that will be replaced by the E90.

[yakev724]

Originally Posted by Rotary Rocket

The car came with the 135 brake set up, I might upgrade to Stop-Techs at some point.

The car should be in the 2800-2900 range and Project U pads will be going in.

The current E36 work horse that will be replaced by the E90.

Very cool.

The 135 brakes are worth ~$1k here on the boards in case you opt to sell down the line.

Also, I assume you're on top of your research but you should know that most of the E9X M3 suspension swaps right over to the non-M E9X cars and should make for a much better handling car on the track.

This is a great thread on the subject: http://www.e90post.com/forums/showthread.php?t=177028

[Rotary Rocket]

I am actually a total nub on the E9X front, ANY help will be GREATLY appreciated. Thank you for the link.

This deal was simply too good to pass up. I had already bought an E90 rolling chassis and was going to do a ground up build, but now I have a head start. My goal is to run this car in the USTCC/WTCC race coming up in September at Sears Points (Ex-Infinion) raceway. Yes, the boys from Europe are coming over for a visit.

[yakev724]

You can purchase the entire M3 kit for ~$2k from Tischer (getbmwparts.com). While you have the rear subframe off for the rear sway, it's worth replacing the subframe bushings as well. Also, you'll need to align the car to M3 specs after installing the parts.

HP Autowerks (hpashop.com) might be your best shot at the best possible track suspension setup, with both M3 and even stiffer aftermarket parts. I'd just drop Harold (username - HP Autowerks) a line and let him make the recommendations. He's one of the most knowledgeable guys here.

[mike-y]

it's possible the car already has a lot of suspension upgrades. The average pro racer just doesn't slap Motons on a race car without also looking into other parts of the suspension.

The already has camber plates, and may have upgrades in other areas. OP, it may help to ask the previous owner if they've upgraded anything else on the car (M3 bits, bushings, etc).

[Rotary Rocket]

Yes, the car does have additional suspension pieces in the form of heim jointed dog bones and what looks to be a derlin insert in the front arm. I am still waiting on the list of "mods" done to this car. He also gave me some sway bars (they are grey and the rear has two holes for adjustment) and hard bushings for the mount. I also don't know what brand they are.

I can see the rear diff and sub-frame still has the original inserts.

What will switching to the M3 suspension arms gain me?

[mike-y]

Originally Posted by Rotary Rocket

What will switching to the M3 suspension arms gain me?

with those other adjustable pieces that are on there and delrin bushings, nothing. it would be a step down actually.

[e90pilot]

Does the car have the 135 rear caliper? If so, I'm wondering what rotor they used to fit the caliper properly. The 135 rotor had the wrong offset and the 328 rotor has the right offset but the wrong diameter.

[e90pilot]

Originally Posted by Rotary Rocket

Yes, the car does have additional suspension pieces in the form of heim jointed dog bones and what looks to be a derlin insert in the front arm. I am still waiting on the list of "mods" done to this car. He also gave me some sway bars (they are grey and the rear has two holes for adjustment) and hard bushings for the mount. I also don't know what brand they are.

I can see the rear diff and sub-frame still has the original inserts.

What will switching to the M3 suspension arms gain me?

Interesting... I haven't seen a proper coil over for the back yet. All the kits I've seen have the spring and shock mountes separatly.

[jbass524]

Can you flare fenders? If so some really wide APEX ARC-8s would perfect. Checkout the Maxxis M3. You might need to go with M3 hubs. If you don't have the M3 front tension rods and rear camber links then you would need those too. There may be something else required but you gain track width.

As someone said earlier in the thread, they are direct bolt in

[Rotary Rocket]

No fender flaring is allowed.

I ended up going with an N52 motor out of a Z4. It is basically a 330i now.

I know I will have to deal with the electronics, but at least it is the "right motor" in the car. We'll see if I will end up regreting this decision.

So much still to do... car is getting painted next...

[3002 tii]

Nice seats! If my weekend warrior were full race car I would've gone with those over my Recaros.

[e90pilot]

How easy is it to get the engine in and working?

[Rotary Rocket]

We did this job at UTI; the lift, cheery picker, and two very good friends made all the difference in the world. It was pretty painless.

This car is a 325i originally, but since this motor was offered in this chassis everything bolted right up. This was the "easy" part.

The harness is the Z4 harness, so the wires seem to be too short. As an example the ECU does not reach the protective box!

The fuel line is too short to connect to the line on the chassis.

I removed the AC compresor, so I'll have to measure and get a custom belt.

The Z4 had electronic steering and we did convert it to 325i powersteering pump. I wonder how hard it would be to convert the 325 to the Z4 electric steering?

My plan is to get the car running first, and then start to modify it for racing purposes. I am truly concerned about all the electronics and the stories I hear... I will look to this community for help as I go forward.

[e90pilot]

Oh, so you got a E89 Z4 engine, the one that had the plastic valve cover. It also had a different ECU than the original 325/330. That's cool how you got it all working. I was kinda wanting to turn my e90 into a track day car a few years after I pay it off. With all the non-essential modules removed, does the ECU give you any issues or does it work fine with all the faults?