Widebody Track Car Build

[Dieselboy]

Originally Posted by lowside67

A little late to the party but really the way to set ride height is not to look at what others are doing which may or may not be correct, but instead set it based on the desired outcome.

The order to actually work out the optimal ride height is:
1) First, pick your spring rates.
2) Keep lowering the car until either:
a) The car has an unacceptable amount of contact with the ground on track (this will be different for each circuit)
b) The suspension geometry becomes so compromised that overall grip is reduced
*** if b is the limiting agent, then the ride height should stay, but then we focus on correcting the poor geometry

The height of the bodywork should not be based on ride height at all - it should be based on removing the springs and simply compressing the suspension to bump stops. Regardless of how high or low your ride height is, the bump stops are always in the same place and represent how far the tires should be able to travel freely without hitting bodywork.

Hope that helps,
Mark

The point in asking for ride heights was to find how far I am from baseline on a near stock setup. Because the fenders had to be cut to install the new suspension and wheels i was not able to get a center wheel to fender distance so I had no idea if I was an inch above or below stock.

I am also running massive tires, with a larger diameter which increases ride height. I want my CG as low as possible without bottoming out. There are aero considerations as well. As a starting point, I am going as low as possible while still maintaining as much usuable suspension travel as possible. The car will eventually be corner balanced, just need seat time to feel out what needs adjusted.

[Dieselboy]

Here is the brake ducting setup.

[Dieselboy]

So I took the car to a local shop down the street hoping they could get me close to what I needed. They were unable to align the car with the body kit on, so off it came. Then they mixed up my "total" Toe numbers and used that as per side

I'll roll with this for now and see how it does. They said they had issues with how deep the wheels are and weren't able to log the pre numbers, but apparently the rear was way out.

I'll go to a performance oriented shop next time and get the corner balance done as well.

What I wanted:


What I got:

[lowside67]

I think you will not be happy with that alignment on track - toe in on the front is going to lead to a very sluggish turn in and potential understeer at entry. Somewhere between 0 toe and 1/8" total toe out is common for BMW track cars' front suspensions.

-Mark

[hoki06]

Agreed. I can't find my old M3 specs but from what I remember... caster was maxed then set camber to desired amount (I was around 4 deg running Hoosiers) and front toe was 1/8" out. Rear was similar camber and 0 toe.

This is a good overview of toe tuning and how it can effect the car. Make sure you're reading the RWD section (starts at the Ferrari picture).
https://suspensionsecrets.co.uk/adjust-tune-toe/

[Dieselboy]

Been a while since I've had a chance to do anything to the car. In line with the rest of the build, I'll be doing paint and bodywork myself. I've never done this before so we'll see how it goes..

Got all the supplies I should need. Now getting all the bodywork scuffed up. Will shoot primer/sealer/base/clear.

[Dieselboy]

Primer is going on today. Its laying down great.

[Dieselboy]

Well, its certainly a learning process having never painted before. Everything was going well until it came to the clear coat. Horrendous orange peel, and by the time I was able to wet sand it smooth I was burning through clear and base in some spots. Color match looks decent though. Only did a few of the smaller parts so shouldn't be too bad to repair.

Base went on nicely


Clear after sand/polish

[Dieselboy]

Getting closer.

[wdb]

I was at the Duryea Hillclimb yesterday and this car made me think of yours. I never saw it with the hood open but rumor was it had a V8.

[Dieselboy]

Originally Posted by wdb

I was at the Duryea Hillclimb yesterday and this car made me think of yours. I never saw it with the hood open but rumor was it had a V8.

That sounds awesome. If my N54 ever pops I am going to LS swap it. Would make life a lot easier lol.

Paint is done, came out decent enough considering it was my first time painting, definitely learned a lot doing it. I have a stage 3 low pressure fuel pump to install, then I just want to drive it through the fall since I've had hardly any seat time.

[houtan]

Not saying anything you’d don’t know already but that came out phenomenal. Nice work.

The upgrades are never ending. Easier said than done, but it’s Nice to stop and just enjoy the car and the work you have put in.

[mKilgore]

Looks great. Congrats and enjoy!

[Dieselboy]

Originally Posted by wdb

I was at the Duryea Hillclimb yesterday and this car made me think of yours. I never saw it with the hood open but rumor was it had a V8.

I just realized this was in Reading, PA. It's a husband/wife team, he drives the mustang and she drives the LS swapped 135i. Looks like it's been setting class records all year. I went to Giant's Despair Hillclimb a few years ago, was an awesome event.

[mKilgore]

Mark Aubele and his wife Michele. Great folks. Mark is here on the forums and there is a build thread of the 135i I think.

[wdb]

The Mustang has an LS3 in it!

[Dieselboy]

Putting the car on a diet, Sparco Evo seats going in. Weighed the stock seats at 60lbs and the new seats at 30lbs each with all the hardware. Pulled the rear seats which weighed in at 55lbs. Also ordered a lightweight battery (ATX30) which weighs 5lbs as opposed to the stock ~60lb battery. I also got the rear trunk battery tray delete panel which should shave another 10-15lbs and ditched the windshield wash reservoir which weighed 18lbs when filled. Total this should net a weight savings of almost 200lbs. Need to get the car on a scale.

[amg6975]

You'd be shocked how much a lot of "nice" things weigh. One surprising one is the headlights, I dropped 20lbs way out over the front by switching to halogens.

Sunroof, door cards, rear carpeting, combox, etc etc etc. 20lbs here and there add up really quick.

[Dieselboy]

Second Evo installed today. Love these seats. Removed the stock battery and battery tray. I ordered the E9X filler panel from Hard Motorsports which says "Can be easily modified to fit the E8X (1 Series), or for your specific needs." This is total BS and I would have been better off just getting a sheet of aluminum from Home Depot and making one myself. Ended up trimming the panel and redrilling almost all the mounting holes. Oh well. The new lightweight Antigravity battery will be going in the corner where the batteries are for the E90. (On the 135i this is where the TPMS module is, I reprogrammed my car to use the TMS and removed all the TPMS hardware.)

[Dieselboy]

New battery in the side pocket with battery tray delete panel in place. Had to drill 2 holes for the 2 power cables that run underneath the car. Saved about 65lbs.

[Dieselboy]

Rollcage and Carbon hood ordered and should hopefully get here in November.

My to-do list includes:

• Stoptech Trophy BBK
• Carbon Sunroof Delete Panel
• Accusump
• Center Exit Exhaust
• DIY Front Splitter and Rear Diffuser

She'll be ready to hit the track come Spring.

Meanwhile the car has been a blast to drive. Got a lot of attention at the last Cars and Coffee.

[wdb]

Steel Stacks! I missed it, volunteered to be a grid geek for BMWCCA at NJMP. Nice picture.