Widebody Track Car Build

[Dieselboy]

M3 front control arms installed. There's about 10mm clearance between the shock and wheel at max camber.

[SKI-R]

Good lord….there is some sheet metal that DEFINITELY needs to go! This is great watching - thanks.

[Dieselboy]

Shift kit arrived after 3 months of waiting. The shift lever is missing the set screws, so more waiting to get it done, but 99% of the way there on the manual swap.











Wired in the reverse light switch and all works. I could have actually taken the car out for a quick drive if it wasn't for the snow..

[Dieselboy]

Here's how the car currently sits. Figuring out ride height relative to other 1-series cars will be difficult due to the new body work, so if anyone can provide their ride height measured in the conventional bottom of rim to fender arch AND provide the distance from the floor to the outer lip of each jack pad it would be super helpful.

I want to do some test drives before I move onto the next stage of the build which will include fueling, LSD, brakes, etc..

I've only backed it out of the garage, but with the solid mounts and manual trans, I can tell it's going to be a visceral driving experience.

[wdb]

"Visceral".

[houtan]

Do you care if the measurements are from a lowered car or are you looking for stock height measurements?

[Dieselboy]

Originally Posted by houtan

Do you care if the measurements are from a lowered car or are you looking for stock height measurements?

Measurements from the ground to the jackpads would be useful for any configuration. Thanks!

[Dieselboy]

I finally got to putting the rivnuts in and bolted the widebody panels to the car. I did a few test drives around the neighborhood and ended up having to move the new oil cooler further forward and had to raise the front ride height 12mm. I'll need to fab some brackets for the new oil cooler mounting location. Transmission feels good and shifts well. Once the weather clears up I'll do a few more test drives before moving to phase 2 of the build.

[Dieselboy]

My biggest gripe with the clinched kit is that the front fender arches are lower than stock, so the car looks lower, but is actually sitting up higher to clear the fender when I turn. Obviously this kit is geared more towards the stanced crowd, but my goal was always to have it more of a GTE spec. Not sure I've prepared myself yet to cut up a very expensive body kit, so I will run it as is for a bit and see how it goes. The rear can come down a bit, but I'll need a helper spring as I am currently as low as I can go without the spring getting loose at full droop.

Front at current ride height


Rear at current ride height


GTE spec fender clearance

[Dieselboy]

Here's a photoshop of the clearance I could get by cutting the fender. I don't think it looks too bad. This would let me drop the front close to 25mm.

[wdb]

Originally Posted by Dieselboy

Here's a photoshop of the clearance I could get by cutting the fender. I don't think it looks too bad. This would let me drop the front close to 25mm.

Attachment 2821159

That looks pretty practical. It also gets rid of the uneven gaps in front and back of the tire versus above it. The wheel arch looks more concentric to my eye.

[houtan]

Yeah I agree. I have no idea how to fix a fender as you described but looking forward to seeing how you do it!

Also, my apologies on the wheel and body height measurements. I meant to do it before I put my car in the air this week and completely forgot. The email notification saying there is an update to your thread is what reminded me. My bad.

[Dieselboy]

Not much to update, have been traveling a lot lately. Drove it a bit and everything feels pretty good. Going to try and get an alignment this week and take her on a long drive.

[Dieselboy]

Working out what I want to do with the brake setup. I've considered rebuilding the fronts with the SS piston kit, new rotors, pads and SS lines, which would put me at ~$1k. The Stoptech ST60 kit is ~$3k, but I can sell my stock calipers and it ends up not being a huge difference. I'm leaning towards the BBK, and just not having to worry about the brakes ever again.

[houtan]

Measured my ride height from the rocker panels. Currently have a full tank of gas.

Rear measuring point is right behind the rear plastic jack pad: 6 5/16”
Front measuring point is right in front of the front jack pad: 5 13/16”

Both measuring points allow you to measure from the bottom of the car frame to the ground. I have been told by TC and HPA the rake front to rear should be about 3/4” and I’m at half inch. I can’t handle the look when it’s at 3/4” rake so looks prevailed in my case.

Adding a picture of my car so you can see how it sits.

[Dieselboy]

Replaced the spark plugs because I had gotten a misfire the last time I took the car out. Went with the NGK 97506 two-step colder plugs. Seems to have fixed the misfire issue. The car ran great, but the JB4 triggered a safety due to over boost (>21psi) when targeting 17psi. Chaged a few settings in the JB4 duty bias inputs so will see if that helps.

Still all stock fueling and ignition (except plugs). I am going to be upgrading all the fueling and ignition once I am sure the car is running the way it should at the current boost targets. I also need an alignment so I can't really comment on the handling as of yet.

[houtan]

I use the same plugs on my n55 and have good luck with them.

Just curious, any particular reason why you are still running the jb4 instead of flash only?

[Dieselboy]

Originally Posted by houtan

I use the same plugs on my n55 and have good luck with them.

Just curious, any particular reason why you are still running the jb4 instead of flash only?

It's just what I have been using since I got the car 2012. The general consensus seems to be custom tune through MHD so once I get my fueling and ignition sorted that's what I will switch too. Right now is essentially just beta testing before I continue sinking money into this pit.

[houtan]

Makes sense. Yeah that’s all I was going to say, with what MHD has to offer for the n54, I would definitely go the flash only route.

[Dieselboy]

I've been very busy with work, but managed to get the 3.5BAR TMAP sensor installed as well as a pair of swift helper springs to give some more height adjustment in the rear. I currently have it set 0.5" lower than previously.

Swift Helper Springs


Pre-Install


Post-Install


Pre-Install


Post-Install

[Dieselboy]

I am also working on a pair of brake ducts for the front rotors. I will 3D print an adapter to fit in the Clinched splitter and run through the undertray to each rotor. I will buy a set of adapters and rivet them to the backing plates.

[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