E30 M3 Steel Bodywork Conversion

[bmwmech1]

Wow!! This is one of the best build threads I've seen so far. Keep up the good work

Thanks man, it's been almost 2 years in the making, but I'm seeing the light at the end of the tunnel getting brighter by the day...

Garey

[Eric]

May 20th?!?!

Also you need any more body parts? Picked up some m3 parts this week. Drop us an if you still need odds and ends.

Can't wait to see it in person

L

levent, clear your inbox, I need M3 parts!

[Eric]

Getting stuff done...

Garey

Garey,

what spring rate ratio did you go with for the rear coil over conversion? I've heard lots of guestimates, about rear coil over spring rates, but never solid information.

[LJ851]

Bodies in white look so f*ckin racy, especially with a well built cage like yours.

Well done Sir!

[bmwmech1]

Garey,

what spring rate ratio did you go with for the rear coil over conversion? I've heard lots of guestimates, about rear coil over spring rates, but never solid information.

Solid info is hard to come by on this topic. I would trust the racers more than anyone, since they are pretty intune with their vehicles/handling characteristics. My car is dynamically a lot different, though, than a standard E30, since I have a 20 gallon fuel cell outside of the wheelbase. Since I'm using 600lb springs in the front, I started off with 550lb springs in the rear. Is it right? Dunno yet, but swapping them out is easy enough, so we'll have to wait and see....

Bodies in white look so f*ckin racy, especially with a well built cage like yours.

Well done Sir!

Thanks man... I agree, after I pulled off the masking, I stepped back and looked at it and smiled and thought... Wow! Because racecar, lol!

Garey

[JGood]

I've heard lots of guestimates, about rear coil over spring rates, but never solid information.

This is my take...

I think the motion ratio of the wheel and true rear coilover would be nearly 1:1 (you'd have to measure wheel travel vs coil travel to verify), so you should be able to pick a spring based on what your target wheel rate is.

The stock e30 spring location is such that you can multiply the spring rate by .45 to get your wheel rate. So a 650lb stock-style rear spring would put you at a 292lb wheel rate.

Sooo, if you want the wheel rates of a typical 450f/650r setup, you could get a 450f/300r true coilover setup.


I'm interested in seeing how your rates work out Garey. Trent was running 400f/375r on his true coilover setup and mentioned it being a bit twitchy, even without a rear swaybar. But as you said, your car is far from stock, weight has been moved all around with the cage and fuel cell.

[bmwmech1]

This is my take...

I think the motion ratio of the wheel and true rear coilover would be nearly 1:1 (you'd have to measure wheel travel vs coil travel to verify), so you should be able to pick a spring based on what your target wheel rate is.

The stock e30 spring location is such that you can multiply the spring rate by .45 to get your wheel rate. So a 650lb stock-style rear spring would put you at a 292lb wheel rate.

Sooo, if you want the wheel rates of a typical 450f/650r setup, you could get a 450f/300r true coilover setup.


I'm interested in seeing how your rates work out Garey. Trent was running 400f/375r on his true coilover setup and mentioned it being a bit twitchy, even without a rear swaybar. But as you said, your car is far from stock, weight has been moved all around with the cage and fuel cell.

Yeah, because of the fuel tank location, I went to a 550lb spring to start. I honestly don't know if I'm in the right ballpark or in a completely different sport, with my choice. Thankfully, they are cheap and easy to swap, so I'm not too worried if I'm off base...

Painting the trunk and engine bay tomorrow night. It's completely prepped and ready to go, just needs a quick wipe down and then tacked. I'll post up some pics when I get done...

Garey

[kingston]

CAN'T WAIT!!!!!! It's got to be an AMAZING feeling to be nearing the home stretch!

[SA E30]

Just a little info. I'm running a 600lbs rear spring (true coil), and 800lbs up front with stock sway in the rear, and H&R up front.

When I drove it around with an aspirated m10, and some worn out semis car handled pretty well, but then that was before the turbo build, half cage and wheel well mounted cell.

Just some no's to chew on... Carry on with the impressive work!!

[bmwmech1]

Just got home... it's go time now, the entire inside of the car is now white. I'll be back over at the shop tomorrow to get it down off the rotisserie and start bolting stuff on permanently. The trunk was a bitch to paint... thank goodness I had it on the spit, since that helped out a ton. Pics...



















Headed to sleep... I'm beat...

Garey

[truism]

nice job! looking great cant wait to see it all one color :)

[bmwmech1]

... cant wait to see it all one color :)

You and me both! This was a major waypoint in the project, though. Now I can actually begin putting the car back together for good... starting today...:-D:-D:-D

Garey

[Garageaholic]

You've come such a long way with this swap. Im awe struck by your level of detail you've taken with this whole project. I truly cannot wait to meet you and your amazing e30. Awesome progress!

[bmwmech1]

You've come such a long way with this swap. Im awe struck by your level of detail you've taken with this whole project. I truly cannot wait to meet you and your amazing e30. Awesome progress!

Thanks man, it's been a long haul, but I'm excited to be rounding third, so to speak. It won't be too long now until we can all get together with our V8 swapped E30s...

Garey

[bmwmech1]

It's back down on the wheels and tires, now the re-assembly commences...





Garey