Elephant Motorsports E30 M3 #217 Ground Up Build

[CosmosVaderM3]

Are you having to meet a minimum weight or something to prevent you from gutting the interior? IMO, it looks heavier than it should for mod competition.

[RacerX]

Are you having to meet a minimum weight or something to prevent you from gutting the interior? IMO, it looks heavier than it should for mod competition.

If you start from the beginning you'll see that the car pictured most recently is merely a SpecE30 car temporarily converted to run in GTS2 for a few races this past season.

Or you can start here: http://forums.bimmerforums.com/forum...6&postcount=97

For pics of the car after it got back from the cage fabricator.

Cheers.

[CosmosVaderM3]

Oops, sorry.

[Damon in STL]

Jack,

I'll give you a call tomorrow....got bogged down with work today.

Cheers!

Damon in STL

[RacerX]

Oops, sorry.

No worries! Cheers.

Jack,

I'll give you a call tomorrow....got bogged down with work today.

Cheers!

Damon in STL

Cool. I'll email you my cell # too. Cheers.

[JohnVanHouten]

Earlier this week, I was able to get the fuel cell cradle fabricated and the car prepped for install. I won't be welding into in the car until later as have a whole in the floor of the trunk is useful for reaching things ;-)

I also haven't decided where I'm going to put the female dry break receptacle. I was going to put it in the decklid, but I'm worried about it collecting dirt, etc. I'm currently leaning toward the left rear fender--something to figure out this weekend.

Here's the completed cradle on the welding table, all TIG welded. The holes are for clearance of the fuel cell flange bolts. It's offset to the right so that I can run a rear muffler if I choose to.


Here's an example TIG weld. I'm pretty happy with the welds, especially since this is the first real piece I've done other than goofing around.


The 15 Gal Fuel Safe cell mounted in the cradle


It will go where the spare tire well was. I drilled out the spot welds and pulled the whole well out in one piece. I didn't get a pic of it squared off, but will later ;-)

[new guy]

Any updates John?

[goquattro]

Looking good.

[Steve J.]

Fuel cell cradle looks familiar, i like it! It needs more lightening holes though

[JohnVanHouten]

Man, I'm heinously overdue in putting out an update. It hasn't helped that both the wife and I have been _very_ busy at work (a good thing these days) so time to work on the car has been scarce. My office is going to 4 day work weeks for the summer, so that will help a lot.

That said, some progress has been made and I'm still shooting for a race in mid-July--we'll see if I can get it all done in time. I don't have a ton of pics, but here's some random ones of what I've been working on, starting with the fuel cell.

Here's the cell set in the trunk. It won't be welded in until all the other fabrication in the rear of the car is done--bulkhead, wing mounts, rear window mounts, etc.


From the underside. It's mounted in basically the same place as the spare, leaving enough room to have a rear exhaust. I'm likely to have a side exit exhaust, but I wanted to have the option:


The cell is mounted as far forward as possible:


Another underside picture:


Using a shallower 15 gal cell should give enough room to have an effective diffuser:


Here's the rear bulkhead pass through welded back in and a prior owners "bass" holes patched up:


Template for the rear shelf:

[RacerX]

I forget, are you cutting out the stock rear shelf or..........???

[JohnVanHouten]

Fuel cell cradle looks familiar, i like it! It needs more lightening holes though

The holes aren't for lightening but to clear the bolt/nuts of the cell flange. The cell is supported from underneath, not on the flange.

As far as further lightening the cradle, I thought about it but then decided against it for strength. The rear wing mounts will also mount to the cradle to transfer the load to the frame rails, so there's a lot going on with that structure.

I forget, are you cutting out the stock rear shelf or..........???

Just covering it with a 22g steel panel. Easier to do that and not much weight added. If I didn't have a cell and the design of the cage I'd be temped to cut it all out, but with the cell there, i'll just seal it up.

[RacerX]

Ah right, I recall we discussed this. Where's my head.

Cheers.

[English]

Amazing, who needs TV. Waiting for updates. Hooyah!

[didzhej]

Great job u've done.

Don't understand why in most cases fuelcell in mounted behind rear axle? Is this a regulations u have meet to? Or some other reasons?

As I understand - weight must be fited between front and rear axles due better weight balance.

My version: http://img22.imageshack.us/img22/5703/dsc00412o.jpg

[OLD MAN]

Great job u've done.

Don't understand why in most cases fuelcell in mounted behind rear axle? Is this a regulations u have meet to? Or some other reasons?

As I understand - weight must be fited between front and rear axles due better weight balance.

My version: http://img22.imageshack.us/img22/5703/dsc00412o.jpg

I do not like the idea of fuel in with me - fuel cell in the trunk can be put lower then where you show it - my E21 is real front heavy in stock form so fuel cell in the trunk helped to balance it out.

Stock fuel tanks are in a really good place and are low in the car, but they do not make fuel cells in the same shapes so not really possible to mount them there.



Any more up dates on the build ??

Looking great.

[didzhej]

I do not like the idea of fuel in with me - fuel cell in the trunk can be put lower then where you show it - my E21 is real front heavy in stock form so fuel cell in the trunk helped to balance it out.

First of all - this cell in a safe box!

Don't forget all honda's etc, that does not have separate trunk, they all have those cells inside. Only thing where it can be not safe - pumps, but them are not very heavy, so they can be fitted behind.

But still, it is very different situation, when u have 20gallons behind the axle in the beggining of race, ant 5-8.. at end of it. Those different in car balance can do more bad things at corners.

There are my thoughts.

[Hammer03]

First of all - this cell in a safe box!

Don't forget all honda's etc, that does not have separate trunk, they all have those cells inside. Only thing where it can be not safe - pumps, but them are not very heavy, so they can be fitted behind.

But still, it is very different situation, when u have 20gallons behind the axle in the beggining of race, ant 5-8.. at end of it. Those different in car balance can do more bad things at corners.

There are my thoughts.

Many sanctioning bodies require a metal bulkhead between the passenger compartment and a cell. That means under the car (like the stock tank) or in the trunk in most cases.

I don't know what Honda hatch-types do, build a firewall? Stick with under-the-floor types?

[OLD MAN]

First of all - this cell in a safe box!

Don't forget all honda's etc, that does not have separate trunk, they all have those cells inside. Only thing where it can be not safe - pumps, but them are not very heavy, so they can be fitted behind.

But still, it is very different situation, when u have 20gallons behind the axle in the beggining of race, ant 5-8.. at end of it. Those different in car balance can do more bad things at corners.

There are my thoughts.

In front of the rear axle low under the car is better, just not easy. The question I would ask is 20 gals of fuel above the height of the axles in the car? We are only running an 8 gallan fuel cell for 25 min runs - hopefully we will not run out of fuel. We should carry this on in a new thread out of this build thread - sorry John.

[D.R.]

A lot of guys build a box around the top of the cell, made out of sheet metal, that serves as the "firewall".

I have one in an RX7 that just fastens with a few DZUS fasteners and pulls out for refueling.

[84318i]

Cool build! thanks for posting weight #s of the bare chassis before/after

[new guy]

John any updates???

[new guy]

John,

Are you alive? I am guessing project is on hold... hope all is well.

Kevin

[JohnVanHouten]

I know I'm _way_ delinquent in updating this thread and I need to get off my a** and do it. First thing I'm going to do is split out into a new thread the stuff into focused on the E30 325 that became much more of a test mule than originally intended and has had a change in direction as well. It has some interesting updates, as well as getting the M20 stroker originally planned for the M3. The 325 will become an interim race car and will either become the wife's car or will be sold.

The M3 has been progressing slowly but now that the 325 is just about in a "just drive it" state, I can focus more on the M3. It has some body work that needs to be done, hopefully this week, so I can then continue on the fabrication needed to get it ready for paint. Since the engine orginally planned for this car is going in the 325, it is getting something more modern...

[davemsport]

Great build!!!

That shell and cage deserves something far more interesting than a worked M20 anyway

In the middle of prepping my own trackcar shell at the moment and getting an S54 ready for it.