E46 Jaffster Build

[JohnVanHouten]

Its pretty decent, took about 2 hours to get it all skinned, cleaned, and I even tossed a high temp paint on the inside (1500*F), as the fuel cell is right in front of it.

If your fuel cell gets up to 1500*F, then you'll have bigger problems than the paint job

[Steve J.]

Well, the jet rocket booster that I have in the trunk thats connected to the "push to pass" button gets kind of hot too

Its more a preventative measure. If there are fumes that ignite, its less "stuff" to burn and continue the flames. But yea...god forbid anything like that happens.

[328ischef]

hey Steve,
while it may be a bit late for dipping since it will effect your cage/welds, the place in pa is about 40 minutes from me, I'd be happy to help you by letting you store the car here until you can get, etc.
Great build!

[Steve J.]

Thanks for the offer, but I decided to go without dipping, its not worth it at this point, since the only welds on the chassis left is the base plates, and those are not bad.

As far as updates, this weekend has been pretty lax on the project, due to weather conditions I did not get the materials I wanted to on Friday, they won't be here until tomorrow.

I did finish up the wing mounts/tabs, so thats checked off the list. Otherwise, I did not do anything else to the car this weekend besides the trunk skin.

I need to get a sleeve for the front struts to mount to the spindle, and then I can mockup the suspension.

[clopez95m3]

Steve, you mentioned you finished your cage design. Meaning the CAD model is done? Would you mind posting a pic of it?

Cheers,
Carlos.

[Steve J.]

Well, I did not bother spending much time on it. I basically just did a bunch of 3d sketches to get the idea down so i can measure tubes for ordering.

Nothing too out of the ordinary. The rear subframe tie in copies that of the GTR, front of rear subframe is like what RRT did, but tying into the rtabs. "X" in the main hoop, and the only thing out of the norm is a large radius sheet metal apillar gusset. 3 tubes to each front shock tower like the motorsport chassis. 3 tubes to each rear shock tower, 1 being the downtube, one from the middle of bpillar, and the "X" from the top of the main hoop.

[ScotcH]

Also, this is the final design I decided to go with for the rear shock mount/subframe reinforcement:

Looks familiar

[Steve J.]

Nice. Familiar, but not the same

Edit: Well, last minute redesign. After some more thought I am now going to go to the bulkhead. I'm doing something like M3 Muscle is doing, with the rear subframe tie in connecting the rear to the center of the cage structure.

I'll also be relocating the main hoop mount to the small area next to the rear seat (in front of rtab bucket). This will raise up some tube/nodes, like the main hoop "X", door bars, and supports to the rear, but its ok, as long as they all intersect, it could actually be stronger than before.

I'm also going to use 1.5x.120 for the main, and 1.5x.065 (assuming i can get it) for the support tubes. If its not available., 083 is more commonly available.

I have to figure out the rear subframe tie in exactly (might go with what m3muscle has, not sure tho), and I also have to figure out what to do with the top of the bulkhead "shelf." My idea is to make a thin (.049ish) sheet with bead rolls go right across the top. Since it has so many holes, and is structural, and my fuel cell is under it (required "firewall" between driver) I need to close it in anyways, and this can help keep that bulkhead rigid.

[leonsutanta]

nice project!!
can't wait to see it done keep up the good work, mate

[Steve J.]

Thanks, its moving along nicely now.

I got the 2" and 1" tubing in today, as well as the .12x plate for all the reinforcements. I cut out the bulkhead reinforcement plates, and I'll bend them and weld them in tomorrow. I welded in the rear shock tower reinforcement plates as well.

I also got the rear subframe "posts" welded in (and capped), so tomorrow i'll sheet metal those, and I'm hoping by the end of the week I can have the rear shock tower reinforcement structure finished.

I have the carbon roof coming in this week (THANKS EVOSPORT ), and I'm hoping to get a template of the main hoop this weekend. Get that bent up, then make the Apillar templates, get those 3 pieces bent, and start caging this bitch!

Pictures tomorrow...i'm spent!

[Steve J.]

Another night another update

I took 15minutes and made a test rig for a brake to put in my 30ton shop press..came out great! I'm going to build a beefy one now. This little dinky one bent 1/8" like it was paper, and a nice sharp bend! Its perfect for all these chassis support plates, brackets, etc.




I cut and welded in the bulkhead cage reinforcements, as well as the 2" tubes for the rear subframe bracing. Once i get the trailing arm bucket posts in (tomorrow hopefully) I'll string up the cage design and post it. I also cut and bent up the main hoop base plates (ran into some more contamination problems). I felt this was a much stronger place than the floor. Plus, right underneath it is the factory subframe brace. Should work out well, as it has other benefits as well.






Carbon roof also came in from Evosport, its friggin awesome! Fits perfect.

[M3 Muscle]

Here is a quick design I might do...it looks worse than it is, as the tubing between the rear shock towers are 1", and the rest will "look" simpler. The green tubes come from the Bpillar harness bar node. The bulkhead has 3 tubes on each side; Down tube, "X," and horizontal bar to the Bpillar harness bar node. All these are Non required tubes, so they are thin wall...and the tubes going to the bulkhead are 1.5x.120.

Looks kinda familiar. I thought that you did not like the X between the subframe braces...?

[Steve J.]

Well, the "X" actually allows me to get loads from almost exactly 4 opposite directions, so it might work out ok. It is a huge trapezoid, which is a no-no, but because they are posts coming out of the chassis, I think its ok, they are still supported well.

There are only so many ways you can string together these points, they are bound to look similar either way, you know?

I think its a great design though, and it should create a super rigid rear end.

I was seriously thinking about creating a super node right in the middle there, and just having a ton of tubs come in from all over, but its not worth the hassle and frustration of grinding all those tubes.

[sandford]

so are your rear damper mounts going to be tied into the bulk head point at all? you are running rear coilovers right? tieing your rear mounts together and to the subframe will give enough strength? i dont know how much force goes up through there so im just wondering for my own car.

[Steve J.]

so are your rear damper mounts going to be tied into the bulk head point at all? you are running rear coilovers right? tieing your rear mounts together and to the subframe will give enough strength? i dont know how much force goes up through there so im just wondering for my own car.

Yes, full rear coilover. The shock tower is stitch/seam welded, with a thick reinforcement plate on the top/side where the shock mounts to. The tubes should be able to handle this vertical load no problem. I can also stick a tube from behind the bulkead to the top of the shock tower, but I think it should be fine.

[saem3]

Dang, I remember a time when I had the energy to stay up and work into the wee hours after the day job.. sigh. Now I'm lucky to make to 10 pm .
You're making up for some lost time, great progress, thanks for sharing with us.
Steve E.

[sandford]

Yes, full rear coilover. The shock tower is stitch/seam welded, with a thick reinforcement plate on the top/side where the shock mounts to. The tubes should be able to handle this vertical load no problem. I can also stick a tube from behind the bulkead to the top of the shock tower, but I think it should be fine.

yeah thats what i was trying to say. im sitting at school just waiting to finish and get back to my car thats sitting in pieces in my garage. this thread is really helping me out. thanks.

[Steve J.]

Dang, I remember a time when I had the energy to stay up and work into the wee hours after the day job.. sigh. Now I'm lucky to make to 10 pm .
You're making up for some lost time, great progress, thanks for sharing with us.
Steve E.

Haha, yep, definitely have to make up for just over a year lost! Its cruising now though, I'm hoping by the end of march I'll have it caged and painted ready for assembly and wiring. Engine should be here shortly. I actually just had two hockey games back to back, and i'm going to go crank away for a couple hours on the RTAB bucket supports.

yeah thats what i was trying to say. im sitting at school just waiting to finish and get back to my car thats sitting in pieces in my garage. this thread is really helping me out. thanks.

The load is still going perpendicular to that support, even if you put a tube on top its still going to have a moment around it...it would definitely help, but I think it should be fine. ~2500# car with aero, no rear swaybar, it won't be producing enough load there to torque around the several tubes supporting it on the inside. e46 is pretty beefy back there surprisingly. If you wanted to really go extra overboard, i would run a tube down to the rear frame rail as well, so it is pulling it in tension.

Ok into the garage I go

[Steve J.]

I'm hoping to get all the reinforcement plates/mounts and rear shock tower tubing done by the end of this weekend. I'm also going to blockoff the bulkhead shelf and seatback (b/c of fuel cell).

I'm waiting for a quote on the tubing order, hopefully I can get that in next week, get the main hoop and apillars bent and get cracking on the cage.

I started using the "pulse weld" technique with the mig, and it works great. I think everyone was spot on with the contaminant coming through from the other side. This Pulse technique allows the weld to penetrate but not to heat up the metal in front of it too much and suck in crap. I should have tried this technique earlier, would have helped a lot with stitch welding.

I'm probably going to modify the rear shock tower design a bit, basically just add the tube on top of the shock mount to tie tubes into. This reduces the moment arm and torque around the support to virtually zero. Should help handle the loads, instead of trying to bend around the inner support that I was going to do before. I just have to make sure I can reach everywhere to weld the tubes to it.

[Steve J.]

Tonight I finished up the RTAB bucket pickup points, as well as the rear subframe pickups. I think I can finish the rear tube structure this weekend (can be done seperate from the rest of the cage basically). The 2" tube is going on top of the shock tower, and will get tied to the rear and front subframe mount on its side, as well as the opposite side rear subframe mount (refer to illustration above).








Spider man attacked my car with green lines! Looks 10x worse than what it really is...its actually very simple beyond what the Motorsport rear setup looks like. The motorsport chassis (non gtr) does not tie into the 6 points pictures here (4 subframe, 2 rtab bucket), and all my tubing for that support structure is under 20lbs, and maybe another 4lbs for the mounts. So under 25lbs of additional cage and it adds tremendous support for the rear suspension.

[sprbxr]

Hey Steve J

Where did you get your swaged tubes for your control arms? I called Woodward and they are having a material shortage on many sizes.

[onasled]

Hey Steve J

Where did you get your swaged tubes for your control arms? I called Woodward and they are having a material shortage on many sizes.

Steve may very well be able to take care of you, but if not, get me the size you need and I'll see if my local shop has them. They usually stock a bunch. Let me know asap as I may be going there tomorrow. If not then next week

[Jonathan@BimmerWorld]

Haha, yep, definitely have to make up for just over a year lost! Its cruising now though, I'm hoping by the end of march I'll have it caged and painted ready for assembly and wiring. Engine should be here shortly.

Looking good, and a lot of progress lately! When do you anticipate to have it moving under its own power?

[Steve J.]

Hey Steve J

Where did you get your swaged tubes for your control arms? I called Woodward and they are having a material shortage on many sizes.

I got them direct from woodward...I actually have a full set of spares, as they are pretty cheap. You might try giving VAC a call, he might have some in stock he can sell you. Otherwise, check some nascar shops, its a pretty standardized part.

Looking good, and a lot of progress lately! When do you anticipate to have it moving under its own power?

Yea...I really only need one more tool/machine before I can safely say I am prepared to build the rest of the car, and thats the lathe...hopefully getting it in 4-6 weeks, when I'll need it. I won't need it until after i'm done with the chassis/cage fab.

Tonight I worked on the rear shock tower tubing structure. I am almost done, just one more tube to fit in and then its pretty much idle until my tubing order comes in next week. I'm going to try and make a mockup of the mainhoop/apillars next week out of scrap tubing i will find locally, and then bend up everything when tubing comes in.

I also got the Apillar base plates welded in, which means I'm done welding direct to the chassis! I'm definitely getting better with the Mig welder. I had to re-learn techniques, and get out of the tig mentality. I'll be mig welding the cage tubing, and tig welding the gussets in...and there are a lot of gussets (hint hint).

If the motor goes together easily (its basically bolting everything up and fabbing some exhaust and intake pieces, although some are already made at Evosport), I'm hoping June/July it could be on the track. I am skipping carbon trunk/hood/doors for now, and the only last piece I'm not 100% on is the Bosch Motorsport ABS system...but i'm working on that Otherwise all I need are turbo components (off the shelf parts), Evosport/AEM race box, AIMsports data, wiring...and everything else I have on the shelf in the garage waiting to be assembled.

[Steve J.]

Made some good progress last night, and finished up this morning. got the rear shock tubes done, as well as the apillar base plates. I'm stuck waiting for tubing now. More updates next week as tubing comes in, main hoop/apillar get bent and I start the bulk of the cage. After that its a lot of sheet metal work for gussets...and I need two large radius bends made

I also made a larger press brake, came in very handy already, bent 1/8" precisely with ease.

Gallery at:http://jaffster.com/E46M3/3-1-08/

(See its not that jungle gym-ish at all)