BMW Compact Rally Car Build

[DaveKern]

Day 2 with the macropoxy went a bit better. On the recommendation of the paint store, I didn't thin out the mixture, so I tried a different painting technique.

I laid paint on about the same as before, but then went back and dabbed the brush all over to give it a uniform texture. Looks like white rhinoliner.



Dave

[J!m]

Can it be thinned with Acetone and sprayed?

Does it need a primer over it if you wanted to paint it afterward?

Does it taste good?

[DaveKern]

Originally Posted by J!m

Can it be thinned with Acetone and sprayed?

Does it need a primer over it if you wanted to paint it afterward?

Does it taste good?

The guy at the paint store recommended not trying to thin this stuff out. No spray gun at my house, so brush method will have to do. This is all the underside too, so if it doesn't come out show quality, I can just go spin it around in the dirt and cover it up. LOL

Dave

[J!m]

I prefer to spray everyting; however in the cases where I can't, I have found the foam rollers to do a great job...

[DaveKern]

Kevlar work begins!



Applied two layers to the passenger side tonight. Tried to be stingy with the resin, and ended up using ~30-36 fl. oz. I think we can do better on the next side, as when done just right it looks dry. From the pic, you can see there's a bit of a shine.

Dave

[mohaughn]

A lot of the retailers that sell flywheels but don't make them themselves, get them from JB Racing here in Florida.

You can call them up and they will send you a matched/balanced set. Most of the race teams I know in the area use them exclusively.

http://www.jbracing.com/index.php

[Jean H.318TI]

sorry for the stupid question but whats the point of the kevlar?

[DaveKern]

Did some more work and just about finished off the passenger side floorpan & rocker. When cutting the large sheets yesterday we ended up with a bit too much, and once the kevlar's wet, there's no going back. So, I had to let those pieces dry, and I cut them off this evening. Then a quick sand on the parts we left, and I added a couple strips to the rocker panel.



I ground off the 'stone guard' to get back down to the bare metal, primed, and then laid down the 4" kevlar strip. Should look pretty nice once it dries, and gives a bit of a "hey, whats on the bottom of that car look?" LOL

Dave

[DaveKern]

Originally Posted by Jean H.318TI

sorry for the stupid question but whats the point of the kevlar?

No stupid questions - ask away!

Several reasons for doing it in my eyes:

1) To help prevent foreign objects from penetrating the floor (and occupants):

http://www.youtube.com/watch?v=wqQhQSbe6fw

Some teams will have carbon fiber footwells/false floorboards to add another layer of protection...but those are spendy, so I figure if I'm going to do composite work, I might as well have it protect the shell some as well.

2) This is probably more of an AWD or FWD phenomon, but with rockspray coming off the wheels and contacting the floorpan, you see the metal start to get very thin. I've heard reports of cars with no floorpan protection being so weak after a season of rallying that you can take a screwdriver and just poke it through the floorboards.

3) The other "cheaper" option for floor protection is to take sheets of HPDE and attach them to the car. The problem with these is A) it can rip off, B) it can trap lots of crap between the sheet & floorpan and grind thru the paint leading to rust. Big sheets of HPDE can be somewhat costly (~$100 to cover the bottom of the car), so by the time you've replaced those 2-3 times, the kevlar becomes the cheaper option. I'm not sure how HDPE stacks up on the weight side of things, but on my Evo, I've got a 3/16" thick sheet protecting the gas tank, and the stuff isn't all that light.

On my Evo, I've run 3 seasons of hillclimbs and the kevlar is still 95% on there. It has started to separate from the chassis slightly, and 2 spots have worn thru (3 layers), where there's a 90 degree edge that faces forward. Thankfully the BMW doesn't have any of these 90 degree spots, and the front wheels aren't driven, so I expect rock spray damage to be much lower on a RWD car.

Some of the higher spec teams will actually buy vacuum bagged kevlar formed to the floorpan (available for popular rally cars like the STi & Evo), and you just bolt them on. The nice thing about these setups is that if you're at an event where you don't need them, its easy to remove to get the weight of the car down some. But, those setups are expensive $800+ IIRC, and not available for the BMW stateside. You also still have the potential problem of them ripping off.

To help combat the kevlar separating/lifting off the BMW, I think I'm going to use a few button head rivets to ensure that it can't peel off. All told, I think I'll have less than $300 into this mod, not including my time. FWIW, I spent about 2 hours last night getting the first side done and another 2 hours tonight finishing off the passenger side. I stayed with the kevlar as the resin hardened, as last night, some of the corners lifted as the resin cured.

Dave

[Jean H.318TI]

okay thanks for the info and yeah safety is always a good thing

[cali-ti]

Looks like a really awesome project. I'd love to stop by and see it some time if that would be possible.

Are you selling any of the parts you will no longer need to help fund the project? If you get the body kit, I would be interested in the hood and hatch (my ti spent 9 years in the dregs of the midwest so it's not exactly rust free). I could also use the original cat-back exhaust if it's in decent shape for Sean's ti.

[DaveKern]

Originally Posted by cali-ti

Looks like a really awesome project. I'd love to stop by and see it some time if that would be possible.

Are you selling any of the parts you will no longer need to help fund the project? If you get the body kit, I would be interested in the hood and hatch (my ti spent 9 years in the dregs of the midwest so it's not exactly rust free). I could also use the original cat-back exhaust if it's in decent shape for Sean's ti.

Yep, selling stuff that's not going back on. At the moment its not looking like I will be able to spring for the Euro compact bodywork...its a challenge just to figure out how to pay for the "must have's," never mind the "would likes."

You're welcome to swing by sometime to check it out, and you can rummage thru the parts stash as well. I think I tossed out the exhaust unfortunately. I'll probably be working on it some over this weekend if you're around.

Dave

[cali-ti]

hopefully I can escape for a bit this weekend to get down there. If so, I'll bring the camera

What kind of hours are you looking at this weekend for working on it?

[DaveKern]

Originally Posted by cali-ti

hopefully I can escape for a bit this weekend to get down there. If so, I'll bring the camera

What kind of hours are you looking at this weekend for working on it?

Sounds good! Saturday morning would probably be the safest bet...I have an idea to incorporate some subaru into the build, so going to do some measuring & cutting at a buddies place later in the day.

Dave

[DaveKern]

Wondering if some of the thread readers here might be able to help me out. I'm looking for a couple of pictures of the bottom of a TI? Hoping someone might have shots of the bottom of thier car from sometime when it might've been up on a lift?

Not really looking for anything in particular...just trying to remember what everything looks like.

Thanks!

Dave