BMW Compact Rally Car Build

[Air Research]

Thanks for the update Dave, now i see what you mean about the shock towers being custom!

What do you mean by 10 degress of layback?

I need a Ti shell bad !!! any donations ???

[pdxmotorhead]

From the side the main hoop may lay(Lean) back no more than 10 degrees, Its to prevent buckling.

Dave

[DaveKern]

Originally Posted by pdxmotorhead

From the side the main hoop may lay(Lean) back no more than 10 degrees, Its to prevent buckling.

Spot on! I think the frame by the back end of the door tilts back at about 6-7 degrees, so at 10 degrees, the roll hoop will tilt slightly more backwards.

The reason we were doing the test fit is to see if I could get my seat far enough back to run a floor mounted pedal set. Wilwood makes some pretty inexpensive parts that will allow for running dual master cyl. and a balance bar assembly. The other option is to order the pedal kit from Harry Hockly Motorsports which bolts to the factory spot on the firewall. The added benefit of this is it'll put the weight of the pedals about 2' lower on the car and allow my fat ass to get as close to the rear axles as possible.

I'm not convinced there's enough room for me to pull this off as we didn't have a seat or brackets on hand to get me as low as I will be. We're going to proceed with the hoop layed back at 10 degrees, and when I go back in a few weeks, I'll make sure we've got a seat available to see if its going to work.

Dave

[Air Research]

Harry Hockly also has this for sale: http://www.hh-ms.com/bmw_full_lhd.htm

a steal for 90,000 $.........

[DaveKern]

Originally Posted by Air Research

Harry Hockly also has this for sale: http://www.hh-ms.com/bmw_full_lhd.htm

a steal for 90,000 $.........

If anybody can give me $85,000 (as in give, not lend), I'll go buy it.

Dave

[DaveKern]

Alright, finally things are going back together!

First shot is of the rear part of the main hoop from the driver's side.



Second shot is the same, but from the passenger side.



Last shot is from the rear hatch opening. You can see some wood we placed on the floor to try and get a feel for seat position.



I'll be heading back to the shop for more updates next weekend.

Dave

[Jean H.318TI]

is the roll cage TI specific or just custom build?

[DaveKern]

Originally Posted by Jean H.318TI

is the roll cage TI specific or just custom build?

I opted for a one-off build rather than use one of the kits from Europe. My main driver for the decision was the fact that the European cages were homologated back in the mid-90s, and there have been plenty of design updates that make rally cages much much safer.

My cage will be heavier as a result, but the hope is that if/when it gets crashed, we'll be able to walk away safely. Should anyone be interested, after the build is completed, I can try to get pricing info.

Dave

[Jean H.318TI]

i would love to get a custom fitted cage for my car, i almost order one from UK but it was too expensive and it wasn't FIA approved, and i want a rally cage cuz is build with 2 people to be in the car not like the others, the passenger side is a litle different

[DaveKern]

Originally Posted by Jean H.318TI

i would love to get a custom fitted cage for my car, i almost order one from UK but it was too expensive and it wasn't FIA approved, and i want a rally cage cuz is build with 2 people to be in the car not like the others, the passenger side is a litle different

The only one in Europe that's FIA approved is the one from Custom Cages. There are several other manufacturers that have MSA approved cages which may or may not work. For my hard earned $, I didn't want to mess with a 'maybe.'

With the exchange rate fluctuation, stuff from the UK is actually pretty reasonable these days, but you're still looking at probably $4500 to buy the cage and have it professionally welded in. I hope to come in well under that for a DOM cage built to 2010 FIA spec.

Dave

[Jean H.318TI]

well im prolly just gonna buy one of the cages from bimmerworld, i know they r not for rally but they would work fine on my street car and DD, plus i dont even go to the track, i just want it for more safety, u know stupid drivers out there (including me) lol

[DaveKern]

Originally Posted by Jean H.318TI

well im prolly just gonna buy one of the cages from bimmerworld, i know they r not for rally but they would work fine on my street car and DD, plus i dont even go to the track, i just want it for more safety, u know stupid drivers out there (including me) lol

Hate to be a downer, but a roll cage doesn't belong in a car that gets DD. If there's even the remotest possibility that your head could come into contact with a bar in a collision, you could be brain-dead instantly...even if the cage ends up saving your life.

As much as it sucks...caged cars should really only be driven when you're helmeted and harnessed in. My Evo has head restraint seats which mean I'd have no way of hitting a bar...an I'm still not wild about driving it without a helmet on.

Dave

[Jean H.318TI]

hmmmm so what can i do to increase the stiffness of the chasis and safety in case or roll over or crash or side impact

[Air Research]

Dave - Thanks for the updated cage pics...I need a free Ti so i can have some fun (anybody with one to scrap on the east coast?)...if DOM is this expensive, what do you think they charge for the custom thin tube cages you see a few teams with...I know Vermont Sports Car fabs them but..."if you have to ask"...

Jean - I have a 325i now and i've added front and rear strut tower bars from Weichers and the convertile front brace from the E36 convertible, not sure if this fit the Ti...If you really want more than that its time to start seam welding and adding roll cage type bars just away from your head...or race seat, helmet and a hans device and you can run that cage on the street...

If you entering into Pro drifting than check the SCCA rules for the Pro Cars and build your cage to those specs...rally cages are overkill for the track...

My advice in the end is to pop a Viagra and rev that baby to all the way in 3rd and have fun...dont crash...dont even think about crashing...if you focus on crashing what do you think will happen???

Stay slideways...Jon

[DaveKern]

Originally Posted by Jean H.318TI

hmmmm so what can i do to increase the stiffness of the chasis and safety in case or roll over or crash or side impact

I think Jon's spot on with his comments.

Keep in mind that when a car is crashed, it's designed to crumple in some areas and stay solid in others, when the occupant is using the safety items (seats, seat-belts, airbags, etc) as designed from the factory.

When you add a cage, you're changing the way it will deform in an accident, and potentially making some parts of the car safer, and some more dangerous. Rally cars use all these extra items in concert with eachother to increase the chances of surviving a catastrophic wreck (5-6pt harnesses, HANS devices, helmets, & FIA cage padding, and all the fireproof clothing items)...but use any one piece without the others, and you could create problems.

One example of this is people who track their DD with full face helmets and airbags. Sounds safe, right? I think I read somewhere that an airbag caught under the chin of a guy's helmet and he ended up with a neck injury. Or, add a harness bar and harnesses and get in a massive roll-over. Stock seatbelts allow your torso to move, harnesses hold your torso in place, so you're at increased risk of snapping your neck should the roof cave in.

Now back to happy fun thoughts!

Dave