Race car build

[e21-Mark]

I want to actually put together a competitive sprint car and have spent most of today going through my parts to see what I can come up with?

I have a February 1976 bodyshell as a starting point and I am going to strip it right back by removing all the glass, trim, lights etc. I have a set of poly windows and will use fibreglass bonnet and bootlid. I wont be running lights etc either.

How far can I go before I compromise structural rigidity? Should I seam or stitch weld the shell? Where else can I remove weight other than obvious stuff like sound deadening?

I am going to have a bespoke roll cage made rather than opt for an off the shelf item. I realise it will have to meet MSA standards but should I extend it to suspension pick-up points?

Suspension will be GAZ and brakes will be 323 items with Wilwoods up front. I'm pretty sure that will be enough as I have had no problems with fade this year and they've been excellent. If Wilwoods fit ok, I may stick to 13'' rims? I guess it depends what power I end up running?

I already have another M30/3.5 sat at the workshop and could pick up m10 5 speed boxes cheaply enough. Obviously I would run a sintered paddle clutch and LSD.

I'm just weighing up options at the moment but would like to get as much input as I can. I've got about 3 months to put something together before the first 2012 sprint event.

[Jason_323i]

Hi Mark

E21's are quite flexible I cracked the B post on mine just by doing track days and running LEDA coil-overs

You want to seem weld between front and rear towers, and run the cage to the suspension mounts, here's a few pics of mine.






Weight loss, cut off every bracket in the car, also a lot of the front sheet metal can come away


Also the doors can be cut down a lot, pedal box is lighter than servo, smaller fuel tank, cut down wiring loom etc.

Might also want to throw the e12 rear axle and front hubs on there

Jason

[TopCat]

Dear Mark
My advice for what it is worth:

I would be inclined to get hold of the regs for a period - pre 76 saloon championship and head for them long term

What i mean is that I am sure that you will soon move on from Sprints and hillclimbs and will look for the best series eligible for your car
My old lot Classic & Sportscar run a series called Deutcsh Mark for eg
http://www.classicsportscarclub.co.uk/F ... ATIONS.pdf

Now these guys run post 1990 in Deutcsh Mark- but there are other series: Swinging sixties, or the Future classics- or Tin Tops
BRSCC run pre 74 saloons- HSCC run a lot lot of 70 classics
If you are after BMWs then there is the Khumo series- but I suspect that you are looking to pitch one of the first E21s against other cars from the early 70s- not get trampled by a whole lot of hot modern BMWs?
So what I would suggest is that you don't modify your car way beyond eligibility for these sort of classic series which you may enter yourself - or increase your car's value on resale later.

HSCC and CS&CC regs require Bolted in cage NOT welded- and so do FIA. The FIA regs are moving forward in time. Doesn't mean that you can't bolt rollcage to all kinds of things by gearbox x member- forward to meet a bolt in from front suspension, same from rear suspension pickups, and certainly the A pillars.
Secondly I would recommend an off the peg set up- say from Safety Devices with the additions as above.
Do keep working lights- handy for trials our evening Sprint and keeping an MOT- which some Regs require I see.
Thing is to find a crowd of similarly minded kindred spirits racing same sort of cars (with different characteristics)?
Also be mindful of engine cut-off points are they 2 litre or 2.5 etc?
You probably can get rid of a lot of stuff high up and at the front, roof strengtheners etc

Hope this doesn't come across as a lecture- not meant!

[e21-Mark]

Not taken as a lecture at all. I value the advice you guys give me as it's been a pretty steep learning curve.

Although the occasional circuit race is part of the plan, I really do want to concentrate on sprint and hillclimb events. I just don't have the budget to go racing or the skills either if I'm honest. Now that I've had a learning season I just want to be in something more competitive next year.

2 things I've decided are

1. I think I've got just the excuse I needed to get a plasma cutter!

and

2. I'm thinking I could use a blue car, Jason has told me about, next season and get the e21 shell ready to move everything across this time next year.

[TopCat]

http://www.andypriaulx.com/
starting in Hillclimbs (in another British Crown Dependency) didn't do Andy Priaulx any harm!
Perhaps you will follow his footsteps to similar glory?
Also be aware the TIME building a car takes if you do not have an unlimited budget!

[kevralpina]

mark double check the regs for the sprint series you want to do as i have rebuilt mine to do roadgoing class which means bolt in cage not to ott and retaining a rear seat capable of taking an adult ,and when i last sprinted i was in the same class as scoobys and mitsy evos etc but for some reason the old girls abs,4 wheel drive and traction control were absent that season so check everything including tyres !

[e21-Mark]

I've got pretty much everything I need now except a 323 subframe and front struts to convert at Gaz.

Early non-sunroof shell (thanks to retro-BMW)
Fibreglass bonnet, bootlid & wings plus extended arches
Poly window kit
Wilwood 4 pots
Gaz Golds
m20/2.5 & 5 speed

The plan is to just get the car as light as possible. I did consider an M52 or something but I need to do this on a budget and 2.5's are cheap and simple to fit. I want the reliability of my M42 powered car.

Anyway, once the new year is here I'll start getting the cage in and prepping the shell for some paint.

[rob0r]

I've got pretty much everything I need now except a 323 subframe and front struts to convert at Gaz.

I've probably got both of those... PM/text/call as necessary, if needed!

[e21-Mark]

Will be in touch early Jan - thanks Rob.

Got some nice flared arches coming from the US and got these cheap to fill them. Also picked up a pair of second-hand Wilwoods.

[e21-Mark]

This is the inspiration for the next race car build. Anyone know the paint colour code please? Is it Golf yellow? Looks a bit more green on here.

[e21-Mark]

A bit more progress today. Thanks to Jim, the new build will have an m10 running s14 injection. Seeing as the shell was originally a 4 pot 320 it'll be nice to have it back in period. It also means it will remain eligible for historic races.





The Wilwoods arrived in the post too.

[Jason_323i]

Good choice of m10 but not many series will let you run the efi

Any idea what is going in the slug

Jason

[e21-Mark]

M52

I'm doing SEMSEC Jason and they won't mind unless I start winning my class which quite frankly, is pretty unlikely.

[drjim]

Cat out of bag and we've not even started.

Nas is sorting me an M52 with M50 inlet, chipped, proper exhaust etc. Should be good fun in the slug.

[e21-Mark]

Sorry Jim, didn't think. I've been a bit ''distracted'' this past day or so.