Building a race car

[JWatkins]

What do people suggest for a good basis for a race E30? I have built race cars in the past but never a BMW let alone an E30.

The M3 E30 is obvious but as a base car is a lot of money it may be cost prohibitive, therefore I am thinking of a 318is.... what do people think?

My criteria is as follows:
Must have the weight distribution and balance that comes with a 4-cylinder engine
Must have an LSD
Must have roll bars front and rear
Must have a decent aero package with front spoiler for ducting air

Questions...
Would you start with a 325 or 318is?
What sort of power could be achieved from a full race 318is engine?
Who builds decent, relaible race engines?
How much could an old M3 S14 engine be found for? (who builds them?)
What do people suggest for gearbox / diffs? )Including ratios).

Lots of questions, and i'm just exploring options before I make a start on this. The car will eventually be used for sprint races of 30 mins per race or so, (not to be confused with sprinting) not as an endurance race car.

Thanks folks.

Jas.

[JungleGus]

great choice, the 4 cylinders handle hands down much better, only downside being down on power

would def start with the iS...maybe move the battery to the boot. the 325's can be made quick but wont feel as balanced. the only problem is being down on power (comparitively). Metric Mechanic in the states do a 2L stroker M42 that makes around 200hp..that engine would be awesome. however they really are not cheap. i imagine megasquirting (to get rid of the AFM) along with some other bits n pieces would make the m42 around 150hp, which would be good for relatively cheap fun

a shortish diff (4,45 or so) with the m42 box would work well i imagine

on the other hand, the m20 2.5 is more powerful, and can get more power from them. engine is bulletproof. but IMO needs more suspension work to handle well and even then its so so compared to the same worked 4 cylinder

hope this helps and doesnt confuse the issue!

[CraigG]

on the other hand, the m20 2.5 is more powerful, and can get more power from them. engine is bulletproof.

the only thing the 2.5 has going for it in terms of getting more power is the displacement. everything else it is old hat.

4v per cyl > 2v per cyl

ive read about hartge doing a 2.3/2.5 stroker kit for the M42. and you also have the S42 engines used in some race series in the states, iirc they are putting out upwards of 300bhp in NA form.

id go for an IS to start with

[keggy]

m42's respond well to bigger throttle body, remap, 325 flywheel so i hear

[e21Jason]

Hi

You rigth about the m3 being a good basis. It depends on the race series regs as all the m3 parts can be swapped into a non m3 shell. or z3 parts can beused to give a 5 stud setup with more choice of alloys/brake setups.

I think you have answered your own question as if you want the balance of a 4cly use the IS and check out m42club.com for info. also LSD and anti roll bars are possible on all e30's

For a decent areo package check out the bmwrdc.co.uk as most e30 run with the m3 type front bumper/splitter and rear wing.

The standard e30 came with a load of ratios in a small case and medium case diffs, the is came with a small case diff, but a medium case is a striaght swap and there are more ratios and after market lsd's for the medium case diff.

The standard gearbox has an over drive fifth the e36 box has fifth as 1.1 and the m3 3.2 six speed fits with a over drive on sixth.

also if you are in the UK bmwtrackdays.com is also a good source of info.

Jason

[northloop]

What race series are we talking about here?

[Brian28]

What race series are we talking about here?

Yup. Chose the series first, then build the car for the series. Either car could potentially be better, it depends which class it races in and what other cars are eligible for that class. You'd also need to check the regs to see which mods are legal, as some of the best ones aren't unless you are racing in a fully modded series. (Where you will very likely be racing against more modern cars with big budgets and better options available to them )

I've just re-read your first post. You're asking for a 4 pot for better weight distribution, so that rules out the 325 anyhow.

[JWatkins]

The series is the BARC tin tops series. It's a sort of home for anything really with ex-DTM cars mixing it with Mini's!

The regs are written very loosely so you can do almost anything you want as long as it doesn't have a bike engine or sequential gearbox. I would want to keep a period E30 engine in the shell though so it's a case of deciding which one to go for. The class structure is class D = 1600cc to 2000cc 8-valve engines; Class C = 1600cc to 2000cc multivalve engines; Class B = Greater than 2000cc; Class A = ex-Touring cars, etc.

I have no intention of winning the series, I just want a solid quick car so either class D or C would suit me.

Thanks for the help guys, keep the suggestions comming!

Jason.

[maxfield]

You thought abbout seam welding the shell.

Building S14's is very expensive though. For a race S14 your talking over 10k at least.

[JimmyC]

The series is the BARC tin tops series. It's a sort of home for anything really with ex-DTM cars mixing it with Mini's!

The regs are written very loosely so you can do almost anything you want as long as it doesn't have a bike engine or sequential gearbox. I would want to keep a period E30 engine in the shell though so it's a case of deciding which one to go for. The class structure is class D = 1600cc to 2000cc 8-valve engines; Class C = 1600cc to 2000cc multivalve engines; Class B = Greater than 2000cc; Class A = ex-Touring cars, etc.

I have no intention of winning the series, I just want a solid quick car so either class D or C would suit me.

Thanks for the help guys, keep the suggestions comming!

Jason.

Is that Rod Birleys Tin Tops at Lydden??

If so some very quick cars in it, even the m3's struggle

An M3 race engine will cost you ALOT circ £10k to get built and be competitive

[e21Jason]

Hi

The regs are very close to the classic modifed saloon regs, as there is so much freedom it makes so much more cost. I would not run an e30 but buy a better handling donor car ie an e36 or 944 to run in a lower class, as with less power you want to spend your money on handling, but you are going to be at the back of the pack.

If you want a race car try the running a e30 318is in the pre 93 classic group 1 and run in the Khumo BMW series also

http://www.classictouringcars.com/pages ... sVer01.pdf

Jason

[JWatkins]

[/quote]

Is that Rod Birleys Tin Tops at Lydden??

If so some very quick cars in it, even the m3's struggle

An M3 race engine will cost you ALOT circ £10k to get built and be competitive[/quote]

Yes, that's the series. I won the championship in 2005, (beat Rod) in my little XR2 which packs a heavy punch. It's time to move on to an E30 now though I think so i'm selling the Fiesta.

Jason

[JimmyC]

Jason (e21jason)- do you run with CTCRC? yellow car??

Jason (watkins)- pop along to snett next weekend if you fancy a butchers at the Pre 93 races, got some spare tickets left over ;)

[JWatkins]

Jimmy, I'm not racing this year but the car is red with a white roof and carries sponsorship stickers from Pi Research.

Thanks for the snett offer, I may take you up on that!

Jason.

[DJ-325I]

If i remember rightly there was a good article in total bmw about a 318is tht competes in the vln series. it had pretty much standard engine, uprated sus and a few other bits. ill c if i can fish out the mag and scan it in and send it u via email?