From digest.v7.n1145 Mon Feb 16 11:47:46 1998
From: Bob Stommel <rstommel_at_iquest.net>
Date: Mon, 16 Feb 1998 09:06:41
Subject: <E30 M3> RE: How should I modify my E30 - M3 ?
>I just bought an 88 M3 w/ 82K miles and it is completely stock. I plan to
take it to CCA Driving schools (as >I've done with past cars) and and
slowly turn it into a quasi club racer-type.
>I realize that the car is a wonderful piece of machinery that is already,
ready to go. But I am looking for a >project and I want to slowly
transform the car. So please no hate mail telling me to learn to it drive
first. >(has actually happend in the past!)
>So my question for the group is what would be the best order of attack and
what are the best bands and types >of components to use? Keeping in mind
that a slow steady investment is also desired. I will probably try to >by
parts used out of the Roundell.
>I was thinking something like: used chip ($100), exhaust, air box,
springs, struts, cam gear, throttle body >(?), brake ducts, brakes (it has
new stock ones). steering wheel, role bar, harnesses. etc.
>Thanks for your help and please e-mail me anything that you might have for
sale too. I am in New York City.
I've owned an 88 M3 for about 5 years. Started out taking it to driver
schools and now it's a CCA club racer.
Here are my suggestions:
- Check for cracks near the bolts holding the engine mounts to the front
subframe. Some of the heavily tracked M3's are showing cracks there. You
can see the cracks from the underside of the subframe at the bolt
locations. The cracks are in the subframe metal. Shake the engine
vigorously and if you hear a squeaking sound, the front subframe is
probably cracked. The crack can be welded. If there are no cracks yet,
install a washer between the motor mount lower nut and the subframe to help
distribute the forces on the subframe near the nut.
- Common modifications are a performance chip, Euro exhaust cam gear, and
Euro (Motorsport) airbox. The Motorsport airbox was an OEM part on the
1990 an 1991 models. Jim Conforti's chip is the best. You can't replace
the throttle bodies without doing the entire throttle intake system because
there are four individual throttle plates as part of the housing (one for
- If you are going to drive the car on the street, stick with the stock
suspension. Most of the aftermarket performance suspensions are too stiff
for the street. The OEM suspension is fine for both street and driver
schools (but adding Bilstein Sport shocks really improves track
performance). There are BMW factory "camber correcting upper strut
bearings" that will add .5 degree of negative camber to the front
make a tremendous improvement in the way the car corners on the track.
- If you decide to install a stiffer suspension, the most common
combination for driver school use is Eibach Pro-Kit springs, Bilstein Sport
shocks, and Suspension Techniques adjustable swaybars. You can get stiffer
systems, all the way up to full coilover kits, for these cars. Turner
Motorsport is a good source for E30 M3 suspension parts.
- If you take the car to driver schools frequently, you should duct the
front brakes by replacing the foglights with brake ducts. Without brake
ducts, the rotors tend to warp on the track. For the rotors, get the OEM
ones from a dealer. The OEM rotors are now the same as the Evolution
rotors. Be careful with mail order for rotors -- there's a lot of junk out
there that will warp on the track. E-mail me if you want a list of
mailorder vendors who sell the OEM rotors.
- Plan to buy a new water pump every few years. For some reason, the E30
M3 engine wears them out quickly. The M3 does not have the coolant leak
problem of the other E30 models, but some of the M3's experience coolant
loss from a worn coolant recovery tank cap. Buy a new cap from the dealer.
The new ones have been "updated." There was also a recall for a cooling
system update which consists of a special valve that was installed in one
the of the heater hoses. You should be able to see the valve in the top
heater hose that runs from the cylinder head to the firewall.
- The OEM steel lower control arms tend to crack on high-mileage or
heavily tracked cars. The lighter alloy control arms can be purchased
mail-order for about $179 each (they're close to $400 each from a BMW
- There is a lot of disagreement on the best brake pads to use. The OEM
BMW pads (Energit, not Jurid) seem to work fine for street and driver
schools. I would recommend using the Energit OEM pads unless you are
racing. If you find the Energit pads fading on the track, switch to
Performance Friction 90-compound pads for driver schools and racing.
- The Bentley manual for the E30 covers most of the same body and
electrical as is on the M3, but the engine and Motronics on the M3 are
different. The factory service manual (on microfiche only now) is the only
thing available on the engine.
- Are the swaybars still stock? If there are stiffer aftermarket
swaybars on the car, you should take a close look at the mounting
locations. The mounting tabs on the front and rear tend to crack with
stiffer bars. The tabs need to be reinforced with extra welded metal if
stiffer bars are installed.
- The next time you take the car to your mechanic, have him remove the
valve cover and look carefully for wear in the timing chain, cam sprockets
and chain tensioner parts. These parts are wearing out on the higher
mileage cars and cause a rattling sound when the engine is cold.
- The stock steering wheel diameter is about 370 mm. Momo makes some
nice aftermarket steering wheels that fit well on the E30 M3. I have a 350
mm one, which just barely covers up the top edge of the speedometer.
- TC Kline makes a beautiful custom-fit rollbar for the E30 M3. I have
one in my car. Call me if you want more details.
- For harnesses, the Schroth 4-point is fine for driver schools. For
CCA club racing, you'll need a 5-point or 6-point harness. I have a black
Schroth 4-point harness you can buy -- it was only used for one driver
school. Let me know if you're interested in it.
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