Discussion: Breaking down each improvement that the E30 M3 has over the base E30

[2mAn]

This thread should really have started with a list of differences and then broken it down from there, there's just too much otherwise.

per your request good sir, I have changed this thread a bit and will update it. I really would like if we have a good list of things people can do.

My whole idea behind this thread was that I want to make my E30 more aerodynamic and less of a flying box so I look at what the factory has done as a starting point and it got me thinking about the other mods I have access to

[petrolhead]

This thread should really have started with a list of differences and then broken it down from there, there's just too much otherwise.

We can all go to http://bmwfans.info/parts-catalog/E30/, and browse the catalogue part by part, click "usage" on each item to see if the part is the same on regular E30 and M3 :).

[Northern]

This thread should really have started with a list of differences and then broken it down from there, there's just too much otherwise.

[petrolhead]

Things from M3 I've adopted to my E30..
Front caster with M3 eccentric bushes. Moves the wheel 2,5cm forward, adding a lot of caster angle and therefor dynamic camber.
Moving the front tyre forward affect the weight distribution also, by 1%ish.

Sway bar links in front similar to M3. Sway bar "response" remains about linear throughout range of wheel travel. Also when you have steering angle, correctly placed drop link points "pull" the sway bar to a preload, ie. it "works more" the more steering angle you have.
Modified wind screen opening for a bonded glass, adds shell stiffness.

4 pot engine for weight distribution 8)


Close ratio box, less rev drop when upshifting. Also the M3 trans mount is 4 point so it adds a bit of stiffess to the pro shaft tunnel.

Throttle bodies and plenum for even mixture and filling.

The washers that reside above E30 rear subframe bushes, can be pressed into a cup shape mimicking M3 type washers, thus they allow less rear beam vertical movement for better wheel angle and roll center control. I myself have shore 95A bushes but I've done that mod to other cars.

[bmnut2002]

Well, I think I kind of get what you are looking for.

-The flared fenders seems rather easy, it was in order to get more tire under the body without modification (i.e. rolling/pulling the fenders.) If you look at the DTM cars, they were A LOT lower than the road cars, so getting those big a$$ meats to tuck nicely under the car required significant flaring.

-The front windshield difference in mounting would have been due to what is considered more important for road car vs race car. In a race car, they were probably going through windshields often, so replacing them quickly took priority hence the bonding of them vs the rubber and lock strip regular E30's received.

-The front suspension changes in geometry is a whole 'nother subject that will probably go for days. Mainly speaking of the different swaybar end mounts.

Actually, the windshield on M3s was bonded in to add additional stiffness to the chassis.

[reelizmpro]

You are talking about a lot of little things that are seeminly trivial on a street car but add up on a race car. All redesigned by BMW Motorsport and sold through BMW. That's why the car is so special. It's purpose built to be modified using factory parts.

[Emre]

Front suspension geometry was different, improving on things like camber, roll stiffness, roll center, etc.

Larger hubs/bearings/brakes and 5-bolt wheels. Aluminum suspension arms.

FAlso the raked rear window was actually designed to clean up airflow over the rear wing and increase downforce.

It's not a big secret that BMW was "influenced" by the design of the 190E, which came out several years before the E30 M3. The thicker c-pillars, raked rear window, and raised trunk lid were all lifted from the 190E. Ditto for the front and rear valences/bumper-covers.

[TobyB]

I just like the DTM rear suspension mods... they're brilliant...

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[M-technik-3]

As mentioned all the upgrades were done so the factory could race with them installed on race series.

[djjerme]

Are you trying to decide what improvements to do on your own car - or is it purely hypothetical?

Because there is a lot of changes that happened to the DTM cars the longer they were raced. If you find some of the threads about upgrades and suspension changes during their factory backed racing careers.

That being said, there is also some stuff they couldn't do, due to rules and what not, which we may be able to get away with nowadays in various classes.

[2mAn]

The flares seem very straightforward. -> More tire without creating drag

The bumpers were probably designed to clean up the air flow into the engine bay and under the car.

Im guessing that was also the idea behind the seals between the fenders and hood

The main thing Im trying to to do is to itemize what specifically was improved using the M3 parts, ie: want to use bigger/ wider wheels -> M3 fenders, or now, any number of flare options out there. etc

[CorvallisBMW]

Front suspension geometry was different, improving on things like camber, roll stiffness, roll center, etc.

Also the raked rear window was actually designed to clean up airflow over the rear wing and increase downforce.

[djjerme]

Well, I think I kind of get what you are looking for.

-The flared fenders seems rather easy, it was in order to get more tire under the body without modification (i.e. rolling/pulling the fenders.) If you look at the DTM cars, they were A LOT lower than the road cars, so getting those big a$$ meats to tuck nicely under the car required significant flaring.

-The front windshield difference in mounting would have been due to what is considered more important for road car vs race car. In a race car, they were probably going through windshields often, so replacing them quickly took priority hence the bonding of them vs the rubber and lock strip regular E30's received.

-The front suspension changes in geometry is a whole 'nother subject that will probably go for days. Mainly speaking of the different swaybar end mounts.

[2mAn]

This thread has legs!


But seriously - are we talking the road car or the DTM car.

The DTM car I am sure had a lot of functionality built in to each mod, but the road car was a little "dumbed down" so that most drivers wouldn't kill themselves and to add some creature comforts.

Im more focused on the general, rather than the specific, so I guess the road car

[djjerme]

This is a great start.

This thread has legs!


But seriously - are we talking the road car or the DTM car.

The DTM car I am sure had a lot of functionality built in to each mod, but the road car was a little "dumbed down" so that most drivers wouldn't kill themselves and to add some creature comforts.