e30 Chassis Stiffness

[robert325is]

On my '89, no wreck that I know of, the passenger side door sticks when corner of the car is jacked up. I can still open it, but there is definitely some flex there. Has anyone tried seam welding these cars, and did it make a noticable difference?

same thing happens with me

[Matto]

On my '89, no wreck that I know of, the passenger side door sticks when corner of the car is jacked up. I can still open it, but there is definitely some flex there. Has anyone tried seam welding these cars, and did it make a noticable difference?

same thing happens with me

My driver door sticks a little when I jack up one corner, still opens fine though.

I heard someplace that the e30 was actually slightly stiffer than the e36 is, anyone know if thats true or not?

[e30 gangsta]

im almost positive seem welding will help any car. If that answers your question.

[Grant]

buy a 4 door. ;)

:nice:

[nando]

is it possible to retrofit an M3 windshield into a standard E30?

Yes. You need the glass, low profile seals, and glue. It stiffens the body and provides and aerodynamic advantage becasue the seal is almost flat.

interesting, my windsheild is completely shot so maybe I'll try this. I bet an M3 windsheild is pretty spendy though.

[grapedrink]

I heard someplace that the e30 was actually slightly stiffer than the e36 is, anyone know if thats true or not?

Yup they are by a long shot. I have had both and E30 by far is a better handeling car. Why do yo think a well setup e30 will kick the crap out of well set-up e36s all day long?

[Stu]

I heard someplace that the e30 was actually slightly stiffer than the e36 is, anyone know if thats true or not?

Why do yo think a well setup e30 will kick the crap out of well set-up e36s all day long?

On a racetrack, I don't think so. Who do you think dominates A, B and C-Mod in BMW CCA racing....E36 M3's..

[Charlie]

Why do yo think a well setup e30 will kick the crap out of well set-up e36s all day long?

Are we talking BMWCCA Bizarro-chapter club racing?

Prep levels being equal, the e36 will smoke the e30 on track.

-Charlie

[royalflush313]

I have said this before and I will say it again.

I dont know about all of your POS bimmers, but my car is really stiff and really fast. Probably the stiffest and fastest car here.


cavernicola, whats your objective with the car? Track car? Weekend warrior? Daily driver?
You say that you wanna beat the rice, well the average ricer on the street, no problem - but ricers who has invested performance gear equivalent to what you have invested in your future bimmer will probably beat you around the track. That's a really general statement, and obviously not true of all Japanese cars, but you get the drift.

The point is, what is the satisfaction in beating the average street ricer with neon lights and chrome wheels? I don't know about you, but I would not be proud of beating such a driver, if I had a turboed 6 banger bimmer with a heavily modded suspension.

I see my car as a nice looking grocery getter car, I like it, but most will not understand our infatuation with E30s. It seems like you are looking for a super car, I really don't think E30 is the one.

[ryan_george]

im almost positive seem welding will help any car. If that answers your question.

What is seam welding anyways?

[Matto]

im almost positive seem welding will help any car. If that answers your question.

What is seam welding anyways?

From what I understand you drill out the old welds while the car is on a frame rack (keep it from twisting the frame with the heat from the welder) and reweld them stronger.

You can also fill parts of the frame with special expanding foam to help stiffen the chassis.

You can stiffen the frame a lot more than adding a cage would without all the extra weight.

[e30 gangsta]

Seam Welding

The problem with rally cars is that they undergo stresses that are much greater than any street car will ever see. Without proper preparation the cars literally tear themselves apart at the seams. A big portion of building a rally car involves strengthening the car to handle the enormous stresses they will have to endure. Seam welding is one of the methods used to provide this additional strength.

The process of seam welding involves removing all of the factory applied sealant and epoxies, grinding the seams of the unibody to bare metal with a wire wheel, and then reinforcing the seams with additional welds on top of the factory spot welds.

This is exactly what we started to do today. Tim spent the afternoon prepping and welding seams at the front of the car. He reinforced the strut towers, as well as lower A arm mounts. After a brief break for tofu and artichoke we continued to ignite various sections of tar and epoxy while welding up the seams of the floor pan.

[325beast]

The E36 shell is stiffer. I've seen somewhere the torsional stress comparisions.

I'm not sure the M3 front glass will work in the normal E30. The lower channel looks different.

[Skafrog]

On a racetrack, I don't think so. Who do you think dominates A, B and C-Mod in BMW CCA racing....E36 M3's..

A Mod is dominated by an e28.
B mod is dominated by whoever shows up that particular day.
C mod is dominated by e36's and e30's. It depends on who is having a good day or not.

*This is all south east racng as a disclaimer.

[bmw_e30]

A 15-20 year old 150k+ mile e30 chassis isn't particularly stiff. It's not fox-body mustang bad, but it definetly flexes under load. Big wheels and grippy tires will exacerbate this. Compared to cars of the same vintage, it's actually pretty decent, The E30 M3's are stiffer than the standard cars, as the windshield is actually a stressed member.

Nothing a strut tower bar and a cage can't fix though.

If I had the time/tools/talent, I'd actually like to sit down and see if I could design and fab up some subframe connectors for the e30, I think it might actually help the car.

-Charlie

Something could probably be made up similar to the X brace that is put on E36 M3's, would just take a bit of work to design/fab. They say with the aftermarket X brace for the e36 you don't even neet an upper strut bar.

From someone that owns an e36 and has installed an xbrace, I will confirm that it makes a very noticeable difference. I'm not sure that the e30 has as many attachment points, but it would be an interesting project as well.

-Charlie

It's been done on E28's before. It is possible on an E30 but there are many design limitations to work out.