E46 M3 coupe and Cab handling question

[Silver]

Hows the handling compare to Coupe and the cab on stock suspension?

[peppernick]

I can most certainly feel the chassis flexing on a convertible. Steering is not as accurate and taking fast corners, the car tends to stray a little. But the latter is mostly noticable when you're doing speeds round a corner that you'll not do in the majority of time.

Convertibles are also slightly more creaky, and can rattle with the hardtop on. Some say the extra 100kg slows the car down but TBH, the convertibles I've driven felt just as punchy.

My list of pros and cons of a vert.

Pros:
Al fresco motoring
Looks
More looks with the hardtop on
Awesome drop even with the mildest lowering springs


Cons:
Flexi chassis
Creaks and moans
Normal sport convertible seats as opposed to M3 seats
Poorer acoustic environment for installs

[Silver]

can chassis flex be reduce by adding under braces and cross bar.....

I driven my frd 350z cab and he add these bits...and it handles betta dan da coupe...was wondering can i do the same with the m3 cab

[peppernick]

All M3s, vert or coupe already come with underbody chassis brace. Front and rear struts will not affect the area where the flexing tends to happen, right behind the two doors.

Imagine an M3 vert as a shoe box without a lid. Bracing the front and back portion of the box is not going to help it flexing down the middle if you twist the box side to side. Only an X-Brace from front to back would; but where are you going to put that on an M3 vert?

[Silver]

aahhh ic....tanxs nick

oh well.....best i stop looking at japanese tuning magazines...got so much tuning stuff...lol

[baz1985]

I guess the cab driver could still outpace a coupe driver if more talented :)

[peppernick]

A more talented driver in a Saxo can outpace an M3 coupe driver but that's besides the point, difference in chassis dynamics between the coupe and vert are unaltered :)

[adood84]

in the end the cab looks better :D:D , and your not going to drive the car hard all the time ;)

[Chaos]

I'll pitch in to add to Nick's comments from the other side. ;)

If you're really really pedantic and concentrating on it (Nick :p), you can feel a small amount of twist in a fast, tight turn. It's hard, but you can just about pick it out. I wouldn't say it was a major feature of the E46 M3 like it was the E36 328 vert I had though, I threw mine around the Nurburg F1 circuit at probably 80-90% of flat-out and it just took it all like a trooper, and all mine's got for handling add-ons is a Pro kit and a strut bar.

Driving them back-to-back is where you feel it though. My opinion is this: It's not that the vert flexes much, because it doesn't in my experience, it's just that the coupe is so damn tight that it feels that way. The coupe's chassis really is an amazing piece of work for what is essentially a 4-seater performance car, and that's why it's called the cheapest supercar on the planet - it's chassis allows it to do things that it really shouldn't be able to do ordinarily and allows the drive to push the envelope out so much further. You can't do that once you take away the roof, as no matter how strong you make the body you still lose the second dimension of structural rigidity that the roof gives, thus the coupe is stronger and the vert is only as good as it is because of the level of engineering that the chassis had to start with. The weight isn't really a factor in a 340bhp car once it's moving, you're dealing in fractions by that stage.

Both of them benefit from a drop, so I wouldn't tend to put handling discussions and stock suspension setups in the same conversation, but I'd sum it up by saying that the coupe handles a fraction better, and the vert looks a fraction cooler. Whatever is important to you is what counts, but the difference isn't major and they can just as easily do each other's good points almost as well.

[Silver]

thanks chaos....

[BeemerBoy888]

Interesting thoughts, as I have asked myself M3 coupe or vert on many ocassions.

I'd agreed with both what Nick and Dan comment and leave the issues of handling to their knowledge and experience.

To throw a slighly different angle to the question. It also depends on whether the M will be your everyday car (on practical issues). Having driven a vert for the last 3 years, i'd say if you need your car to ferry people around, the verts has almost absolutely no space in the back seats :o In a coupe, you could easily fit 4 adults in the car, a vert is a struggle. (right Flex bro :confused: :D )

There are definitely more creaks and moans on the vert, but my 10 pence opinion is the vert does look a little better (for the possers in us *cough* :o )

I guess it depends what you want your M for. The status quo or the real hardcore driving experience, coz trust me, 9 times out of 10, when the roof is down, you'll be cruising and not hammering it. :)