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      01-02-2013, 11:07 AM   #1
Gladius
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Compare and contrast the M coupe and M roadster

Sounds like your last high school english class, right?

I've been pining for an M coupe but there are only about 50 of them ('06-'08) in existence in the color I really want. So I'm entertaining the notion of a roadster as it's more likely I can find what I want (and at a lower price) if I widen my options.

However, I would like to track the car. The BMW CCA here in CO doesn't let roadsters into their DEs, although I know other clubs do (and open lapping days have allowed them).

So the question is, what kind of performance compromises would I be making in going to the roadster? I assume they are heavier, but how much? What about stiffness decreases, and how does this impact handling? Finally, I expect that the cloth top has an increased maintenance/repair cost - how are those holding up now that the cars are 5-6 years old?

(And if you know of a space grey M coupe that's available, let me know! I'm willing to travel/ship the right car...)
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      01-02-2013, 11:43 AM   #2
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If you track the car a lot I would go with a coupe. I got a roadster mainly because I got a great price on it. I only go to the track occasionally and our club allows roadsters. The soft top on mine is in great shape, the motor did go bad though (was on the way out when I got it). Now that I have it though I think I would get a roadster again given the option. I find the coupe a bit claustrophobic inside for my taste and driving around with the top down on a nice day cant be beat IMO. However like I said if I was serious into performance and tracking the car I would of gone coupe (or a different car as the coupes were probably out of my budget). Whatever performance disadvantages there are to the roadster I'm probably not a good enough driver to notice anyways.

The only real down side for me is the look of the roadster with the top up. It just doesnt compare to the coupe. Although top down I think it looks pretty sexy.
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      01-02-2013, 11:46 AM   #3
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The roady is actually lighter than the coupe but not by a very wide margin. Cloth tops are very durable it is the motor for the top that can be cause for worry. You just need to keep it clean from gunk.

You should probably get the coupe and compromise on color instead of coupe vs roady
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      01-02-2013, 12:15 PM   #4
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If you want to track it, get the coupe. I got a roadster because I went in search of any roadster last year and coupe was never an option. Now that I have it, I want to track it and can't. I can auto cross, but I really want to go to track days and that ain't happening in Ohio without a roll bar installed.

If you don't care about the roadster experience, the coupe is the better option for track.

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      01-02-2013, 12:42 PM   #5
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Consider Silver Grey.
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      01-02-2013, 12:49 PM   #6
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What about buying a hardtop for the roadster? Would that make it legal for track days?
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      01-02-2013, 12:59 PM   #7
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even if legal it would add a whole lot of weight, kinda counter-intuitive for a track day
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      01-02-2013, 01:13 PM   #8
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Adding a hardtop won't make it legal in Ohio. Not sure about other states. They require a welded in roll bar setup here. Wish it would make it legal for me, because then I could have my roadster and track it, too.

The Porsche events sometimes allow roadsters because of all the Boxsters out there but again, not in Ohio.
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      01-02-2013, 01:27 PM   #9
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The hardtop rule is BMWCCA not a chapter rule. After our national meeting this last February , the convertible rule is not changing anytime soon . No BMW chapters should be allowing ANY convertible at any DE that does not have a full roll cage.
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      01-02-2013, 01:56 PM   #10
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Quote:
Originally Posted by Gladius View Post
Sounds like your last high school english class, right?

I've been pining for an M coupe but there are only about 50 of them ('06-'08) in existence in the color I really want. So I'm entertaining the notion of a roadster as it's more likely I can find what I want (and at a lower price) if I widen my options.

However, I would like to track the car. The BMW CCA here in CO doesn't let roadsters into their DEs, although I know other clubs do (and open lapping days have allowed them).

So the question is, what kind of performance compromises would I be making in going to the roadster? I assume they are heavier, but how much? What about stiffness decreases, and how does this impact handling? Finally, I expect that the cloth top has an increased maintenance/repair cost - how are those holding up now that the cars are 5-6 years old?

(And if you know of a space grey M coupe that's available, let me know! I'm willing to travel/ship the right car...)
Dont settle. There are many owners of Ms on here that have gone from M roadster to M coupe and the other way too. I suggest you make up your mind and go for the one you think you are going to want most. Its not becoming any easier to find Ms so try and make up your mind the first time around.

The roadster is about half as stiff as the coupe BUT its still stiffer than 90% of sports cars (coupes included) out there, the coupe just happens to be exceptionally stiff...

I bought the coupe because it was always my dream car, while the roadster was not. For me, you cant beat the looks.

I suggest maybe taking a look at the other silvers out there. I owned a z4coupe in silver gray and was dead set on getting a silver gray M coupe. I ended up finding a Ti-silver M coupe and i really couldn't be happier. The color is just perfect.

Good luck with your search, i suggest that when you find the right one you jump on it ASAP, the good ones dont last long.
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      01-02-2013, 02:44 PM   #11
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What does "DE" mean?
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      01-02-2013, 02:48 PM   #12
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What does "DE" mean?
Driving Event.

Also sometimes labeled HPDE (High Performance Driving Event).

NASA, SCCA, and BMWCCA usually always follow the same rules, no convertibles w/out full roll cages.
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      01-02-2013, 03:06 PM   #13
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I picked the roady over the coupe because it has 10,000,000,000,000,000 miles of headroom.

If you're looking for a track day monster, there's probably better (and cheaper) options than an M Coupe.

If you're looking for a weekend car with an occasional track day (and can actually comply with the track rules) then you can't beat the roady. And given the higher price of the coupe, unless you drive each one back to back, it won't be a major difference in handling.

Also, the price difference would allow you to do some suspension upgrades to the roady to help stiffen it up.

I'm surprised that convertibles are banned where you live, given the popularity of the Miata, Atom, K-Bow, Boxster as track day cars.
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      01-02-2013, 03:16 PM   #14
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You can always get a roady and do trackdays with NASA & PCA.
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      01-02-2013, 03:53 PM   #15
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i track my roadster reguarly, its awesome, i love it!!! Its torsional rigidity figure is NM is higher than a lotus exige....... ive never once driven it and though.... hmmm this car is sloppy.... never.... both are great choose the one you like the most...... i went for the roadster and never once have regretted that decision. Coupe or roadster, they are both a rare beast over here in the UK.....

Their was a nice post of all the numbers im sure someone will dig it out for you.....
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      01-02-2013, 05:15 PM   #16
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I personally like the look of the coupe better. I do mirror other's comments that the roadster would probably feel a lot more "open", as the coupe takes a little bit of getting used to as it's quite a bit more difficult to see out of than most cars. It's tough to see out the back and the sides, but it just takes a little getting used to.

I am about 6'2" and if I was any taller it would be extremely cramped but I fit in it OK.
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      01-02-2013, 05:49 PM   #17
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Wait for a coupe if you want to track with the BMW CCA, and in general it's better to have a coupe if you want to track. The coupe may be slower on track than your E90 M3, but with all the feedback and small size it's sooooo much fun!!
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      01-02-2013, 06:40 PM   #18
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Quote:
Originally Posted by 03BeastCharmer View Post
Wait for a coupe if you want to track with the BMW CCA, and in general it's better to have a coupe if you want to track. The coupe may be slower on track than your E90 M3, but with all the feedback and small size it's sooooo much fun!!
In a perfect world, I would have an M coupe to complement my SI roadster. But alas, that is likely never to happen.

Re torsional stiffness, here is a quote from page 45 of BMW Z4, Design, Development and Production, by David Lightfoot:

"While the torsional stiffness of the Z3 had been 5,600 Nm, the Z4 achieves 14,500 Nm. That's two and one half times better without adding weight; a phenomenal achievement. The importance this development had on dynamic capabilities is hard to overstate. To provide perspective on the rate of technological change BMW has achieved, in 1990, the 8 Series, BMWs expensive technological tour de force coupe, was rated at 11,000 Nm. This was a a closed car and the best BMW had ever achieved in a coupe!"
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      01-02-2013, 07:25 PM   #19
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slightly OT, but aren't the roll hoops on the roady integral to the frame? Just wondering how F1 cars are allowed as they essentially have a similar (in concept) open cockpit
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      01-02-2013, 08:40 PM   #20
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3point0 not even close to the same F1 are their safety requirements are light years more detailed than ours. I will say this, as an HPDE Chair and certified BMWCCA instructor I personally don't want to instruct in an convertible. Rollovers are very rare and after 8 years I have never seen one. Saying the bmwcca does not want any chance of a fatal injury from a accident in a convertible BMWCCA requires a full cage, 6 point harness and arm restraints not ANY convertible at a BMWCCA HPDE
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      01-02-2013, 08:49 PM   #21
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For you numbers people, the Z4 Coupe's torsional stiffness is almost 32000 Nm.
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      01-02-2013, 10:15 PM   #22
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Quote:
Originally Posted by elwsso View Post
I personally like the look of the coupe better. I do mirror other's comments that the roadster would probably feel a lot more "open", as the coupe takes a little bit of getting used to as it's quite a bit more difficult to see out of than most cars. It's tough to see out the back and the sides, but it just takes a little getting used to.

I am about 6'2" and if I was any taller it would be extremely cramped but I fit in it OK.
I'm 6'5" and if I were 6"6" my head would rub. In fact my head rubs with a helmet on. I need to duck a little bit to see through my rearview and at stop lights. Note my head in the pic below haha.
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