M3 Suspension upgrades really necessary?

[captainM3]

I like my 95 M3 but want to try some upgrades.

Wouldn't BMW put pretty good suspension (Springs/Shocks-Struts) on their cars anyway?

I did some suspension upgrades on my 94 prelude, now it drives like a go-Kart but handles like it's on rails.

I'd rather not butcher my M3 for the sake of modding it.

Is it worth the trouble or is OEM good enough?

[BJO]

bmw puts good suspensions on the cars, but they still have to keep costs low by using items that are not the top of the line. the bmw oem shocks are good, but they do not last long.40k is about avg. koni will be better a shock with a lifetime warranty. you do not have to change the springs.

[paul e]

BJO is right.. My oe front struts were toast by 35k miles, and this is Extremely common.. And it sucks.. I think Most makes of cars from the factory include shocks which last longer than 35k miles!.. It is one of the major weakenesses in our cars, along with the lousy rear shock mounts and towers, and fifth gear gates, etc... Replace with konis or bilsteins, and I dont think youll have to touch them again. Aside from their longevity problems, yes, the oe suspension is an extremely good one, providing arguably the best handling of any car out of the factory ...

[wsmc831]

my m3 with new bilsteins > my old m3 with worn Boge's


totally different car, in a good way.

[M3 Pete]

I just put Vogtland springs and Koni shocks on my car and the ride is decidedly and very noticeably firmer. Not harsh, but quite firm. If you like the current ride, I'd replace just the shocks and see how that works for you. Bilsteins are going to be stiffer than Konis, which are stiffer than the OEM replacements.

THe stock suspension is awesome, but lots of us like to tinker.

[vik]

There's a LOT more to suspension geometry than I pretend to understand -- the effect that lowering a car has on the tire camber curve, as one example. To me a suspension should be designed holistically. Throwing this spring and that sway bar onto a car invalidates (at least partially) a ton of work that BMW did to design and calibrate the OEM suspension.

So I have decided to trust the BMW engineers with respect to geometry and spring/sway bar rates, but I will replace my stock shocks with Konis when they wear out, because to me that's more of a longevity issue than a calibration issue.

But that's just my humble opinion. :)


-vik

[ChipM]

No, for a street car if you keep good shocks and other wear items in good shape then there is no reason to touch anything else unless you just like to tinker.

[M3 Pete]

There's a LOT more to suspension geometry than I pretend to understand -- the effect that lowering a car has on the tire camber curve, as one example. To me a suspension should be designed holistically. Throwing this spring and that sway bar onto a car invalidates (at least partially) a ton of work that BMW did to design and calibrate the OEM suspension.

-vikbut you also have to realize that BMW has to make the car appeal to the masses. If you can tolerate higher spring rates, you can improve the cornering ability of the car, just ask anybody on the track forum. BMW would go broke if it produced a car for the enthusiasts on this forum, because the mainstream public would not buy it. BMW made the best car they could taking into account the "live-ability" of the suspension. The car rides the fine line between ultimate performance and a nice ride.

Now I agree that if you slam the car, it does mess with the geometry, which is why I opted for a mild drop (about 1-inch) rather than some of the more radical options. Even so, I doubt most BMW buyers would tolerate stiffness of the ride, on some freeways with repetitive concrete seams, the car pitches back and forth like a bronco. But put it hard into a corner and you better hang on!

Another thing to consider is driving style. Most people do not (and cannot) reach the limits of the car's stock potential, especially on the street. For them, there is no point to do any upgrades, the car is beyond their capabilities just the way it is. I'm not slamming those folks, they are saving money and are perfectly happy!

[vik]

but you also have to realize that BMW has to make the car appeal to the masses.


BMW would go broke if it produced a car for the enthusiasts on this forum, because the mainstream public would not buy it.
I agree with the essence of your post: BMW shot at one particular target with the car. But I would disagree that the M3 is made for the "masses" -- it's a pretty aggressively tuned car.

I guess everyone has to ask themselves where they are relative to BMW's target. If I was on the high side of the target -- i.e. if I autocrossed the car competitively -- I'd think about lowering and stiffening it to quicken the transitions.

But I actually think that I am dead center on the target. For me the car is a daily driver first, a track car second, and an autocrosser third. I want the car to be comfortable on I-94 in Detroit, and I want it to talk to me in the esses at Watkins Glen, and I want to have fun at the SCCA autocrosses, and if I don't place, that's ok. The stock suspension does all of those things for me fantastically well, and I don't know that I could improve on it.

Look, I'm not some kind of factory purist. I used to own an Audi A4 that was low and VERY stiff, and it did make it more fun to drive. But a stock M3 suspension is light years ahead of a stock A4 suspension and doesn't need that kind of help, IMO. Bottom line is this: I think BMW did in fact produce a car for the enthusiasts on this forum, but the enthusiasts on this forum don't believe it!

That said, that's what works for me and me alone. If you like your car better modified, then modify it you should. That's why Baskin-Robbins makes 31 flavors! :)


-vik

[M3 Pete]

I agree with the essence of your post: BMW shot at one particular target with the car. But I would disagree that the M3 is made for the "masses" -- it's a pretty aggressively tuned car.

-vikRemember this was not a cheap car when new, over $40K in the 1990s, pretty pricey. Plenty of people bought it not because they wanted an especially aggressive car, but because it was the top of the line 3-series. Look around at who is driving new E46 M3s, which is also quite aggressively tuned for a factory car. There are a few enthusiasts, but I see plenty of slow women drivers, executives who just want the look, and others who fit the typical demographic of a $50K+ sporty car. The 330i would be more than enough for most of them, but it doesn't have the "cache" of an M3. BMW still has to make the car appeal to them, they amount to a large component of the new M3 sales.

Even so, I agree with you that BMW reached an excellent blend of performance and ride quality. I actually think my stock 97 M3 has a better ride than my old 95 325i with the factory sport suspension.

[BimmerMPower]

What do these shock upgrades usually cost?

[ChipM]

What do these shock upgrades usually cost?

Decent performance shocks are in the $600-700 range. OE replacements (except with a lifetime warranty) can be had under $300.