I've reading some M5 reviews. Most are very favorable. The March 2000 Road and Track comparison with the E55 repeatedly knocks the M5 for significant understeer. Perhaps playing around with tire pressure could alleviate some of it. What are your experiences? I do not have an M5 yet, so I'm hoping for your first hand impressions.
The criticism is valid. This is engineered in for safety reasons and makes the car less "fun" than it could be, especially on the track or in autocross situations.
HOWEVER the car is still an amazing handling car, especially considering its weight and ride quality. It is capable of generating amazing steady state cornering grip, and in the higher speed sweeper type turns you can still adjust your line with your foot. You CAN get the tail to come out with too much throttle (power-on oversteer) but it is virtually impossible to get it to over-rotate under braking. At the limit in a steady-state situation, it will indeed understeer. All of us who participated in the August even at Sears Point have nicely rounded outer tire edges to prove it!
The Dinan suspension (and others) do reduce the understeer and make the car a little more neutral at the limit. This probably makes it more fun, but also reduces the safety margin if you turn DSC off. This reduces driver confidence, which may explain why the STOCK M5's were outperforming the Dinan-equipped cars at Sears Point. Of course, the biggest variable is the driver here - but assuming we were all roughly equal, I think the difference was driver confidence - those of us with the stock cars were actually comfortable pushing a little harder. I think in the hands of a true pro, the Dinan Stage III cars would be quicker around the track.
Hope that answers your questions.....
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Greg, you are so right about the driver confidence thing! I took my Cobra R to the track a week or so ago and I was certainly not confident enough to push this thing any where close to its limits... why? because it had a strong tendency to oversteer coming out of the corners. It has no DSC to keep you out of trouble, and will roast the tires in corners if you are too heavy on the throttle.
However, I am convinced that once I get over this fear and learn how to push the car to edge without stepping over the cliff, I will be much more competitive at the track. You would not believe how powerful this thing is?!!!! by the way, I was keeping up with the 996TT on the straights! of course, he was kicking my butt everywhere else... better driver and a great car = kick Andy's butt! But man, I had fun!! Can't wait to go back.
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Andy
'00 Imola Red M5 - sold 4/02
'00 Mustang Cobra R - #155 of 300
'02 F-250 SD Powerstroke Crew Cab 4X4
'00 Honda Accord V6
I have to agree with Greg and Andy. Driver confidence is what will make you do deeper in the braking zone and what will make you accelerate earlier out of the turn. The car does little difference. It's just like mountain biking, if a rider is good on this bike, he'll be good on any bike. Fear will make you fall off your bike because if you fear that you'll fall off your bike constantly, it'll happen...guaranteed! The rider makes the difference! samething applies to driving IMO
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Last edited by VanCooper; 28th October 2001 at 08:58.
To markedly decrease the cars tendency towards understeer you would have to install an after-market suspension upgrade such as the Dinan Stage 2 or 3 package. It seems most people on the board prefer the Stage 3, which then makes the car very neutral handling.
You can however go a long way towards decreasing the amount of understeer BMW unfortunately designed into the car and it will cost you nothing. Simply reverse the BMW recommended tyre pressures front and rear, i.e. put 4 lbs more pressure in the front than the rear tyres. This does work quite well. I run this set-up on the street at all times regardless of the pressures I'm running, (I vary the pressures depending on whether I'm looking for increased comfort or am planning on cruising at higher speeds/greater load, etc. Regardless, I always put 4 lbs more in the fronts than the rears). This decreased tendency towards understeer was very obvious on the track. Yes the car still understeers, but much less than running higher pressures in the rears as 'recommended' by BMW.
thebishman
I can double that. I've just come back from the BMW CCA driving school at Laguna Seca. I've started with my normal setup of 41 front and 43 rear. My instructor urged me to try a lower pressure in the rear. I ended up with 42 front and 38 rear. It makes quite a difference. The car is much more balanced. Still a tendency to understeer, but much less of it. I was close to getting the Dinan stage 3, but after this experience, I may just stick with the stock suspension.
understeer?
by the way, I was keeping up with the 996TT on the straights! 
of course, he was kicking my butt everywhere else... better driver and a great car = kick Andy's butt! But man, I had fun!! Can't wait to go back.
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