Living with a Supercharged M5 from Discovery Automotive

[bbloch1114]

Originally Posted by Lscman

Well, this is the quandry (dilemma) faced by folks getting custom mods. In this case, thorough/proper engine testing & tuning absolutely requires a "full" capacity clutch. There is no feasible alternative. When you replace an organic clutch and test-tune a high power engine at the same time, the clutch can easily become overdutied & burn out. What is the builder supposed to do? Proper tuning of such a setup requires thorough load testing at all RPM and throttle positions. I am sure the builder minimized clutch damage during this process, but a fresh organic clutch is simply VULNERABLE. I am simply stating that the organic clutch may not have failed if break-in was accomplished on the street, several months before the motor was modified and test-tuned. These days, a Stage 3 or similar race disk is the proper solution for scenerios that involve engine testing, tuning or racing during the clutch break-in cycle.

All of that may be true, but don't forget this fact -- the clutch should never have been installed in a supercharged car -- period. Here is a reminder of what SPEC said about that clutch:

"We have received the clutch kit from your 2001 BMW M5. The clutch kit your mechanic sent to us for diagnosis is an original equipment BMW 850i unit. Given your car has over 600 hp, there is no surprise of the condition of the stock 850 clutch after 1500 miles of usage. Having built high performance clutch kits for the 850 models for several years, we know that the factory unit is not sufficient at those power levels for extended use, and would NOT, under any circumstances, be recommended.



David Norton
Vice President, Operations
S.P.E.C., Inc Clutches and Flywheels"

And that is the only thing that matters -- wrong clutch for the application. Of course DA should have replaced it for free -- especially since they never should have installed it in the first place. I guess the reason for installign the wrong clutch can be understood -- Shadowman wrote to me that he was "not a clutch expert" -- of course that was after my clutch fried and he said he wouldn't pay for it.

The new SPEC clutch I have now has 40% less travel (a clutch stop is now installed) and has an OEM feel, yet is can handle about 800 HP. It is a full disc made of semi metallic carbon.

[Lscman]

BBlock,

The Spec mfr statements are not compelling, since they did not note that the clutch saw excessive torque during break-in. This glaring omission is lame. I do agree that a race-compound disk is more compatible with this powerplant. I would have chosen a race disc for such a powerplant. If testing & tuning were being conducted during clutch break-in cycle, this would almost obligate the use of a race-compound disk.

I am unclear why the stage 1 street organic clutch was chosen when the Stage 3 race disk is sold for the 11" clutch. Perhaps the person recommending the clutch was unaware that the engine was going to be flogged during clutch break-in? I assumed this purchase was made before the race compound stage 3 disk was released. If so, then it was also purchased before mfrs were selling decent race clutches for M5. The first decent, streetable race clutch was designed by MIB & friends, not SPEC or UUC.

The stage 1 11" 850i organic disk setup with it's 50% greater surface area was the strongest streetable combo on the market 12 mo ago. With proper break-in, it is unbeatable for street use behind most powerplants and most drivers. After it debuted, higher temp race disks were offered for this setup that offer quick break-in with a higher max torque rating. These disks are capable of elevated torque levels out-of-the-box and not nearly as sensitive to proper break-in. This is why they are called race clutches and why they do not exhibit wonderful modulation and driveability qualities like the stage 1 and OEM disks. You can't have everything.

Powertrain develop, testing or tuning generally requires a race clutch or an organic that has seen proper break-in. Abusive launches require a race disk under all conditions. Some 400 HP motors require a race disc for certain drivers and certain venues. Absolute advise is not possible because everyone drives differently.

[NJ M5 2002]

Originally Posted by bbloch1114

If I had to do the whole thing over again... no way. Unless of course I was considering the kit that AA is coming out with -- twin superchargers, 550-570 HP, target price... $15,000 -- and a warranty. Smart buyers will wait for that one instead of Dinan's or DA's or anybody else's. You cannot beat that price -- I only wish that I had paid that price. Of course, if you want an 800 HP version, AA is not going to do that, but the character of those two power level M5s is so different, you either want one or the other. I think the lower power version is more the everyday car being that it is quieter and less high strung.

I can't wait!! After being burned by Osh and talking to Sean on the phone, maybe someone will finally put out a realistically priced kit. Great!!

[bbloch1114]

Originally Posted by Lscman

1) "...First and foremost, a prudent break-in was clearly not followed. You NEED to drive like granny until break-in is complete! This is NOT an option with organic materials!!!!!!! If you want max torque out-of-the-box for flogging a new combo, you need to choose a race disk with hard compound. One can "hope" that a fresh organic clutch will hold, but frankly you need to do more than cross your fingers or blame the hardware. It's clear this super high performance one-off powertrain combo was "tested" by several drivers(builder/magazine/owner), while a fresh organic street clutch was "hoping" to break-in at moderate-to-low temps and loads. This did not happen...this is not proper break-in. Is anyone claiming that this motor did not see more than 1/2 throttle during this testing phase when engine response, mixture, timing and other parameters were being checked at all throttle and RPM positions??? No, of course not. Think. This is a recipe for failure, period. ANY high load slipping from hard launches inside the 500 mi mark will greatly reduce max torque capacity. An OEM organic street disk found in most cars will not transmit maximum torque for at least 500 to 1000 miles. When an organic clutch kit is not carefully broken in, the disk material will see elevated temps that leads to chronic burning and glazing damage. Once this occurs, a runaway condition will occur where the metal surfaces of the flywheel and pressure plate will be destroyed due to reduced torque capacity."
.

So, no matter how you slice it, the clutch should have been replace by DA. They dynoed it, the had the magazine editor driven around in the car and they drove it at full throttle for sure -- in fact, the writer called me the other day and was describing how fast the car accelerated when he was in it.

So, DA damaged it, it wasn't adequate and yet, there are those of you who think this is perfectly acceptable. You are in the minority for sure though. Shadowman knows only too well that there are quite a few of the 5700 or so viewers of this post that now wouldn't touch him with a 10 foot pole.

And when Active Autowerkes comes out with their $15K dual supercharger kit -- that puts out as much power as mine -- but does so with a more reliable 8 injector setup and for about $40K less WITH A WARRANTY -- I predict that DA's supercharging M5 days will be over.

By the way, DA is on another Bimmer site telling the world how he fixed my car after RMS screwed it up, but I am only one of the people he mentions. It is part of a smear campaign against RMS that is really a push for new customers. I'll be visiting that site today to at least set my part of the record straight.

[TurboCarrera]

Isn't it a ***** to spend a lot of money to performance modify a good car only to find that you end up with a car that sucks when it is done? This board, and every other car board, is well-populated with expensive brake, suspension, and engine performance downgrades.

Steve
00 M5 100% certified bling-free

[bbloch1114]

Originally Posted by TurboCarrera

Isn't it a ***** to spend a lot of money to performance modify a good car only to find that you end up with a car that sucks when it is done? This board, and every other car board, is well-populated with expensive brake, suspension, and engine performance downgrades.

Steve
00 M5 100% certified bling-free

Yes -- it does, but I am pretty confident that this time when I get the car back, it will finally be done correctly. I say this because of the detailed conversations I've had with Karl at AA and because I know exactly what they are doing. Still wish I could have the $15K version though instead of the nightmare $57K version.

Oh well.

[Lscman]

Originally Posted by bbloch1114

So, no matter how you slice it, the clutch should have been replace by DA.

I disagree, unless the owner asked for a stage 3 racing disk and DA specifically recommended the organic Stage 1.

If DA did their job right, they thoroughtly tested & tuned the car before delivery to the customer. This requires full throttle testing. DA was testing & tuning the engine, not the clutch. Slight variations in timing or A/F ratio can blow the factory $25K S62 motor. DA needed to flog the combo to be sure the motor is precisely tuned & lasts. If DA did not do their job properly, the clutch might still be good (lol), but who's to say for sure. Spec blames the clutch compound, right? Parts in souped up cars being acceptance tested & evaluated tend to fail at an increased rate. Owners need to accept such issues instead of trying to blame somebody.

[Lscman]

Originally Posted by bbloch1114

And when Active Autowerkes comes out with their ...............I predict that DA's supercharging M5 days will be over.

You are comparing proven stuff you can buy today to stuff folks are promising for tomorrow. AA was sluggish to release a good M5 solution. It is geared for folks who want to wait...reminds me of Microsoft vaporware demos. You are also taking AA at their word (wrt specifications) with no independent production testing yet. Wait until production units show typical teething issues. It will happen.

I'm sure DA and other players are planning stuff for tomorrow too.

Try an organic 9-5/8" clutch behind that AA kit. You won't be able to tell the difference between clutch in or out.

[bbloch1114]

Originally Posted by Lscman

I disagree, unless the owner asked for a stage 3 racing disk and DA specifically recommended the organic Stage 1.

If DA did their job right, they thoroughtly tested & tuned the car before delivery to the customer. This requires full throttle testing. DA was testing & tuning the engine, not the clutch. Slight variations in timing or A/F ratio can blow the factory $25K S62 motor. DA needed to flog the combo to be sure the motor is precisely tuned & lasts. If DA did not do their job properly, the clutch might still be good (lol), but who's to say for sure. Spec blames the clutch compound, right? Parts in souped up cars being acceptance tested & evaluated tend to fail at an increased rate. Owners need to accept such issues instead of trying to blame somebody.

Maybe in your world the owner pays for an improperly broken in or in adequate clutch, but not in mine or in many others. You should go to DA and get the "proven" DA kit that I have -- proven to not make the power, to not be able to be driven and proven to be very expensive.

I'd love to see you spend $50K to $60K and then still be so supportive of the vendor who delivered you crap.

[Lscman]

Marcvip,

Your comments are rude and unsolicited, as usual. Are you an expert? State your credentials.

Why do you continually denigrate me for owning a 540i? What model car does your mechanic own? How many superchargers have you installed, tuned & sorted out? How many track miles do you have driving supercharged V8 cars? How many engine dynos, chassis and chassis similators have you operated as a test engineer?

I have plenty of experience in this area. One such vehicle has over 50K miles on it with supercharger, many of these miles at sustained full throttle. It is not a 1/4 mi toy either. I ran this car in many club events across the Northeast USA. I personally tested turbocharged engines on engine dynos in the largest test facility east of the Mississippi. I have conducted dozens of comprehensive durability tests on chassis dynos.

BBloch,

I am just explaining why a fresh organic clutch disc might get stressed during supercharged engine tuning. It's not my role or goal to blame anyone or applaud fingerpointing. Please recognize I am not trying to minimize the financial agony you've gone through trying to build a reliable one-off supercharged M5 car before a mass production kits were released. How much do you think Dinan would have charged you for such a project? I do understand your frustration after hearing AA is releasing a kit. Pioneers like you who want something custom or unique done to such a low production car often bear a substantial financial risk and/or burden for such research and development. I have seen much larger sums of money spent at premiere tuner race shops on 427 Mark II GT-40's, Ferrari, Lotus and various exotics with modest or poor results.