New SPEC clutch/flywheel/track report - The Unofficial BMW M5 Messageboard (m5board.com)

Bugeater · 28th March 2005, 08:08

I replied to the SPEC poll thread, but figured I would start a new one that had the specific topic heading:

I put in the stage 3 SPEC Hybrid 3 weeks ago. New version. Kevlar/Organic hybrid. I will have around 1,000 miles on it by tomorrow. I am taking the car to VIR Virginia International Raceway to see how this car performs on a 3.3 mile roadcourse...I'll give ya'll a report then if you want it...

So far the clutch feels good. Oh yeah I opted for the lightweight flywheel too. Chatter is obvious outside the car but I think everybody already knows that. As for durability of the clutch, we shall see.

Bought from Ben at Rogue. Nice guy. Total I believe was 1750 or thereabouts.

By the time I get back I should have about 1,500 miles on the clutch/flywheel combo, with 200 miles being hardcore track time if weather permits. I hope the stock brakes hold up (Stock hardware with race pads, complete brake fluid replaced with superblue and powersteering as well, and stainless lines)

POST TRACK WEEKEND.

Clutch and flywheel now have about 1,600 miles on it. They also have 2 days and eight hot sessions around VIR fullcourse. Just got back (225 mile trip) home and everything is fine. Clutch/flywheel worked flawlessly. My issues started out as a VERY BAD brake shutter that took 3 full sessions to go away. I originally thought it was a warped rotor, but ended up most likely being the conversion of street to race pad. Hawk HP10's.

By the second day I had no issues, and simply enjoyed flogging the car to the limits of the brakes, suspension and tires. Some observations:

1. Stock braking is not too bad. I honestly didnt expect the car to stop as well as it did for its weight, and stock pilots. I did get brake fade with the Hawk HP10's after awhile, but they held up pretty good. Overall an "OK" pad. Not great bite, but decent. I have not had the wheels off to check wear on the pad or rotor. Can anyone confirm or deny if the PFC 01's have a pad that fits our stock caliper? Its basically the best pad out there for the track.

2. Dinan Stage3 Koni suspension is not a poser mod. Its a little soft (anyone know the spring rates?) but its very compliant over gators and doesnt let the chasis unsettle in less-than-perfect transitions. Its a very good compromise street to track. I was on firm setting. I had the shop dial in -1.9 front, -2.2 rear camber. 6.0 castor with .20 total toe. My feeling is that I could/should have dialed in more camber up front. Anyone agree/disagree?

3. Pilots are probably not a good choice for track use, but not unusable if you want to go have fun. They will keep you out of trouble, but do go away quicker (push) each session if you run multiple HARD sessions in a day. I felt that 42 pounds hot was a decent pressure with ambient outside temps around 50 degrees.

4. The UUC shifter that is installed in my car has a dead spot left of second gear!?! Is this normal? What I mean is that There seems to be a place right below reverse that you can "attempt" to put the shifter in, left of second. Under quick downshifting manuvers I tried to put the car in second and missed the gate to second and hit this deadend....New to me.

5. The stock LSD is decent for high speed sweepers, but a variable lockup or quaife would be nice for powering out of slow, tight exits. First gear in the M5 (which I really like) really necessitates a quaife type unit. Probably a mod for hard-core track rats, or guys that want everything offered the car. Is there a swap out there from another model/year that can be used?

Im not sure of all the issues of the previous SPEC clutches, but I dont seem to have any. Keep in mind I only have 1,600 miles on mine, but I did baptise it by fire.

My car has 87,000 miles on it. Bought it 3 weeks ago knowing the clutch was fried. The Dinan mods were obviously done by the previous owner. Pretty **** impressive car to flog it like I did and have it perform so well. THEN drive a couple hundred miles home! Whenever I get a little nitpicky about some of the performance aspects I had to tell myself to quit comparing it to my racecar...900 pounds lighter, on Hoosiers, and with a power/weight ratio of about 7. Once I put it in prespective I just shook my head and smiled. Really was amazed at the performance of this sedan.

Hope some of this helps....Sorry for the obnoxiously long post!

mottati · 28th March 2005, 08:24

Thanks for the report, good info. Is this clutch the 240mm unit? Is this the spec billlet flywheel that has been discussed in previous threads as forthcoming?

As for your comments on camber, there is no adjustment with the dinan plates, what you get is what you get. I agree with you that it's a pretty decent set up for a mostly street, occasional track car.
thanks!

gsfent · 28th March 2005, 16:51

Good report. If you have clutch chatter, can raising the idle speed help like it seems to do for the UUC variant?
As to camber, if you can dial in a little more front, OK, but I would take some OUT of the rears. It will allow the back to rotate a little easier and therefore not work the fronts as much. 42 psi hot in the front is very good IMHO.
Regards,
Jery

EdP · 28th March 2005, 18:00

Quote:

Originally Posted by Bugeater

I had the shop dial in -1.9 front, -2.2 rear camber. 6.0 castor with .20 total toe. My feeling is that I could/should have dialed in more camber up front. Anyone agree/disagree?

I'm wondering how you were able to get to -1.9 front? I thought, maybe incorrectly, that -1.5 was close to max with the Dinan plates. I remember one post from someone who said he got a little more with Dinan plates,
maybe, -1.7.

Redshift posted that he dials in -2.2 front for track days with his GC adjustable plates. The definitive Ground Control coilover suspension discussion thread - step on in!

FWIW, Dinan Stage 3 specs are -1.5 front, -2.2 rear camber. 6.5 castor and .20 total toe.

MPRESIV · 28th March 2005, 19:18

Bugeater, is your SPEC clutch kit model SB633 and the flywheel SB63A?

Thx.

marcvip · 29th March 2005, 05:14

Ok...so I finally got around to installing the new SPEC billet stage 1 clutch kit with the OEM lightened dual mass flywheel...........I drove it for 20 miles and my first impression is "wow".........identical feel to factory with no extra pedal effort and a slightly lower engagement point due to the removed SAC mechanism. Completely quiet setup without any need to increase idle and slightly quicker acceleration due to a 9 pound flywheel weight reduction.....all this just as expected for my daily driver.......unfortunately I have to break in the clutch for a few hundred miles before I start smoking the tires.........

Bugeater · 29th March 2005, 05:49

Hey guys, sorry for the late replies. My work blocks this IP for some reason...?

MPRESIV,
I am unsure the part numbers, but you could get them from Ben at Rogue Engineering. The Invoice does not show a part number, simply "Aluminum Flywheel and SPEC Hybris 3". Their number is 201.444.8150 Good luck!

Edp,
The stage 3 suspension came with camber plates that allowed more front negative camber, and I am under the impression that I could dial in a fair amount more...someone correct me if I am wrong! I know Redshift personally, and was lucky to get a ride-along with his better half while he was out flogging his new toy. BTW, I though the ground control setup he had was comparable to the Dinan setup in ride stiffness, compliance, with a little more rebound. He too recommended dropping the rear camber and putting whatever the plates would afford me in the front. I think he is right.

gsfent,
Clutch chatter. I read some other people's posts on raising the limiter to 900, so I experimented and tried to hold rpms around there or higher...around 900-1100. I personally still had some chatter even at 1100. It was reduced but not removed. I dont know how much reduction was evident from outside the car since I was holding the gas pedal down! I agree with you on the rear camber...

Motatti,
Yes and Yes. 240mm and Billet Flywheel. I *can* adjust camber, I believe you cannot adjust castor (in the rear).

** Anybody know anything about my UUC shifter issue? (see original post)
Or other pad choices for stock calipers?

Thanks everyone!

Teutonaddict · 29th March 2005, 06:49

Great write-up, Bugeater! Glad to read how you've become one with your machine in three weeks' time. I particularly like your synopsis.

Quote:

Originally Posted by Bugeater

My car has 87,000 miles on it... Pretty **** impressive car to flog it like I did and have it perform so well. THEN drive a couple hundred miles home! Whenever I get a little nitpicky about some of the performance aspects I had to tell myself to quit comparing it to my racecar...900 pounds lighter, on Hoosiers, and with a power/weight ratio of about 7. Once I put it in prespective I just shook my head and smiled. Really was amazed at the performance of this sedan.

Mine has 78K miles, but made its first trip to Road Atlanta just after the breakin service with 1500 miles on the clock. In fact, I miss the frequency of track time I was able to manage a few years back.

Quote:

Originally Posted by Bugeater

Or other pad choices for stock calipers?

Your best resource from this forum is Dave Zeckhausen: guru of all things E39 brake-related. I sourced my Axxis Deluxe Plus street pads and PFC01s for my StopTech front BBK. And you're right about the PFC01s: worth every penny!

When I was tracking on my stock brakes, I opened up the factory air channels, did the Motul, stainless lines, and used Mintex C-Tech 1144 pads. At the time, I was using Mintex Red Box for street pads. The C-Techs held up pretty well for high-temp streetable pads, and I never had bedding or deposition problems when switching back and forth from street to track.

At the time I first started tracking the Beast (she'll be five years old on Thursday!), those Mintex 1144's were about the only track pads available for the stock calipers. In that time, a number of alternatives have surfaced.

Hope that helps! And keep that grin up!
-Dave

Redshift · 29th March 2005, 07:14

First of all, welcome Bugeater (John) to the board. John is a great guy, everyone, he will feel at home here. We had some great fun this weekend at VIR with our "toys", that's for sure. John, I'm sorry I didn't get a chance to get out there and show you how that M5 really scoots, but I think my wifey did a good enough job. I wanted to drive your car and feel the clutch and flywheel setup, but never got a chance.

Get on the phone with Dave Z tomorrow and order your StopTechs so we can play again soon. When are you headed back out? Our next event is April 9-10 w/THSCC at VIR South.

Gustav · 29th March 2005, 08:58

m5board.com seems popular at your work

Quote:

Originally Posted by Bugeater

Hey guys, sorry for the late replies. My work blocks this IP for some reason...?