Spent my WHOLE weekend under my Roadster...

[David Hodgkins]

After a mere 4 thousand miles, my aluminum racing clutch was toast so I decided to change it out. I built my roadster with a Quartermaster clutch and aluminum flywheel. Starting from a dead stop has always been a pain on the street because you can't just dump it like you would on the track. Also the aluminum flywheel (it turns out) has a profound effect on the general manners of the car. It always bucked in low RPMs and was not a lot of fun to drive. I couldn't hold a constant RPM either at street or highway speeds. I was ALWAYS accelerating and then coasting. If I tried to hold it at a constant speed it would start bucking. I thought it was a problem with the tune but it turns out that the difference in the rotational mass between a steel and aluminum flywheel and clutch was DRAMATIC.

Another issue I've had is the Hydraulic throwout bearing(HTB). The difference between a HTB and a standard throwout bearing(TB) is this: An HTB works like a piston. It straddles the transmission input shaft like a standard TB but the piston extends to actuate the clutch fingers instead of riding on a clutch fork. It worked fine but in order to adjust it I had to TAKE OUT the transmission and add (or take away) adjustment rings(Spacers). I've had my transmission in and out of my car 3 times in 4 thousand miles. That's fine for the track but not for street duty! SO, I decided to change it out to a standard TB and clutch fork, actuated by a FORTE external hydraulic clutch slave. Mike's solution uses an adjustable pusher type slave that actuates the clutch fork. BTW I HIGHLY recommend Mike.

It took all weekend but my car was REBORN today! Changing from a hydraulic throwout bearing (HTB) to a standard clutch fork with a hydraulic slave was a LOT of work! But as I'll explain, going from the aluminum flywheel/clutch setup to a SPEC clutch and steel flywheel was HUGE in the way the car drives now!

during our 2-day odyssey we found out that the sleeve on the front of the tranny used for the HTB was different than standard. When I got my new clutch it came with a throwout bearing that had a LOT of slop on the sleeve. Also the sleeve was too short for a standard throwout bearing. Anthony (Antney), Frank(frankeeski) and John(JJ'sSnakepit) coordinated between themselves and produced a plethora of new T5 sleeves to try. They all had a thicker sleeve that fit the new throwout bearing perfectly. Anthony produced one that was solid steel, fit the T5 to a tee, had the proper sleeve diameter and was long enough so that the TB wouldn't slide off when actuated.

They also helped me true up the transmission for the new Quicktime Bellhousing (another FORTE part). It took a long time to button everything up, bleed the clutch line and make some adjustments for setting the clutch fork but at 5pm today we took the roadster off the lift. The new flywheel and clutch were a revelation. All the bucking disappeared and starting from a dead stop was super smooth! The car is a JOY to drive for the first time.

I learned a lot this weekend, chief among them is that an aluminum flywheel and race clutch setup is the WRONG setup for the street, and how much a steel flywheel can make a difference in the way the car behaves.

THANK YOU Frank, John and Anthony for your friendship and help! I REALLY appreciate it! Now my car drives as good as it looks!

[Frank Messina]

Congratulations Dave on getting your car sorted. I'm sorry you had to go through all this but at the same time glad you can finally enjoy it. I've never been a fan of an aluminum clutch/flywheel for the street but whenever you try to counsel against it somebody jumps up with "I have one and I love it". Oh well, you're squared away now. Happy motoring.
Frank

[h82crash]

Glad you got your car sorted. Too bad about the AL fw and clutch, now I'm concerned 'cause I'm about to buy an aluminum flywheel. I however, was not going to go with a lighter clutch kit. I've heard and read about the starting issue but never about the bucking. The reason I was going this route was to reduce deceleration during downshifting. In another car, BMW, I went from a dual mass flywheel to a single mass (reduced weight by 35%) and the change was 100% positive. If I miss my downshift throttle blip, I wouldn't kiss the windshield anymore. I'm looking for the same results here. I hope I have better luck.

[JKleiner]

Originally Posted by h82crash

The reason I was going this route was to reduce deceleration during downshifting.

Unless I'm misunderstanding you I believe you are thinking backwards; a heavier flywheel will decelerate slower than a light one.

Glad you got it sorted out Dave!

Jeff

[TimC]

I'm thinking the lighter FW will spool up and cause less drag during decel. The heavier steel FW will drag the engine down and cause you to pucker up to the windshield.

Glad you got your shifting woes cleared up. Track stuff looks and sounds cool but not always the right part for the street.

[h82crash]

Tim has it right, the car decel not the flywheel. If you've ever driven a car with a dual mass FW you'll know what I'm talking about, those can cause your drive wheels to skid on a downshift.

[AC Bill]

Originally Posted by h82crash

Glad you got your car sorted. Too bad about the AL fw and clutch, now I'm concerned 'cause I'm about to buy an aluminum flywheel.

One of the very first things that I read on this forum, when I first began my build, was to NOT use an aluminum flywheel. I'm thinking that was great advice..

[Jack Wojack]

There’s nothing wrong with using a full size aluminum flywheel that accepts a 10.5 inch clutch pressure plate assembly in these light cars. I’m using the Fidanza aluminum flywheel with the King Cobra clutch/pressure plate and experience none of the symptoms that David describes. Now I do have 3.73 gears in the rear end which does come into play to some degree.

I think the set-up that David replaced is one of those ultra-low moment of inertia multi disc 7.5 inch clutch/flywheel set-ups. Those are for racing, they act like on On – Off switch; either engaged or not engaged. These are two totally different set-ups.

Jack

[Greg_M]

David,
I agree about the Quartermaster clutch and racing aluminum flywheel not working for street use. The late Don Voorhis had one on his car and it was an absolute POS to drive. Launching sucked, engine reved like a chainsaw, RPM dropped all the way to idle from 5K rpm at every shift.

We changed it to a King Cobra/FMS steel flywheel and never looked back at that mess.

Greg

[SeanHM]

Race parts just typically don't translate well to the street. Especially clutches. Glad you got a more enjoyable car on your hands now.

[QSL]

congrats on getting it sorted!!! that rocks!

[David Hodgkins]

Jack, here's a pic of the old setup:


I THINK it's an 8.5 clutch and yes, it was like an on/off switch.

Greg, the way you describe it is perfect. Good visuals! I've heard good things about the king Cobra, I went with SPEC because the dealer was close by and came with several recommendations.

Thanks for the note Sean and Mike, missed ya bud! Next time!

[h82crash]

Originally Posted by Jack Wojack

There’s nothing wrong with using a full size aluminum flywheel that accepts a 10.5 inch clutch pressure plate assembly in these light cars. I’m using the Fidanza aluminum flywheel with the King Cobra clutch/pressure plate and experience none of the symptoms that David describes. Now I do have 3.73 gears in the rear end which does come into play to some degree.
Jack

Thanks, Jack. The Fidanza is exactly what I'm looking at, with near stock PP and disk, I think I'll be fine.

[Wayne Presley]

Who suggested you put the small QuarterMaster in the first place?

[JJ'snakepit]

Well Dave
I was really glad when you couldn't get that bolt in the top of the tranny. I had such a bad feeling about that fit on the throwout bearing but I could understand your frustration about getting it done that night. I am really glad we quit when we did. Over all it was a great experience. Thank God for Frankeeski's Lift and such a well equipped garage. I hope Frank recuperated from his not feeling well. Last night I had the best night of sleep in months and months. Dave when you get a chance give me a call. I have something I would like to give you. JJ

[Someday I Suppose]

David, good to hear you got it sorted out, sounds like a long weekend for sure, but worth the effort, enjoy that sunny winter weather and drive the heck out of it.

-Scott

[David Hodgkins]

John, thanks for your help! I'll call you this week.

Scott, how ya' doin' man? I took it out today a couple of times. I plan to do a lot more cruising this month!

[SJDave]

Originally Posted by Wayne Presley

Who suggested you put the small QuarterMaster in the first place?

I don't know who suggested it for the other Dave, but Gordon Levy suggested it for me and I had the same experience....well even more frustrating because I got one of the "special" clutch discs that had the wrong center bushing and wouldn't allow the clutch to release...already mounted to my Stage 4 Levy Engine...I should have checked it before installing it but wasn't aware of the issue from the forum. The chatter was totally unacceptable, you could only release at idle or high enough to spin the tires...of course the STage 4 died 70% of the time when releasing at idle.

I switched to a Ram steel billet flywheel and King Cobra clutch from Mike Forte and the external hydraulic setup and am very happy with the car now. My engine was completely redone by Gromm Racing in San Jose and is very quick revving due to the head work and cam chosen by Gromm, I don't think I could react fast enough if I had an Aluminum setup, keep bumping into the rev limiter all the time and it is set to 7000 rpm. Extra oil passages were added to the block to feed the thrust bearing and cam bearings; standard procedure for Gromm when building hi-po small block Fords. Engine is safe to 7300 according to Bob Gromm. I can highly recommend Gromm Racing for a complete engine, head work, or repair...great shop...an Expert!

[Daddy-O]

Nice write-up guys. Validates the whole concept of 'street' setup.

[Greg_M]

Originally Posted by SJDave

I don't know who suggested it for the other Dave, but Gordon Levy suggested it for me and I had the same experience....well even more frustrating because I got one of the "special" clutch discs that had the wrong center bushing and wouldn't allow the clutch to release...already mounted to my Stage 4 Levy Engine...I should have checked it before installing it but wasn't aware of the issue from the forum. The chatter was totally unacceptable, you could only release at idle or high enough to spin the tires...of course the STage 4 died 70% of the time when releasing at idle.

Ditto Don Voorhis car. Ditto on the messed up clutch disc as well. GL nor QM had a solution that wouldn't take 6 weeks and Don did not have 6 weeks to give. We dropped the tranny, pulled the clutch then had it machined locally on our dime, put everything back together and it still sucked.

If someone offers you a QM clutch with an AL flywheel for the street, run far away screaming.

Clutch after only 300 easy miles:






Greg

[2yrproject]

I just did a similar swap from the QM Extreme 8.5 to a Spec 2+ clutch and aluminum flywheel. I've only had the car out for one drive so far, but initially it's so much better. The car has much better driveability and manners. I went with the aluminum flywheel for a faster revving setup and so far, I'm very pleased.

No more bucking and chatter. The best part is the irritating rattle from the bellhousing (floater plate) is gone.

Thanks for the input Dave and Frankeeski. Looking forward to more drive time now !

[Mike Forte]

Hi,
I think building a street car has to always be in mind while building these cars. We tetter on the edge of being a racecar and streetcar. Many similarities but very different needs. My racecar has/had a Tilton triple 5.5" disc setup with a 105 tooth flywheel. Very small setup and the engine was very low in the chassis with the drysump oil system.
Remember I said "racecar". Could it be driven on the street? Yes, I suppose but with many compromises in driver comforts.
Don't throw away those race parts. They can be used on a "racecar" where it was built to be used...
While specing racecar parts, make sure plenty of questions are asked so you get what is BEST for your needs...

[tad240]

This is great information to pass along regarding the 8.5" diameter racing clutch.

However to clarify for others that may get the wrong impression about aluminum flywheels, I have an 11" steel clutch coupled to a McLeod aluminum flywheel and none of these issues exist with that combination. It is "street friendly".

[2yrproject]

Mike, good analysis and I agree that all of these components have their place and each builder has their own expectations about what's the right setup for their car. In this case, there was a learning curve for me. Hopefully the information helps someone else down the road.

Tad240, I'm glad I went with the aluminum flywheel again. The QM clutch choice seems to have been much more of an issue to me than anything else.

It's really a good idea to talk to lots of folks to find out the best choice for you.