Which clutch for Toploader to Tremec swap

Grubby · #1 (**permalink**) 11-09-2010, 03:18 PM

Guys,

I have removed my toploader and getting ready to install a TKO600. I had NAPA order a clutch disk for 75 Vette. It is very close to the 11" I removed with one exception. The round stock part that is splined is offset towards the engine about 3/16" when compared to the Ford type disk I removed. I see no obvious problems with this. It looks like the part will not come in contact with the pilot bearing.

Is this the right part? Can someone give me the correct GM application to ask for? My pressure plate is 11" diaphram installed by ERA.

Thanks.
John

otto · #2 (**permalink**) 11-09-2010, 04:48 PM

John, call mike@ fortes parts conn. he can set you up with what you will need , he is also a vender here
regards Bob

Excaliber · #3 (**permalink**) 11-09-2010, 04:55 PM

I recently changed my ERA from a top loader to a TKO600, with new clutch and pressure plate. I called Brent, at B2Motorsports. I too had an 11" clutch, after replacing it TWICE before the TKO I wanted to upgrade to something that would really hold!

Brent got me covered real nice, works great, even with slicks, the clutch holds!

502-759-1431
http://www.b2motorsportsllc.com/productpage.htm

blykins · #4 (**permalink**) 11-09-2010, 05:50 PM

I'll be glad to help, but I'll need a little info.

1. What engine are you running?
2. Do you know what brand pressure plate you have?
3. How much horsepower do you have?

It's true that the 1-1/8x26 input shaft size is a GM size, but you don't necessarily go searching for GM applications when looking for components. A NAPA disc will be organic on both sides, so depending on the pressure plate, it may or may not meet your horsepower needs.

Feel free to email or call:

brent@b2motorsportsllc.com

502.759.1431

Grubby · #5 (**permalink**) 11-09-2010, 06:10 PM

Brent,

Email sent. I suspected a GM part may not be the correct solution. Doing this job one time should be enough.

John

blykins · #6 (**permalink**) 11-09-2010, 06:32 PM

Sent you one back.

It surprises me that dealers end up installing stock replacement clutches with 500hp engines. It is true that a 2400 lb Cobra isn't as hard on a clutch as a 5000 lb vehicle, but you still need to select a clutch accordingly. I see 550hp SBF's paired with King Cobra clutch kits (300-350hp kits at best) or 500hp big blocks running NAPA clutches. It just doesn't work and owners end up going back and redoing the whole clutch assembly.

Grubby · #7 (**permalink**) 11-09-2010, 07:37 PM

In previous big block muscle cars, I remember clutch pedal effort as being very high. They had long style clutches and mechanical linkage.

The Cobra has a slave cylinder. How much increase in pedal effort should I expect going from the OEM clutch to a Long style?

John

blykins · #8 (**permalink**) 11-10-2010, 02:44 AM

It will increase, but the RAM clutches are designed to get a lot of the holding power from the disc and not the pressure plate. It will be more than you're used to, but it won't be a leg breaker.

patrickt · #9 (**permalink**) 11-10-2010, 05:44 AM

Brent, what's your view on pulling the little splined donut out of the back of the TKO?

blykins · #10 (**permalink**) 11-10-2010, 07:01 AM

If you can, do.

If you can't, don't sweat it.

Jim Holden · #11 (**permalink**) 11-10-2010, 08:38 AM

Before you make a decision, talk to Doug at ERA...

Jim

Excaliber · #12 (**permalink**) 11-10-2010, 08:43 AM

I've had both type pressure plates in my ERA, as well as several types of clutches. The difference, on my car, in clutch pedal pressure is barely noticeable. In fact, I never gave it a second thought as to which one was more difficult than the other. Either way, it's easy enough.

patrickt · #13 (**permalink**) 11-10-2010, 08:45 AM

Jim's idea is a very good one. I would call Doug up and ask him what disk and PP he would put in and then get it. But if you decide to upgrade to the 7/8" Tilton master, keep an eye on your clutch fork.

Excaliber · #14 (**permalink**) 11-10-2010, 08:55 AM

One problem with calling ERA might be that they would lean toward a good solution that is "adequate" without getting carried away. That may be fine for you, not for me! Having gone through a few clutches I was ready to do this one with the best holding reasonable on the street setup I could get my hands on.

I doubt ERA would recommend a double puck type clutch disc because of it's potential to chatter when used on the street. Brent also expressed some concern in that regard. True, at times, when conditions are just right, I can get a little chatter. 90% of the time I don't. I prefer the peace of mind that the clutch gives me, so it's the best call for me. I don't expect to have to replace THIS clutch anytime soon.

Now if I recall, the disc Brent recommended (and I'm running) was 10" vs my existing 11". I was concerned about going to a SMALLER disc, but size isn't everything. The type of friction material is the key. Some VERY aggressive clutch discs are quite small.

blykins · #15 (**permalink**) 11-10-2010, 09:00 AM

The clutch I recommended to John was the next one down from Ernie's. It shouldn't have any bad street manners.

I believe in having more than enough clutch....not limping along and having to replace it a short time down the road.

blykins · #16 (**permalink**) 11-10-2010, 09:03 AM

Quote:

Originally Posted by patrickt

Jim's idea is a very good one. I would call Doug up and ask him what disk and PP he would put in and then get it. But if you decide to upgrade to the 7/8" Tilton master, keep an eye on your clutch fork.

The clutch that he currently has was installed at ERA. It's a LUK brand (stock replacement) clutch kit; your basic Autozone/NAPA/Advance Auto replacement clutch. His engine is approaching 500hp. I don't necessarily think I'd follow the dealer's advice again.

This is something I try to stress with customers. If you have a specific question about the car, contact the car manufacturer/builder. If you have a specific engine question, contact an engine builder. Likewise, if you need help regarding a drivetrain component, contact someone that has concentrated experience in that field.

strictlypersonl · #17 (**permalink**) 11-10-2010, 09:47 AM

Quote:

Originally Posted by blykins

The clutch that he currently has was installed at ERA. It's a LUK brand (stock replacement) clutch kit; your basic Autozone/NAPA/Advance Auto replacement clutch. His engine is approaching 500hp. I don't necessarily think I'd follow the dealer's advice again.

Strange. We use McLeod/Weber parts unless otherwise specified or supplied by the builder.

Excaliber · #18 (**permalink**) 11-10-2010, 10:14 AM

Terminology review:

A "rag" clutch. Basic and typical clutch composition on both sides covering the entire surface of the disc. Typical of a clutch you might buy from NAPA or where ever.

A "puck" style clutch. Little "pucks", spaced apart, not fully covering the entire surface of the disc. Composition varies, size varies. Typically obtained from a more serious "race type" outlet.

Or a combination, rag on one side, puck on the other.

Jim Holden · #19 (**permalink**) 11-10-2010, 12:45 PM

I would still call Doug to discuss. Often the engine supplier will supply the disc/clutch setup. That doesn't mean you have to take his advice, but he has always been on the right track with his advice to me.

Jim

Grubby · #20 (**permalink**) 11-11-2010, 04:17 PM

Jim - good advice.

Doug said it was certainly a Center Force clutch. He said to simply call Summit and order a clutch disc that is 11", 1 1/8"-26 and it would fit. He also gave me some other tips on doing the trans swap. Super nice guy, just like the rest of the gang in CT.

I ordered a new Center Force clutch disc today.

John