It worked really well, right up until it didn't.
Now I can be in 4th or 5th and stomp the gas, and make it slip.
The clearances were a a little close when I assembled it, so I was hoping that it was just a matter of the pressure plate fingers moving outward as the disk wore down, but that proved to not be the case. (Fabricated and installed 1/8 shims between the block and tranny, to test. Made no real difference.)

So... what are all you "tractor motor" folks using for clutches?
I know this same question was asked, a while back, but there has been a lot of water over the dam since then.
I'll even listen to "spec" suggestions, as bad as the "2" was in my 3.4 car.

Thanks.

------------------
Raydar
88 Formula IMSA Fastback. 4.9, NVG T550

Praise the Lowered!

I use a Krupp. It's never slipped, even while breaking in. Of course, I never drop the clutch since I really don't want to kill the Isuzu.

As you know,the 4.9L puts out 275 ft lbs of torque in a narrow power band. While there are many Fiero owners here that love the stick and frown on the automatics, they were designed for the power and will last. If this is out of the question, try a high end Spec.
As for a strong clutch- the Spec 3 supposed to be strong but we had one guy in the club that fried that with a 3800SC in short order. I installed that clutch and 3 months later the flywheel looked like cracked cheese (with spider cracks) and the clutch disc was worn to the metal. After a second Spec clutch, a month later his Getrag grenaded.
The bottom line is that when you exceed the design limits of the Fiero drivetrain you've got to expect and live with periodic replacement.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Center force dual friction in my 4.9 Isuzu drivetrain. 2-3 years old at this point. Light on the pedal with smooth engagement. But the tranny's making noises now

Steve,

I am using a SPEC Stage 3+ on my 3800 SC Series II engine and so far it is working well. I also used this on the 383 but do not have a lot of time or miles on this machine. I have used the McLeod Sintered Iron clutch on the 3800 SAC Series III motor (around 300 hp and 300 ft/lbs torque at the wheels based on dyno) for about 20,000 miles and it is still holding well. Note that this is an instant on/off clutch that is quite grabby. BTW, I also have about 8,000 miles on a SPEC Stage II in a turbo 3.4 application and so far so good.

Nelson

Thanks everyone.
One of my requirements is that the car still be easy to drive, even in the occasional bit of heavy traffic.
I am leaning toward the Spec 3+, even though the Spec 2 that I had in my 3.4 car was horrid. Chattered when it was cold, and slipped when it was hot.

Sintered iron? I don't want something that is going to be like an on-off switch. It's why I went with the Ram in the first place.
(To be honest, I'm hoping that I find an installation issue with the Ram. There were a couple of things that I had questions about, after the fact, that were just fine as installed, but may have become a problem with a bit of wear. (Clearance between the center hub, and the corners of the flywheel bolts, for example. I did a bit of "clearancing" but maybe not enough.)

Dennis.. It sounds like your guy with the Spec 3 is one of those people who could break a crowbar in a sandbox.
And, since you brought it up (as you usually do), the automatic is out of the question. Cadillac trannies don't do anything quickly - by design. It was never in the gear I wanted to be in. I went to a lot of trouble to swap in the 5 speed. (But you already knew that.) Never going back. The automatic is why I almost sold the car, a few years ago. I'd swap a different engine into the car before I went back to an automatic.

Centerforce DF? I had a Centerforce in a 305 Firebird. Don't think it was the DF, though. It grabbed okay, but vibrated like hell, from day one. (It was the one with the counterweighted release fingers.) How many miles are on it?

The Krupp looks interesting (never heard the name, before yesterday) but I'm thinking it looks "grabby" due to the "puck" design?

Once again. Thanks, all.

[This message has been edited by Raydar (edited 06-07-2015).]

I'm shocked that more don't use the old tech from the days of nascar busch cars that had v6's and multi disc clutch, that up's the surface area 10x's
buick ran back then so it should not be hard to find set up's for the 3800 .
or make it bolt to a catty flywheel..

quote Originally posted by Raydar: Thanks everyone. One of my requirements is that the car still be easy to drive, even in the occasional bit of heavy traffic. I am leaning toward the Spec 3+, even though the Spec 2 that I had in my 3.4 car was horrid. Chattered when it was cold, and slipped when it was hot. Sintered iron? I don't want something that is going to be like an on-off switch. It's why I went with the Ram in the first place. (To be honest, I'm hoping that I find an installation issue with the Ram. There were a couple of things that I had questions about, after the fact, that were just fine as installed, but may have become a problem with a bit of wear. (Clearance between the center hub, and the corners of the flywheel bolts, for example. I did a bit of "clearancing" but maybe not enough.) Dennis.. It sounds like your guy with the Spec 3 is one of those people who could break a crowbar in a sandox. And, since you brought it up (as you usually do), the automatic is out of the question. Cadillac trannies don't do anything quickly - by design. It was never in the gear I wanted to be in. I went to a lot of trouble to swap in the 5 speed. (But you already knew that.) Never going back. The automatic is why I almost sold the car, a few years ago. I'd swap a different engine into the car before I went back to an automatic. Centerforce DF? I had a Centerforce in a 305 Firebird. Don't think it was the DF, though. It grabbed okay, but vibrated like hell, from day one. (It was the one with the counterweighted release fingers.) How many miles are on it? The Krupp looks interesting (never heard the name, before yesterday) but I'm thinking it looks "grabby" due to the "puck" design? Once again. Thanks, all.

I never tell anyone what to use. Just trying to state what will last.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

quote Originally posted by Dennis LaGrua: I never tell anyone what to use. Just trying to state what will last.

Of course.