TheHeadFL

OK, my clutch is slipping a bit now on launch and shifts at the track (I can't 60' better than 2.15 without clutch slip) and I am looking for a replacement before it goes totally out.

For clutches, I am considering:

Spec Stage 3
Spec Stage 4
McLeod Street Twin setup (I'd rather not have to go this far though)

For flywheels, I have considered:

Fidanza Aluminum flywheel
GM stock replacement LT1 flywheel
SLP billet steel flywheel

Now, I have heard that SPEC seems to be having problems w/ the Stage 3s, and that Stage 4 clutches are similar for street using, and are unsprung. So I keep hearing differing opinions on that one. I hear the Stage 4 is great, and then that its too extreme. I am leaning towards the Stage 3, despite the "reliability problems" which in my opinion seem more prevalant because that clutch is so popular. (I think that the percentage yield of that clutch is probably average, but being that it is so popular, the actual raw number of defective units its higher)

Anyway, on the flywheel side, I want to replace my flywheel. I do not like the idea of turning it because it screws with the engagement point of the clutch a little bit. The number one contender for me right now is the SLP billet steel flywheel. I like that it is 7 lbs. lighter than stock. Now my question is, has anyone used this flywheel, and is it noticeably different than stock? Is 7 lbs too much lighter? I also considered the Fidanza, but my friend has one on his 429 cid LS1 and he thinks it may be too light to launch effectively. If I can't decide, of course, I will go with GM stock replacement, but I would prefer to lighten the flywheel a *little bit* to free up a bit of power.

Finally, if I got the SLP flywheel, what are the chances that I am going to need to have it balance checked? Would it come prebalanced for the LT1 engine? Also, I have heard that SLP "reccommends" a new hydraulic setup (GM PN 12559912 I am told) but I am unclear on whether this is really neccesary.

Thanks,

-Ryan

TheHeadFL

BTW, what does the stock flywheel weigh??

94formulabz

20-21 lbs.

You do realize the street twin price includes flywheel right? I got my Al Street Twin for 900 shipped. If you are willing to wait for group prices and stuff you can get down into the sub 1k price range.

I don't have any experience with a spec stg 4, but the stg3 and a street twin aren't even in the same league for driveability.

-brent

TheHeadFL

Yeah I did know that the Street twin includes flywheel but its still quite pricey considering what I'm looking at now.

I thought I read somewhere the stock flywheel is 30 lbs?

94formulabz

well, brent franker has it listed as 20 or 20.5 on his site. I know that with Al street twin the flywheel is lighter but your adding the floater plate so the whole assembly works out really close to the stock clutch weight.

I thought that a spec stage 3 with aluminum flywheel was in the 900 range. Now granted its not fair to compare a street twin sale price to full msrp. But since you are considering an Al flywheel it comes close to overlapping. Did i mention that my street twin drives WAY better than my good friends stage 3?

-brent

94formulabz

Oh yeah, and you get the new adj master cylinder...... you'd think i own stock in McLeod.

-brent

onebadponcho

Join the club, Ryan.....I'm also looking at getting a new clutch; mine isn't slipping - yet, though.....

I'm looking at the Street Twin (even though I don't need it) or the McLeod single disc. I've searched on here and I don't think I've ever read anything bad about McLeod clutches; have heard nothing but good things about them....

TheHeadFL

McLeod is starting to sound better... but I did hear they wear on our input shafts or something... any truth to that?

94formulabz

I've never heard that, but i haven't had mine long enough to require disassembly.

I can tell you that lining up both friction disc's to get the tranny in can be a major bitch. Since i know your going to end up getting one and i've been meaning to share what i learned from the installation; here is the tranny installation method I used after 2 botched installation attempts using the supplied alignment tool:

-I made the pressure plate finger tight so i could slide the friction discs if i wanted to but they held their position.
-Install Tranny. Since the pressure plate is loose you shouldn't need longer bolts to "draw the tranny in" as some people suggest. It may be helpful to have the tranny in gear so that you can rotate the input shaft using your driveshaft. That is not 100% neccesary though.
-Snug up the Pressure plate bolts through the clutch fork hole in the bellhousing. Remember you buddy that helped you get the tranny in, have him get you a beer and then go lay up front to turn the motor over for you so you don't have to go back and forth. I snugged them up evenly in 3 increments using a star pattern (well two triangle patterns) like your tightening 6 lug nuts.

If you use that method the first time to reinstall the tranny it will save you HOURS; unless by some miracle you actually managed to align the clutch disc perfectly using the tool and in that case you will have wasted about 15 minutes.

Master cylinder installation tip:
-The holes for the Ubolt to go through are perfectly toleranced with zero clearance, drill out the holes in the mounting plate slightly so you don't have to struggle with the Ubolt in tight quarters.

Those tips are somewhat street twin specific and supplement the other guides out there such as: http://www.bfranker.badz28.com/fbody/t56.htm

TheHeadFL

How many miles do you have on your street twin, and how is the daily drivability?

By the way, what is involved in installing the hydraulics, and why are they needed?

jchevy

I have broken the sprigns out of the center hub on 2 mcleod performance disks in the last year. At the time i was only putting down about 330 hp. It was a good grippy clutch though, i will give it that.

94formulabz

I only have a couple of thousand miles on my street twin.

Daily driveability: When i backed it out of the garage to test it out i was absolutely amazed and knew i had made the right choice. I was so excited i let my buddy try it out and he was so jealous that he started cursing the guy he bought his car from who had installed the spec stg 3. I have driven the stage 3 recently so i can confirm its still a PITA. No problem in stop and go traffic every morning on the way to work. Pedal is ever so slightly firmer than stock.

I believe the mcleod master cyl has a smaller (someone correct me if i'm wrong) piston so it doesn't move as much fluid thus making the engagement zone larger and smoother (like stock). It has an adjustable rod so that you can adjust the engagement position from the floor / pedal height. I guess some people have purchased the mcleod master cyl to use with other clutches, but why not just get the whole mcleod package since you know it all works together.
The hydraulics are kinda a pain to install because you need to reach around the brake master cylinder and work "blind".

If you do a street twin search and pay carefull attention to who actually owns one and who doesn't, you'll notice all the owners are very positive.

Only drawback is price. I did get lucky and got a killer deal on mine.

-brent

TheHeadFL

Regardless of what clutch and flywheel I go with, I have heard that I should match-balance the new flywheel to the old one. How neccesary is this really on a stock motor?

(I have a new motor and presumably the same flywheel as the old motor and I can't imagine they rebalanced it when they installed it)

94formulabz

Ahh match balance..... ask the expert internet lemmings telling you that the name of the shop were they got theirs "match balanced". Then make a note to self to avoid that shop at all costs because they are charging you labor for something they didn't perform.

The Mcleod will be good to go, and i'd hope any other new flywheel would be within factory specs as well. The factory just used decent tolerances and bolted the motors together, they did not balance each flywheel individually when they were building them, so even if your new flywheel was identical to the old one it still may not be perfect. Soooo.....

If you have a rebuilt bottom end with an internally balance crank, then get a neutral balance flywheel (remove the counterwieght and sized bolts on the street twin and it is neutral balance)

If you have a stock bottom end neutrally/internally balanced at the front and externally balanced at the rear, just buy one to stock spec. (leave balance weight installed on street twin)

P.S. when i was shopping around for a clutch i saw the same posts and double checked with rich that it was unneccesary just as you are doing.

-brent

TheHeadFL

Haha, good advice on the machine shops then.

Yeah my motor is a GM crate LT1 replacement engine w/ 4 bolt mains. Nothing special in the bottom end, but it was one of the last LT1s ever made (judging by the date sticker that was placed on the block and heads)

If I can't swing the dough for the McLeod (i.e. I can't find a nice GP on it or something, best price I've seen lately is $1060) I will probably end up using a SLP flywheel and an as-yet undetermined clutch.