quote Originally posted by fieroman87: .46 lbs of lost rotating mass IS an improvement and you'd see it in a side by side test but i'd think that the weight would have been better when lost tward the OUTSIDE of the plate ring, thus lowering enertial forces. -Arty

I was thinking the same thing. it looks like you would have be very serious to have the lightened pressure plate be worth the cost.

I think they drilled them on the inside to keep more friction surface toward the outside where there's more leverage. Those are some expensive holes there.

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Alan Frazier
'88 coupe auto 74k miles for sale
'86 GT-'92 3.4 TDC 5 speed(sold)
'84 2m4 daily driver

Well I talked to David again today, it appears there's some confusion on what I'm supposed to be getting and what I am getting. After I explained that the weight of the two pressure plates is only about a half pound different, he mentioned that I must have had one that was partially lightened but didn't get holes drilled in it. Apparently, the lightened pressure plate is supposed to have a machined piece for the friction plate rather than a cast piece. Both of the pressure plates I have use a cast friction plate, one with holes and one without.

We'll see what comes of this. Frankly, I'm a little less than enthused about the "speed holes" in the friction plate, *especially* because it's a cast piece...those holes could become major stress risers, although they are at least chamfered. I emailed pictures to David and I'm waiting on a response of what will happen next.

To be continued...

Bryce
88 GT

WOW, sounds like the light weight package is far from worth it, at least for us!!!

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
thespeedshop@sbcglobal.net
My build thread

quote Originally posted by neverendingproject: I think they drilled them on the inside to keep more friction surface toward the outside where there's more leverage. Those are some expensive holes there.

I'm sure that's why... the loss of surface area is worth more at the outer edge... worth more to inertia and worth more to friction. I guess friction won out in that compromise.

Ahh... so the lightened pressure plate is a billet piece of steel rather than a casting... For some reason I was expecting and aluminum pressure plate cover or something fancy... The billet pressure plate just seems kinda old school.

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Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

[This message has been edited by Will (edited 10-29-2004).]

quote Originally posted by Will: Does that 20.84 include the disk?

Yes, that is the flywheel, friction disk, pressure plate, clutch bolts, and flywheel bolts. The whole clutch/flywheel assembly minus throwout bearing.

Bryce
88 GT

quote Originally posted by Nashco: 3.34 lbs - Friction Disk Assembly 8.00 lbs - Flywheel Assembly 9.56 lbs - Standard Pressure Plate Assembly 9.10 lbs - Lightened Pressure Plate 0.40 lbs - Included Hardware 21.3 lbs total [std pressure plate] 20.84 lbs - Total With Lightened Pressure Plate

At $400 for an 8 lbs aftermarket flywheel (vs a 14.5 lbs modified GM flywheel) you're paying $61.54 per pound of weight lost.
At $80 for a 2 lbs drop in PP weight, you're only paying $40 per pound of weight reduction. Who says it gets more expensive as you go?
Anyway, it sounds like the 2# drop in PP weight is at least as worthwhile as the whole act of buying the flywheel.

So that should get you down to ~19.3# for the complete assembly with the "real" lightened pressure plate.
Compared to 3.34 (disk) + 9.56 (PP) + 14.5 (GM FW) + 0.4 (hardware) = 27.8 pounds...

Overall the SPEC setup drops 8.5# of engine speed rotating mass, which is a reduction of 30.5%... HUGE difference. The Northstar already revs pretty quick with the 28# setup, it ought to be VERY nice with the 19# setup.

Interestingly the even the standard weight clutch assembly with GM flywheel is lighter than the "standard" weight Chevy flywheels of yore, which were about 30#.

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Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

For those interested, I talked to David again today. He verified that I didn't get what I should have gotten, and that the new pressure plate should go through tech this week. He told me the standard pressure plate uses a 1018 friction plate, and that the machined friction plate for the lightweight clutch is 1040. I'll let you know more when I receive the (third and hopefully) true lightweight pressure plate.

Bryce
88 GT

I ordered mine the other day, I ordered the alum. flywheel and the stage 3 K clutch package. I was wondering how many others ordered the stage 3 K?

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
thespeedshop@sbcglobal.net
My build thread

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
thespeedshop@sbcglobal.net
My build thread

That's what a 3K looks like, eh? Congrats! You finally got it!
I think I'd rather have a 4-puck... easier on the synchros

[This message has been edited by Will (edited 11-10-2004).]

quote Originally posted by Will: That's what a 3K looks like, eh? Congrats! You finally got it! I think I'd rather have a 4-puck... easier on the synchros

Sure, but what about the rest of the trans? I'm assuming you're saying they're easier on the synchros because of the reduced inertia? I wouldn't want a four puck because they're basically an on/off switch, which makes the shock loads to the gearsets and trans shafts a lot higher, typically. There's also the driveability factor...you can kinda sort slip a six puck a little bit, where as you are foolish to expect it out of the four puck.

Of course, to each his own, just curious what your logic is Will.

Bryce
88 GT

Yeah, inertia. You can slip anything if you calibrate your foot well enough.

If the disks are made the same with regard to marcel and hub springs (or lack thereof), then a 4 puck won't be any worse than a 6 puck.

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Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

quote Originally posted by Will: Yeah, inertia. You can slip anything if you calibrate your foot well enough. If the disks are made the same with regard to marcel and hub springs (or lack thereof), then a 4 puck won't be any worse than a 6 puck.

You must have a much better calibrated foot than me; I've only driven a few four pucks, but they chattered like a mofo. Also, the reduced intertia of the clutch will make a difference in torque spike loads Since we're already cutting the rotating mass in half with the Spec parts, I think it's safe to say that making that argument pointless. The difference in friction characteristics between the 4 and 6 puck would show much more difference in peak torques during shifts than the clutch inertia, obviously.

Bryce
88 GT

A LOT of times people get 4 pucks with ridiculously aggressive friction material just because they can. That's why it chatters, rather than just the nature of a 4 puck.
A 4 puck DOES have higher surface pressure at the same clamp load than a clutch with more friction area, so it will tend to exaggerate non-linear behaviour of the friction material...

I'm not worried about torque spikes during shifts... The reduced inertia of the disk allows the synchronizers to spin the disk up or down faster, resulting in faster shifts with less blocker ring wear. The clutch disk is a very large fraction of the total moment of inertia of the transmission input shaft and whatever gear you're shifting into. Reducing the MOI of the clutch disk by a certain amount reduces the amount of work the synchros have to do during a shift by almost the same amount.

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Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

[This message has been edited by Will (edited 11-12-2004).]

quote Originally posted by Will: I'm not worried about torque spikes during shifts...

Why not? This is the one of the most fatigue-inducing events the transmission sees. Sure, part wear is a concern, but we can't ignore torque spikes. I've done a fair amount of research in this area at work, and I'll say I was shocked at the loads involved during shift transients, it's amazing stuff...I wish I could afford that sort of instrumentation on my own stuff!

Bryce
88 GT

Torque transients are a function of the MOI of the flywheel and engine components... which is being reduced with the aluminum flywheel.
They are also a function of how hard the clutch comes down, which will be pretty hard with the stage III...
They are alos a function of how fast your left foot moves, which you can control. If you're worried about torque transients, slow your foot down a little bit and don't bark your shifts.

You understand what I'm saying about lower synchronizer load and faster, easier shifts with a 4 puck?

I'm thinking on a much smaller scale than you..microseconds rather than averages. With reduced MOI for the rotating assembly, torque spikes can actually increase in magnitude. As you know, there is inevitably some slop in the drivetrain (axles, gears, synchros, etc.) and there are also power pulses coming through it every time a cylinder fires. When a cylinder fires, it twists things up really hard in the positive torque direction, this then causes a reactionary negative torque when everything untwists before the next power pulse comes. In the testing I did, we were recording so accurately and at such a frequency that you could literally see the engine firing pattern looking at the torque data. So, with a reduced MOI in this application, it would actually allow the delta from peak positive torque to peak negative torque (with each cylinder firing) increase because the lighter rotating assembly would be loading up in the negative direction sooner and with more velocity when the next torque application came due to the firing cylinder. Of course, this is so focused that with every engine/trans/drivetrain configuration it will be different, but that's what I saw in my testing and it makes sense when you see the data. By increasing MOI and changing from sprung/unsprung clutch hubs (and modifying spring rates) you could tune the application to have much less damaging peak to peak torque cycles, but the end user would have little to no idea that the vehicle was any different between any of the configurations (especially when modifying spring rates). Due to this phenomenon, certain combinations of unsprung hubs were actually less damaging and smoother than a sprung hub.

So, perhaps now you see where I'm coming from. That's why I was saying that my argument is pointless is that the reduced inertia may seem better but actually be more harsh on your drivetrain, but without some $weet instrumentation you'd never really know. How you shift also has a LOT to do with drivetrain loads, obviously.

Bryce
88 GT

I see where you're coming from now... I think you're getting WAY down in the weeds, though

For reference, what was the delta T you were looking at and how many cylinders in what configuration did the test engine have?

I'm sure you've seen chassis dyno charts of a automatic cars... A car with 300-350 RWTQ can easily spike 500 on the shifts. That's what I'm worried about.
I'd take a stab at a rudimentary mathematical model, but I think I'd have to make too many simplifications and it's too late at night to think about the full complexity.

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Turn the key and feel the engine shake the whole car with its lope; Plant the gas pedal and feel in your chest neither a shriek nor a wail but a bellowing roar; Lift and be pushed into the harness by compression braking that only comes from the biggest cylinders while listening to music of pops and gurgles. Know that you are driving an American V8. There are finer engines made, but none of them are this cool.

Luck, Fate and Destiny are words used by those who lack the courage to define their own future

Like I said, getting that in-depth is just talk since without some fancy instrumentation you'd never really know what to expect.

Unfortunately, I'm not at liberty to talk about the details of my research at work.

Bryce
88 GT

installed the flywheel today and it looks great, bolted right up and lines up nice!

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
thespeedshop@sbcglobal.net
My build thread

looks great...

Yes it does, what a great feeling to see how it turned out, I think we did good.

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
thespeedshop@sbcglobal.net
My build thread

Awesome... seeing is believing.... Now to see about a trade of a spec 3800sc plate for a northstar one.. LOL

And last but not least the one last item we need made!!! Mass produced motor mounts or a ready fit cradle!!
Cause thats the one thing that has me scared to dive into this motor swap... I can't fab my own.

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Ferrari 308 GTB rebody on a modified 86SE chasis Soon to have a highly hooped up 3800SC..Ohh yeah baby!!
Contacts _ AIM / Zildjianfx _ Yahoo / djdraggin
Remember, always brush your milk, drink your teeth, dont do sleep and get eight hours of drugs.

quote Originally posted by DjDraggin: Awesome... seeing is believing.... Now to see about a trade of a spec 3800sc plate for a northstar one.. LOL And last but not least the one last item we need made!!! Mass produced motor mounts or a ready fit cradle!! Cause thats the one thing that has me scared to dive into this motor swap... I can't fab my own.

DJ, the hardest part is getting started. if you do like Will and weld (or have someone weld) in the front x-member before you cut out the original you should do just fine. For my swap my tools are a battery powered sawzall, battery powered drill, a bench grinder (no bench) and the standard sockets, wrenches, hammers, files etc. oh, I need to include the cheap lincoln weldpac 115 welder. I bet you could do this if you take your time. go for it! "no hijack intended"

So has anybody run the new Flywheel yet, I am waiting to still mount my motor?

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
219customs@verizon.net
My build thread

I still haven't got the proper lightened pressure plate. David hasn't returned my calls or emails for a couple weeks now and it's getting pretty frustrating. I've got two pressure plates from them already, just not the right ones. After the holidays I'm going to really hound him and see what the deal is.

Bryce
88 GT

Wow Bryce, I am sorry about that. I did go back and forth with him over the yaer so I feel bad about this! I say stay on him and call me if things don't work out after the new year. I will try to help if I can, I did talk to him about the rings for the 88 brake upgrade I put together and samething was just taking to much time.

Again guys if anyone has a problem with anything that bought from Spec, we did deal with David Norton as the salesmen for Spec.

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
219customs@verizon.net
My build thread

Nashco any word there buddy?

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
219customs@verizon.net
My build thread

how did this deal work out
has the center hole size issue been fixed yet??
has anyone got this flywheel/clutch setup driving now???
what is the current total cost for the complete FW/clutch/PP/throwout bearing??

I need one, but want to hear you guys are happy and driving with these parts
before spending the $$$

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Question wonder and be wierd
are you kind?

Sorry Ray B, I can tell you I have mine mounted on the motor without anytrouble, thay do line up on there nice. I do not have it running yet. I think the flywheel is being sold for $400, and for a custom aluminum flywheel thats cheap! I paid just around $300 for my clutch. When you call over there ask for David Norton and tell him Robert from 219 Customs and from this forum sent you. I have talked with David alot over the last year.
Bobby

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
219customs@verizon.net
My 86 GT build thread
MY 88 Northstar build thread

quote Originally posted by GSXRBOBBY: Nashco any word there buddy?

I called a couple days ago and David told me that they were waiting on me to return a pressure plate before they'd send me the correct one. It sure would have been nice if they told me that a couple months ago, rather than telling me it'd be in the mail that week! He said, "We need to make sure we're not going to get shorted," which made me chuckle because that's exactly what I was having to deal with. I asked David to take a look at the pressure plate and verify it's the right one before I send mine back, but of course he hasn't returned my call, so I'll call tomorrow and remind him.

I just bought a house, so it'll be a while until I can afford an engine to bolt this thing up to. I thought about selling my CBR to pay for it, but that would be taking one step forward and two steps back in terms of getting my speed fix.

Bryce
88 GT

quote Originally posted by GSXRBOBBY:

How much did you pay all up with shipping?

$684 shipped for the N* flywheel (with flywheel bolts), stage 3 HK model clutch, normal weight pressure plate, throw-out bearing and the clutch alignment install tool. i think it is a great deal.
that was October 2004, prices may have gone up some.

Shipping? Not to much at all, maybe $20. It all came in one box around 3"X15"X15"

I got one!

The flywheel is very light, but the pressure plate was very heavy, I was wondering if was possible to get the pressure plate in a lighter version?

Would this be an option?

Thanks!!

James.

Call David and ask?

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Bobby from NW Indiana
93 Northstar and 5 speed Getrag
219customs@verizon.net
My 86 GT build thread
MY 88 Northstar build thread