Thanks...100% agree, backs up what i read a wile ago on a ls1tech.. with lunching a 3400 lbs car with traction all the rotation mass on a heavier clutch an flywheel will help.. but to heavy (my opinion) of one will hurt ur ET.. so there should b a sweet spot in the weight.. agin my opinion.

 

Drove my buddies 996 Porsche, they have a way light clutch, a bit more " finesse " is needed do to the light clutch, put a heavier clutch in there and normal driving from a stop would be a breeze due to the rpm raising higher as you let the clutch out without having to give it gas. A lighter clutch is harder to launch and slip the clutch

 

When I replaced my clutch and flywheel, I did quite a bit of reading on this since I wanted to know what the pros and cons were. For drag racing where achieving the lowest ET is important, getting all the stored energy to the wheels as quick as possible will give you lower 60fts which also reduces ET (assuming traction is present). The heavier flywheel will do a better job at this than a lighter one.

Here is one articles that I had saved at the time:

http://www.stangnet.com/mustang-foru...ywheel.576766/

 

Good kill! Isn't you're trap slow for the mods ? Or does the DA suck were you are at?

 

Wrong. look at my sig, I have the 112

 

Quite a few car manufacturers use light weight flywheels in their performance cars. Good example is the 03/04 Cobra.

 

Stock 5.0 clutch is also quite a bit lighter than the ls1 clutch

 

This^^^

This is true for launching, a heavier flywheel is better because it stores more energy ie inertia. However after you launch that inertia is doing nothing but slowing you down.

Moment from Force*Dist-lever arm I'm assuming you're talking about the moment the clutch assembly puts on the crank as it spins correct? That's fine but remember inertia works both ways. Once you have it going its not hard to keep it going. BUT thats not what an engine does from the time you leave the start line to the redline you are trying to accelerate a mass which has to overcome that moment of inertia. You are, as you said storing energy in the flywheel at this point, energy that could be going to the wheels. Then when you shift the mass keeps the rpms from dropping very quickly (inertia is released) but then you reengage the clutch and the engine must now overcome that inertia again and then fight it again back to the redline as it once again puts energy back in.
Storing energy at 6k is not necessarily a good thing...


Imagine you are turning a 10 foot dia windmill by hand that weighs 200 lbs. Now imagine that windmill being 6ft in dia and weighing 130 lbs. Which will be easier to spin and take less energy from you? The same goes for an engine at 6500 rpm all the extra energy it takes to keep that clutch spinning is hp lost to the wheels. The lighter assembly will make the car a bit trickier to launch but theres an easy fix for that, more rpm or more air in the tires. Mustangs use a 40lb clutch and some go lighter while fbodys weigh over 50lbs, theres simply no need to be that heavy it just hurts everywhere in a 3500lb car.

Mach just curious because you mentioned moment...What is your profession?

And unless Nick gets a stupid deal on an ls6 or buys the new dorman copy he should look out for a used fast. The days of a cheap ls6 manis are over. I got 675 for mine a few months ago with fuel rails/injectors on it. Then bought my 102 with ls3 injectors and rails for 750.

Monster makes great clutches but people jump on their dick so much on here its annoying, fact is the clutches are VERY heavy and I personally dont think they drive that good after being in multiple cars with them. People overlook the weight and just go with it because its the brand everyone has. However they do hold a good chunk of power so its all about needs and wants.

 

Stock '99 WS6 LS1
Flywheel:__________25.5 lbs.
Pressure plate:_____22.0 lbs.
Clutch:____________5.5 lbs.
Total:_____________53.0 lbs.

LS7 setup:
Aluminum flywheel #198171:_______13.5 lbs.
GM LS7 pressure plate from #24238412:____25.5 lbs.
GM LS7 clutch from #24238412:___________7.5 lbs.
Total:________________________________46.5 lbs

Just found this.. Looks like a good set up to me. Lil bit litter but enough to keep the energy alive and transfered to the tires..

 

Electrical Engineer - Work: Controls and Automation Eng (Pharmaceutical Process Control)

Most of my electives in college were ME and Physics classes which is probably why I mentioned "moment arm".

 

Oh good stuff brother, well if you have an contracdictions to what I said feel free... lol I'm Mech E, just getting done with school and job hunting lol. Most of my electives are electrical and higher level fluids/thermo based

I wouldnt run the ls7 because of the self adjusting pressure plate alone. That design sucks and is what causes a lot of the shifting problems that plague ls cars to begin with. Blocked out of gear and clutch pedal on the floor being some of them. It can also be hydraulics.

By the time you factor in an alum flywheel also you are in the 600 rang so its not a great budget option

 

I figured you were ME by the explanation you gave which was dead on. Sometimes I wonder why I did not go with ME instead. It seemed I was always more fascinated with those classes than any other. Thermodynamics being one of my favorites.
Good luck with the job hunting! I think you picked a good time to be an engineer since the US currently has a shortage of them. You will do well.

 

So not wrong, I said I didn't know which you had. And I'm on Mobil, I can't see your sig.

 

No they're not... stock hydraulics are ****.

Don't waste your time with a new MAF, just go SD.


You guys arguing the light weight clutch/flywheel thing are funny. You dont have to be an engineer to figure this stuff out, the testing/results are out there for everyone to see. A light weight flywheel in a relatively low powered car (e.g. op's car) will almost always cause bogging issues, which will kill your ET. And no, the small benefit of putting a ****-hair more power to the wheels for the rest of the run will not make up for it. But don't mind me, I know nothing about making low power combos go fast...

 

the good news is the tracks lack in maintenance on the board made the 8 look like a 6 lol. dont worry my first time at the track wasn't the best either.

 

Put some slicks on it to make it a race car.


On serious note, the power is there to run solid 7's. Just need the proper drive-train and tires($$$$).

 

That's not terrible really for a ls1 intake. My ls1 made 305whp on a mustang dyno......but it ran 12.6 @112.8. Very similar to the rest of your car, stock gear, stock catback (slp dual dual came on my car) stock suspension on lowering springs, very near stock weight (!jack/spare). I did have a spec clutch and aluminum fly.
It will mostly depend on your traction. A heavy flywheel with stored energy will do you no good if you do not use the energy.
There is no durability issues with a light clutch and a v8......you don't have to slip them like a 4cly or v6.

A lighter flywheel don't work better in roll racing because it stores less energy.......I works better because it's easier to turn. Like I said stored energy is only good if you have the traction to utilize it instantly.
It don't do anything for cylinder pulses that I've seen.


FYI.......Auto converters can be as much as 30lb lighter than stock.
The problem with ls stuff is the clutch is to heavy from the get go. The article is about a mustang. They've had 40lb clutch/fly in them since the 70's.
Most honda's have a 30-32 lb clutch as stock. That gutless poopy 4cly don't seem to have drivabilty issues.
The 9lb weight change they did ain't **** and their engine is not a very good piece if 9lb of stored energy helped them get down the 1/4 .15 quicker. A aluminum ls flywheel is 13lb lighter than stock.
Not just a 5br0......mustangs since the 70's have had a 40lb~ clutch.
Alot of guys run a stock flywheel with that ls7 clutch which puts them adding almost 10lb on their crank on a already to heavy set-up.

 

I still run a stock mc. It seems fine. I can't say I've seen to many issues with the stock hydraulics. It seems the stock pressure plate is the problem to me mostly.

What kind of gains did you seen goin SD? I still have a maf.


It's not there for everyone to see. I seem to have pretty good results with a light clutch/fly. Most guys do not run 100% traction, a heavy clutch/fly is only useful when that energy can be released instantly. Once the rpm has dropped on the heavy clutch/fly it has to be reaccelerated. I'm sure you know what weight does to acceleration.

But i would like to hear if and what you have run for clutch/fly combo's and your results.

 

I was not saying the Porsche had poor drivability due to the lighter clutch, just a bit more finesse for everyday driving. If you were to teach a first timer how to drive a manual, same car, they more than likely would struggle more with the way light clutch as opposed to a little heavier one

 

Agreed. After I changed my clutch and flywheel out, it was like re-learning to drive a manual all over again. The light weight flywheel required more rpm and slip on take-off from a light. It took me some time but I have gotten used it again. It did also get somewhat easier to drive after the clutch broke-in.