Flywheel weight clutch stage?

[somedude_001]

There was a guy at Road Atlanta in Oct that got his leg cut off coming down turn 12 when the clutch/flywheel assembly let go. Since our's is FWD and not RWD, we don't have to worry about legs, since it's going to come right up our crotch.

I was really worried the first few times I wound my ATX out to 8500rpm. my converter is 37lbs and that is a lot of RPM...

 

[1993MTXSHO]

^ you've driven my car with a 9lb fly its not the fly wheel that makes it a b to drive in traffic it's the pressure plate on the clutch

I have to disagree, I believe it's the combination, the flywheel will make the most difference IMO. The lighter flywheel will make it trickier ot drive even on a stock clutch, but it's really not as bad as some say it is.

True, your car is very easy to drive. ****, your clutch pedal is softer than my SHO.

My spec stage 2 feels lighter then my stocker did, old worn out clutches and such I guess can feel worse.

^ thats very true it can be very difficult to get use to the lighter fly wheel... it really is like driving a whole different car! but thats all it takes is getting use to and once you do its amazing

I have to say It took me a couple days to get used to, I then parked my car for 2 years, and hopped right in and had no trouble.

The 9lb and stage 2 are really a sweet combination. It's perfectly fine for DD and isn't as horrible to engage as people say it is. The only thing I would say is that if you do a LOT of stop and go traffic, be aware that the 9lb flywheels don't take heat as well as stockers, so in that case I would say a 17lb or a lightened stocker would be your best bet. All it is, is that you have a smaller window I'll say, to slip and engage the clutch, where you will have to give it a bit more gas to keep the engine's momentum up. It's really not difficult to do after you get used to it. Plus it's sweet when people want to drive your car, and they can't. People always wanna drive my sho, and I have this thing about people driving my cars, but I finally will give in sometimes and let them, saying if you stall it once, you're done. They get in, stall it right off the bat, and then they're done

 

[wasianguy05]

I have to disagree, I believe it's the combination, the flywheel will make the most difference IMO. The lighter flywheel will make it trickier ot drive even on a stock clutch, but it's really not as bad as some say it is.



My spec stage 2 feels lighter then my stocker did, old worn out clutches and such I guess can feel worse.



I have to say It took me a couple days to get used to, I then parked my car for 2 years, and hopped right in and had no trouble.

The 9lb and stage 2 are really a sweet combination. It's perfectly fine for DD and isn't as horrible to engage as people say it is. The only thing I would say is that if you do a LOT of stop and go traffic, be aware that the 9lb flywheels don't take heat as well as stockers, so in that case I would say a 17lb or a lightened stocker would be your best bet. All it is, is that you have a smaller window I'll say, to slip and engage the clutch, where you will have to give it a bit more gas to keep the engine's momentum up. It's really not difficult to do after you get used to it. Plus it's sweet when people want to drive your car, and they can't. People always wanna drive my sho, and I have this thing about people driving my cars, but I finally will give in sometimes and let them, saying if you stall it once, you're done. They get in, stall it right off the bat, and then they're done

What have you done to your sho? What mods?

 

[HoustinoJillian]

i currently have a 17 lb flywheel and a CM stage 1 clutch. (on a modified SHO)

ive also had stock flywheel/ stock clutch (on two different stock SHO's, my 89 and old 95)

and ive also had 17 lb flywheel, stock clutch disk, hd pressure plate. (on the same modified SHO.

all three versions have been fine as DD. and all have been fun too.

my clutch foot/leg sometimes gets sore in really long traffic, but i've had this happen back in my stock clutch/flywheel days too.

go with what your preference and your budget (after all your maintenance is done) allows.



edit- to be honest, on a stock SHO, i don't see much point in getting anything other than a stock flywheel and clutch. spend money first on 60k, then secondary maintenance, then get yourself a nice y pipe and exhaust.

 

[BlackonBlack89]

easiest way to pick a F/W. what are your future plans??

N/A :go with a AL one.

Boost: stick with a steel unit.

people blow this subject out of porportion a little.(IE relearn how to drive stick) I only noticed faster rev ups.

 

[jbserra]

easiest way to pick a F/W. what are your future plans??

N/A :go with a AL one.

Boost: stick with a steel unit.

people blow this subject out of porportion a little.(IE relearn how to drive stick) I only noticed faster rev ups.

I agree, that it *should* just be a matter of getting used to it, but I've driven stick for 14 years in many different cars, and I'm still not used to this one after 1500 miles. Revving it up higher hasn't been that great in the snow, either.

1993MTXSHO:
Question about "don't take heat as well as stockers". What is the end result? Am I going to warp this thing if I'm burning the clutch longer at higher RPMs or will it just fade a little as it heats up?

 

[yamahaSHO]

One note I should make: If you plan to boost and/or get a Clutch Masters Stage III clutch, I would recommend NOT getting an aluminum flywheel.

 

[St Louis SHO]

I've seen several aluminum flywheels dish, only allowing contact on the very outside of the disc.

So in other words, 17lb or stock.



- James

 

[wasianguy05]

I guess the real question is, is there a significant difference in the stock - 17 lb - 9lb flywheel

 

[St Louis SHO]

Either way you go, you lighten the rotating mass. I would just go stock if I were you to avoid problems later on down the road. There are MANY people running stock flywheels on high HP applications.

- James

 

[yamahaSHO]

I went back to stock.

 

[wasianguy05]

So lightening the flywheel wouldnt help increase the hp to the wheel. Im just thinking of different areas to work on other than the motor, intake and exhaust. I honestly dont plan to have this car as a daily drive all my life. lol. just most of it.

 

[bigblock]

i have a 9lb flywheel and a stage 2 clutch in my 93, and my 90 is stock. for a dd car i would go with my 90s set up (stock). i like how the stage 2 clutch on my 93 engages quick and the pedal weight is good but it would be a pain in heavy traffic. i guess with the 9lb fly wheel im freeing up some hp but i've never really looked at it that way. all it does to me is help the car rev up quicker thus getting to the power band faster. for a DD i would not recommend my 93's set up, for a toy yes (thats what my 93 is anyways). go with stock

 

[jbserra]

I'm going to update my previous posts. About 2 weeks ago, it was like someone flicked a switch. Take offs are much easier now, but I still have an occasional issue launching. Perhaps I just passed my break-in period, but it was at 1500-2000 miles, instead of the specified 500 miles. Otherwise, maybe I've been reprogrammed to use the new setup. I'm not sure which, but the result is better driveability. Seriously, it was really bad up until a couple weeks ago.

So, now I'm more happy with my clutch/FW decision. The next problem I'm dealing with are the "Artic temperatures". My car doesn't like to pump fuel when it's cold out, so I'm stalling the car for different reasons...

 

[Storm-Chaser]

Andrew, Mark, and James have it correct.

In the absence of changing the geometry or design of the clutch pedal and/or clutch lever on the transmission, the pressure plate is what affects the "feel" of the clutch as you depress/release the clutch pedal. Increasing the clamping force, increases the "heaviness" [stiffness] in the feel of the pedal. It's what determines how much leg-force is required, which in turn affects how quickly you winnies' legs tire-out . . . .

The weight of the flywheel directly affects how fast the engine revs, as well as how well it holds a given rpm as the clutch is engaged and horsepower is transferred from the crankshaft to the transmission input shaft. Light-weight flywheels will rev faster, since there's less rotating mass to accelerate, but heavier-weight flywheels hold the rpms during clutch engagement better as a result of having more inertia to overcome. One benefit I haven't seen mentioned, is how a heavier flywheel will not over-rev as badly in the absence of a rev-limiter, since it takes longer to accelerate if the flywheel is truly balanced. It will also hold rpms higher for a longer period of time when the clutch is disengaged and the engine is free-wheeling.

James brings-up another important point which hasn't got much attention - wear. Aluminum is going to wear much faster than any type of steel, and is more prone to warping. The end result is that it is a higher maintenance-level flywheel, which will require more frequent servicing, especially under hard use.

^ thats very true it can be very difficult to get use to the lighter fly wheel... it really is like driving a whole different car! but thats all it takes is getting use to and once you do its amazing

My .02...for it's size, the SHO has about the heaviest pressure plate you will ever see (big cast piece, instead of most being stamped). The original 9.25" clutch was a small (lighter) stamped piece, with the same size flywheel. Ford had to beef up the clamp load of the pressure plate (which we all know), and did this, but didn't really change the flywheel, or the flywheel weight. Result? Several lbs were added to the original engine rotating assembly.

The original 9.25" clutch was also smaller, and it's moment of inertia less than the 9.75" unit, which has the bulk of it's weight at the extreme edges of the flywheel.

All that to say:

1. A steel flywheel in the 17 lb range is probably closest to the original weight of the SHO clutch (read that to be, original Ford designed rotating assembly weight)

2. Because of the extreme weight, and placement of weight on the 9.75" cast pressure plate, an alum flywheel is not a huge drivability issue IMHO. With a more aggressive friction material, it can be trickier, but with a full facing disc, it's never been an issue with me.

If you live in an urban area and are on/off the clutch all the time, starting off on hills with 1/2 dozen bags of dog food in the trunk, then maybe a steel unit would be better.

For hi-po use, either unit whizzing @ 7,500 rpm is probably better than the stock cast piece (having a stock cast PP is bad enough). There was a guy at Road Atlanta in Oct that got his leg cut off coming down turn 12 when the clutch/flywheel assembly let go. Since our's is FWD and not RWD, we don't have to worry about legs, since it's going to come right up our crotch.

I've seen several aluminum flywheels dish, only allowing contact on the very outside of the disc.

So in other words, 17lb or stock.



- James

 

[AREA 91]

I have all 3 flywheels.

 

[Shoaz]

I have all 3 flywheels.

In the same car?