Steel vs Aluminum flywheel for Street/Strip C5 Manual Transmission
05-02-2017, 09:48 AM
#1
Melting Slicks
Thread Starter
Steel vs Aluminum flywheel for Street/Strip C5 Manual Transmission
I'm looking for advice from those who have used a manual transmission with a C5 or C6 corvette to run 9.99 or quicker.
The goal is to accelerate off the line as quickly as possible and be able to shift as quickly as possible using a stock 6060 transmission.
All things being equal, which is better, aluminum or steel flywheel with a manual transmission at the drag strip and at runway racing events?
The goal is to accelerate off the line as quickly as possible and be able to shift as quickly as possible using a stock 6060 transmission.
All things being equal, which is better, aluminum or steel flywheel with a manual transmission at the drag strip and at runway racing events?
05-02-2017, 09:59 AM
#2
Melting Slicks
Thread Starter
I'm looking for pros and cons, advantages and disadvantages.
I've had an aluminum flywheel for the last 8 years starting with the stock combo all the way to the 427 TT combo now. I need to make a decision and I'm trying to decide if I should stick with aluminum or go to billet steel.
In this case, going to steel would add ~13lbs to the rotating mass of a 10" twin disc assembly. ~ 41 lbs vs 54lbs. My last setup was 38 lbs, but I'm switching to something with more capacity.
I've had an aluminum flywheel for the last 8 years starting with the stock combo all the way to the 427 TT combo now. I need to make a decision and I'm trying to decide if I should stick with aluminum or go to billet steel.
In this case, going to steel would add ~13lbs to the rotating mass of a 10" twin disc assembly. ~ 41 lbs vs 54lbs. My last setup was 38 lbs, but I'm switching to something with more capacity.
Last edited by Turbo-Geist; 05-02-2017 at 10:00 AM.
05-03-2017, 09:58 AM
#3
Melting Slicks
Thread Starter
I figured this might be the best place to ask this question. Based on the lack of response, I guess the knowledge has left this area of the forum.
05-04-2017, 07:54 AM
#4
Le Mans Master
Member Since: Nov 2005
Location: Kendall Park NJ
Posts: 6,964
Likes: 0
Received 335 Likes
on
247 Posts
Short answer would be aluminum as it works better in most cases for our cars. A lightweight steel flywheel has a strength advantage but will not be as light as aluminum. Moment of inertia is a bigger concern in all cases and will dictate how a car will leave. To mitigate a bog, a larger MOI will better pull a car out of it. However, to rev quicker, a smaller MOI is ideal. So much for the short answer.
05-04-2017, 06:18 PM
#6
Melting Slicks
Thread Starter
Short answer would be aluminum as it works better in most cases for our cars. A lightweight steel flywheel has a strength advantage but will not be as light as aluminum. Moment of inertia is a bigger concern in all cases and will dictate how a car will leave. To mitigate a bog, a larger MOI will better pull a car out of it. However, to rev quicker, a smaller MOI is ideal. So much for the short answer.
This car has plenty of power (~1000) but the car is a little heavy (3500 lbs) and the gearing and suspension currently isn't optimal for 1/4 mile. 28 inch tire, 2.26 1st gear, 3.42 rear gear and lowered with GT2 coilovers. The car has seen some 1.55 60 foot times. I need to add more boost on the launch to really get it moving but was having a situation where the throttle would shut and send the car into reduced engine power mode. I think I may have solved that issue, but then started having clutch issues.
Just from reading, it sounds like it takes a fairly large amount of weight/MOI difference to really influence the 60 foot times. I came across a few examples where people were comparing 10# flywheels to 40# flywheels and picking up 0.2 seconds. I'm looking at a difference of 14# between the two.
I decided to just stick with the aluminum since it has been working well enough for the last 8 years.
05-05-2017, 11:05 AM
#7
Le Mans Master
Member Since: Nov 2005
Location: Kendall Park NJ
Posts: 6,964
Likes: 0
Received 335 Likes
on
247 Posts
Great responses, Gary. I wanted to ask something in the tire thread but didn't want to mix topics. I'm starting to realize the difference between weight for the sake of weight and MOI. Can you give me an idea of what your setup weighs and a ballpark MOI. I was surprised at how hard it looks like your car hits the tires. It's not violent, but it does get out of the hole very well. Maybe gearing is at play also?
This car has plenty of power (~1000) but the car is a little heavy (3500 lbs) and the gearing and suspension currently isn't optimal for 1/4 mile. 28 inch tire, 2.26 1st gear, 3.42 rear gear and lowered with GT2 coilovers. The car has seen some 1.55 60 foot times. I need to add more boost on the launch to really get it moving but was having a situation where the throttle would shut and send the car into reduced engine power mode. I think I may have solved that issue, but then started having clutch issues.
Just from reading, it sounds like it takes a fairly large amount of weight/MOI difference to really influence the 60 foot times. I came across a few examples where people were comparing 10# flywheels to 40# flywheels and picking up 0.2 seconds. I'm looking at a difference of 14# between the two.
I decided to just stick with the aluminum since it has been working well enough for the last 8 years.
This car has plenty of power (~1000) but the car is a little heavy (3500 lbs) and the gearing and suspension currently isn't optimal for 1/4 mile. 28 inch tire, 2.26 1st gear, 3.42 rear gear and lowered with GT2 coilovers. The car has seen some 1.55 60 foot times. I need to add more boost on the launch to really get it moving but was having a situation where the throttle would shut and send the car into reduced engine power mode. I think I may have solved that issue, but then started having clutch issues.
Just from reading, it sounds like it takes a fairly large amount of weight/MOI difference to really influence the 60 foot times. I came across a few examples where people were comparing 10# flywheels to 40# flywheels and picking up 0.2 seconds. I'm looking at a difference of 14# between the two.
I decided to just stick with the aluminum since it has been working well enough for the last 8 years.
I need to type faster.
First:
My setup that has served me well is an RPS BC2 with an aluminum FW that weighs in around 25 lbs.
Never calculated the MOI; however, just knowing that it has a smaller diameter and weighs a lot less, makes the MOI smaller than many other clutches/FWs.
Next:
Your 60's are good considering your weight and effective gear ratio. That being said, you would be better served with changes if looking for maximum acceleration from a standing start. Changing the effective gearing will be more critical than your clutch kit MOI. There will be tradeoffs though.
Trans Ratio-
Your gearing is great for roll racing where you need to keep your shift drops low. Tough to get the car out of the hole.
Rear Differential-
3.42s are great for extended distance races. They can keep you from shifting into 6th. If your diff is out of a C6Z or ZR1, then you have a far stronger rear. If not, a gear swap will help.
Tires-
28s provide a longer contact patch but a 12"x26" has great traction also. You may need mini-tubs or fender flares to accommodate these much wider tires.
Making any or all of the above changes will assist you in attaining your goal stated in your first post. Cost, strength and tradeoffs should be considered. Keep us posted.
Final Note:
My new clutch will be a redesigned BC2 with a lightened steel FW that should weigh in at 30 lbs.
Rob Smith and I discussed the pros and cons of both steel and aluminum as they relate to safety, durability, affect on the trans during shifts, and of course; launching.
Last edited by GARY2004Z06; 05-05-2017 at 01:29 PM.
05-18-2017, 05:41 PM
#8
clutch kit weight effects
I just spent an hour typing a response but I was timed out.
I need to type faster.
First:
My setup that has served me well is an RPS BC2 with an aluminum FW that weighs in around 25 lbs.
Never calculated the MOI; however, just knowing that it has a smaller diameter and weighs a lot less, makes the MOI smaller than many other clutches/FWs.
Next:
Your 60's are good considering your weight and effective gear ratio. That being said, you would be better served with changes if looking for maximum acceleration from a standing start. Changing the effective gearing will be more critical than your clutch kit MOI. There will be tradeoffs though.
Trans Ratio-
Your gearing is great for roll racing where you need to keep your shift drops low. Tough to get the car out of the hole.
Rear Differential-
3.42s are great for extended distance races. They can keep you from shifting into 6th. If your diff is out of a C6Z or ZR1, then you have a far stronger rear. If not, a gear swap will help.
Tires-
28s provide a longer contact patch but a 12"x26" has great traction also. You may need mini-tubs or fender flares to accommodate these much wider tires.
Making any or all of the above changes will assist you in attaining your goal stated in your first post. Cost, strength and tradeoffs should be considered. Keep us posted.
Final Note:
My new clutch will be a redesigned BC2 with a lightened steel FW that should weigh in at 30 lbs.
Rob Smith and I discussed the pros and cons of both steel and aluminum as they relate to safety, durability, affect on the trans during shifts, and of course; launching.
I need to type faster.
First:
My setup that has served me well is an RPS BC2 with an aluminum FW that weighs in around 25 lbs.
Never calculated the MOI; however, just knowing that it has a smaller diameter and weighs a lot less, makes the MOI smaller than many other clutches/FWs.
Next:
Your 60's are good considering your weight and effective gear ratio. That being said, you would be better served with changes if looking for maximum acceleration from a standing start. Changing the effective gearing will be more critical than your clutch kit MOI. There will be tradeoffs though.
Trans Ratio-
Your gearing is great for roll racing where you need to keep your shift drops low. Tough to get the car out of the hole.
Rear Differential-
3.42s are great for extended distance races. They can keep you from shifting into 6th. If your diff is out of a C6Z or ZR1, then you have a far stronger rear. If not, a gear swap will help.
Tires-
28s provide a longer contact patch but a 12"x26" has great traction also. You may need mini-tubs or fender flares to accommodate these much wider tires.
Making any or all of the above changes will assist you in attaining your goal stated in your first post. Cost, strength and tradeoffs should be considered. Keep us posted.
Final Note:
My new clutch will be a redesigned BC2 with a lightened steel FW that should weigh in at 30 lbs.
Rob Smith and I discussed the pros and cons of both steel and aluminum as they relate to safety, durability, affect on the trans during shifts, and of course; launching.
My story here goes back years when I replaced clutch with aluminum fidanza flywheel, I couldn't understand why the car wasn't reacting to this weight loss (remember Gary 11.197 in 2013 then I hot lapped for months to only get 11.196 ) ...
fast forward and I got a Used Rps Twin Lite.. the Pressure plate is WAY light YET its a Steel flywheel Which I thought I could use fidanza instead,. but its an Unique design and does Not interchange...
at the same time I got nuts and Started weighing all 3 clutch set ups and Discovered that the Fidanza set up had a Heavier then stock pressure plate which made the whole kit as heavy as stock..
so my question is what matters most,. the Flywheel be lite ? or the entire cltuch kit ?