BOB WINSKI

Hi Guys,I have to buy a fly wheel for the LS1 motor this week.I was thinking of getting a Aluminum flywheel. Any advantage or should i stick with the steel one. Has anyone used one in there motor .Your thoughts,Thanks Bob W

wmf62

simply driveability... the lighter wheel will rev faster but have less enertia; depending on many factors: engine torque/trans gearing/rearend ratio.

personally, if i'm not going to be winding the snot out of it on a frequent basis, i'd stick with the steel one.
Bill

wolfman64

Bob,

I just removed this flywheel from a brand new GMPP LS3 crate engine. Is this what your looking for? I do not know if it will match up to an LS1.

Paul

wmf62

that would be for an automatic transmission.
Bill

wolfman64

Yes, I know. He had not specified auto or manual.

wmf62

true, but when he said 'aluminum' that kinda ruled out automatic.

Bill

wolfman64

Knowledge above my pay grade!

midyearvette

aluminum...

wmf62

you get paid???? i'm envious, i just get SS...

Bill

RJ1

Bob just installed a RS 5 speed with aluminum flywheel. First gear is so easy now taking off. But how much is the higher first gear ratio on the new trans impacting that? Probably a lot since the aluminum's lighter weight is supposed to make it harder taking off in first.
A very nice side benefit is it saved 19 pounds. Good for performance and gas mileage.
Engine is a lighty modified 327 CI.
Do a search there are a couple other discussions on this subject.

itsonlyairandfuel

Do you really think you will notice the difference. After the motor is loaded, trying to accelerate 3000lbs plus? But the steel flywheel absolutely will make it easier to launch the car. If you can make sure your flywheel is SFI approved. Safety is the most important factor. Good luck on your project. Ron B.

pw2006

I have an LS3 with a lot of horsepower and chose a steel flywheel. It turned out to be a pretty good thing. My current clutch pedal ratio is ~ 2:1 ratio with a hydraulic clutch. It was pretty much an on/off switch. The clutch geometry is currently being massaged, but I will likely only get a 3.5:1 ratio which is still pretty tight, as the ideal is in the 5:1 to 6:1 range. I also had a 3:45 rear, which I just swapped out for 3:73s. This combo should work out much better. If I had an aluminum flywheel, I'm sure it would be harder to take off from a standstill, without lighting the tires up too often or frogging the car. My car is primarily street driven, but I plan to start autocrossing it this summer. Your results may vary..

RJ1

Ron I noticed a big difference but as stated in above post the higher numbered first gear from the new RS 5 speed installed at the same time as the new aluminum flywheel has a big effect. I am sure the higher first gear makes the big difference but hardly any revs to get it moving from a stop compared to the M-20 trans and steel flywheel.
The flywheel is a Hays billet aluminum #20-330. SFI approved 11 pounds.

midyearvette

all this worry of inertia for leaving a stop light is really not a concern for a car that weighs like a c1-c2
it's not like a 48 buick 3 on the tree
i have put a light flywheel in a 250 horse c2 with 336 and a wide box and it really woke things up......jmo....
helps with downshifting too, slows the car down quicker, if you care

BOB WINSKI

Paul i forgot to add it in i need one for a tremic 6 speed

wmf62

certainly not 'worrying'; a heavier flywheel just makes life easier for a 'daily driver'. a 250hp is more of a 'torque monster' than, for example, a 365.
Bill

jdk971

i believe my builder, put a 18 pound on. jim

cv67

Running a heavy billet steel FW on a street 383 well over 550hp love it.
No dragging the motor down, chugging bogging etc. Makes it so easy to drive
If you make good power its going to accelerate about the same anyway.
Revving in N who cares.

BOB WINSKI

Thanks guys for all the response .I will post some pictures in the near future on this build.Bob W