Flywheel question

[EGhatchintheham]

Ok, so I just purchased a new transmission to replace my cx trans. I got the jdm unit (which has the same ratios as the U.S. si unit, right?). Anyway, should I get the stock flywheel milled down to around 12 lbs. or just buy an aftermarket flywheel?

[Black91CRXsi]

I'd just get an aftermarket one. It may be difficult to properly balance the stock on after milling it that much. My .02 cents...

[transzex]

it's not had to balace a cut down stocker......just takes time.

Time is money, by the time you add in the labor, it'll be about the same price as a 12 lb aftermearket unit. My cost $175 to be cut and balanced.

[carby]

Damn I feel lucky I got my flywheel for $1.00 off ebay.

[dkid15]

Wtf are you serious is it one a spec, clutchmasters or some name brand like that.

[speedfoos]

I'd go with the aftermarket one as well. Not that any decent machine shop won't back their work, but you'll get a warranty when you buy a new, lighter flywheel.

[EGhatchintheham]

Yea, well I think that's probably what i'll end up doing...maybe i'll get the stocker milled down after i put in the aftermarket just to have one for whatever reason. Any suggestions on weight? It's an NA setup right now but I am going to be turboing it by the end of the year. I was think 12 lb. is good b/c the more load the engine has the earlier it will spool a turbo.

[93 red ls]

do a little searching !!
http://www.d-series.org/forums/showthread.php?t=58235

referance this post lsd motorsports is still offering them 115 shipped for d series!

[speedfoos]

There are arguments for all ends of the spectrum. Some folks swear by the 20 pound stocker, saying anything lighter than that and its hard to launch, RPMs fall to quickly, etc... when compared to those 7.5-8 pounds jobbies.

Then again, I've seen vids of some 13 psi cars running the ultralights without any problem and they swear by them. I don't know. I split the middle and went for an 11 pound Exedy. I'm not boosted (yet), but I love my new setup. IMO it offers the best compromise between reducing my rotating mass for a quicker rev, and keeping the load for a faster spool (when I get boost). So there's my .02.

[93 red ls]

11 OR 12 lb ftw!

[carby]

Mines 12lb. Works great! That launching stuff is crap. It's all in your throttle control.

When I got mine I had it machined and it wasn't quite flat. The guy at napa was asking me why the hell I was machining a brand new flywheel tho.

[EGhatchintheham]

Alright, well hopefully the 12lb will work well for the boosted setup as well as the NA so I think that's what I'll go with. I am just ready to get that trans here...this cx trans is brutal on the everyday, haha. I looked up the ratios on the slowboy racing calculator and if I could take it to the redline in 5th gear with my current trans, tires, and engine I would be at a healthy 220 mph. Not too bad for the ol honda, haha.

[hulkbuster]

Okay Transzex or Carby I have a question since we are kinda on the subject of what I want to ask. If I buy a new Pro-Lite flywheel maybe say 8 lbs, don't I need to get it "surfaced"? You know so it will "bite" better?

[Eyal 951]

11 OR 12 lb ftw!

[cory jordan]

idk. 7 lb fidanza on a d15b vtec turbo 5.5 psi or so for now.(boost creep) but soon to be 14. with 7.5k rpm shifts i never fall out of vtec. and launching is fine. doesnt bog for me.

[Eyal 951]

idk. 7 lb fidanza on a d15b vtec turbo 5.5 psi or so for now.(boost creep) but soon to be 14. with 7.5k rpm shifts i never fall out of vtec. and launching is fine. doesnt bog for me.
it has nothing to do with falling out of vtec. Its about putting more load on the motor to spool the turbo earlier.

[transzex]

Okay Transzex or Carby I have a question since we are kinda on the subject of what I want to ask. If I buy a new Pro-Lite flywheel maybe say 8 lbs, don't I need to get it "surfaced"? You know so it will "bite" better?

fucking better not have too!!!!!!

Do you resurface your new rotors before they are installed?

[transzex]

idk. 7 lb fidanza on a d15b vtec turbo 5.5 psi or so for now.(boost creep) but soon to be 14. with 7.5k rpm shifts i never fall out of vtec. and launching is fine. doesnt bog for me.

You've never launched hard then have you????

Slap on some sticky slicks and launch from redline......car noses over when the rpms are dragged down by too light of a flywheel, sometimes enough to really mess up a low psi turbo car, flat on it's face!!!!!

It is a balance of traction vs. power. You got HP and having traction issues, then go light. 190-200 whp launching at 7500 rpms with a 12 lb flywheel was about perfect, esp. using nitrous.

It's part of the tuning equation AND driver's style plus how the race will be abused, I mean raced.

I do know that my 12 lb is a bit too light for DD with 3.722 FD, so when the Y7 tranny goes in, so does the 15 lb CX flywheel.

[cory jordan]

with boost by gear and a two step and radials i have no need for slicks i am not impressed with some one who runs on slicks. what your car will do when it is called upon. is what means most. to me.
this of course is not a dedicated race car.
a guy i know runs almost 2 seconds diff with out slicks and still thinks he's the cock's walk.

and i have always wondered, if you like more rotation weight on launch why not put heavy rims on and use a heavy flywheel. its the same theory. more weight is applied using more hp to turn the weight there for using more of the power to turn the now heavier wheels and not give you traction problems.

why not use a light weight flywheel and heavier rims for that matter. .
. i mean if you want to have less of a traction issue. just put on heavy rims . it just doesnt make any sense to me. maybe i just dont get it. =(

[hulkbuster]

Nah I guess your right. That's why I specifically asked you I know you know your shit thanks man.

[carby]

Nah I guess your right. That's why I specifically asked you I know you know your shit thanks man.

It's true that you better not have to. I got mine for $1 so I had a lot of money left over and had it resurfaced with my brake rotors for free. It can't hurt but it shouldn't be needed.

Personally I don't have as much faith in $1.00 ebay shit as most people. That's why I did it.

[transzex]

if you like more rotation weight on launch why not put heavy rims on and use a heavy flywheel. its the same theory. more weight is applied using more hp to turn the weight there for using more of the power to turn the now heavier wheels and not give you traction problems.


With clutch disengaged and engine reving, the flywheel's mass has stored kinetic energy where as the heavy wheels at rest do not.

Now if you had a heavy flywheel and heavy wheels, car in gear and engine tached out, then kicked it off the jackstands, the heavy wheels would help since they's have stored energy. But they would ONLY help if you had the traction to hook up all that energy.

[cory jordan]

thank you . =) but where is the line of sacrifice
for .002(just a random number) of a second saved in traction could it be made up for with better acceleration and reduced rotation weight? or weight in total.,granted 14lbs isnt gonna be a half second. but on the right set up. wouldnt it be better to have a light flywheel, and what about from a roll?. any advantages?

[transzex]

from a roll depends also.......if your in gear and not downshifting, lighter is better.

If your down shifting and have the extra .1 second to let the rpms climb before before dumping the clutch, you'll slingshot ahead.....

My D15B7 12 lb. vs. 18 lb. was .15 seconds difference in the 1/4 mile, all of it was in the first 60 feet. 18 lb. was faster.

But look at the times I posted from 8/2005, I was about the same with more HP, smaller slicks, and the 12 lb. light flywheel. You have to get the sled moving first, that is the biggest balance of power and traction.

Now once the car is moving, the lighter should be faster, but that depends on the driver.

Now road racing, WHOLE different ball game, lighter is better, esp. so you don't shock the driveline on downshifts under threshold braking.

[cory jordan]

ahhh. i see

[BigTuna]

Too many people worry about Mph in racing, racing is won and lost at the 60'. If i cranked the tire pressure up on my slicks or ran street tires I could pick up 2mph, but would lose .3 to .5 off of my ET. A good ET and low mph is a sign that the car is hooking. For allmotor cars we use a simple ratio to figure out if the 60's is acceptable.

1320 divided by MPH equals ET guestimate
My car
1320/98.1= 13.45 I ran 13.51 which is .006 slower, anything under .01 in fwd is good.