i searched but couldnt really come up with the answer i was lookin for

heres the deal and its very annoying to me.......... a while ago on the stock flywheel i was consistently trapping 98-99 mph on my basically stock itr, which has a 14lb flywheel i beleive......... i have now added more mods to the car and am now making 186whp and i also added an act pro-lite flywheel on the car.......... now i am only trapping 94-95mph which frickin pisses me off cus i know it should be WAY higher of a mph

its not my launches i knock off consistent 2.1-.2's and my question is..... is it typical to lose that much mph with a lightened flywheel? it sucks so bad and i really dont feel like taking it all apart and putting the stock unit back on

if it turns out this is typical then ill have to go back to the flywheel cus it really does feel slower than it used to and i know im making a good 20whp more than i was when i was trapping 99

thanks for any help
--chris

 

Im guessing that you times are going slower with the lower traps. I dont think i have heard of anyones times getting worse after a lighter flywheel. It usually isnt much of a difference but i usually hear times getting better. I have a fidanza 8lb flywheel and a new exedy clutch and my car feels a lot fast but then again i didnt take it to the track for before and afters but i would have to say that my car is faster than is was before. Good luck though!

 

lightweight flywheels belong on lightweight cars. u lose too much rotating mass to keep momentum goin in the bottom half of the motor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1 2 NV &raquo;</TD></TR><TR><TD CLASS="quote">lightweight flywheels belong on lightweight cars. u lose too much rotating mass to keep momentum goin in the bottom half of the motor.</TD></TR></TABLE>

so you think i would actually benefit by going back to the stock flywheel? my trap speeds would go back up also correct? and my heavy ITR weighs in at about 2600 without me in it bc of the little bit of extra stereo equipment im luggin around (i had all of it in with the faster traps also)....... add me to the mix and its pushin 2800lb

 

i changed quite a bit of stuff in my setup in my 99 EX coupe just like u did. one of the things i changed was the flywheel. my mods i had changed should have theoretically netted me more power but in my case my light flywheel killed my 60s. my trap speeds were higher but i attribute that to the power mods i had at the time and the B16 trannys lower gears. i used to pull 2.0 60s all day every day and then when i "added power" and the flywheel it was hard for me to cut 2.0 60s.
stock flywheel is around 16-17 lbs if i remember correctly and i dropped to a 8 or 9lb flywheel. yes it revs faster but it also falls faster, plus my car weighing at a hair over 2500lbs then add me 180lbs it needs the rotational mass to keep a heavy car moving.

 

The flywheel would not cause you you to lose almost 5 mph traps, its something else that is causing it.

If you were racing uphill a light flywheel would slow you down a little, but there is no way a lighter flywheel will cause you to lose so much trap speed in the 1/4. I have a 8 lb flywheel and when it was installed i definitely did not lose trap speed.

a Light flywheel is simply less rotating mass after the crank where it meets the clutch, making the engine accelerate and decelerate faster... check other things because it is not the flywheel.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by roadawg &raquo;</TD></TR><TR><TD CLASS="quote">a Light flywheel is simply less rotating mass after the crank where it meets the clutch, making the engine accelerate and decelerate faster... check other things because it is not the flywheel.</TD></TR></TABLE>

mass is mass, so how would accelerating be negativly effected by reducing mass when there is a hill.

 

well there would be no other explanation for my loss in trap speeds that i could think of......... can anyone else think of anything?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by krustindumm &raquo;</TD></TR><TR><TD CLASS="quote">

mass is mass, so how would accelerating be negativly effected by reducing mass when there is a hill.</TD></TR></TABLE>

It's got to do with momentum.

A heavier flywheel will naturally have more momentum. So when you take your foot off the gas when going up a slight incline or a hill, the flywheel helps the car maintain its current forward movement.

If you have a lighter flywheel you will have less momentum when you shift gears; and if you are going up a hill the lighter flywheel will slow you down the slightest bit in-between shifts.

This is irrelevant to his problem anyway and has nothing to do with the thread.


Have you dyno tuned the car to make sure you are making the power you think you are?

 

good thing I ran across this post because Im in the middle of buying some new parts for my car and a lightened flywheel was on the list of parts to get. I have been doing some searches about them and this makes me think twice about getting one. I just didnt know if they were worth me spending the extra couple hundred bucks for one?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by roadawg &raquo;</TD></TR><TR><TD CLASS="quote">Have you dyno tuned the car to make sure you are making the power you think you are? </TD></TR></TABLE>

yea i just tuned it last week actually........ thats where i got my final number of 186whp/133tq...... you can search my name and find the dyno in the ITR forum......... before when i was trapping 98-99 it was in the 170whp range and on that exact setup i lost speed down to 95ish when i put in the flywheel

 

bump..... what other things could cause me to drop speeds like that?

 

what have you actual times done though..
Sometimes if you car accelerates faster and gets better traction you will run a faster time at a lower trap speed..
I notice alot of peoples including my own best ET's have a lower trap speed.. for me I've run an 11.73 @ 112mph but yet I've run an 11.877 @ 116mph
the MPH isn't a guide to how fast it is..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ringgold &raquo;</TD></TR><TR><TD CLASS="quote">I just didnt know if they were worth me spending the extra couple hundred bucks for one? </TD></TR></TABLE>

For me I didn't notice any performance gains or faster times, but the car is more fun to drive, the motor spins so quick compared to the stock flywheel. If you have the cash go for it, but if you are looking to get faster for cheap, dont bother because a lightened flywheel will not make your car faster.

I think the clutch you have will make a difference also in conjustion with the flywheel, if you have a nice racing clutch and a really light flywheel it will make it even more fun to drive.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cjames235 &raquo;</TD></TR><TR><TD CLASS="quote">

yea i just tuned it last week actually........ thats where i got my final number of 186whp/133tq...... you can search my name and find the dyno in the ITR forum......... before when i was trapping 98-99 it was in the 170whp range and on that exact setup i lost speed down to 95ish when i put in the flywheel</TD></TR></TABLE>

Did you go to the same track as the first time you were trapping 98- 99?

 

as far as clutches go i got a exedy organic with the pro-lite fw

my times dropped as well my best is a 14.2@99........ since my mph has dropped my best is a 14.4@95

and yes this was all done at the same track in MANY different temps and humidities and i still havent been able to get over 96mph

the only thing i can think of is the flywheel did it as i took it back to the track a week or so afterwards and thats when the traps dropped.......... i guess the only way for me to tell is to put the stock back in and take it back to the track so i can either rule it out or prove that its what made it slower

--chris

 

12 NV and Hondog ...what flywheels are you running on your setups?

 

Did you always have the same clutch? it could cause that too, maybe your just burning the clutch at high rpms, thats what my car did the last time i went to the track...

 

no i didnt have the clutch when i was running faster........ it was with the stock clutch and flywheel......... now i have an exedy organic and i know that its not slipping at all

 

JUN ultralight for me.

 

Yeah, you have to also change the clutch when you change the flywheel... Samething happen to my brother's 96 GSR.. But, he says the flywheel makes a difference... and mines on the way

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ClovisGSR &raquo;</TD></TR><TR><TD CLASS="quote">Yeah, you have to also change the clutch when you change the flywheel... Samething happen to my brother's 96 GSR.. But, he says the flywheel makes a difference... and mines on the way </TD></TR></TABLE>

read a little closer........ when i was running faster i was on the stock clutch and flywheel.......... i lost speed when i put in an exedy organic clutch with a act pro-lite flywheel

i didnt change just the flywheel i changed both

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1 2 NV &raquo;</TD></TR><TR><TD CLASS="quote">JUN ultralight for me.</TD></TR></TABLE>