[sti-06]

Originally Posted by rasheedn

i didnt notice much difference after installing ACT prolite

what i did notice is that i need to rev to 5500 now to launch the car otherwise it just bogggs down even with LC !!

yeah thats a known downside along with faster revs

[pooster.online]

Originally Posted by AnorexicSTI

What boost are u hitting then? And is this even after a retune? In all gears?

hittting 15-17 psi.. 15 in lower gears.. can't break 18 in 6th.. I'm probably gonna get a retune to try to resolve this, but I gotta finish all the mods before the tune tho.. so itll be awhile.. it just sucks cuz the car doesnt run as fast as it used to..

[esqdgg]

sorry to throw this a bit off-topic.. feel free just to pm me an answer so to not clutter up this thread...

but this less rotating mass discussion got me thinking about other less rotational mass in other drivetrain areas.

would these less mass rotational issues also occur with the acpt driveshaft? (please pm)

[the4jbaps]

Pooster,
If you're running stage 2 on the Accessport you're only supposed to see 17.5 psi +/- .5 psi. Not uncommon to only see 18 psi on gauge. Unless you had it protuned?

[rasheedn]

Originally Posted by sti-06

yeah thats a known downside along with faster revs

isnt faster revs an upside????


a bit off topic question: does a lighter flywheel affect the life of the clutch??

[blindfold]

another route is to get a lighter driveshaft, ACPT makes a decent one

[98ss]

I have a 05 with ACPT DS.
I am also running stage 2 protuned with catted DP and stock cat back. Panel drop in filter.
Mustang dyno put down 290 ft-lb and 260 hp. 20 PSI peak taper to 16?
My IDC is 95% max on stock injector.
Torque come on hard at 3500 RPM but drops off, I guess thus the lower HP. As HP is function of torque and RPM.

Currently still on stock FW, but I guess if the OEM clutch dies, I will go lighten FW as well.
Pro of reduced spinning inertia:
1. Faster revs up
2. Faster rev falls (this allow me to shift faster, I have stiffer diff bushings as well)
Con of reduced spinning inertia:
1. MPG took a hit as I am on throttle more frequently
2. Have to shift fast and not as relaxed, like previous said, more of a on/off feeling.
3. Higher rev to get going from stop to prevent stall? ( I rev to 1500~2000 to get going from complete stop)
4. More gas to match rev for down shift as well, again this sucks for MPG.

I think do you all notice that if you have the AC on, revs will fall faster between shifts?
I feel that is a good way to mimic how it would feel shifting with reduced inertia. It is a double edge sword. It sucks in stop and go, but it is great when you are hauling, you can shift really fast and be faster off the clutch. Lighten DS allow me to be faster and smoother at the same time, to me it is worth it. It suits the nature of STI I think. Makes the motor feel more rev happy.
My 2cents

[ilikepie]

I just installed an ACT flywheel along with street disk clutch and it feels great. It seems to rev a little quicker, but not too much. I honestly didn't notice too much of a difference. How much does the stock flywheel weigh, 17-18lbs? The only reason why I went with it is because my stock couldn't be machined.

[ChristianCGM]

I think that a lot of you are forgetting that one of the major functions of a flywheel is as a heat sink. A lighter flywheel will not be able to hold the heat as well as stock flywheel. When light weight flywheels get hot they warp and get hot spots. This lessens the life of the clutch as it does not have a consistently flat and level surface to press against. This is not to say this will happen to everyone that has a light weight flywheel, but if you drive your car hard then its probably better to have a stock replacement or resurfaced. When I mean drive you car hard I am not talking about the people that do a few highway pulls a weekend and say yeah I drive my car hard because the clutch, pressure plate and flywheel are not really working that hard as there is typically less torque above 4500 rpm as there is below 4500 rpm. In my eyes to only reason to get a carbon fiber driveshaft is because it's stronger not because it's lighter.

[Neanderthal Racing]

there's a lot of wisdom there, christian.

[AnorexicSTI]

Originally Posted by ilikepie

I just installed an ACT flywheel along with street disk clutch and it feels great. It seems to rev a little quicker, but not too much. I honestly didn't notice too much of a difference. How much does the stock flywheel weigh, 17-18lbs? The only reason why I went with it is because my stock couldn't be machined.

It can be machined, but only a bit and it's very difficult... not really worth the effort.

[AnorexicSTI]

Originally Posted by ChristianCGM

In my eyes to only reason to get a carbon fiber driveshaft is because it's stronger not because it's lighter.

1. I disagree. 10 lbs saved in the driveshaft is very significant as it is rotational weight... the 1 piece design vs a 2 piece design like stock also helps as u don't get a power loss at that extra u-joint. the extra joint also adds a bit of "slop" when getting on and off the power.

[ChristianCGM]

^I understand what you are saying and am not going to argue against the mechanical drag and torsional spring rate of a stock vs a carbon fiber driveshaft. All that I am saying is that there is a certain power level where a carbon fiber driveshaft is actually needed for strength; which is the only situation where I would consider putting one on my car.

[Gixx6]

I had a lightweight flywheel (went from 19lbs to 9lbs) in another one of my cars with a 6 puck sprung clutch and I will never do it again. You lose all streetability of the car, must rev it higher in order to be able to get off the line especially without chatter, made hill starts a pain.

[white04sti]

I got the ACT HD clutch and Gruppe-s flywheel (14lbs) in miami traffice with no problems at all