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New clutch and flywheel

1660 Views 15 Replies 8 Participants Last post by  ace996
Just got my Spec clutch and LPE flywheel installed yesterday at HPE. Man does the flywheel make a big difference, the car wraps noticeably faster. While I was there I also installed my Hotchkis sway bars. Theres a night and day difference in the way it handles on sharpe corners even the steering seems tighter.
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Parker said:
Just got my Spec clutch and LPE flywheel installed yesterday at HPE. Man does the flywheel make a big difference, the car wraps noticeably faster. While I was there I also installed my Hotchkis sway bars. Theres a night and day difference in the way it handles on sharpe corners even the steering seems tighter.
Do you have the fg2 package on your car?
Parker,
Explian how much different it feels with the lighter flywheel? Revs quicker? Any losses down low? Does it feel faster in your seat of the pants dynometer?
No I dont have the FG2 suspension, I have the Eibach pro-kit on it with the factory CTS shocks in the rear. What a huge weight difference in the flywheels, it picked up more power down low and revs MUCH quicker than stock, and yes it does feel faster in the seat of my pants...lol.
How are the shifts? Easier to make a smooth shift?
The shifts have always been smooth before and after. The SPEC isn't much different than the way the stocker drives.
Really, my car always has a noticeable jerk when letting the clutch out between gears during normal driving, unless of course I wait till the motor comes down for a rev matched shift. I suppose my definition of smooth is a little extreme...smooth = don't feel the shift.
Mat - Yes, even MT magazine commented that it was nearly impossible to drive the V smoothly. I find the going up a gear or two and lugging it is the smoothest. Although if you have an aftermarket exhaust, like me, it's not the most quiet way. Other than that, if I want to make it very smooth I shift on decel.

Parker - Did you blow your stock clutch? Is the Spec unit higher rated?
My shifts have always been smooth. No I didn't blow the stock clutch up, but I wanted to put the LPE flywheel in, so might as well get a new clutch so I wouldn't have to pay for the labor twice. Im not sure what the SPEC is rated to, on another note...the stock clutch held fine with over 600ft/lbs of torque and right at 600rwhp.
Another help for smoother shifting is a StealthV tune, believe it or not. No more throttle hang...or less of it at least. For me, this made quite a difference.

On a clutch note - my stock clutch did NOT hold up to the 525+ (est) hp/tq I'm making now. Parker must drive his V in a nicer manner than me :sneaky:
Wild, Parker,
You guys are making some serious HP. I can't get my car to hook up well. I understand 1st gear, but even shifting into 2nd, alot of time is wasted on spinning and skipping. Think about it, if you are spinning enough to get sideways that's alot of time scrubbed off the 1/4 mile.
What are you guys doing? Laying down rubber between every shift?
Replacing the dual-mass flywheel assembly with a modern flywheel assembly is one of the best and easiest modifications to make. There is more power everywhere. It shifts easier. Any good ECU tuner like Stealth or TPIS can easily tune your ECU to adjust the rev drop to gear speed, to make shifting still easier. You can still take off in second gear.
As for horsepower increase, it seems hard to measure, but it is truly there. Following is a quote from Graham Bell, a Brit tuner whose books are an excellent source of knowledge.



Graham Bell in his book "Four Stroke Performance Tuning" writes:

“Over the years there ahas been a fair amount of controversy with regard to flywheel lightening. Some claimed that a lightweight flywheel improved acceleration due to reduced inertia, others stated that the only benefit was better crankshaft life because the twisting load on the end of the crank was reduced, and there was less risk of flywheel explosion due to inertia load on the centre of the flywheel being lessened. At this time we can state and prove that any reductions in an engine’s reciprocating mass or rotating mass will improve acceleration. Thus lightweight pistons, rods, cranks, clutches and flywheels all benefit performance.
The problem was that we had n reliable means of measuring the performance advantages of light components. However, the situation changed when relatively inexpensive computerised engine dynos like the Superflow SF-800 became available. These dynos can accelerate an engine at a fixed rate and accurately print out the horsepower on a tape. This means that we can programme the dyno to accelerate the engine at, say, 2000 rpm per second, and record the power levels every 250-rpm. When such a test was carried out on a 388 cu. in. Chev speedway engine, it recorded almost 25 hp more when titanium rods and a light flywheel were fitted. The driver claimed that the car was quicker by about a half-length out of turns, which backed up what the dyno had showed. Tested with a static load as we had to with the older dynos, the engine showed no difference in hp when the lightweight parts were fitted.”
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I spin when I downshift in 3rd at 60 and hit it, the car gets really squirley.
My clutch starts slipping pretty badly after 2 or 3 consecutive runs and my car is still paper filter stock!
My stocker has always held just fine.
The throttle-induced rpm hang adds to the problem we experience with the dual-mass FW. There is a little bit of give with the dual-mass and then it grabs...jerky,clunky shifting is the result. When I switched over from my MRSpyder, it felt as if the V had two clutches...one engaging just a tad sooner than the second. In reality, the dualmass may help with driveline vibration or power-pulse shocks at low rpm (why they exist for diesel trucks) but it sucks for performance driving...and still makes me feel like a manual-tranny newbie.
-ace
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