anyone with an aluminum flywheel

[STUGOTS]

is it true it feels like adding 100 hp and makes great take off and you notice a huge diffrence.

I hear it is one of the best bang for the buck products out there.

any thoughts??

also a decision beteween that and exhaust what should i go with on a basicly stock 99 R/T except for jesel j2k rockers, K&N's and smooth tubes?

 

[Steve 00RT/10]

It is a very good bang for the buck. Not a 100 HP though. The engine spools up immediately with the lighter flywheel. I noticed absolutely no low end problems at all taking off from a stop . I did it last year--should have done it before that. I am very happy with it. The 1/4 mile guys say keep the stock wheel for rotating mass and torque. 1/4 miles are not my main interest.

You can pick up a Fidanza flywheel(17.5 pound) for $389....That's what mine was. If you want your car to sound proper.....you gotta do the exhaust too.

Steve

 

[STUGOTS]

so it does make you lose torque??

 

[Steve 00RT/10]

so it does make you lose torque??

The drag guys say yes. I called Fidanza and they said it's a wash as HP is being applied to the wheels quicker. My tires break loose much easier with the lighter flywheel so there must be some truth to the Fidanza claim. I don't have a horse in this race....only repeating what I've been told.

Steve

 

[opnwide]

The drag guys say BUY ONE! As if a 488ci Viper needs all that rotational mass to efficiently launch. The Viper does quite well at the drags with an alum. flywheel.

 

[2MANYTOYS]

I don't think you lose any torque. My only problem is that I should have done it sooner.

 

[Joe Dozzo]

Sorry, but I have a different experience...

1.7 Rockers - NO difference in SOTP (seat-of-the-pants) meter
Alum Flywheel - NO difference in SOTP meter
Smooth Tubes / KN - NO difference in SOTP

Headers - MAYBE a minor difference in SOTP meter...

3.45 Gears - Noticable improvement
Roe S/C - BIG improvement

 

[1TONY1]

I am de-installing mine this week. Cam lope/drivability is much worse with the aluminum flywheel. I do notice it revs quicker in nuetral. I'm interested in the change going back. Maybe I need to video the before after of the rev.

 

[STUGOTS]

after hearing what most of you think i think im gonna go with one AFTER my headers and exhaust tho

 

[Steve 00RT/10]

The drag guys say BUY ONE! As if a 488ci Viper needs all that rotational mass to efficiently launch. The Viper does quite well at the drags with an alum. flywheel.

The drag guys I talked to were running the big power cars. High 9's and 10's

Sorry, but I have a different experience...
1.7 Rockers - NO difference in SOTP (seat-of-the-pants) meter
Alum Flywheel - NO difference in SOTP meter
Smooth Tubes / KN - NO difference in SOTP

Headers - MAYBE a minor difference in SOTP meter...

3.45 Gears - Noticable improvement

My own experience:

Headers----very little SOTP---Sound of 'unrestricted' Belangers/3" pipe--Priceless!!

Fidanza Flywheel----more SOTP than the exhaust. Instant spool up. If I'm not mistaken, NASCAR type cars use a flywheel that weighs only 5-6 pounds. They do that for a reason. Instant revs....power to the ground quicker...better braking due to much less rotating mass.

3:45 rear end----most SOTP!

I am de-installing mine this week. Cam lope/drivability is much worse with the aluminum flywheel. I do notice it revs quicker in nuetral. I'm interested in the change going back. Maybe I need to video the before after of the rev.

I have the newer cam. No loping to start with. Have never had any driveability issues. I have friend with a '98 GTS(older cam). He thinks it was a better mod than the Belanger exhaust for SOTP. He has no driveability issues either. It was his input that convinced me to get one.

Steve

 

[ViperRay]

Stugots,
I think you should do the exhaust mods first. Interesting the disparity of experiences though with the flywheel. I took my GTS out to the track (road course) this past weekend after installing the RPS aluminum flywheel and am very happy with the improved throttle response. There is no significant change in the idle and my car (exhaust mods/filters/tubes and now flywheel only) dynoed at 492 RW torque 2 weeks ago. So, I guess I'm saying I'm happy with it but don't think it's a must have if you don't road race your car.
BTW, a lighter flywheel doesn't adversely affect torque. It's equivalent to lightening the car and therefore accelerates faster. Think of it this way... when you accelerate, you must not only move the weight of the car linearly, you must also overcome the moment of inertia stored in the rotating components (ie:flywheel). The energy expended rotating these components is not used to move the car forward. Lightening the flywheel allows more of the energy to move the car forward.
As an example, in say 2nd gear, removing 1 kg from the outside circumference of an average flywheel is equivalent to reducing the weight of the car by 12 kg. As the aluminum removes more than this (not all from the outside of the flywheel of course), the equivalent weight savings is substantial (stock flywheel 42 lb, aluminum 17 or so). You do the math. Of course, the effect is greatest in first gear and least in 6th (it's effect is sensitive to gearing... the number of engine revolutions for each tire revolution). That's why virtually all race cars use small/light flywheels.
As for SOTP...I noticed it on the track

 

[STUGOTS]

ok cool thanks alot Ray i understand the concept 100% now,that was a great way of explaining it i will go with the headers and exhaust first.

BTW viper speed has a 12 pound flywheel

 

[joe117]

What ViperRay said was the truth. It was also the same thing I told you in your other thread, asking this question.

There is science behind this question so asking people about SOTP and what they think isn't really the way to go.
It is a fact that the reduced flywheel weight will make your car accelerate faster.
No serious race car uses a stock weight flywheel.

Will a 12 pound flywheel be good?
Yes, it will make you accelerate faster.
Will it make you car less suitable for the street?
Perhaps it will.
You will find that almost anything you do to your car to improve performance, will have a downside for use on the street.

As for gears, when you change the rear ratio, you really only gain in first gear. After you shift 1 to 2, you no longer have an advantage over the stock rear still in first gear. It trades back and forth as you shift again.

And by the way,
Did you remove your oversize TBs?
If not, your first step to increased performance is to do that.

 

[Steve 00RT/10]

As for gears, when you change the rear ratio, you really only gain in first gear. After you shift 1 to 2, you no longer have an advantage over the stock rear still in first gear. It trades back and forth as you shift again

According to my software, you are right.... to a degree. It does trade back and forth due to the shift points when doing straightline acceleration. However, taking a snapshot of any from / to point ie 60-100 or 100-135, shows the lower gearing to easily beat the stock rear end. For example 5-100 shows a 1.35 second advantage for a 3:45 rear end. The stock rear end will beat a geared car to 150 by a little over a second, but if you take a snapshot from 150-180, the 3:45 takes over with a 2.65 second advantage. Another example: 40-100 in third gear---.79 second advantage to the 3:45. 40-100 in 4th gear---1.55 second advantage to the lower gear ratio. There is definitely SOTP feel in these times. Most of the driving/playing I do falls into these parameters. It should help for xcrossing as well with 2nd gear having more grunt..especially in tandem with the lighter flywheel.

Steve

 

[STUGOTS]

the reason im not going with new gears is

1.don't wanna kill my top end

2.im getting a Roe S/C soon and i wouldent be able to hook up

Joe i never actually put them on i bought them they are here in the box but i have called the best tuners around and they all say that losing power using 70mm's on a stock motor is just a rumor and is not true,and if ya think about it there right now can they i mean REALLY if more air can kill power then smoothies would also as would k&n

 

[FE 065]

..i mean REALLY if more air can kill power then smoothies would also as would k&n

Not so. Bigger throttle bodies = less velocity.
Like a port that's been reamed out to big.

With the stock TBs there's virtually no vacuum at WOT already. At least according to my vacuum gauge.

Larger TBs would just make the situation worse, unless you did work inside the engine to create higher vacuum.

 

[Steve 00RT/10]

1.don't wanna kill my top end
2.im getting a Roe S/C soon and i wouldent be able to hook up

Top end on my car is diminished by 2 MPH(183-181). In reality, I am not likely to get up there. I've been to 162 on a track. The car had more, I decided that was about fast enough for that day. No top, no back window, side windows down. Quite a rush! 150 comes pretty fast--I've done that several times, but from 150 up, you have a little more time to think about things that could happen.

There are Roe SC cars with 3:45's. I'm sure it's a challenge to hook up from a 1/4 mile standpoint, but the acceleration in 3rd and 4th gear would have to put a big smile on your face.

Steve

 

[joe117]

Steve,
All those snapshots, 60-100 and the like, you claim a big difference in acceleration time for a 3.45 over a 3.07.

I don't know where you get that information. The way I understand it, there will be almost no difference in the 1/4 mile time.

If you are talking about staying in one gear and making a run from 40-100 or something like that, I guess you will see an improvement. The problem with that is, people don't just sit in one gear and go from one speed to another.

They will change gears when it is to their advantage, depending on how they are geared.

I still say, the only real advantage to changing rear gears is that in first gear you have a better ratio. After that, it's back and forth as you shift up.

By the way, I did change mine to a 3.55, it made sixth more useful for me.

 

[joe117]

Stugots,
You need to hit the books. Do a little study on what actually makes a car do what it does.

You will never understand any of this by just asking people what to do.

You need to understand the basics and there are lot's of books teaching basic performance.

 

[ViperRay]

Stugots,
Don't confuse air volume with air flow. Larger TB's have more volume BUT the velocity of air moving through them is consequently diminished so that the overall air flow (volume per unit time) may be decreased. Bigger is not always better. A lot of engineering goes into figuring out what the optimum components are in any given package. Now if you alter flow through the heads (ported, etc.) larger TB's may make sense. Doing headwork is also tricky and not simply a matter of making bigger openings...it's flow that matters, period.
If you want to make mechanical changes to your car, you really should do some reading, otherwise you will be at the mercy of the opinions of others who may be equally lacking in knowledge but don't know it. There's nothing wrong with asking questions of this board though (I do it frequently) as there truly are some experts here whose opinions can be considered along with your own knowledge on a given subject.

 

[Steve 00RT/10]

Joe,

The only difference I claim is what my software program tells me. It figures RPMs,optimum shift points, and multiple other car statistics. I inputted my car's information from the dyno and all the other Viper parameters the program uses as criteria. In any gear(not just first), from a set speed and assuming traction, the lower gears will beat the stock gears. I knew that before. There is no question about that. In the 5-100 example--both gear sets are in third gear at a 100. Therefore the lower gear wins even though they were somewhat back and forth on the way to third gear due to shift points. 0-60/5-60....again, the lower gear wins--both had to shift to second before 60 and the lower gear then takes over. From 0-150 the stock gear wins due to the 3:45 shifting to overdrive at 134 or so. Up to 134, the 3:45 wins by 1.5 seconds. The 1/4 mile has the stock gear ahead by .07 seconds.

Granted, the program may not be completely accurate due to so many variables, but with all the inputs the same, except for the rear gears --the numbers should be pretty much relative to each other. It was helpful to me in deciding to get a lower gear.

Steve

 

[Paul Hawker]

While a lower gear is not guaranteed to make your car faster in all circumstances, it will make it a lot more FUN!
Benefits of the 3.5? is that it FEELS FASTER.
Every track will have a gear that might be best suited, but for the street, the lower gear just makes the car feel livelier.

An added benefit is that 5th and 6th are better feeling for cruising.
Gas mileage may suffer slightly.

The benefit of the aluminum flywheel is similar. It feels snappier. Road racers like the quicker response to make heal and toe match revs quicker. They will also come off the corners a little quicker. Less stress on braking also, plus easier downshifting.

 

[FE 065]

New issue of Road & Track has a story on the $460,000 Porsche Carrera GT

Specifications for the 3500lb, 605hp/435lb-ft V10 equipped car include: no flywheel and a clutch of only 6.6in diameter/7.7lbs. contributing to its' 11.3@130mph track times

any questions?

 

[Fiorano]

I'm pretty sure R&T is wrong about the weight of the Carrera GT. The car weighs close to 3000 or 3100 lbs. The only decent US car mags are Automobile and Sports Car International.

 

[Bill B]

Taken from the Porsche USA site:
Unladen weight (DIN) 3,042 lbs (1,380 kg)

 

[Tom F&L GoR]

The graph in this article explains where and how the gear change helps acceleration.

http://socal.viperclub.org/techtips/gears.html

 

[FE 065]

Gear changes (?) and actual weight aside. Porsche goes to great lengths to reduce any flywheel effect between the engine and trans.

 

[C O D Y]

A buddy of mine wants to takes his out. He too is not happy with the drivability of the car with it in.

I am de-installing mine this week. Cam lope/drivability is much worse with the aluminum flywheel. I do notice it revs quicker in nuetral. I'm interested in the change going back. Maybe I need to video the before after of the rev.

 

[joe117]

CODY,
Does your buddy have a stock rear ratio?

 

[Andrew/USPWR]

what is Cam lope?
I have an aluminum fly wheel and was considering having it taken out also. I drive the car on the track a lot, but I want it to 1st be a great everyday car.
I put the flywheel on when I first bought the car. What I have is a car that very hard to drive at low rpms without it jumping and lurching a lot. Is that because of this flywheel or just a crapy driver?