Alm or steel fly?

[grandkodiak]

Should I get an aluminum or steel SPEC flywheel? i dont know if my car has enough modifcations to justify an aluminum, i dont want it to run or drive like ****... and i'm also getting a carbon shaft and 4.10's so i think i;ll still need the weight of steel. anyone informed out there on the subject? i need to replace the stock one anyway, its in crappy shape... but i dont know whether to go stock, or spec steel/alum.

[Savage_Messiah]

Forgive me for asking but by carbon shaft i assume you mean carbon fiber driveshaft?

....why?

[BMF]

Whatever you decide buy an SFI approved flywheel.

Do your feet and car a favor and buy a Steel bellhousing like a LakeWood or a McLeod.

[NJSPEEDER]

you don't want weight in the driveline or any other part of the car. go with the aluminum.
the concept of running a heavy flywheel is correct, for the first 15ft. after that you are just dragging around all the mass of steel to try to accelerate the car.
you will have to adjust your clutch release and launch RPM, but you will be quicker and faster with the aluminum flywheel.

[Tru2Chevy]

Originally Posted by Savage_Messiah

Forgive me for asking but by carbon shaft i assume you mean carbon fiber driveshaft?

....why?

Because it only weighs 7 lbs

- Justin

[qwikz28]

Originally Posted by Tru2Chevy

Because it only weighs 7 lbs

- Justin

and is damn strong

[1QWIKBIRD]

Originally Posted by NJSPEEDER

you don't want weight in the driveline or any other part of the car. go with the aluminum.
the concept of running a heavy flywheel is correct, for the first 15ft. after that you are just dragging around all the mass of steel to try to accelerate the car.
you will have to adjust your clutch release and launch RPM, but you will be quicker and faster with the aluminum flywheel.

There was a real good article in one of the recent Car Craft or Hot Rod or Popular Hot Rodding mags that explained the physics of and it and then they backed it by using a 5.0 mustang that was running consistent high 10's and the results were pretty stout. I forget them exactly so I don't want to mislead, but the physics of it were very convincing and the proof was on the dragstrip. I tried searchin the web for the article, but no luck. If I can dig it up I'll forward a copy if you are interested....

Chris

[BonzoHansen]

Originally Posted by 1QWIKBIRD

There was a real good article in one of the recent Car Craft or Hot Rod or Popular Hot Rodding mags that explained the physics of and it and then they backed it by using a 5.0 mustang that was running consistent high 10's and the results were pretty stout. I forget them exactly so I don't want to mislead, but the physics of it were very convincing and the proof was on the dragstrip. I tried searchin the web for the article, but no luck. If I can dig it up I'll forward a copy if you are interested....

Chris

It was in PHR. The argument for a heavier flywheel is that it retains energy, but I believe they proved that some other attributes make up for the loss of knetic energy, so they believed the lightweight was the way to go.

[1QWIKBIRD]

yeah that's the basic idea...the definitley recommended the lighter flywheel assuming you could compensate slightly with more rpm at launch...it's all about the moment of inertia....and the force required to overcome it....damn I have to find the artice, cause it was good, not only for clutch/flywheel speak, but for the entire driveline. One example they gave was the carbon fiber driveshaft....kind of a waste unless you are at the ragged edge and looking for every last ounce that's left, the reason being that the diameter of there drive shaft is small and there for the MOI is small, and you reach a point of diminishing returns. The flywheel on the other hand is 22-24 inches in diameter so the MOI is much higher as a function of the weight and its distance from the center of rotation....it's something along those lines.....

Chris
(frantically trying to find the article now)

[1QWIKBIRD]

Originally Posted by BonzoHansen

It was in PHR. The argument for a heavier flywheel is that it retains energy, but I believe they proved that some other attributes make up for the loss of knetic energy, so they believed the lightweight was the way to go.

Found the article, PHR February 2006.....The SPIN Zone.....definitely worth the read.....its talks about everthing on the driveline that is spinning/rotating from the balancer out to the rear wheels and tires....

Chris

[Ian]

and I was under the impression that a heavier flywheel would help in drag racing because it would help retain engine RPM between shifts. and an aluminum flywheel would be good for road racing because the RPM's cnage a lot so you would want the motor to speed up and slow down quicker.

I'm no scientist though!

[NJSPEEDER]

Originally Posted by Ian

and I was under the impression that a heavier flywheel would help in drag racing because it would help retain engine RPM between shifts. and an aluminum flywheel would be good for road racing because the RPM's cnage a lot so you would want the motor to speed up and slow down quicker.

I'm no scientist though!

once you are ashifting the engine will fall to the RPM that matches the wheel speed regardless of flywheel weight. if a driver is spending enough time between gears that having all the inertia of the heavier wheels is important then that person could use more practice, not a heavier flywheel

[1984camaroz28]

Originally Posted by NJSPEEDER

you don't want weight in the driveline or any other part of the car. go with the aluminum.
the concept of running a heavy flywheel is correct, for the first 15ft. after that you are just dragging around all the mass of steel to try to accelerate the car.
you will have to adjust your clutch release and launch RPM, but you will be quicker and faster with the aluminum flywheel.

i have do disagre with you on this. If you dont have the turn momentum of the steel fly wheel to get a 3000# pound car out of the hole its gona hurt ur time. Ive seen a few cars boging bad with alum flywheels. Also for a side note HPE also recomended a steel flywheel

[BMF]

Originally Posted by 1984camaroz28

i have do disagre with you on this. If you dont have the turn momentum of the steel fly wheel to get a 3000# pound car out of the hole its gona hurt ur time. Ive seen a few cars boging bad with alum flywheels. Also for a side note HPE also recomended a steel flywheel

If the car is bogging its in the tune up, the clutch setup, the suspension setup, tire pressure, ect.

A stick car shouldnt leave like an Automatic. In low HP automatic car, the best launch is acheived through "dead hooking" the car.

While a stick car requires some wheelspin as its pitch rotating (on the launch) to build wheelspeed and not bog the motor.

Watch a well sorted out stick car leave the starting line, its pretty exciting, Steve Ficacci's A/Stick 68' Camaro comes to mind. This car is a pretty good example of what i'm talking about, the tires slip as its wheelstanding on the launch.

You cant fight the laws of physics and expect to go fast, simply put, the less rotating weight, the quicker it will accellerate.

In conclusion, slip the clutch or the tires, if this is a car racing on a Prepped track with good tires, if not then it will be tough to get it to hook with a slight tire spin. Instead they will give up, meaning they will spin uncontrollably and the car will slow down.

Street tires will definetly just Give up and spin uncontrolably, where-as the correct launch would be started with a 1/4 revolution of spin, then a slight "skipping" of the tire as it slips/hooks/slips/hooks while the car pitch rotates.

[BMF]

BTW, car magazines are pretty much Useless, they're filled with bad information, wrong information, and biased information.

They're out there to advertise the "trick of the week" part, and that will bias the information in the articles to support buying the trick of the week part.

The best thing you can do with a car mag is throw it in the garbage.