Flywheel choice for 2.5L TIII

[iTurbo]

So I've built a 2.5L TIII for my Spirit R/T. I have 3 different flywheels I could use.

1. Stock TIII

2. TU lightened steel (with crank sensor notches).

3. TU aluminum with notches for crank sensor and outer ferrous flame spray coating. (I'm a little nervous that this will actually work)



Given that I have already decided to use an A568/A523 hybrid with OBX limited slip and 3.50 final drive, I'm thinking that the stock steel flywheel would be best. It's a 'heavier car', but it's also 2.5L so who knows? I'll be using a TU blue plate/6-puck clutch if it makes any difference. Thoughts?

It will certainly be used on the highway more than anything else. Probably 250 whp tops. It looks like I'll be selling the car to my older brother who works at a coal mine and a long commute. But fun on the street is also important.

[tryingbe]

Long commute? Stock.

[iTurbo]

His commute consists of cruising at 65-80 MPH the whole way with no stop-and-go traffic. Probably a few WOT punches here and there to get a pass over with.

[86Shelby]

I'd lean towards stock for family so it's easier to drive. Then again my family has a much lower threshold of roughness they'll put up with in a car than I do for the sake of performance.

[Reaper1]

Either stock or lightened TU. I used a "race lightened" TU flywheel on my Shelby Z with a 6-puck/purple TU clutch. It was MUCH easier to drive than the aluminum flywheel. I was in a LOT of stop-n-go traffic. The ONLY thing that sucked was the fact that you can't really slip a ceramic clutch all the well, so what I did was hang back a little, leave it in 1st and ride the brakes to regulate my distance. Eases up on the use of the clutch.

[iTurbo]

Looks like stock is the way to go. I'll save the others for future projects. Thanks guys.

[GLHNSLHT2]

Aluminum all the way. But it suits my driving style much better than stock. I shift quick wether it's hard or easy, match revs on d'shifts, and love the extra responsiveness of the motor. The torque of a 2.5 and the revs of a DOHC should be a sick combo with an aluminum flywheel.

[iTurbo]

Interesting Jay. I have often thought an aluminum flywheel would be especially well suited to a 2.5L because of the additional torque. I do love rev matching while downshifting using both sides of the right foot and more throttle response is always good in my book.

If I were to keep the car, I would totally go this way. Beings that I'm selling it to my brother, I'll keep it for the next project. My other older brother now seems to think a TIII would be pretty nice in his Omni GLH..

[GLHNSLHT2]

1st drag race with it in my ShelbyZ with a mild 2.5 8v was fun. Lined up on a 3 lane 1 way next to a friend and a school bus full of kids. Sitting at the light thinking of all the things people have said knocking aluminum flywheels basically. Analyzing it all I determine I need at least 500 more rpms than usual to get a good launch. So up to 3500 she goes, I'm doing the normal stab the gas as hard as you can and lift on and off to keep it around 3500 and spool the turbo. Light turns green, I side step the clutch and burn both front tires off through 1st and 2nd trying to get it to hook up. Way way way too much rpm. But everyone said I'd need it. I must be abnormal because I found I needed 500rpm LESS than with a stock flywheel. With the 1st generation custom cal 2 step (very crude as it's just a rev limiter) on the street it's set for 2grand. Side step the clutch, the tires give maybe a 6" scratch on the blacktop and off you go. At the track where it's sticky I have it set for 2850 on street tires. I do a 2nd gear burnout out of the waterbox John Force style. Stand on the 2 step and side step the clutch. Get's usually a 2.260ft but I've managed a 2.1 doing that. Not slick territory but it's consistent.


With the UDP the starter turns the car over like a machine gun instead of the usual wrrr wrrrrr wrrrr vroom. I've really become a believer in the less recipricating weight the better no matter what. Just have to adjust you driving style a bit. I'm a firm beliver in that you should never slip a clutch, especially a ceramic one. It'll chew any flywheel and the pads. Lots of Porsche Carrera GT clutch issues because people didn't know how to use a ceramic clutch.

[Reaper1]

I'm not saying you are wrong. I just happen to have had the polar opposite experience, but my car was a 2.2. I couldn't get a consistent launch at the track...I would start at 2500rpm and it would bog all the way to 4000rpm. I still never got a clean launch. On the street to get going without burning the tires off I would rev it gently then let the clutch out quickly, not dump it because then the car would shake and buck until it got going. Trying to maneuver the car at low speed was not fun at all. On track it was great! I could more easily rev match for sure.

Maybe the difference is the 2.5, I don't know. All I can tell you is my experience with an aluminum flywheel was not that great.

I swapped to the 1st generation TU "race lightened" steel flywheel and have been extremely happy with it! As with all car mods: YMMV

[GLHNSLHT2]

Maybe it is the 2.5, maybe it's just my 2.5 I don't know. My 2.5 liked 500rpm higher shifts at the track than the 2.2 I yanked out from under the top end. So it's always been an oddball against what everyone has said things should be like. Gonna find out soon though as I'm putting it on a 2.2 setup in about the same weight car. If it doesn't act the same I'll be yanking the 2.2 and building a 2.5 Tall deck setup for it.