Weight of 18 spline Iron 4 speed

[timmycharger]

I will be buying one of Passon's Overdrive Hemi 4 speed complete transmissions in the next month or so but im not sure if I want to dish out an additional 1k for an aluminum case or not.  My car will see the track wearing slicks in the future so I am running a Lakewood bellhousing which is very heavy by itself.  How much weight will I be saving by going to aluminum, anyone know the weight of a stock iron transmission?

Its mainly going to be a street car, and I am putting the steel hood back on, power steering/brakes, AC so Im already adding a ton of weight there, I am replacing the heads with aluminum so a few lb savings, so Im not sure if Im worrying too much about it and should just go with the iron case. Any thoughts?

[Dino]

More weight will keep the car on the ground better so there.   

I don't know how much weight it would save though or what difference it would make on the strip.  How much faster would you like the car to be for $1K though?

[timmycharger]

More weight will keep the car on the ground better so there.   

I don't know how much weight it would save though or what difference it would make on the strip.  How much faster would you like the car to be for $1K though?

Dunno, Im using the same motor, just changing the heads and converting to a 4 speed, I would like the car to be as fast as it was before the restoration, which was 12.80's.

[Troy]

Passon should be able to tell you exactly how much lighter their parts are. A quick search on the internet showed 110-135 pounds for iron and about 80 pounds for the later 23 spline OD versions. With the 18 spline gearset you're probably a bit higher than the OD. I'm not a big guy but I can pick up an 833 from the floor and move it around fairly easily so I always assumed it was just a bit over 100 pounds. That 135 figure seems really high. Soooo, maybe 25-30 pounds in weight reduction? It's not unsprung weight and it's in the center of the car so I'm not sure of the "real" advantage. You'd be better off spending the money on lighter wheels and brakes OR at least aluminum radiator, water pump, heads, and intake.

Troy

[timmycharger]

Passon should be able to tell you exactly how much lighter their parts are. A quick search on the internet showed 110-135 pounds for iron and about 80 pounds for the later 23 spline OD versions. With the 18 spline gearset you're probably a bit higher than the OD. I'm not a big guy but I can pick up an 833 from the floor and move it around fairly easily so I always assumed it was just a bit over 100 pounds. That 135 figure seems really high. Soooo, maybe 25-30 pounds in weight reduction? It's not unsprung weight and it's in the center of the car so I'm not sure of the "real" advantage. You'd be better off spending the money on lighter wheels and brakes OR at least aluminum radiator, water pump, heads, and intake.

Troy

Thanks Troy, good point about the weight being in the center of the car. I think I may be ok as I am now running an aluminum radiator, waterpump housing, intake, and aluminum wheels just for the track

[Troy]

Well, even if an auto is lighter (and not by a whole lot I don't think) the drive train losses are less with the 4-speed. Just hope you can shift as fast as the auto! Be careful though as the "shock" with slicks is likely to break stuff. Hope you have a Dana.

You're probably saving close to - if not more - than 30 pounds with the aluminum heads.

Troy

[timmycharger]

  Be careful though as the "shock" with slicks is likely to break stuff. Hope you have a Dana.


Yep, got myself a Strange S60, should be plenty strong, frame connectors and a safety loop too!! now that I think about it, I went from an 8 3/4 so Im adding weight there too!!