Aluminum Spool

RJ · 09-26-2007, 06:55 AM

Looking for feedback on aluminum spools, good/bad or indifferent. Has anyone done a back to back against a lightweight steel spool on a chassis dyno?

FED 387 · 09-26-2007, 08:56 AM

NO- But the weight of your car is usually the determining factor as to wehther or not you can/should use an Alum Spool---2800 pounds is about the break off point over that a steel under an alum one. Maybe if you have a heavy LOW horsepower combo you might be able to get away with it but you will have to monitor the R&P closely---Otherwise steel will be the way to go---Also think of this if you take off 2 pounds of spool weight the engine thinks that you took 7-8 pounds of vehicle weight out cuz of the rotating mass is now less---Comp 387

Randall Klein · 09-26-2007, 09:47 AM

We risk running them in our SS '56 & '57 Chev's at 3700 lbs with a trans brake and steep gearing...of course one broke in the water at Dallas a few years ago at 8 cars...that hurt...worth an easy .08 in our cars. In talking with Mark Williams tech, of course like all "on-the-edge" parts subject to inspection and breakage...at the wrong time

Risk reward

Dave Goob Cook · 09-26-2007, 05:40 PM

It will be of most benefit to low HP cars with steep gearing....

When considering which parts of rotating mass to eliminate, you work you way down from the mass with the most diameter, and remember that the speed at which you are attempting to accelerate that mass is a huge factor in the effect at the time slip.

A vehicle with a starting line ratio of 15:1 would benefit more than a vehicle with a starting line ratio of 9:1 from all mass behind the transmission being lighter, long stories and wild theories short.

A properly lightened steel spool might actually have a very similar moment of inertia that an Aluminum spool, because of the weight being removed at a farther radius point from center.

Obviously, the part of the vehicle's rotating mass that would have the least effect on moment of inertia would be drilled axles, the benefit of that is more in reduction of total rotating mass and unsprung weight.

goob- if b*llsh*t were a bidness, I'd be a billionaire.......

Sean Ward · 09-29-2007, 08:25 PM

what is the heaviest car you should run a spool in

Tommy Gaynor · 09-29-2007, 09:59 PM

I had one in my 3530 lbs LT1 98 Camaro and it made it less than 20 runs. The guys at strange told me so but I thought I was smarter! Well I was wrong. I have been told the guys running one from Mark Williams are living. For a 12 bolt it requires machining the case for a larger OD bearing. I think it is a lot of work and money for a very small gain. After installing the lightest steel spool from strange I saw no ET loss! Just my 2 cents

Rod Greene · 09-30-2007, 12:58 AM

I have been running one since 1999. Thousands of runs with a stick leaving at 6800 in a 3300lb car. Mark Williams builds the best stuff

Dave Goob Cook · 09-30-2007, 05:33 AM

The M/W stuff has it's own spline angle, superior for sure.

09-26-2007, 06:55 AM	#1
RJ Member Join Date: Oct 2002 Posts: 248 Likes: 0 Liked 0 Times in 0 Posts	Aluminum Spool Looking for feedback on aluminum spools, good/bad or indifferent. Has anyone done a back to back against a lightweight steel spool on a chassis dyno?

09-26-2007, 08:56 AM	#2
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 327 Liked 280 Times in 150 Posts	Re: Aluminum Spool NO- But the weight of your car is usually the determining factor as to wehther or not you can/should use an Alum Spool---2800 pounds is about the break off point over that a steel under an alum one. Maybe if you have a heavy LOW horsepower combo you might be able to get away with it but you will have to monitor the R&P closely---Otherwise steel will be the way to go---Also think of this if you take off 2 pounds of spool weight the engine thinks that you took 7-8 pounds of vehicle weight out cuz of the rotating mass is now less---Comp 387

09-26-2007, 09:47 AM	#3
Randall Klein Senior Member Join Date: Dec 2002 Location: Lincoln, Nebraska Posts: 784 Likes: 45 Liked 317 Times in 66 Posts	Re: Aluminum Spool We risk running them in our SS '56 & '57 Chev's at 3700 lbs with a trans brake and steep gearing...of course one broke in the water at Dallas a few years ago at 8 cars...that hurt...worth an easy .08 in our cars. In talking with Mark Williams tech, of course like all "on-the-edge" parts subject to inspection and breakage...at the wrong time Risk reward

09-26-2007, 05:40 PM	#4
Dave Goob Cook Member Join Date: Dec 2006 Location: Indy Posts: 422 Likes: 0 Liked 0 Times in 0 Posts	Re: Aluminum Spool It will be of most benefit to low HP cars with steep gearing.... When considering which parts of rotating mass to eliminate, you work you way down from the mass with the most diameter, and remember that the speed at which you are attempting to accelerate that mass is a huge factor in the effect at the time slip. A vehicle with a starting line ratio of 15:1 would benefit more than a vehicle with a starting line ratio of 9:1 from all mass behind the transmission being lighter, long stories and wild theories short. A properly lightened steel spool might actually have a very similar moment of inertia that an Aluminum spool, because of the weight being removed at a farther radius point from center. Obviously, the part of the vehicle's rotating mass that would have the least effect on moment of inertia would be drilled axles, the benefit of that is more in reduction of total rotating mass and unsprung weight. goob- if bllsht were a bidness, I'd be a billionaire.......

09-29-2007, 08:25 PM	#5
Sean Ward Member Join Date: Apr 2006 Location: Grand Island FL. Posts: 389 Likes: 0 Liked 0 Times in 0 Posts	Re: Aluminum Spool what is the heaviest car you should run a spool in __________________ Sean Ward NHRA s/ss/comp#2882 SW4 MOTORSPORTS

09-29-2007, 09:59 PM	#6
Tommy Gaynor Member Join Date: Aug 2002 Location: Vancouver WA Posts: 250 Likes: 1 Liked 3 Times in 2 Posts	Re: Aluminum Spool I had one in my 3530 lbs LT1 98 Camaro and it made it less than 20 runs. The guys at strange told me so but I thought I was smarter! Well I was wrong. I have been told the guys running one from Mark Williams are living. For a 12 bolt it requires machining the case for a larger OD bearing. I think it is a lot of work and money for a very small gain. After installing the lightest steel spool from strange I saw no ET loss! Just my 2 cents

09-30-2007, 12:58 AM	#7
Rod Greene Senior Member Join Date: Mar 2002 Location: TN Posts: 514 Likes: 355 Liked 204 Times in 72 Posts	Re: Aluminum Spool I have been running one since 1999. Thousands of runs with a stick leaving at 6800 in a 3300lb car. Mark Williams builds the best stuff __________________ Rod Greene Real men shift for them selves. Slowly working on TA Challenger for D,E/S and a 72 Challenger for SS/K, L as if I don't have enough other projects.

09-30-2007, 05:33 AM	#8
Dave Goob Cook Member Join Date: Dec 2006 Location: Indy Posts: 422 Likes: 0 Liked 0 Times in 0 Posts	Re: Aluminum Spool The M/W stuff has it's own spline angle, superior for sure.