Lightweight Axles
 

Has anybody actually seen any benefit switching to axles that have been gundrilled for weight reduction? I know in theory they should be quicker, be what about real world results that amount to a measurable amount of difference. Thank you in advance

Re: Lightweight Axles
 

I didn't actually see a change but you have to believe all the little reductions add up. So does the cost. Is it worth it? If you want to be all you can be I guess it is. Thats what the army says.

Re: Lightweight Axles
 

Think of it this way for every pound you lighten on a rotating mass the engine sees it as a 4 times reduction --the further out rom the center of rotation it can multiply even more---so if you take out 2 pounds of axle the resistance that the engine has to overcome is approx. 8 pounds plus the car actually weighs less also--Comp 387

Re: Lightweight Axles
 

I have never noticed an quantifiable difference.....quit putting them in any of our cars about 5 years ago......not saying there is not something there just have a lot of other places to throw money at for us!

Re: Lightweight Axles
 

Several years ago I put the whole lightweight rear package in my 3600 lb. A/SA Camaro. Aluminum spool, lightened ring and pinion, rifle drilled axles with all extra metal removed from the flanges, titanium studs, etc. Took 24 lbs of rotating weight out, put 24 lbs in the box.
Total improvement was ----------------------- nothing!!!!!!!
Nothing in 60', 330' or anywhere else.
Might be some help in a lightweight car with a low torque engine, I don't know, but no one I have talked to ever said they picked up anything except a lighter wallet.

Re: Lightweight Axles
 

That being said, reducing unsprung weight had to help suspension. With shocks and springs seeing that much less weight to help them work better in keeping the tire planted. May not show up on the ET Slip as HP to the wheels is increased only very slightly but car may have an easier time getting down a marginal track which could show up in win lights.

Re: Lightweight Axles
 

If I had to purchase ANY rotating suspension/drivetrain part right now, it would be the lightest I can find......

(then, I may even cut on it!:eek:)

Wade O

Re: Lightweight Axles
 

I'm with GTX John and John Mason. I've put all that in mine and found zero. Did, however clean the splines out of the aluminium spool on the starting line at Memphis two years ago, 1st round of eliminations. Had Byron Latino on the tree too. :-(

Jerry Hass was with a red Hemi car parked across from me. He walked over after everybody got back. He said he was standing by my car when it happened. He asked if I broke an axle. Said I didn't know yet. He asked how many splines, I said 35. He shook his head and asked if I had an aluminiuim spool. I said yes. He says "There you go, stop throwing your money away there". He said he quit putting that stuff in cars he builds, no gains, but sometimes problems. I saw zero change in 60' or anywhere else. I put my steel spool back in.

Just my exprience.

Re: Lightweight Axles
 

Listen to Wade.

Lightest AND smallest diameter.
Taking two rotating parts of the same weight lets say a solid axle verses a larger diameter gun drilled axle the larger diameter part of the same weight takes more energy to accelerate to the same speed. In fact a lighter part that is significantly larger in diameter can take more energy to accelerate.

Here is some casual reading on the subject;

http://en.wikipedia.org/wiki/Moment_of_inertia

Now when it comes to aluminum verses steel spools I think there is much more too it than rotational inertia. I think flex and friction may play a big role.

So just build your whole drive train out of titanium then we can start talking about $200,000 stockers LOL

Re: Lightweight Axles
 

Most manufacturers specifically recommend NOT TO USE aluminum spools in cars that weigh over 2800-3000 pounds ---You MIGHT get away with an aluminum spool in a heavy (over 2800) car if it is a real LOW HP car---No hi torque hi HP applications for HEAVY CARS using aluminum spools- No trans brake/stick shift cars either--Rotating mass is where its all at---In stock/SS stock applications yer not looking for that last hundreth or thousandth like in a Comp/Pro Stock Application--that is the most likable application for aluminum spools/lightened ring gears/scalloped flange rifle drilled axles NOT stock or SS---Comp 387

Re: Lightweight Axles
 

Our car is 3200 pounds with a stick and a MW aluminum spool. We ran a best 60' this summer of 1.38. Sounds like the clock is ticking.

Re: Lightweight Axles
 

I guess I have it all wrong then. :confused:

Re: Lightweight Axles
 

LOL? I was in Orlando some years ago and walked by a SS Hemi car. They were changing the center section in the rear. The axles were sitting behind the car. They were a shiny grey, unlike any axles I have ever seen. I commented to a friend about it. He walked over and picked one up. It wasn't steel.

_________________________________

Andy Stone 1102 A/S 1112 SS/C

Re: Lightweight Axles
 

Bill, you are exactly right. I have talked with a couple of Pros extensively on this topic. Its the flex that kills the Pro Stock cars. Trust me, if aluminum would live, even for just 2 passes, AND be faster, it would be in their car.

Ed, what Haas said to you is right, but, as is said here before, apples and oranges with what we do and a Pro Stock car, I'll never have to worry about the later!:D

As for longevity in one of our cars, when I finished my car in late '07, I put an aluminum Moser spool in. Tim Irwin told me at that time that they had previously had breakage problems, but, got it fixed. I have had the rearend apart at least 3 times a year since then. The axles are as tight as day one with no visual signs of problems. Without gears installed and dial indicator check, it still only has .001 runout. You be the judge........

Wade O

Re: Lightweight Axles
 

Wade, what will live in a foot braked 283" stocker won't necessarily live in a trans braked SS car. When I pulled that spool out it had .004" run out. Jerry Hass was with that Hemi SS car because he built it. Not only Pro Stock cars.
I have talked to others that made only the light spool & ring gear change as I did, and nobody found any gain. I'm usually between 1.29 & 1.34 in 60' with the steel spool, exactly the same with the lightened ring gear and aluminum spool.

Re: Lightweight Axles
 

Ditto: Wade & Bill.

Re: Lightweight Axles
 

Mopar Jeff---Most Comp cars weigh considerably less than a Stock/SS car ---pro cars all weigh 2350 min wt- MOST COMP cars weigh about 1180-1600 for a dragster and from about 2300-2900 for a door car although some are a little lighter or heavier depending on the combination/class---granted most pros have 1190-1300 hp but they are spinning the tires a bit at the hit with the power they have and they all have 40 spline set ups too--Most pros run the 9 1/2 inch Dewco gears along with the Dewco spool---Some run MW or Strange and a few use a Moser spool---The high HP Comp LIGHT WEIGHT cars all use 40 spline parts mostly Dewco some also use Strange/Moser/MW too- Those lightweight cars weigh anywhere from about 1100-2400 pounds weight wise--- no comparison to a 3500-4200 pound Stock /SS car they also use Carbon Fiber or aluminum drive shafts Again NOT recommended for HEAVY cars.--I'm not trying to convince ya on what to run just merely trying to enlighten ya on why certain types of cars utilize certain kinds of parts. If it works for YOU great but ya better be diving in that rear end every weekend or so to check for any signs that might predict failure--Those 10,00 RPM launches are brutal on drivelines--I honestly believe that the typical Stock or SS car RARELY pulls the rear or axles out to check them and if at all maybe one time a season whereas we take the driveline out after every other weekend to check !!! If alum works for ya or Titanium is legal and ya don't wanna run steel OK---If ya are happy with Steel stuff OK too----It's all in your combo what works for me may not work for you and vice versa-- Your still not looking for that coupla extra thousandths which can translate into hundreths tho like a comp or Pro car is--Comp 387

Re: Lightweight Axles
 

Ed wright that 1.29-1.36 60 foot is .06 in ET which in a Comp car translates to about .12 in ET at the 1320----No Comp car is gonna give up a TENTH +++ to run a steel setup versus an aluminum/ liteweight axle set up--- never gonna happen---Comp 387

Re: Lightweight Axles
 

I built my car with a complete MW Dana 60 w/ CM tubes and used the ultra-light 40 spline axles. I wanted the 40 spline for the strength in a 3160# -3320# stick car and as Stocker axles are long (compared to a comp car for example) I wanted the weight out. I bought with the lightened ring gear and the light-weight STEEL spool as I believed an aluminum spool was too much of a strength compromise. I can not document the ET savings as I have always had it in my car. I do know that I have NEVER had a rear-end problem and have changed gears several times and they always look brand new. Same with the axles.
So is it worth it? I don't know but the piece of mind is priceless. Of course some people can't substantiate the cost difference of anything pricier than Moser.
And the stories I hear are an aluminum spool and driveshaft are crucial on the small engine cars (300" or less).

Re: Lightweight Axles
 

Wade & Bill..................

The guys that get it....get it

The guys who don't ....don't

Take care,
Bob

Re: Lightweight Axles
 

For those of you who know us, you know how much I hate to agree with Bob
but in this case, as much as it pains me to do so, he's right. Man that hurt!!

Re: Lightweight Axles
 

Re: Lightweight Axles
 

a little off the subject, but still rotating weight. tubes vs. no tubes? i'm running tubes right now. i didn't ever want to mess with constantly airing up. but with a heavy (3560#) hi torque stick car, i thought it would also stiffen up the sidewall on my M/T 31x10.5W on a 12" rim. any thoughts about this kind of rotating weight?- Dan

Re: Lightweight Axles
 

Gotcha, ED. I cant say as far as SS, I was only talking Stocker lingo. I know you guys are WAY more violent on the launch. But, I will say this, if I was to put an SS 283 in my car today, I would see how long the stuff would live before replacing it!!:) I dont feel sorry for them axles or spool one bit!:eek:

Wade O

Re: Lightweight Axles
 

The actual engineering term everyone is talking around is "effective mass". Effective mass is the combination of rotating and non-rotating mass on a vehicle and in the case being discussed here is what effect does it have on accelerating a vehicle.

I think the general rule of thumb is multiply the vehicle mass by 1.1 to get a ROUGH idea of the actual effective mass.

The catch is actual effective mass changes with transmission and rear end gearing. The effective mass in first gear is roughly 1.25 x's weight and 1.15 x's weight in second gear for appoximation purposes.

I'll post more latter about the what are the big hitters for effective mass later.

Re: Lightweight Axles
 

OK Chris,
You are beginning to touch on an area that I have a comment or example of what happens with weight/mass.
Yes, I have the lite weight 40 spline gun drilled MW axles and the MW lite steel spool (alum dosen't support the gear I run on the flange enough and deflects causing gear breakage)
I have the suspension on my V-6 Camaro set up to ET. it doesn't dead hook. It has controlled tire rotation on the hit. When I run it with the wheelie bars, just hanging.. not tapping the ground, It slows the car down a consistent .006. In the video's you can see the tire rotation on the hit is different. It is the effect of unsprung weight on the suspension. (shocks and springs) I have tried a couple different shock settings to get the hook, with and without the W/bars, the same. It just doesn't happen. Vic at ETRC tells me I could get it to do the same thing (rotate the tire on the hit) if I used the wheelie bars to tap the ground and kick the car/suspension up on the tire. I'm too lazy to try it and it works well the way I have it. No sense gettig lost....I'm of the opinion that excess unsprung weight is the real enemy, esp in my low Torque/HP combination.

Re: Lightweight Axles
 

Might want to read that again. 1.29 was with the steel spool. That is the range my 60's fall on different tracks and weather conditions. Not the difference between the two setups. I saw absolutely no difference at all, or I would have put another one in. I don't know why you think comp cars are the only ones after that last few thou. If that applies to your SS friends, they must be of the bracket race persuasion. Not all of us are. You guys are too when trying to avoid CIC. That's if your fast enough to worry about CIC. Are you?
I test more than most comp cars around here. Ask anybody local. Had the engine out five times in three races. Diferent cams, moved the cams, changed the heads, etc. More new stuff coming.

Re: Lightweight Axles
 

Don't do it.

Re: Lightweight Axles
 

Well, my first alum spool broke coming out of the water at Dallas Nat's down to 8 cars and maybe it was "my day"...dunno...bought another, MW said to keep an "eye" on it.....3700 llbs trans brake, 265 CI

Anyway, I called DEWCO about a titanium spool, just to see if there was one, how much etc, thinking it would be stronger and lighter.....he went into a long disertation that I mostly could not understand....but he said flex/bind would kill more than lightweight would help

Re: Lightweight Axles
 

I would listen to Don (Dewco) too. Some guys find it difficult to accept that when your therory doesn't prove out, it's time to adopt a new therory.

Re: Lightweight Axles
 

I called MWs today as I was a little concerned about what was being said about aluminum spools. I told them I will weigh 3500lbs+ with a stick and was concerned their 40 spline aluminum spool I have in my Dana 60 wasn't going to be tough enough to take the punishment.

He assured me that the aluminum spool (8lbs) was every bit as strong as the lightened steel spool (16lbs). I told him I had no problem swapping it out for the steel one if it was stronger but he continued to insist it wasn't necessary.

I tend to believe the racers actually using the parts more so than the manufacturer so I'm kind of torn now. Anyone using a Dana with a aluminum spool and had problems?

Re: Lightweight Axles
 

Many of the problems with both aluminum spools and 9 inch Ford aluminum differential cases has to do with deflection of the parts under hard accleration(hole shots)---If you think about how you install either a Dana/12 bolt or Ford 8.8 ring gear you are actually spreading the housing a few "thou" to do it. and if you have an alum spool instead of a steel one the aluminum will deflect more than the steel will---Vehicle weight ,engine HP,type of trans (stick/auto) trans brake or not and rear end gear ratios all come into play here and actually have everything to do with if the parts will live in your application---If you have ANY doubts call the spool manufacturer tech line and get their recommendations---What works in my car may or may not work in yours----Ask the tech people they will not lie to you--asking around on forums like this one can confuse some people---Go right to the source ask em they are more than happy to help--Comp 387

Re: Lightweight Axles
 

Strength also has to do with the ratio you are using. A 6.50 gear with a very small tooth count pinion is more prone to fail due to deflection than a 4.56 with a bigger pinion. Yes, the alum will deflect more than steel, but the ratio is the deciding factor. Think about what is happening when the ring gear moves away from the pinion. The contact area gets smaller and moves to the thinner/weaker part of the gear. As I said in my previous post the Alum deflects too much for the gear ratio I'm using. It might not for the gear you are using.

Re: Lightweight Axles
 

I ran the MW aluminum spool and 40 spline rifle drilled axles in my Demon for over 15 years leaving the line at 7000 plus in a car the weighed 3300 + most of the time. Never broke anything. Never even cracked a tooth. I ran 5:57 or 38's. Nothing better than MW.

Re: Lightweight Axles
 

FED387, I don't agree with you about 'Ask the tech guys, they won't lie to you'. Maybe not lie but they will error on the way too heavy duty side. Virtually all of my drivetrain components were opposite the advise of their manaufacturers who assured me they would either break outright or wear prematuely. Weight and friction loss are too big of an issue in Stock and SS to take their conservative 'don't want our brandname badmouthed if I'm wrong' attitude. I've learned a lot over the years by looking at cars that have been in my shop and their undersized light duty 'mistakes' which seem to have held up for years without breaking. None of us want to break parts at an inoppertune time but look at the fastest cars and you will see some pretty flimsy parts, I don't think it's by accident. The smart and fast guys are more than happy to tell you that 1350 ujoints, power robbing 9" Ford rearends and all of those cool looking heavy duty parts are the hot setup.

Jim Caughlin
SS 6019

Re: Lightweight Axles
 

Fed 387,
Thanks for your detailed explanation, and I was only referring to the part about Stock/SS guys not looking for every last hundredth or thousandth. I would imagine most people when building or changing a car, weigh the options and try to squeeze anything extra they can. That is how you become the fast car of the class. Any class that is going to potentially be heads up would obviously do that if funds permit. No ill will intended at all, just making a statement.
When I built my rearend, I would have put an aluminum spool in because I have a low horsepower combo. The only problem was that no one makes one for the Ford 8.8. So I went with the lightened steel one instead. Maybe I wasted some money on all that good stuff back there, but at least I tried, and I can't ever put the blame on not buying the best stuff. Take care and thanks for your input.

Re: Lightweight Axles
 

I have had same MW alum. spool in Demon most of the time for last 15 years.
I replace the R/Pinion around 75-100 runs when it get noisy which is about twice as often as the other cars with steel spool. No visible twist on MW axles that were in the car when I bought it (35) but they are not drilled. 1.36 @ 60 weighing as much as 3500 but usually 3350.

Rod: Putting that very Dana you were talking about into my Demon today!

I guess that old rearend doesn't owe me anything at this point.

Re: Lightweight Axles
 

Thank you to every one for your thoughts and opinions.