Axle and spline count recommendation for a drag car?

[Nightmist66]

I love the 4.33 in mine. Miles per gallon? Nah, it's smiles per gallon! When I finally got my car to the track this fall, it was going through at about 5600@104mph. This was with a 27in drag radial. I was launching around 3k. I will be installing my new subframe connectors before I head back in the spring and will get a real set of slicks and launch harder and see what happens.

Here is what I like to use to calculate things- http://www.summitracing.com/popup/calcsandtools/gear-ratio-calculator

Before you run off and buy "a real set of slicks" note that a lot of us "real slick" users are switching to Drag Radials.  Switching from M/T 3055 28-10.5x15 slick to a Hoosier 275-60-15 DR lowered my 60' by about .05 with the 302.  When we bolted them on the Mustang it picked up a full tenth ET in the 1/8 mile and almost 1 MPH.

Is your car an auto or stick? I understand for stick cars you want a stiffer sidewall, which is part of the reason I want to try some slicks. The other part is that I need to improve on my 60', because it is picking up on the top end. I need to launch harder(maybe 4-4500rpm), and I don't believe a "softer" sidewall drag radial is going to benefit me there. I could be wrong.

[Rory428]

Back when I had an automatic in my Fairmont, I had a 9" with a factory N case, and 33 spline Strange spool and axles. For most of the the time with the C6, it had a 8" convertor and transbrake, which I would normally launch at WOT, 5200 RPM. With the C6, the best numbers at the track were 1.40 60 foot, and 10.55 ET@126MPH, weighing 3200 lbs.
When I switched to a Jerico 4 speed in 2000, when I took the 9" apart, I noticed that the 33 spline axles had twisted about 1-1 1/2 splines, so when I crunched the prices, it made sense to upgrade the rearend for the clutch .Although a 9" would be fine, it was cheaper to sell the existing 9" and go with a Dana 60, which we installed Strange 35 spline axles and spool,billet caps, and a T/A load bolt girdle cover. 15 years of dumping the clutch at 6000-6600 RPM, and the 35 spline axles still look perfect. So I do prefer to error on the side of "overkill" when it comes to axles. That said, my 85 Mustang , with a 331 SBFord has gone 10.3s and 4s , also with a 4 speed, dumping the clutch between 5800-6200 RPM, yet it only has a set of street/strip Moser 31 spline axles in the 8.8., that I installed in 2003 when I started running the car in Stock Eliminator.
As for wheel studs, the Mustang uses ARP 1/2" wheel studs, 3" long (5 lug), and the Fairmont used to as well, but about 10 years ago, I switched to 5/8" studs, and I like them much better.
I never broke the 1/2" studs, but after a while, the long shank lug nuts start to gall up where they go into the aluminum wheels, with the 5/8" studs, the shank of the stud has a sleeve that fills the holes in the wheels, and thus does not use shanked lug nuts, rather there are aluminum spacers and flat flanged nuts. In addition to no more galling/binding of the nuts, this setup reduces the amount of "wasted" stud hanging out past the lug nuts.  I know on our drag cars, we are not always needing to change tires as fast as the Wood Brother NASCAR team, but its still nice to remove the nuts in 1/2 the time as before. Plus the larger nuts and studs will employ higher torque specs.

[Falcon67]

Is your car an auto or stick? I understand for stick cars you want a stiffer sidewall, which is part of the reason I want to try some slicks. The other part is that I need to improve on my 60', because it is picking up on the top end. I need to launch harder(maybe 4-4500rpm), and I don't believe a "softer" sidewall drag radial is going to benefit me there. I could be wrong.

Auto, 4200 stall with 4.11s.  You have it backwards - Unless the slick is made specifically with stiff sidewalls, Drag Radials have the stiffer sidewall.  There are some stiff sidewall slicks - 3055S as opposed to a regular 3055.   The MT web pages can sort those out. The DRs are a bit more "picky" about burnout and suspension setup.   The MT DR page notes that their DRs work best with an auto, so a stiff sidewall slick might be better for your application.  I'd call them as ask - they know their tires.

http://www.mickeythompsontires.com/strip.php?item=ETDrag

[Falcon67]

M/T 3055 Slick, 13 lbs pressure - note the wrinkles


Hoosier DR, 16 lbs pressure

[cjshaker]

I did quite a bit of research on the tires before I bought my M/T Streets. Nearly everyone agrees that the bias ply is best for a stick car unless the suspension is in perfect tune. The re-hooking drawback with radials that Jay mentioned is an issue that many have talked about. Alot of pros are going to the radials for the top end advantage, but I think I made the best choice for my car. The biggest pain to me, with the bias ply, is having to jack the car up if it sits for a couple weeks. Not a big deal though.

And I'm definitely sticking with the 9". The last thing I want is someone telling me I've got a Chrysler rear in my car    I've seen plenty of cars running a 9" that are pushing 1000 hp or better. I believe housing flex becomes the main problem once power and traction start climbing, which can lead to other problems.

[turbohunter]

Hope you don't mind Doug but as long as we're talking about axles, studs and such, where do you guys find quality lug nuts.
Bought some off of Summit. They sucked. Had coating garbage in them and I gauled some threads before figuring out they had to be chased. Also not the best fit to the mags. Just don't feel like quality parts.
A taller hex would be great also.

[ScotiaFE]

I got some ARP wheel studs from Summit.
Fit perfect with the nut from the Pro Star wheel.. And fair price.
There must have been something wrong with those Summit studs.
The threads are rolled and if you have to chase them then the whole theory of the rolled thread is lost.
Of course you will need to get the right ones for your setup, the right knurl, length and such.

http://www.summitracing.com/int/parts/arp-100-7703/overview/

[turbohunter]

Sorry Howie
Lugs
Fixed it to be more explanatory.

[cjshaker]

No problem Marc, it's all related and good info. One of the local tire shops that I frequently deal with has a big bin of lug nuts, of all different styles. That's where I got the rear through-lugs for my car. The fronts use a special lug nut that is specific to the rim though. You might try stopping by one of your local tire shops and checking out what they have. Typically, it's kind of hard to go wrong on lug nuts. Those Summit jobs must have been pretty cheap.

[turbohunter]

Those Summit jobs must have been pretty cheap.

They were Billet Specialties. Thought those would be ok. I've since found some more to try but was hoping to get some real word experience talking.
Tried my local shop they didn't have what I need.
Need a shank lug with open end.

[Nightmist66]

Hope you don't mind Doug but as long as we're talking about axles, studs and such, where do you guys find quality lug nuts.
Bought some off of Summit. They sucked. Had coating garbage in them and I gauled some threads before figuring out they had to be chased. Also not the best fit to the mags. Just don't feel like quality parts.
A taller hex would be great also.

Got my lug nuts from Summit when I ordered my wheels and tires. I went with McGuard P# MCG-64000. These are for 1/2"-20. Couldn't be happier with the quality, chrome finish and threads are excellent. Cost me $50 for all 20. I bought the Moser wheel studs(P# 8020) when I bought my Moser 31 spline axles. No particular reason, they seemed quality for a decent price.

[Nightmist66]

Falcon67: I did get my M/T drag radials to wrinkle w/ 18psi. I didn't go lower on pressure because they seemed to hook with a good burnout and decent track prep. I was fighting cold temps. that day(about 50°F, but did drive to the track and home) and one lane was lousy on prep at the line.

[turbohunter]

Thanks.
Prolly just bought the wrong brand.

[FE Jonny]

I have seen 31 spline axles hold up to 600 HP with 35" tires and a stick. Don't fix it if it ain't broke.

[Nightmist66]

I have seen 31 spline axles hold up to 600 HP with 35" tires and a stick. Don't fix it if it ain't broke.

I concur.