Floater or 40 spline?

Putting together a BBC/blown alcohol altered and am facing a dilemma....the 9inch it has, a non braced 9 inch w/Strange aluminum center, 33 spline dutchman axles, new Wilwood brakes....I hope to run high 6's
I am thinking I need to brace housing, add nodular carrier and go to 40 spline stuff and likely should build it into a floater but....if the car doesn't go over 200 mph do I need a floater? Sure could save some money by not floating....any input?

 

Floater

I believe anything with a blower on it needs to be a floater. Just a good idea anyways. IMO


Corey

 

A 40 spline will take you legally to 6.0 ET. Pro Stockers run a 40 spline aluminum spool at 6.50. Where your current goals are you certainly don't need the floater. But since your spending money what are your long range goals. That should be what determines your move.

Blessings........Ron Clevenger.

 

floater

according to NHRA rule book , full floating axle mandatory if any vehicle runs 6:50 and quicker or goes 210 m.p.h.and faster.

 

ever watched a car at the big end break an axel? not to cool...I wouldnt run a blown car without a floater. but my ex-wife would tell me it is safe to..Dave

 

I did have my axle break, i used a 40 spline thought i would get away with it, luckly we didnt crash but after it broke we had to get a floater anyways.

i sent my 40 spline to Gforce race cars they converted it to a floater cost about 3500 great deal.

save money buy it right the first time

 

i am going to throw my 2 cents in here on this one....this comes from experience. do yourself a big favor....put a floater in the car. save your money, and do it right the first time. if you are determined to run a 9" ford, i would buy a Mark Williams floater kit, some of his 40 spline axles, and get one of those new Moser housings. if you do end up running a stock type housing, make sure that you run a back brace on it, that is the weak link on that housing. if possible stay away from having tubes that are over a few inches long. when you weld the spindle to it....it then becomes the weak link. here is a pic of the one that was in our car. we used a stock housing, put a back brace on it, and sleeved the inside of the tube where the spindle welds to it......still broke it. i feel if we would have had a " sheetmetal" type housing with NO TUBES that we would still be running it in the car. THERE IS NO OVER KILL WHEN IT COMES TO SAFETY.

 

That was changed to 6.0, don't have time this morning but will post copy from rule book later. I'm sure we could all post reasons and examples to go one way or the other. The bottom line is, do what makes you comfortable within the rules.

Blessings............Ron Clevenger.

 

This would apply to Advanced ET (6.00) or Top Dragster, Top Sportsman which are also to 6.00.
The rules say a floater is permitted but not mandatory to 6.00.
See the amended rules for a copy upgrade.

Blessings...........Ron Clevenger.



2010 NHRA Rule Amendments
Last Amended January 6, 2010
2010 NHRA Rule Amendments
As of January 6, 2010

Page 4.14
DRIVETRAIN: 2
REAR END (12/21/09)
Aftermarket axles and axle-retention devices mandatory. Welded spider gears
prohibited. Wheel studs must be 5/8-inch minimum. Aftermarket full floating or live axle
assembly permitted, mandatory on any vehicle that runs 5.99 and quicker or 240 mph
and faster. Independent rear suspension prohibited.

 

Just my 2 cents but I think its a good idea to run as good an axle setup as possible on a blown car. The rules go strictly by et/speed but when you think about the kind of abusive tire rattling torque often experienced with roots or screw blown apps particularly in a heavy/big tire car like a promod if you are making a change you may as well get the strongest stuff you can.

 

thanks

thanks again for all the input...it is appreciated.

 

9" floater housing

I got a stock 9" floater housing from Mark Tigges that went 5's in a TAFC w/ zero problems, the solution was that they had sheet metal flanges welded on so the Spindles would bolt on, no heat on what is probably an all ready heat treated spindle. I have pics but cannot post them, I can e-mail them if needed.

I have a bare stock HD 9" housing, MW spindles, MW 5 on 5 floaters hubs w/ rotors and studs that are extra that I can sell if someone needs them.

Trevor Sherwood
Soldierboy0098@yahoo.com
616-642-6009

 

Trevor....
Mark sent me pics of it.....another reason that i think mine broke was the length of the tubes on each side. yours has hardly any length at all compared to mine. i think the fabbed housings, if built right with almost no tube length on each side are plenty strong. there's just less flex in a shorter tube. just my 2 cents
Darren

 

floater diff

i have a fc that finished 10th in nhra in 1986, it has a stock 9inch with back brace and floater ends. it has 35 spline floater axles also. now this thing went 5.60s at 260 on nitro in 1986. the problem is that i have about 5 sets of axles that are twisted on the splines of the axle. apparently teams had to carry many sets of axles due to this problem. the differential was made by casaraz, a craftsman of the day. would i run this today on a modern nitro motor. i dont think so. i think this is a extreme example of something that was made to work where it really shouldnt have. im sure the ring and pinion life was crap with 9 inch parts. i have seen new tafc run with a 91/2 with billet centers get decent parts life, but if i were to build a new car today, the price of a floater from strange or mw complete is hard to beat. the safety aspect of not having a wheel fly off somewhere and the tried and tested units have proved themselves over time. if you ever loose a wheel, you have zero control where its going, and is probably going to make you taste the wall very hard usually going the wrong way,which is where most people get hurt. somebody gave me a good bit of advice once, 20k on a race car is cheap compared to a month in the hospital! pay me now or pay me later