Schiffy Posted January 18, 2014 Report Share Posted January 18, 2014 Ok, so i've got a post about the the rearend in the suspension forum, but now to ask about the guts of the rearend... I'm making right at 300rwhp (this engine made that in it's previous car, so give or take a few is how i'm basing it) Is it really a necessary thing to upgrade to 31 spline carrier and differential right now, or should i just spend the money to rebuild my current 28 spline diff and get some hardened axles? we'll start at 300, but as with most people, over time i plan to make more and more power. the question is, should i upgrade it now, or use that money elsewhere and come back to the rearend when it really needs it? with that question comes this one. with only 300ish rwhp, I've looked at some 15X10 and 15X8 wheels. i like the thought of the wider rim for the wider tire and larger contact area, but is it a necessary expense? granted the difference in price is like $40 for both, so it's not a huge issue price wise. the car currently has 4.10 gears as well, though i'm contemplating jumping to 4.30's or 4.56's. could a 15X10 with a sticky tire be to much for 300rwhp and cause me to bog? whatcha think @SniveTroll @duffdaddy Link to comment Share on other sites More sharing options...
copmagnet Posted January 18, 2014 Report Share Posted January 18, 2014 Unless your going to be doing high RPM dumps on radials like I am, you don't really need 31/33 spline rear end, spend the money elsewhere and come back to the rear end once your making the power or doing something that requires it. I'm not sure if I'm going to explain this right, but keep raising your launch RPM until it stops bogging, I bog is I launch low, launch higher and I don't bog. Link to comment Share on other sites More sharing options...
Sleeperstang1994 Posted January 19, 2014 Report Share Posted January 19, 2014 I agree 31's are not necessary for what your looking for at this point. If you decide to add the 31's it wont HURT anything. also stay away from yukon axles's and differentials... ask @WildWillyWalker Link to comment Share on other sites More sharing options...
WildWillyWalker Posted January 19, 2014 Report Share Posted January 19, 2014 I'm the kind of guy that thinks, if I'm in there and I'm going to spend money, I might as well do it right the first time. I needed a new diff so if all I needed was axles to make the 31 spline happen, why not. I guess it all comes down to budget though. I'd probably wait to get in there until you have to. And yes, I have an 03/04 Cobra diff and 31 spline Yukon axles. Stock length axles, but I had to shim my caliper bracket because it wouldn't fit with my Cobra rotors. It was a huge pain in the butt. PLUS, they didn't machine the hub center correctly and my wheels get stuck. I hope to get a nice set of wheels (3-piece, fingers crossed) by the middle of this year and I'm pretty sure I'm going to go buy new axles first so I don't screw up the wheels.... I'll be going with Moser or Strange. Link to comment Share on other sites More sharing options...
Det_Riot Posted January 19, 2014 Report Share Posted January 19, 2014 If you're even considering to make more than 300whp you might as well build the rear end now while its coming apart. Do it once do it right. Make it bulletproof and you don't have to worry about it no matter what you do Link to comment Share on other sites More sharing options...
Schiffy Posted January 19, 2014 Author Report Share Posted January 19, 2014 I was leaning towards building it, but I needed some other opinions. Haha... Link to comment Share on other sites More sharing options...
SniveTroll Posted January 20, 2014 Report Share Posted January 20, 2014 Link to comment Share on other sites More sharing options...
Blackmage Posted January 20, 2014 Report Share Posted January 20, 2014 I would rebuild the rear with the carbon discs from the 03-04's and be done with it for the time being. Link to comment Share on other sites More sharing options...
Prokiller Posted January 20, 2014 Report Share Posted January 20, 2014 i was going to do this when i had the axles out for longer studs. ended up just putting it back together because i couldn't justify the extra thousand dollars for stuff that wasn't broken. it's certainly on my list of upgrades to do eventually but i'm going to wait. i say stick with a 28-spline for now until you either need it or the right deal comes along. Link to comment Share on other sites More sharing options...
SniveTroll Posted January 21, 2014 Report Share Posted January 21, 2014 i got all my parts at great prices. however, the labor i paid for was worth every penny. Link to comment Share on other sites More sharing options...
Schiffy Posted January 21, 2014 Author Report Share Posted January 21, 2014 i got all my parts at great prices. however, the labor i paid for was worth every penny. i do 99% of my own work with the exception of machining, and welding, and the welding i either have Matt or my neighbor Mark do for me, so it's still backyard mechanic style. Link to comment Share on other sites More sharing options...
Moderators Psychorugby Posted January 22, 2014 Moderators Report Share Posted January 22, 2014 @Schiffy send them down here. I'm having a helluva time finding a welder to rent. Link to comment Share on other sites More sharing options...
Schiffy Posted January 22, 2014 Author Report Share Posted January 22, 2014 @Schiffy send them down here. I'm having a helluva time finding a welder to rent. Haha... My neighbor mark does a lot of welding. I wish I could post pics of the cage he built in his Jeep. He got out of mustangs a few years back and got into building rock crawling jeeps. The jeep cage was intense. Welds were beautiful. Link to comment Share on other sites More sharing options...
SniveTroll Posted January 22, 2014 Report Share Posted January 22, 2014 i didnt have much help when i first got here. look up joe gambino and a certain dave london shelby. its a monster. Link to comment Share on other sites More sharing options...
Schiffy Posted January 22, 2014 Author Report Share Posted January 22, 2014 well hurry up and get back and we can work on the red sled... hahaha Link to comment Share on other sites More sharing options...
revhead347 Posted February 11, 2014 Report Share Posted February 11, 2014 I wouldn't worry about it for now. Unless you are dumping the clutch on sticky tires, you probably won't break anything. I went with hardened 28 splines when I did my axle a long time ago because at the time they didn't make 31 spline axles at the time. I have to take it apart to change the pinion seal and locker soon. Axles never gave me any trouble after multiple launches on slicks. Kurt Link to comment Share on other sites More sharing options...
SniveTroll Posted February 12, 2014 Report Share Posted February 12, 2014 not really much to work on except paint. its the step child portion of this car. besides frankenstein engine. Link to comment Share on other sites More sharing options...
