Floater setup--yes or no

[GrnDragon]

Lots of good info and discussion going on here!

Does anyone know off-hand which inner axle seals will work with a 35 spline axle? I have been looking for a while and all the seals I find only claim to fit 31 spline.

And throughout this entire thread I didn't see any mention of the GMR setup, that's what I decided to buy.

[DFRESH]

Originally Posted by GrnDragon

Lots of good info and discussion going on here!

Does anyone know off-hand which inner axle seals will work with a 35 spline axle? I have been looking for a while and all the seals I find only claim to fit 31 spline.

And throughout this entire thread I didn't see any mention of the GMR setup, that's what I decided to buy.

Yeah, I was hoping Jason might chime in here--why did you decide to go with his setup?

[GrnDragon]

Originally Posted by DFRESH

Yeah, I was hoping Jason might chime in here--why did you decide to go with his setup?

I decided on his after A LOT of research, but at the time the only Full Floaters that were available were Moser, Speedway, and The GMR. I was sold on the bearing spread and MUCH cleaner hub design and finishing that GMR did.

But today there are a couple more options to consider Baer and Chicane/Speedtech. I don't really like the Baer kit, it just doesn't look as stout at the GMR setup but it does include the e-brake which is nice. When I look at it I think of a swiss army knife, there are piece/parts everywhere and it may do the job but not as well as other setups.

Now I am REALLY intrigued by the Chicane/Speedtech kit, it's a really good design and I really like the fact that they use some OEM off the shelf components. I would jump all over this if ABS was something that I really wanted to have, but again comparing hardware between GMR and this design I would say GMR is the stronger design.

This is all my opinion, and I haven't actually done any stress analysis on any of the kits nor have I run the GMR stuff yet so I don't know how it will handle the racing environment.

[sik68]

I experience a lot of knockback as well, but this is coming from a guy who has floating calipers. I use C5 calipers with a 7/8 Wilwood MC.

Around Buttonwillow & Thunderhill, and the El Toro track and autocross, I can do a few laps and know reliably which braking zones I will experience knockback; some corners are completely trouble free, and some corners the pedal is undoubtedly soft in the same zone lap after lap..."gotta pump it up for turns 3,5,8...etc"

Deflection is definitely part of the problem; 28 spline axles and the original 8.2" rear aren't what I would call stiff.

But there is also another nagging problem and that's axle play (inboard/outboard motion of the axle). I'm guessing I'm not the only one who has 3/16" of axle freedom, and if you go around a combination of corners where one or both axles moves, there's another source of pads spreading. This became very clear to me in autocross; there is much more severe and abrupt lateral weight transfer and consequentially I must pump the brakes around the whole track to keep the pedal up. Also very prevalent after hitting track curbing on road courses, where you get a lot of impact that can move and deflect the braking system.

I am about to install a 5lb knockback spring under the piston (or maybe a pair under each for 10lbs) to see if it helps.

The residual valve we all know does the same thing. I bought one but haven't installed it yet. I hate messing with brake lines so I want to try the springs first. Running a quick number on residual valves: 10psi residual pressure on a 40mm diameter (C5) piston = 19lbs. So it will be pushing against the piston almost 4x harder than the spring I'm installing.

If you keep the caliper pins lubricated and free from binding, the springs or valve should be able to do their job. I don't know if 5lbs, 10lbs, or 19lbs of force is enough, but I am going to start with 5lbs and work my way up.

I will be sure to post the spring install and results after RTTC.

[Vegas69]

Get rid of that 3/16 end play and your problem will be solved. That's way to much slop for any caliper set up. I bet someone has figured out an economical solution. Otherwise you are putting lip stick on a pig.

[sik68]

Originally Posted by Vegas69

Get rid of that 3/16 end play and your problem will be solved. That's way to much slop for any caliper set up. I bet someone has figured out an economical solution. Otherwise you are putting lip stick on a pig.

You've seen my car, it's lipstick everywhere on that pig!

Totally agree though...ultimately I need a new rear but that's a can of worm$ I don't want to open right now. I blame the Investing 102 thread.

[Blake Foster]

From the info "I" can find . this car uses the ZR1 rear hubs and mono block calipers (fixed i will assume)



sorry pic is small , 2011 C6R

[Vegas69]

Originally Posted by sik68

You've seen my car, it's lipstick everywhere on that pig!

Totally agree though...ultimately I need a new rear but that's a can of worm$ I don't want to open right now. I blame the Investing 102 thread.

Pull those axles and figure out a way to attach a shim to the axle ends. It won't cost you squat and will fix your problem. Send the rest of the money to the Todd Akes "I need another BEER fund" Hendertucky USA.

[frojoe]

Originally Posted by Vegas69

Get rid of that 3/16 end play and your problem will be solved. That's way to much slop for any caliper set up. I bet someone has figured out an economical solution. Otherwise you are putting lip stick on a pig.

I measured the axle flange end play at ~ 0.011" on my 8.5" 10 bolt with Moser 31spline axles and Detroit TruTrac.. then I removed the posi's "center spacer" that prevents the axles from traveling inwards and allowing the c-clips from popping out. Measured this spacer's width and made a new, wider one, that brought the axle flange end play down to ~0.001". Figured it would be good to allow some running clearance for heat expansion and to avoid bearing preload. I have yet to drive it but I have 7/8" manual master and 4piston fixed Dynalites in the back, hoping to test out within the next couple weeks. Not sure if this is helpful for you Torino-bearing'd guys but simply an idea.

[GregWeld]

Originally Posted by frojoe

I measured the axle flange end play at ~ 0.011" on my 8.5" 10 bolt with Moser 31spline axles and Detroit TruTrac.. then I removed the posi's "center spacer" that prevents the axles from traveling inwards and allowing the c-clips from popping out. Measured this spacer's width and made a new, wider one, that brought the axle flange end play down to ~0.001". Figured it would be good to allow some running clearance for heat expansion and to avoid bearing preload. I have yet to drive it but I have 7/8" manual master and 4piston fixed Dynalites in the back, hoping to test out within the next couple weeks. Not sure if this is helpful for you Torino-bearing'd guys but simply an idea.

I'm not a metallurgist - but allowing for only .001" growth in axle length (figuring 20+ inches?) certainly doesn't allow for much heat expansion.