CV joint issues on track cars

[new2subaru]

Originally Posted by Icecreamtruk

No, you dont shift any more than you would with a 4.1, you are just 1 gear higher all the time (where you'd be on 3rd on the 4.1, you'll be on 4th on the 4.88, and so on). The main difference is how 3rd to 4th and 4th to 5th are closer than 2nd to 3rd and 3rd to 4th so yes, it stays better on the power band, but not a huge deal breaker. If you have to pass the 6th (so you get over 110mph), then 4.88 is worse, the car just stops accelerating at that speed in 6th gear, while in 5th it will go until around 120-125mph usually.

Thanks, it looks great in the video (Power band) Would you do it again?

[Icecreamtruk]

Originally Posted by new2subaru

Thanks, it looks great in the video (Power band) Would you do it again?

For the tracks I race at, I would do a 4.56 instead. Im barely having to shift into 6th in 2 of them, I would prefer to avoid it.

[new2subaru]

Originally Posted by Icecreamtruk

For the tracks I race at, I would do a 4.56 instead. Im barely having to shift into 6th in 2 of them, I would prefer to avoid it.

Thanks for the info and feedback.

[racingfool]

Originally Posted by rice_classic

yet I’ve solved the axle thing.

Not sure why it’s such a difficult puzzle. Keep the heat out of it, put in the good grease and let it breathe.

Is this what you did? Seems like a no brainer.

Originally Posted by ayoshioka1

cusco drivers side axle heat shield



pn: 965-047-A

Why don't these guys do the same?

During the 14-hour Daytona race, the car suffered just one issue: An axle failed as the nearby exhaust pipe got it just a little too hot.

“It basically burns the grease off,” Robb notes. “You have to run motorsport grease and motorsport boots.”
Alex is having some race-spec axles built. He figures they’ll last a season or two.

https://grassrootsmotorsports.com/ar...-miata-answer/

[rice_classic]

Originally Posted by racingfool

Is this what you did? Seems like a no brainer.

No - I wasn't going to pay "cusco" prices for a piece of aluminum.

I did this:
https://www.ft86club.com/forums/show...&postcount=111

And this:
https://www.ft86club.com/forums/show...&postcount=134

Originally Posted by racingfool

Why don't these guys do the same?

For the same reason I didn't for the last 2 years, sometimes you don't realize you need something until it becomes blatantly obvious. The same reason why I wrapped my front/overpipe to keep the heat out of my transmission so I don't have to change the fluid as often.. but I did 2 seasons of racing, often replacing my trans fluid before I thought "Hey - I could make this situation better easily, cheaply and legally."

[racingfool]

Originally Posted by rice_classic

No - I wasn't going to pay "cusco" prices for a piece of aluminum.

You made your own. Good job.
Just meant, did you install a heat shield.
Seems a no brainer...thanks.

Originally Posted by rice_classic

For the same reason I didn't for the last 2 years, sometimes you don't realize...

But they're building new axles and no mention of a heat shield, I don't get it.

[Matt93SE]

So I'm about to rip apart the axles on my car and do a maintenance inspection & repack-- Ordered a couple tubes of redline CV-2, but I'm curious as to a specific volume to repack back into the joint? Any guidance on that?

I'll be adding heat shields like what you did as well. I had similar on my RX7 and it really helped get heat out of the car. prior to those treatments, the exhaust was so hot, it was melting the wiring inside the car and burning up electronics. I wrapped the exhaust, put a couple layers of DEI heat shield stuff on the bottom of the car, and added another layer inside. maybe 3lb total added to the car, but I could put my hand on the floor of the car at the end of a race in the same location the pain had previously turned black and blistered away.

[rice_classic]

Originally Posted by Matt93SE

So I'm about to rip apart the axles on my car and do a maintenance inspection & repack-- Ordered a couple tubes of redline CV-2, but I'm curious as to a specific volume to repack back into the joint? Any guidance on that?

About the same amount as what came out. I "mostly" fill the cup but not the boot. Smarter people than me actually weigh out their amounts but I figure if I put too much in, it will find its way out and help rust proof the undercarriage.

[Matt93SE]

Originally Posted by rice_classic

About the same amount as what came out. I "mostly" fill the cup but not the boot. Smarter people than me actually weigh out their amounts but I figure if I put too much in, it will find its way out and help rust proof the undercarriage.

LOL reasonable assuming it was done right by the last guy. the axles have CRYO TREAT on them in yellow paint pen by previous owner(s), so I know they've been gone through before-- and are thus worth rebuilding vs. just replacing w/ junkyard spares when they die.
I was also planning to just yank the boot, toss them into the parts washer and walk away for a while.. way less effort than manually cleaning!

Been trying to find a proper FSM to download, but all the links I come across are either invalid or my work computer deems the site unsafe. usually that info is somewhere in the maintenance procedures, but alas...

[Matt93SE]

Well that was a bust.. my tuner called and said the axles were so noisy on th dyno, he thought they were gonna blow.

So I picked up some junkyard axles and swapped them until I could open and find out what was up.

I got em open last weekend and these axles are toast. All the wear surfaces are pitted and galled. They weren't going to blow up on the dyno, but they were definitely done.
Don't know how much track time was on them, but they were cryo treated by previous owner and packed with some *really* thick grease. Maybe that lengthened their lifespan, but theyre done either way. No part lasts forever!

I'm currently swapping the rear to a 4.3 from a 2017 and have some of the PBM diff riser bushings on the way. Will rebuild the junkyard axles w/ redline CV2 while its all apart and see how long they last me.

[Sphinx]

Originally Posted by racingfool

Is this what you did? Seems like a no brainer.

Why don't these guys do the same?

https://grassrootsmotorsports.com/ar...-miata-answer/

What are "motorsports boots"?

Is there any data that the heatshields are helping?

[e21jason]

The official TGM upgrade is high temp grease and a 3mm roll pin a breather for the boots

GKN make a motorsport boot.

https://www.merlinmotorsport.co.uk/p...rd-gkn-ms6j002

And we got an bulletin from Seat for the TCR cars to wrap wire lock around the valleys' off the CV boots to increase the life so they do not expand as much with heat