Track forum general chit chat.

[rhyary]

Originally Posted by Move Over

How many of ya'll have gone with the core4 motorsports hubs at least for the front? I am doing all my wheel bearings now and need a set for the front so I figured it would be a good time to do them.

I'll likely do MSI 12mm thread in for the rear as they are much harder to replace cleanly (my current hub is seized to the axle with no sign of letting go).

Any feedback on (good or bad) for the core4 fronts?

I recommend 14mm thread on the rear instead of 12mm.

[Move Over]

Originally Posted by rhyary

I recommend 14mm thread on the rear instead of 12mm.

That requires the m4 rear hub which is pretty pricey.

I just spent the last 30m on the phone with core4. I'll likely at least do the fronts since I am purchasing new hubs anyway. Lorenzo said at the very least the front should be done with a press in, as most of the failures he sees on the e9x is the front.

Rear is a bit tricky as Bartledoo said, if you have an axle that is seized(I do lol) you'll need a whole new carrier (which I have a 20k mile carrier on its way with an axle and a hub). I've exhausted all options in getting the sucker out including a hydraulic press.

[e36clubracer]

Originally Posted by b4hand

Kelse92

I did the core4 fronts with F8x hubs and 14mm press ins. Its a plug and play setup. Just take the front brakes off and its four bolts. Hardest thing was breaking the bolts loose as they are loctited from the factory. Honestly for the average mechanic I am it was a very simple install.

Great piece of mind for any track car!

[b4hand]

Originally Posted by Move Over

Lorenzo said at the very least the front should be done with a press in, as most of the failures he sees on the e9x is the front.

This is interesting as the fronts are the easiest.

[Move Over]

Originally Posted by b4hand

This is interesting as the fronts are the easiest.

I may have worded incorrectly, let me rephrase. He mentioned I should definitely do the fronts, and could get away with a strong thread in stud in the rear

[Move Over]

Originally Posted by e36clubracer

I did the core4 fronts with F8x hubs and 14mm press ins. Its a plug and play setup. Just take the front brakes off and its four bolts. Hardest thing was breaking the bolts loose as they are loctited from the factory. Honestly for the average mechanic I am it was a very simple install.

Great piece of mind for any track car!

Yeah fronts are cake, did you do all 4 or just fronts?

[Kelse92]

Honest review on the Core4 stuff, and I've already talked to a few people like Alex on FB and IG. I'm a big fan too, but there's some caveats to doing it and if you want to do all 4 you just need to know what you're in for to do them.

I love that I bought all 4 corners press-in for the peace-of-mind. I went with 12mm all around because I have seen other heavy cars use the 12mm press-in (corvettes/GTR's come to mind among others) and they seem to do fine. But for me, I was already stretching the budget personally by buying all 4 corners when my original plan was to just buy fronts... so the extra $250 for the 14mm was just stretching it too far when I was already over what I budgeted. The all-4 as it was really ended up being an impulse buy on Black Friday while we were at the track and before I was even able to swap wheels and start the day I had 2 broken studs on the car. Ugh. Wasted an hour and a couple of sessions changing the studs before I could get out on track which was really frustrating when it was a beautiful cool morning lightly attended members day at the track.

Fronts are a piece of cake. I actually haven't finished my fronts yet though because we started with the rears (figuring they would be more difficult) and they are NOT something you can easily DIY at home without the proper tools. It took a lot of time and effort to do the rear and we ran out of time Saturday to do the fronts but I don't think the fronts will take more than an hour this coming weekend.

For anyone considering this also consider the extra parts you will/may need to do the rears. New OEM wheel bearings are $100/ea and will be needed as the old ones will not be reusable once you pull out the hub, and you will need new axle nuts. The nuts are cheaper at $10-ish each, but just know to order them ahead of time. And most people will probably need to order a socket to remove them, they're an unusual 36mm 12-pt. We used an air hammer to carefully remove the axle, disconnect all of the arms and remove the carrier to take to the press, and needed 10 tons of force on the shop press to remove the hubs and old bearings from the carrier and then press-in the new parts. If your car is from the north rust may also play a role in difficulty. I was lucky and only had light surface rust to deal with because my car has always been a southern car.
I would say I'm decently skilled at the nuts/bolts stuff and my partner is a Porsche mechanic and together the job still took us 5 hours just for the rears. If paying for shop labor on an install depending on what your local indy shop charges/hr that's an easy $700+ labor bill. I have also heard of people with higher mileage cars running into issues of seizing axles (like above) and having to buy new ones while trying to do this work, so just tread at your own risk/skill level.

I think a thread-in is probably fine to stick with on the rear. I have broken up to 9 different studs on my car at this point in just 2 years and the majority of them have always been the front. Particularly my right side front as thats the side that seems to see the most stress on my car driving on mainly CCW laid-out tracks. Only 1 or 2 have been rears. As long as you have a really high quality set of pliers that can grab the threads most of the time broken studs can be pulled from the back of the hub if you didn't use red-loctite.

[DRLane]

Kelse92 Is correct, it's far more involved than the fronts. But with the right tools, it's not horrendous. I also have a lower mileage car with minimal rust and the aid of friend that's done it 10x on their endurance race cars.

Need new bearings, snap rings, axle nuts, and axle socket. Plus these specialized tools which I'm happy to own for anticipated future replacements.

Here's what Tom shared with me when I did it.

Axle removal: OTC Front Hub Installer and Puller - 7208A
Install on hub and tighten onto axle shaft until it's tensioned nicely and hit the head with a mini-sledge hammer to pop the axle and start moving it. May need to cycle that a couple of times in the beginning, but then it'll start sliding out easily with threading in the pull threaded rod.

Bearing tool: TRIL Gear 23 piece Universal FWD bearing tool
Pulls the bearing race out of the trailing arm/upright housing.
installs new bearing into housing
Pulls hub into bearing

Axle installation: CV Axle Shaft Puller / Wheel Bearing Hub Installer Kit
Pulls the axle back into the splines of the hub
You'll also want heavy duty medium sized snap ring pliers to deal with the retaining ring. Using these tools makes much easier work of dealing with the rear.

[Move Over]

Originally Posted by DRLane

Kelse92 Is correct, it's far more involved than the fronts. But with the right tools, it's not horrendous. I also have a lower mileage car with minimal rust and the aid of friend that's done it 10x on their endurance race cars.

Need new bearings, snap rings, axle nuts, and axle socket. Plus these specialized tools which I'm happy to own for anticipated future replacements.

Here's what Tom shared with me when I did it.

Axle removal: OTC Front Hub Installer and Puller - 7208A
Install on hub and tighten onto axle shaft until it's tensioned nicely and hit the head with a mini-sledge hammer to pop the axle and start moving it. May need to cycle that a couple of times in the beginning, but then it'll start sliding out easily with threading in the pull threaded rod.

Bearing tool: TRIL Gear 23 piece Universal FWD bearing tool
Pulls the bearing race out of the trailing arm/upright housing.
installs new bearing into housing
Pulls hub into bearing

Axle installation: CV Axle Shaft Puller / Wheel Bearing Hub Installer Kit
Pulls the axle back into the splines of the hub
You'll also want heavy duty medium sized snap ring pliers to deal with the retaining ring. Using these tools makes much easier work of dealing with the rear.

Thanks DRLane

I have my subframe fully out right now, so it's a good time to do it, I'm just a little nervous that my "new" spindle/hub/axle assembly won't come apart as my last one was seized. Lol I'm going to give it another crack with the new assemblies. I'd really like to do the rears to match the front.

Tom from Core4 mentioned MSI is way back ordered though, like over a month out so all he's able to provide is ARP, which I think I'm good with. Any input between the two?

[DRLane]

Originally Posted by Move Over

Thanks DRLane

I have my subframe fully out right now, so it's a good time to do it, I'm just a little nervous that my "new" spindle/hub/axle assembly won't come apart as my last one was seized. Lol I'm going to give it another crack with the new assemblies. I'd really like to do the rears to match the front.

Tom from Core4 mentioned MSI is way back ordered though, like over a month out so all he's able to provide is ARP, which I think I'm good with. Any input between the two?

Nope, given we trust ARP for our rod bearings I wouldn't hesitate to trust for studs.

[Move Over]

Originally Posted by DRLane

Nope, given we trust ARP for our rod bearings I wouldn't hesitate to trust for studs.

Booya! Agreed

[redpriest]

I don't understand the fuss about all this press-in stud stuff. Maybe I'm behind the times but I have never had a problem with studs as long as I changed them pro-actively every 12 track days or so. I've only had a stud break on me once, when I was changing wheels to go home - and these were probably 15 or so track days old at that point.

I've seen the core4 videos where a dude lost a wheel on fresh studs but I have to think that was installer error or something else is going on. What kind of stresses are you guys putting on your tires? I've had Pirelli DH tires, and I've had some viscious spin-outs etc. and never once broke a stud on track.

Maybe you folks in the center and east of the US are running some hardcore tracks with way more stresses than us in the Pacific? Or maybe it's climate differences?

[Move Over]

Originally Posted by redpriest

I don't understand the fuss about all this press-in stud stuff. Maybe I'm behind the times but I have never had a problem with studs as long as I changed them pro-actively every 12 track days or so. I've only had a stud break on me once, when I was changing wheels to go home - and these were probably 15 or so track days old at that point.

I've seen the core4 videos where a dude lost a wheel on fresh studs but I have to think that was installer error or something else is going on. What kind of stresses are you guys putting on your tires? I've had Pirelli DH tires, and I've had some viscious spin-outs etc. and never once broke a stud on track.

Maybe you folks in the center and east of the US are running some hardcore tracks with way more stresses than us in the Pacific? Or maybe it's climate differences?

I've actually not broke a stud either in the 11 sets of studs I've had. I spoke with BW after Core4 and they mentioned 99.9% of the time a stud that fails either has been improperly torqued or the wrong spacer size has been used. They use thread in for all their cars including race cars.

The only reason I'm considering them is the fact I need new hubs up front and my hubs are out in the rear, new hubs are 300 bucks, decent studs are 100 bucks. Their front hubs with pressed in studs are 450, not much of a difference.

[derbo]

Originally Posted by redpriest

I don't understand the fuss about all this press-in stud stuff. Maybe I'm behind the times but I have never had a problem with studs as long as I changed them pro-actively every 12 track days or so. I've only had a stud break on me once, when I was changing wheels to go home - and these were probably 15 or so track days old at that point.

I've seen the core4 videos where a dude lost a wheel on fresh studs but I have to think that was installer error or something else is going on. What kind of stresses are you guys putting on your tires? I've had Pirelli DH tires, and I've had some viscious spin-outs etc. and never once broke a stud on track.

Maybe you folks in the center and east of the US are running some hardcore tracks with way more stresses than us in the Pacific? Or maybe it's climate differences?

From the talks, it seems you shouldn't need to replace pressed-in studs for the life of the wheel bearing vs this constant replacement of press-in to avoid breakage. I feel like rust would become an issue on the studs at that point when the coating is removed.

[redpriest]

Originally Posted by derbo

From the talks, it seems you shouldn't need to replace pressed-in studs for the life of the wheel bearing vs this constant replacement of press-in to avoid breakage. I feel like rust would become an issue on the studs at that point when the coating is removed.

Yeah I read that too but I'm not sure I really believe it - the amount of wheel changes I do in a year make me nervous especially given the metallic flaking I see on every stud I use from repeated changes.

I mean, you shouldn't have to change wheels either but even forged wheels can hit a berm the wrong way and crack or bend. Eating an entire hub replacement cost vs a $100 set of studs on a 12-track day basis seems like it would take a while for it to pay for itself.

[Bartledoo]

I only broke one rear wheel bolt running scrub slicks and aero. They were about 25 track days old. I think it finally broke from exiting deep on harsh gator curbs one day. I went with the 14mm MSI press-in because the worse thing I can think of happening is a damn outside front wheel falling off somewhere like Pacific Raceways. Doesn't make any sense to me not to have the safest option when the added cost is not really that big. I also don't want to change studs every half season or more.

[DRLane]

Originally Posted by redpriest

Yeah I read that too but I'm not sure I really believe it - the amount of wheel changes I do in a year make me nervous especially given the metallic flaking I see on every stud I use from repeated changes.

I mean, you shouldn't have to change wheels either but even forged wheels can hit a berm the wrong way and crack or bend. Eating an entire hub replacement cost vs a $100 set of studs on a 12-track day basis seems like it would take a while for it to pay for itself.

There is compelling evidence that press-fit studs are stronger and less susceptible to shearing. A cursory glance at the contact point dimensions as well as how the studs connects to the hub suggests that. It only takes one stud breaking at the wrong point on a track to result in a lost wheel or totaled car. You can absolutely replace the press in studs too if so desired, and they're just as economical as BW race studs.

The whole tracking activity is a balance of risk tolerance, maybe we just leave it at that? Would hate to see studs be the "track" version of the rod bearing debate.

[Bartledoo]

Originally Posted by DRLane

Would hate to see studs be the "track" version of the rod bearing.

Too late I broke the bolt and felt very lucky that I noticed it between sessions. Then I saw that hall of fame video list on the core4 site and, I'm not gonna lie, I was spooked and ordered the primo package that night.

[tsk94]

Unlike rod bearings, it appears the stud 'issue' isn't blown out of proportion. lol

[Shmelgy]

Originally Posted by slicer

You will have zero issues With 275's. I thought you had gone to 295 and 305 square. That's where the rear fit will become challenging

I don't remember if I ever ran the 305 DH square with spacers. They actually are narrower than the 295 RR.

Per usual, I'll update when the new wheels come in

[Move Over]

The race shop I get alignments at had an interesting question about the core4 hubs, he took one look at them and asked "what happens when the splined stud spins in an unsplined hub"? He was genuinely interested, not being an asshole. Lol. He said most cars with press studs have splined hubs.

Obviously didn't have an answer but something for me to follow up with Tom.

[dparm]

Originally Posted by Move Over

The race shop I get alignments at had an interesting question about the core4 hubs, he took one look at them and asked "what happens when the splined stud spins in an unsplined hub"? He was genuinely interested, not being an asshole. Lol. He said most cars with press studs have splined hubs.

Obviously didn't have an answer but something for me to follow up with Tom.

It's a good observation but I would be shocked if Core4 hadn't already thought about this.