172 replies to this topic

[SaulSpeedwell]

 For all I know the difference in G force loads could be noise. Jim Drago/Saul care to comment about G force loads?

 

Here would be my comment:  Whether the original SSB cars on puny 185/70-14s, or RA-1s from 2002, or SM7s today, we've always been reaching somewhere around 1 "G" and hammering on curbs at some tracks, and slamming on the brakes, and pounding the 1500 lb/in bumpstops, and running into each other, and running 12 and 24 hour enduros, and blah blah blah.

 

But going from 43mm offset (SSB) to 38mm (2002 era Koseis) to 2014-era 20-ish mm offset, AND running taller and wider and heavier and stiffer-sidewalled tires has probably multiplied the bearings loads TENFOLD (???) from what it was designed for?  Double the unsprung weight, double the bending moment due to doubling the scrub radius from offset, +30% bending moment from cornering due to +30% sidewall height, >2X stiffness of the Eibach spring versus OEM, stiffer bumpstops than OEM, etc.?

 

It seems we have reached a "tipping point" w.r.t. bearing reliability.  My old-but-long-gone stock of "OEM grade" bearings with "OEM grade" grease have still been soldiering on, unless my guys simply aren't telling me about it.

 

I'm amazed we don't replace them every session.  I think we can still do something to find and make better bearings, but if you guys really want to solve the problem, I'd be working with the SMAC/CRB/Hoosier for a 2-year sunset on 205/50-15 tires to something smaller, and get away from 20mm offset and back to something more reasonable. 

 

-MB

[Jim Drago]

Here would be my comment:  Whether the original SSB cars on puny 185/70-14s, or RA-1s from 2002, or SM7s today, we've always been reaching somewhere around 1 "G" and hammering on curbs at some tracks, and slamming on the brakes, and pounding the 1500 lb/in bumpstops, and running into each other, and running 12 and 24 hour enduros, and blah blah blah.

 

But going from 43mm offset (SSB) to 38mm (2002 era Koseis) to 2014-era 20-ish mm offset, AND running taller and wider and heavier and stiffer-sidewalled tires has probably multiplied the bearings loads TENFOLD (???) from what it was designed for?  Double the unsprung weight, double the bending moment due to doubling the scrub radius from offset, +30% bending moment from cornering due to +30% sidewall height, >2X stiffness of the Eibach spring versus OEM, stiffer bumpstops than OEM, etc.?

 

It seems we have reached a "tipping point" w.r.t. bearing reliability.  My old-but-long-gone stock of "OEM grade" bearings with "OEM grade" grease have still been soldiering on, unless my guys simply aren't telling me about it.

 

I'm amazed we don't replace them every session.  I think we can still do something to find and make better bearings, but if you guys really want to solve the problem, I'd be working with the SMAC/CRB/Hoosier for a 2-year sunset on 205/50-15 tires to something smaller, and get away from 20mm offset and back to something more reasonable. 

 

-MB

 

We will be discussing that tonight on the CRB call and likely something will go out for member input

[davew]

I would be against changing the wheels. Only because everyone, me included, has a huge investment in wheels that would be instantly worth scrap weight. But on the other hand, But, I do sell wheels !!!!!

 

I agree, the tires are toooo sticky and probably too big. I like the SM7 compound over anything else we have used, including Toyos. But, the smaller tire must work on a 7 inch wide wheel (see above).

 

I also believe the tire contract is up for bid after the 2014 season. Assuming I am correct, any tire being proposed should be made public and be offered at the tire manufacturers expense to the larger teams for evaluation. Try them in the real world; slow guys, fast guys, easy tracks, Mid Ohio type tracks, let them sit for 60 days, run them 15 heat cycles, run short enduros and long ones. Let's face it, the last 2 tire changes have turned into problems. The switch to R888 was a disaster and the SM6 is fast but expensive in the real world. The SM7 seems to be a great tire, but is starting to get a bad reputation as hard on equipment. This is the same proposal I made for previous evaluation cycles.

 

Just my 2 cents.

 

Dave

[FTodaro]

My 3 cents is that we need to do way more investigation into the issue before we make costly changes. Rules are not going to replace good car preparation, now i know that Drago's comment to me will be that i do not drive hard enough to fail a hub but i have maybe had one or two fronts that i replaced early because they started to wiggle more than i liked but no outright failure of a front hub.

 

My point, car prep is big, i have not lost a hub self destructing. I do repack frequently, check at a tire change,  and always repack after any rain. I know some have lost hubs who just put on new ones, but there are a lot of other hubs out there that have been on for along time and abused and not failed.

 

So I too would not want to start over replacing all the rims and tires i am holding with out a logical reason to do it.

 

I have been ordering several hub, and i might also suggest to add to Mark's list that the manufacturing process has been changing "going cheap".

 

I have two different sets of NTN hubs and the heat treatment (Harding) of the races is significantly different. so not all hubs are created equal even from the so called same MFG.

 

Lots of reasons things can happen,

[Charlie Hayes]

Well finally back in the shop from the trip to Ohio. Couldn't believe how good the weather was, almost comparable to West Coast weather we have out here. Beautiful blue skies and perfect air quality. Was also very cool to put some faces to the names. Everyone was very nice and pretty low key weekend. 

 

Thursday's test was pretty good. The track day organization was determined that we were running the Pro Course for the Majors weekend, so thats what we got to practice on. We were on 2 cycle tires to start and stickered up for a session. Car was over stuck in the rear with a few quick adjustments it was then ok again but the used tires had a slight edge for myself and what I liked to feel with the car. Car was pretty damn quick out of the trailer well into the 42s in the first session of the day which was surprising for me. 

 

Fridays qualifying sessions were just about the worst sessions one could have in my opinion. Late to grid up on Q1 which was obviously our fault, not knowing anyone out there doesn't help either. So getting a gap to a car that you have no idea how it will perform is pretty complicated. Running with the other SMs it was clear that going to Ohio with the softer engine I had was a slight mistake. Never want to blame anything on the power but loosing 4-5 car lengths due to my straight line "handling" was upsetting. Managed 8th with a 44.2 on the last lap with a few passes due to frustration but obviously not a perfect lap in anyway shape or form. Q2 was the most upsetting because we went over some data and figured a few things out. Got to grid 2 hours early was first in line and went out slow for the out lap for everyone to be on track only to come around to the green and through turn 1 to find a group of 6 or so cars 2 wide going extremely slow in the bus stop...   Then proceeded to scrub tires on the back stretch. What could have been a few lap qual session due to clear track became a fight for another gap and figuring out who was ok to be behind. Another last lap qual session was upsetting. Oh well what goes around comes around. Ended up 9th for the green on Saturdays sprint race. 

 

Saturdays sprint was ok they were calling the green on the front stretch and the start was a little spread out and not as tight as can be. Still was waived green and we went. Had a ok start went third into turn 1 and came out tight with everyone else. Four of us got got split from the lead pack it was Novak, Webb, and Todaro and I. We ran a good clean race for a while and the passes we made on each other were pretty bold and clean. It was until Frank got loose on the exit of madness while side by side with Kyle Webb with Kyle on the inside of Madness and Frank in the dirt they both came back together and no touching but Kyle got wide on the exit right under the honda bridge, dropped the left rear and came spinning in front of me. I locked all 4 up to miss him and he got tangled in the wall. This made a good gap to Frank but I put my head down and tried to make it back to him. He made a mistake in the carousel allowing me to pass him into turn 1. He tried for a few laps to get by me into turn 7 off the back straight and finally made it stick on the white flag lap. Finished 6th and bettered my lap time in the race to start 8th for Sundays race. 

 

Sundays race had a better start knowing what could happen, I made a tire change and a slight rear ride height change to help the car in the important rights. I felt like the car was very good but now running tight in the top pack with Novak, Sterns, Hille, and Rowely. Car was a lot more freed up and was faster but a little edgy if anything towards the middle of the race. Got the car up to 4th for a while before falling asleep on the 4th gear shift on the front straight. This brought Novak closer and it went down hill relatively quick from there. He pushed me for a lap or 2 on the back stretch to finally without contest drove past me into the braking zone of the back stretch. Then opened up another opportunity for HIlle and Rowely to come in and the both got me good in one shwoop. Hille retired soon after and this left me with just Rowely. Had a good guy to chase and we were both in the same power boat compared to everyone else. Ran tight together for a while and finally tried to setup a pass at the line on the checker was fender to door to him and that was that. 

 

As for hubs Mid Ohio was the first time both of us (Jason and I) did not change 1 single hub. We have done on average 1 to 3 hubs per weekend since the SM7s and our other cars have done the same. Have tried a bunch of different options with all the same results. Even the same with the earlier cars also, not just the heavier 99+. 

 

Cant wait to see some of these guys on the home turf in a few months. 

[Jim Drago]

I would be against changing the wheels. Only because everyone, me included, has a huge investment in wheels that would be instantly worth scrap weight. But on the other hand, But, I do sell wheels !!!!!

 

 The switch to R888 was a disaster and the SM6 is fast but expensive in the real world. The SM7 seems to be a great tire, but is starting to get a bad reputation as hard on equipment. This is the same proposal I made for previous evaluation cycles.

 

Just my 2 cents.

 

Dave

 

 

In the real world, the r888 was not bad at all, we( me included) just all complained as tires were fresh and didnt know how to use them, by the time we went back to RA1, I think most had the R888 figured out just fine.  The SM7 should not  be harder on equipment than the SM6.  The SM6 had more grip than the seven.  We went through no hubs this wekend on two cars, but Novak did have a set of our hubs on his car.  I don't think we have a epidemic of failures.  Cars are making more power than ever before, set up and driven better than ever before and going faster than ever before, failures will always be part of that equation. We certainly need to look at all we can, but we will always be dealing with something IMO. We just dont want it getting out of hand. 

[Bench Racer]

 

As for hubs Mid Ohio was the first time both of us (Jason and I) did not change 1 single hub. We have done on average 1 to 3 hubs per weekend since the SM7s and our other cars have done the same.   Have tried a bunch of different options with all the same results.  Even the same with the earlier cars also, not just the heavier 99+. 

 

Worth repeating ^.

[Mike Collins]

I've said it before (for years), I'll say it again...The Hoosier tire is great.  Its just to big!  They need to make a 195/50-15..  It would fit on the same rims..no rubbing, less grip, longer lasting tires..less stress on the wear parts.

[Waterboy]

I've said it before (for years), I'll say it again...The Hoosier tire is great.  Its just to big!  They need to make a 195/50-15..  It would fit on the same rims..no rubbing, less grip, longer lasting tires..less stress on the wear parts.

 

 

Did you say something?

[Killian]

I've said it before (for years), I'll say it again...The Hoosier tire is great. Its just to big! They need to make a 195/50-15.. It would fit on the same rims..no rubbing, less grip, longer lasting tires..less stress on the wear parts.

Even more to the point, I'm not sure on the actual physical width of the SM7 vs SM6 but other series have been running the SM6 on 9 inch wheels for awhile. They're more like a 225 width in reality.

[Jim Drago]

Did you say something?

since when does anyone start listening to him

[Bench Racer]

I've said it before (for years), I'll say it again...The Hoosier tire is great.  Its just to big!  They need to make a 195/50-15..  It would fit on the same rims..no rubbing, less grip, longer lasting tires..less stress on the wear parts.

Is anyone hearing???       

 

A similar issue raised it's ugly head (IIRC breaking hubs and wheels flying off) in the early 2000's with the 1st gen Mazda RX7 SCCA production cars. The bearings in those hubs were not an issue, they were tapered rolller bearings with seperate outer races. There was meat and space to redesign. They cured the issue with redesigned front hubs/brake rotors. With the OEM hubs, they did all the similar on track stuff SM drivers do at faster speeds.

 

kcraceware.com

 

 

EP Mazda RX-7 front hub/rotor assembly.  Direct replacement for '84-'85 GSL-SE front brakes.  Designed to be used with the stock Mazda bearings, seal, and dust cap.  Hub is billet aluminum and can be supplied with your choice of metric or SAE wheel studs.  Hub also comes with the bearing races already installed.  Rotor is heat treated and has directional vanes.  Uses stock caliper.  This assembly is vastly superior to the stock, one piece, cast iron hub and rotor, as well as being 5+ pounds lighter.

   

[Johnny D]

I've said it before (for years), I'll say it again...The Hoosier tire is great.  Its just to big!  They need to make a 195/50-15..  It would fit on the same rims..no rubbing, less grip, longer lasting tires..less stress on the wear parts.

 

Are you really getting 205 ??

I thought that was a pretty cut and dry width dim ?

 

If not, there's your problem to begin with.

J~

[SaulSpeedwell]

Yeah, I hear you guys on the wheels, but haven't we managed to effectively sunset and obsolete 7 years worth of CARS?!?!?  (Slattery bait ...) 

 

If the hub failure thing is being overblown, it wouldn't be the first time, but how many failures, DNFs, replacements, and nights spent repacking before you'd rather spend a "measly" $1600 on 4 sets of 35-38 mm wheels?

 

No more long studs, no more spacers, no more fender rolling, no more rubbing.

 

However, I do NOT campaign a car in this class, so my vote absolutely should not count!

[pat slattery]

Yeah, I hear you guys on the wheels, but haven't we managed to effectively sunset and obsolete 7 years worth of CARS?!?!?  (Slattery bait ...) 

 

If the hub failure thing is being overblown, it wouldn't be the first time, but how many failures, DNFs, replacements, and nights spent repacking before you'd rather spend a "measly" $1600 on 4 sets of 35-38 mm wheels?

 

No more long studs, no more spacers, no more fender rolling, no more rubbing.

 

However, I do NOT campaign a car in this class, so my vote absolutely should not count!

Our obsolete car will be making its way to the June Sprints.  I know, not the best 1.6 track but we have to start the season somwhere. 

[JRHille]

I'm sure Shawn will represent the car as best as it can possibly be

[Danny Steyn]

Hi all - greetings from Porto Allegro Brazil..... Thanks to Jim, Frank, Kyle, Justin, Charlie and others for the detailed write-ups, and to Justin for posting the video. For those of us that can't be there racing with you,  it is REALLY GREAT to be able to read about your races, and your individual perspectives on what went down... just wish more would post race write ups and videos.

 

Congrats to all the podium finishers, and especially to Jonathon Davis for his Majors debut with a podium on Saturday and the race win on Sunday. Way to represent Jonathon. I know Mike Rossini is over the moon with your results.

 

WRT tires, here are my $0.02

 

• RA1 - really great tire, but hated the shaving different thicknesses for different tracks. Lasted long time, and we all had so many years on them that everyone had them figured out. Great SM tire
• R888 - struggled at first, got them figured out and then loved them. Switched before we really could dial them in for every track. This tire had potential to be a great SM tire
• SM6 - unbelievably fast sticky tire that had 2-3 hero laps and then would fade. Costliest tire to ever be used in SM - everyone had to sticker up when the field was deep - mid corner speeds just stunning - DESTROYED lots of wheel bearings. Loved everything about this tire except paying for them. Lets please NEVER spec a tire that offers so much more speed when fresh.
• SM7 - an AWESOME SM tire, can get serious HC's, no apparent value to stickering up, typically the fastest laps come at the end of every session. Have not destoyed any bearings on the SM7 despite 8 race weekends and double dipping each weekend. 
• RA1 Unshaved RAIN tire - they desperately try to kill you in the rain, but this tire lasts several seasons and is a tremendous equalizer, as those with talent and larger stones spend more time on the limit.Very little observable performance difference between a fresh set and a set with several HC's
• H20 RAIN tire - most expensive SM tire ever. Even more so than SM6. Just a single rain session and it is immediately slower than a set of fresh sharp H20's. In 4 years on RA1's I used two sets, but I am on my 5th set of H20's in two years and way less rain sessions. I would love to see a more durable rain tire specified for SM. But this tire makes everyone feel like a hero in the rain, Just amazing water pumping action. Sucks to be the driver behind trying to find a way around, just cannot see anything.
• HOOSIER - Love their product, and their service - just don't like spending so much on tires. would like to see them stay on as SM supplier
• TOYO - have decent tires, but no real service to speak of. Seem to be very active with NASA. Would be my 2nd choice for SM tire supplier

 

AND.... I definitely saw more hub failures with the sticky SM6's.

[Michael Novak]

I like others failed a left front hub Sat.  Appeared to be in good shape before the race but I could feel something going on by lap 3-4. Sunday was a lot better except for starting 10th.  We thought the 2 HC tires might be good and they were. 

Charlie Hayes--Nice meeting and racing---We all will race with you out here any time. As described in other posts lots of battling between Stearns, Rowley,Hille, and Hayes for me...   Voytek and Davis were left to battle each other.  I think we were all surprised when Drago pulled off----at least we had a chance then..    Jim had his new car hooked up--fast and smooth is hard to beat.

 

Video below....     One day I will edit them----It runs out before the end but gets most of the action.

 

 

 

[FTodaro]

Hi jack continues,
Just wanted to make my point about my opinion on hub failures, below is a picture of two NTN hubs I bought from same supplier at different times. I have positioned them as I have to you can see the heat tracings left behind by the heat treatment of the races, in the mfg process that hardens the steel in the race area.

As you can plainly see the left hub was barley touched, the right one is well done. The left hub will fail long before the right hub. I think the issue is the hubs. Period.

Attached Files

•  image.jpg   29.04KB   4 downloads

[Johnny D]

The hub was from Mazdaspeed, stock other than me putting in ARP studs. It had around 30 hours on it and one rain session/race. Never had contact on it, only one major off, but plenty of running over curbs at MMP. Always run on Toyo RR's.
 

 

Worth repeating ^.

 

Now don't you wish you had Todd's problem.

J~