SCCA Solo CM : State of the Class : 2021

[-pru-]

First off, congrats to Ben Martinez on his 2021 Solo Nationals CM Championship; hopefully he shares video of his runs as he was locked in! Also, hats off to the remaining members of the podium John Ryan (2nd) and Eric Clements (3rd).

Although I do not have numbers for every North America Solo event, CM participation definitely declined in 2021; Champ Tours, ProSolo, and Nationals CM entries were way down compared to previous years. That said, I believe 2021 to be a blip in an otherwise health class; I look forward to 2022 and a return to normal participation levels.

The above noted, even with the record low CM entry of 11 for the 2021 Solo Nationals, the average entry since 2009 (first year in Lincoln) is sitting at 19 with the high being 30 in 2018. Again, I am optimistic that we’ll again see 20+ CM entries at the Solo Nationals sooner rather than later.

While at the Solo Nationals, I spoke to numerous folks about joining CM with several actively pursuing cars. The interest is there and hopefully we will see some new faces shortly. To that end, I am sadden to note that Sue Eckles has placed her 1983 Reynard (ex-Ray Thomas) up for sale. Please let me know if you or someone you know is interested and we’ll put you in touch with Sue; it truly is a “turn key” car.

Finally, I want to discuss tires; via Ron Ver Mulm of R&S Racing (Hoosier Tire Dealer), the R25B 20.5x7.0-13 bias front (#43164) has been discontinued being replaced in the same size but in a new R20 compound (forgive me but I do not have the Hoosier item number for this new tire). I am going to reach out to Jeff Speer Product Manager at Hoosier Racing Tire to discuss this change as well as plans for the R25B 22.5x7.2-13 A2500 bias rear (#43309); that is, if/when this tire will continue and/or move to the R20 compound as well.

FYI: For those not in attendance, both Ben/Jaime and Eric/Mari utilized the R20 front at this years Solo Nationals. Both Ben and Eric noted that the first runs on this compound came during competition as they has JUST come off the production line the previous week! Both also noted that they did not discern a notable difference from the previous R25B compound nor did they make ANY set up changes to accommodate the new tire.

Hard to believe, but Sep/2021 marks 10 years since the SCCA Solo C Modified (CM) FaceBook page was launched! Please share your CM thoughts and well as point interested folks this way.

Take care,

Chris Pruett
(aka “-pru-“)
50 CM
1985 Swift DB1

[racerjon1]

I am going to reach out to Jeff Speer Product Manager at Hoosier Racing Tire to discuss this change as well as plans for the R25B 22.5x7.2-13 A2500 bias rear (#43309); that is, if/when this tire will continue and/or move to the R20 compound as well.

It will be good to confirm, but from what I understood talking to Eric and the F-Mod folks, when the R25 compounds are gone, they all change to the R20. So, R25 = discontinued, R20 supersedes it.

[mboian90]

Chris,

I have run 4 events in CM this year since June with the potential of 2-3 more depending on lot availability for our Region. I had the car apart over the the first half of the year modifying the car in prep for attending a competition licensing school in June. I didnt attend Nationals this year for a few reasons related to this. The first logical race weekend for me to attend post driver school wasnt until Labor Day weekend in Houston. Logistically it didnt make sense for me to attend both this and Nationals so I had to pick. I was very torn since all my time and money this season had thus far been directed at attending my first club race. What ultimately pushed me the direction I took was tire availability. After the competition school I went to buy a set R25Bs and Hoosier was out with expected delivery time in the August time frame. Not being excited about having zero driving or development time on the "right" tires before Nationals, I decided to go to the club race instead. Some regrets last week while watching the live timing...

I ran the spec FF tire for the driver school and found the required setup changes a little more involved than I thought. Out of curiosity, a little while later I called Hoosier to ask about radial options for autox (dont remember who I talked to specifically). I asked if there was an FF comparable sized radial tire in the A7 compound available or in the works and his response was something like "you already have it, the R60 and A7 rubber compound are the same". He did later say there was still a large difference between the R25B and the R60/A7 which is already generally understood. Either way it gave me the confidence to drive the rest of this season on the FF radial tires. As an added bonus, used FF tires are readily available which I took advantage of for my regional only needs.

The performance has actually been better than I expected. The first corner of the first event I ran them was comically bad but after doing some tweaking, as well as knowing what to expect first run, it has been good. I think a large help has been living on the Gulf Coast where it is 90F+ for most of the year. I dont have a great reference point to know overall performance impact. In the 4 events I was FTD for all 4 and was top 3 in PAX for the 3 events in my small home region. The 4th event I ran in Central Kentucky and I was 19th out of 57 in PAX. Having not run with that region in 10 years I couldn't draw a good conclusion on what that means. I did also have some handing problems that I would blame on running on a very different lot for the first time (everyone has excuses ).

By no means take the above to suggest I am advocating for the radials, but for me I may continue to run on them. I am looking at double duty for the car next year and it would greatly simplify life. It will take some convincing myself that the probable performance disadvantage it worth it for more fun per dollar. The only other logical conclusion would be to buy a second racecar!

Matt Boian
14 CM

PS: Is that a Honda hat I see?!?

[-pru-]

It will be good to confirm, but from what I understood talking to Eric and the F-Mod folks, when the R25 compounds are gone, they all change to the R20. So, R25 = discontinued, R20 supersedes it.

Jon,

Appreciate the feedback; it's inline with what I have heard as well. Still planning on talking to Hoosier as I'm really curious as to when they expect the R20 rear to be produced. For my next full set, I'd really like to have matching compounds on both ends of the car.

Take care,

[-pru-]

I went to buy a set R25Bs and Hoosier was out with expected delivery time in the August time frame. Not being excited about having zero driving or development time on the "right" tires before Nationals, I decided to go to the club race instead. Some regrets last week while watching the live timing...

I ran into the same issue when I went to purchase tires for Nationals back in mid-Jul; the R25 front was VERY difficult to find. Luckily, I was able to secure what I needed. I knew LATE Aug was time frame for front production; I was just surprised to see they were made in the NEW R20 compound.

I ran the spec FF tire for the driver school and found the required setup changes a little more involved than I thought...I asked if there was an FF comparable sized radial tire in the A7 compound available or in the works and his response was something like "you already have it, the R60 and A7 rubber compound are the same".

John Ryan and I brief spoke about moving CM to the FF Spec radial tire. While I'm not a fan of that idea due to the camber changes that are required to make the radials work (and the associated cost if a chassis cannot get there with "OEM" suspension), I do see the point of moving to a harder/longer lasting tire. That said, your comment about the FF Spec radial being the A7/R60 compound does offer a path forward; the CF Spec tire for MOST of the country is the R60 Bias. That is, LONG TERM (i.e if/when Hoosier says "enough of this sticky R20 stuff for just Solo") CM can seamless switch to either the FF Spec radial or the FC Spec bias; they are the same compound - pick which one suits you / your car. PS - Ben noted that for his 100+ degree CA days, the R60 works great (after a run or two).

PS: Is that a Honda hat I see?!?

Nice catch. Yes it is and no I'm not running a Fit; it's a free hat that more or less matched the shirt (MP4/4 Honda) Had I thought I'd be on the stage, I would have picked something different (i.e. Hoosier or Ford related )

Thanks for all of the feedback and look forward to seeing you and the Piper back in Lincoln!

Take care,

[racerjon1]

John Ryan and I brief spoke about moving CM to the FF Spec radial tire.

Eric and I had a conversation about a CM spec tire...

While I'm not a fan of that idea due to the camber changes that are required to make the radials work (and the associated cost if a chassis cannot get there with "OEM" suspension),

God please no to the current SCCA FF spec radial tire for the reasons mentioned. I fought that while road racing the Swift, saw what others had to do to make it work - either through longer rod ends, or getting new suspension made.

To me, the largest benefit to CM is that It doesn't seem to matter what chassis. Get it working, set it up how you like, drive it. Sure a newer chassis might have more mechanical grip, but longer wheelbases, wider tracks etc. create compromises which balance out with the older cars. Whatever gets talked about/done/suggested should be with the primary idea of keeping older FFs in the mix on the solo course, and so high-camber requirement radials should go below the bottom of the list.

It's funny that the defined purpose of C Modified is "...to maintain the value of these cars for Club Racing and therefore their market value, and to prevent special Solo®-only Formula F vehicles." but older camber-limited cars are now worth more as solo cars than road racing cars and are generally "solo specific" at this point (at least in the SCCA world), so I'm not sure how to maintain the value or create solo-specific FF's without losing the purpose of the vehicle any more than the SCCA already did. ^{(Required Note: This is my personal opinion and not the opinion of the SCCA, of which I am employed by.)}

I do see the point of moving to a harder/longer lasting tire. That said, your comment about the FF Spec radial being the A7/R60 compound does offer a path forward; the CF Spec tire for MOST of the country is the R60 Bias. That is, LONG TERM (i.e if/when Hoosier says "enough of this sticky R20 stuff for just Solo") CM can seamless switch to either the FF Spec radial or the FC Spec bias; they are the same compound - pick which one suits you / your car. PS - Ben noted that for his 100+ degree CA days, the R60 works great (after a run or two).

The one great thing about the Spec FF radial is the longevity of the tire as measured in heat cycles. I have regularly seen consistent times through 18 heat cycles and have heard similar data. The "crispness" of the tire seems to go away, but the maximum grip does not. I've also purchased used tires from pro teams to save money, and in my experience the reason they change often is because of flat spots and not grip levels.

So - if the R60 delivers similar heat cycle lifespan to the Spec Club Race tire without the requirement for camber, I'm absolutely all for it. But.. (and the real purpose of this post) is that we should also be considering the Toyo R888 or Hoosier vintage FF tire to closer match the other FF club racing series in North America.

[-pru-]

So - if the R60 delivers similar heat cycle lifespan to the Spec Club Race tire without the requirement for camber, I'm absolutely all for it. But.. (and the real purpose of this post) is that we should also be considering the Toyo R888 or Hoosier vintage FF tire to closer match the other FF club racing series in North America.

Let me clarify my position; as long as Hoosier continues to supply front/rear tires in the R25/R20 compound, I'm NOT currently in favor of a spec tire for CM.

My point is IF/WHEN the production of R20/25 ceases, the SEB/MAC could move to a CM spec tire; either that the R60 CF bias OR A7 FF radial (competitor choice). Hopefully we're a LONG way from that point, but I just wanted to start the conversation.

Also, I'm not opposed to either R888 or any other vintage option, but I feel the CF/FF Hoosiers would be the easiest transition.

Take care,

[jdr17]

Congrats again to Ben and also to Pru - glad to see you in the trophies (though to John P's chagrin ).

One minor correction - the R25B 22.5x7.2-13 A2500 bias rear was #43309, but is now #43305 due to an internal material change. I was told to expect no change in performance. I didn't back-to-back them, but ran the '05s from the beginning of the Pro Finale with no changes to normal setup and didn't observe any difference in the car's behavior.

While I'd also like a longer lasting tire, I think some of the appeal of CM is the amount of raw quickness you get for a very reasonable initial cost and changing that by a lot could lessen the overall appeal of the class. Hoosier rates the vintage tires as harder than even the R75 (https://www.hoosiertire.com/tires/circuit/ - chart at the bottom). So I would not be in favor of going to those.

I had a set of R888s when I first got the Dulon that I thought I might run locally or for rains. The massive stiffness difference between the R888 and the canti rear bias is HUGE and makes that impractical (I'd have to change springs with tires as even completely disconnecting the roll bar couldn't touch the oversteer with the R888's). Also, wouldn't the R888 also be optimal with a lot of camber, creating the same issue as the road race radial?

I think Pru's suggestion that when the time comes, allow the road race radial or the R60 bias is a good path to look forward to.

• preserves a decent amount of raw quickness
• allows modern FF's to cross over and run their tire (forcing them into a vintage or R888 doesn't seem right)
• allows vintage FF's or CF's to run a tire that is appropriate (though if crossing from a vintage tire or the R888, there will be adjustments)

Seems like it preserves the value of the newer cars to be dual purpose and preserves the value of the older cars as vintage/CF cars without required changes. And doesn't stop anyone from running the radial on an older car if they really want to.

One thing I'd be curious to see is if the A7/R60 shows as big a difference between asphalt and concrete as the R25B seems to. I talked with Barry and Dave a bit and Barry said one of the big reasons he sold the car was lack of local competitiveness - they loved driving the car at Lincoln, but lacked competition (in class or on index) at home. I totally understand this and expected it going in and told myself it would be ok since I had plenty of good pax days behind me from ES . But some days, looking at PAX results on asphalt is a bit depressing.

[Ocho]

Brad here - jumping in to add what we (FMod) were told about the R20 tires.

Hoosier has about 100 sets of R25b left in our FMod sizes. when those sell out they will re-stock with the R20 compound which we hear is very similar to R25b, but slightly better in all areas. So we're all excited to try them out.

I think the R20s are going to be a better tire for autocross - we've never had an issue with r25s but if we can get more grip, we'll take it!

Anyway - long live the Modified life! I think in 2022 we should have a friendly competition to see who can get more cars/drivers out to Nationals. Wouldn't it be awesome if we had an entire heat to ourselves, just FM and CM? We would each need to get at least 35-40 drivers (so 20+ cars) but I know we can do it.

For The Glory!

[racerjon1]

Anyway - long live the Modified life! I think in 2022 we should have a friendly competition to see who can get more cars/drivers out to Nationals. Wouldn't it be awesome if we had an entire heat to ourselves, just FM and CM? We would each need to get at least 35-40 drivers (so 20+ cars) but I know we can do it.

Like.

[CM/FFdriver]

Ok here's my opinion on the R25 and the R60.

The R25's and soon to be R20's are Great tires, Pru you know whats very interesting about you finding those 2 front tires in the R25 is in some ways an interesting outcome, I'm happy that they put the R20 on the front of my car with the R25 in the back, I think it made it more neutral car then I thought. Think about it the rear is a little lose sure to the fraction to a fraction but it felt really good those 2 days.

I talked to Jeff about the R60/R7 compound and felt that the tire is great for Crows landing where is never under 90 degrees but if you were to only say this would be a spec tire you would lose a lot of people in CM, R60 needs heat so the poor people in the eastern states where it's cooler most of the year, Also if Hooiser was to do that it would open up a Tire War, right now I know of Pirelli's, Avon's, that make hill climb tires, so if Hooiser said "hey lets just do the R60's and let them work it out" people would buy other tires to go fast, so then SCCA would have to get involved to allow 1 tire, again losing CM people.

I didn't get in this class to get restrictions on tires, engines, weight, I love to keep working to get faster everyday and I love the cars with the fat tires in the back. To make it clear it we all went to a harder treaded tire then I'm out.

Next weekend 9.27/28th I will be testing the R60 with 30 autocross laps on the the R25's/R20's with 12 runs on them the same weekend I want to see the time difference my guess in .500 to .750, if it's more time then that at crows then I've learned something and maybe I'll have to look at running the R20's more often.

Also we have a very big black top surface were again it gets over the 90's all the time, I may try the R60 there to see the difference there, I've run the R25's and used 1 set all year and paxed very high at every event.

Ben

[Chuckles]

Ben, have you tried the R35 compound. My understanding talking with people who have used the R25 and R35 compound road racing is the R35 has higher grip than the R25 but operates at a higher temperature window and you need to be in the temperature window to get the higher grip. Although I haven't looked lately if the R35 is still available.

Chuck P.

[-pru-]

I think in 2022 we should have a friendly competition to see who can get more cars/drivers out to Nationals. Wouldn't it be awesome if we had an entire heat to ourselves, just FM and CM? We would each need to get at least 35-40 drivers (so 20+ cars) but I know we can do it.

For The Glory!

Brad,

Thanks for the R20 feedback; the consistency of the message is encouraging. I’m just hoping we see the R20 rear soon; my current R25 rears are some of the first of a batch of 60 made in Jul/21. That has to be close to years worth of inventory!

Also great to see your car back in the fight on day 2 after nearly breaking in two on day 1 (for those not in attendance; Brad found/fixed 3 major frame cracks that if not caught would have made the car a “taco” on the next good bump!).

Finally, I would love to have an entire heat of just CM/FM; I believe we came close back in 2017 when CM, FM, and KM ran together (that was a LOUD grid!). FM definitely has the entries (mid 20’s); if CM numbers return to normal (mid 20’s) we would be close. Challenge accepted!

Take care,

[-pru-]

...if Hooiser said "hey lets just do the R60's and let them work it out" people would buy other tires to go fast, so then SCCA would have to get involved to allow 1 tire, again losing CM people.

I didn't get in this class to get restrictions on tires, engines, weight, I love to keep working to get faster everyday and I love the cars with the fat tires in the back. To make it clear it we all went to a harder treaded tire then I'm out.

Ben,

Again, I'm not in favor of moving/mandating a harder tire. I just wanted to point out that IF the R20/25 goes away, Hoosier has other options (i.e. the FF and CF Spec tire). That is, there is a least options in the CORRECT sizes (i.e. CF cantilever rear) so CM will hopefully never get in the position where NO (viable) tires are available.

Although there are folks working on bringing manufactures into the class (which I applaud), I have yet to see anyone run (recently) on anything but Hoosier's, hence my comments regard the Hoosier FF/CF Spec tires. It will be interesting to see how this plays out...

Take care,

[-pru-]

Although I haven't looked lately if the R35 is still available.

Via the Hoosier web site, the R35 is no longer listed as available in FF sizes...

[Gary Godula]

Neither the bias ply or radial Hoosier FF tires in the R60 compound are viable for competitive autocross competition.
The radials should be off the table for any consideration. Much heavier and slower than the bias ply tires.

Does Goodyear still make FF tires in the R120 compound?

[Lynn]

It appears that Goodyear does not make Formula F tires.

[mboian90]

I would also like to clarify that I was not suggesting a move to a spec tire. My intentions this year were different than most. I had a rare moment of being a realist and not a racer so I was just looking for round tires, preferably in black. At $400 for a used set it kept me autocrossing this year and next which is the most important part.

A detail I left out of my prior post is that there is another CM in my region. We somehow have still managed to race each other and have fun despite being on different tires.

I also forgot I technically have a National Tour win on the radials! I beat my co-driver and we were the only 2 CM entries . As long as none of you guys make the trip to Texas I may win a second at some point. "Competitive autocross" is a relative term to some of us .

Matt Boian
14 CM

[TedV]

wow
The silly season started early this year.

Anyone else notice a thread like this happens every time Hoosier makes a change to the tires from a construction to a compound? The last time there was a huge panic about soft autocross tires, the conversation with Jeff paraphrased = SCCA is not the only market in the world that buys these sizes of soft compound tires. Yes the front size is way more popular so it definitely will never go away. The rear sells enough to keep making them for the foreseeable future. Tell everybody to not worry. Then we laughed about the time I got my hands on some tires produced for the British hilclimbs and how long they might last in 90+ degree heat. I think they were softer than the wet compound.

The R## on the sidewall is just a relative number. Just because the radial has R60 on it, does not mean it is the same exact compound as on a bias ply R60. When people want a tire that lasts and is consistent, perception is a hard compound number is what you want. Hoosier could have labeled it R43 and folks would complain it wont last like the R60 bias ply. I believe Hoosier wanted to streamline production, component inventory and have a tire that is more consistent to produce than the bias ply. As Gary pointed out the tires labeled R60 are not grippy enough to be fast autocrossing. My old flexi-flier chassis was more enjoyable, predictable, easier to drive on old tires but the times were not there.

Has Hoosier said they are going to stop production of tires that can be run on CM FF? I'm gonna go with no, they haven't. I'm pretty sure if there was to be an end to the production of the rears, they would look into a viable solution. They are in the business to sell race tires, not just a marketing gimmick or tax write off.

Have some , relax and lets see who can come up with cars to run for the 2022 season Hmmm, if ya go to the spec FF Radial R60, that will also fit on the Gen3 SRF. downside is 400 pounds more, but at least 20 more HP than a top FF, would fire the tire faster, enclosed body would hold the heat better. Hmmm, I need to see the gearing in the SRF

[bassracer]

I'm going to assume one of the Canadian street/tread tires could be more fun in Solo than the Hoosier Radial or vintage tread. Nothing will ever be as good as a sticky soft slick. So anything harder is going to be slower. But I think for overall enjoyment the tire still needs to be able to get into its operating range during a solo run. Based on how much I work the radials on formation laps in club racing, I'm not sure the radial will be able to do that, especially in colder climates. I don't have the data though...

[Gary Godula]

Brandon,

I agree. The radials are also much slower than the CFF Bias Ply R60s, particularly in turn-in response and braking. It is actually kind of frightening to watch the video from my rear view camera when racing with cars on mixed tires, like FRP RCFFS, where the bias ply cars almost hit me in every brake zone because their brake points are so much deeper than what the radial tires can do.

Cars/Drivers that I was 2-3 seconds faster than when I was running R35 bias ply and they were on R60 bias ply are now 1 second faster than me when I am running the radials. I have been working hard to get the radials to within 2 seconds of my previous lap times on bias plys. Only there at one track (Grattan), and I am still 1.4 seconds off at that track.

I do not have much good to say about the radial tires. They are slow. They are heavy. They have poor transient response. They are difficult to tune the car to. They are difficult to get any tactile feel from. My car never feels happy on them. Other cars never look happy on them.

Anyone who says they like how an FF drives on radial tires has never driven one on bias ply tires.

The loss of the Hoosier R25 tires would blow up any Autocross index (Pro Solo/PAX/other) which would prevent FF/CM from having any possibility of being competitive in a combined class or for the overall.

[Jim Garry]

Presently, when you get the car right, a Formula F provides an incredibly rewarding experience. Hands might shake getting out of the car.

Take away the soft tires that heat up reasonably well and the fun would be gone. As Ben mentioned, anyone autocrossing a CM car in the northern half of the country, especially in the northeast, would have a terrible time if the R20/25 was not allowed. I'd get a Miata and be done with it.

[Gary Godula]

Jim,

The radials suck for more reasons than just the R60 compound. They have no feel, no feedback, no response. The steering wheel feels dead, like a video game. You do not know what the car is doing until it is not going in the direction that you want, and by then it is usually too late for small corrections to have an effect. There is no "edge" to the tire...it is either there or it isn't. There is nothing in between. Watch the in-car footage from the Runoffs or the June Sprints and notice that the cars are either understeering like a pig or oversteering in a big way. They never look balanced. They never look happy.

The car has to be driven differently as well, more aggressively, more confidently. You cannot just feed the car into a corner, it will not respond. You need to load the tires quickly due to the deflection of the tires and the resulting static camber that needs to be overcome to get the tread of the tire to sit flat and generate full lateral load. You would also need to lead the car more due to the slower transient response created by the larger lateral tire deflection. I cannot see that being a good combination on cold or warm tires in a slalom or series of offsets.

Driving an open wheel car is a very visceral experience. The noise, the response, the feel, the feedback, the sensory overload, these are the things that make driving one of these cars so enjoyable. The radial tire provides none of that. It takes most of the fun away, regardless of the format the car is driven in.

[jdr17]

Catching up:

1. Any tire an be competitive if everybody (including the SVs) is on it

2. PAX/RTP and PSI can be adjusted pretty quickly (even proactively) - see SSC

3. 1&2 don't matter if a significant number of folks don't find the experience fun any more. I thought 'the line' might be somewhere between R25 and R888/vintage, but apparently it's pretty close to the status quo. Hopefully the 'foreseeable future' (I was given those exact words as well regarding the canti rears) turns out to be a long time.

4. Chris started this same thread over at rrax and I added on a question for those that have left or have considered the class but not actually taken the plunge - why? There were only a handful of responses, but none mentioned tire cost/wear/availability, so no evidence there that the current tire status quo is affecting class size.

5. Regarding more suppliers (Avon) and the adjacent thread about a possible batch for 2022, what came out of the tests that may or may not have happened in 2013? (before my CM time) - https://www.apexspeed.com/forums/sho...010-Avon-tires

6. I did a little cyber stalking and looked up Ben's results from Sacramento (asphalt) for '20/'21and Barry & Dave's results from CO (asphalt) for '18/'19. I had to do a little math on Ben's but Rocky Mtn solo uses the same points formula as Steel Cities. Ben averaged a score of 970 (3% off the winner on PAX) which is pretty good and would be 10th in the 2020 steel cities year end standings . Barry and Dave were very close and together averaged 955, not bad and still top 20 at SC, but apparently not to their satisfaction (they are currently 1st & 2nd in Rocky Mtn standings for 2021 with a 993 average with the STX car ). My '20/'21 average at PittRace (asphalt) is only 927 .

[Lynn]

Catching up:

1. Any tire an be competitive if everybody (including the SVs) is on it

If you want to kill SoloVees completely, that will do it.

[jdr17]

Catching up:
1. Any tire an be competitive if everybody (including the SVs) is on it

If you want to kill SoloVees completely, that will do it.

If anybody actually ever proposes it, I'm pretty sure it'll go down in flames

OTOH, if the Avons in A15 or A94 or XXX is a significant enough advantage, then (according to the thread currently adjacent to this one) it only takes a group of folks with a combined ~$20k to make them happen for FF...

[OneWayOut]

Spoke to Hoosier Midwest today, and they confirmed the following tires can be ordered:

$259 R20 20.5x7.0-13 front (#43164)
$312 R25B 22.5x7.2-13 rear (#43305)

I was also told 43305 will only be available in R20 when the remaining R25Bs sell out.

[CM/FFdriver]

A detail I left out of my prior post is that there is another CM in my region. We somehow have still managed to race each other and have fun despite being on different tires.

I also forgot I technically have a National Tour win on the radials! I beat my co-driver and we were the only 2 CM entries . As long as none of you guys make the trip to Texas I may win a second at some point. "Competitive autocross" is a relative term to some of us .

Matt Boian
14 CM

Hey Matt,

The funny thing in reading your post is when I first got my car I asked the person who was running in CM in the SFR "how long did tire last for you" he said "All year long" well in a very short time I found that that didn't work for me. My first 3 years in the car I went through 3 sets (more sliding than anything else) of tires now I buy 2 sets.

When it came to real competition I loved what Jdr17 said about Paxing I use it at every event and battle out with XP, DM, because they are very close to raw times and then do my best the max out my time against STX, STR, STU, SS, and AS because I have to be 4.000 faster and more, for me very motivating.

These cars are so much fun to drive at speed, anyone that maybe coming to Calif. call first and see if there an event going on that weekend and I'll let you drive my car.

Ben

[Jim Garry]

Quick update on Hoosier tires. I contacted Jeff Speer this week with some questions. He said that Hoosier has in stock 45 cantilever rear R25B slicks and must sell these before introducing the R20 version. Seeing as I have no tires except some real old ones, I'll be buying two of those rears soon. That still leaves 43 rear tires, or 21 people making purchases. So if anyone is holding off making a purchase in the hopes that they'll be able to buy the newer compound rear, it looks like it will be awhile. Maybe even not until early 2023.

Jeff said the sale of the cantilevered rears "has slowed tremendously". At least part of that is surely because of the low turnout of CM Formula F's in 2022. But Jeff says that there is virtually no difference in handling. So it shouldn't require a set up change (or at least not much of one) for those of us using the R20 fronts and R25 rears.

Looking forward to getting out there soon.

[CM/FFdriver]

for 2022 chalk me up for 3 full sets, now 18 people.

Ben

[chrisw52]

I am ready to purchase, but have unfortunately, other financial obligations that are in the way

[t walgamuth]

I have stayed out of this discussion because I don't feel qualified to make any comments. For myself the problem is always getting heat into the tires. Any harder compounds would be a negative for me.

I'll be buying a set of four soon.

If I can find a young strong co driver I'll buy another set for nationals at least.

[t walgamuth]

I bought a new set of slicks today.....radials. I noted they are heavier and the belt is very very strong. I am concerned that they will require a different set up. I love my current set up on the bias plies.

I am heading up to South Bend on Sunday. My favorite track....small enough to remember all the turns and a little slick.

[Gary Godula]

I bought a new set of slicks today.....radials. I noted they are heavier and the belt is very very strong. I am concerned that they will require a different set up. I love my current set up on the bias plies.

I am heading up to South Bend on Sunday. My favorite track....small enough to remember all the turns and a little slick.

Woo hooo!

I would not celebrate if I were you. The Hoosier spec radials suck. They suck for club racing and the REALLY SUCK for autocross. You would probably be better off on old bias ply slicks.

Yes, they are approximately 15 lbs heavier per set than the bias ply tires.

The first issue is that you will encounter is that the radial front tire is 2"+ taller than the bias ply tire, so you will need to lower the front ride height by over an inch.

Second issue is that they are R60, the hardest tire compound available for a Hoosier FF tire. They do not have anywhere close to the grip of a bias ply R20/25. The tires will never get anywhere close to their operating temperature in autocross on anything less than a hot, sunny 100F day.

Third issue is, as a radial, the tires need a lot of static camber to perform close to their potential, in the order of -3 degrees front, -2 degrees rear. This compromises so many other aspects of the vehicle dynamics, particularly braking and turn-in response.

Fourth issue is transient response. The tire is very slow to respond to direct changes, and fairly unpredictable at it. The tire needs to be lead a lot more, particularly in a slalom. You will need to start turning left while the car is still going right. The steering wheel also needs to turn further as the radial tire has more carcass distortion and therefore requires more steering input, same reason as the need for increased negative camber.

Fifth issue is tire pressures. In club racing, we are starting off around 17psi cold front and rear, and aiming for 20-21 psi hot. This is higher than the bias ply tires, where I would start at 14/16 f/r and aim for 18/20 psi hot.

Sixth issue is tire workload. The radial tires only do one thing at a time, either braking, turning, or accelerating. It does not like to combine those tasks, which means the tire will not trail-brake or rotate well under throttle. If you try to trail brake, it will most likely just understeer way off line. The same is true for corner exit, if you try to rotate the car with the throttle, it will probably just understeer.

For me, the tires are very steering rate sensitive. On my car, if you try to feed the steering in slowly, the car will not respond and yields increasing understeer as more steering is fed in. If the steering input is quick and firm, the front pitches into the turn and the rear end comes around in oversteer. Very unpredictable at times.

I am hoping to do some autox testing on the radials later this season to sort out some of these issues for club racing. Hopefully I can throw a lot of changes at the car and try to gain confidence in the turn-in response of the car without killing myself.

Good Luck.

[t walgamuth]

Thanks for your comments. Hoosier is not offering any choice at this time. Thanks for pointing out the height of the front tires. I'll need to give the front more brake too with the increase in diameter.

I was celebrating running at Tire Rack.

[Jim Garry]

Thanks for your comments. Hoosier is not offering any choice at this time. Thanks for pointing out the height of the front tires. I'll need to give the front more brake too with the increase in diameter.

I was celebrating running at Tire Rack.

I just bought a set of bias ply R20 and R25 tires for my FF.

[t walgamuth]

Wanna sell em?

[Jim Garry]

Sorry Tom. I bought them for this weekend's National Tour. You can buy them at any Hoosier distributor.

If someone told you that the radials are your only option, they were very mistaken. Perhaps they misinterpreted what you said and mistakenly believed you are an SCCA road racer.

[t walgamuth]

Do you think I can return the tires for the bias ply?

[Jim Garry]

I believe if you've mounted them you'll be hard pressed to have them take them back. But give them a call. Especially tell them that you were given bad information about what was available to you.