CraigStu

Started AXin this car in 2020 in CAMS. I chose that because I had added Z51 F and R bars to the car which came w/ F bar only. Also Added Z51 F shocks but rears were BOd so I fabed mounts for QA1 DA rear shocks. So I figured either the rear bar or the rear shocks kept me out of AS. This past fall I saw the info about C7s moving to BS and decided to read through the rules again since I hadn't looked at them since 2020. Well heck, DA shocks, incl w/ a canister, are legal in Street classes. Now that makes no sense. I can't install a $150 bar but I can install four minimum $300 shocks. Also I look at the Street class option package swapping verbage and a Z51 package must be complete. So that means dry sump engine, different gears in the trans, possibly different springs,etc. So the other day I am looking at rules again thinking there must be another class option. Read through the allowed mods and STU looks good. But then I get to the list of cars and no 19 Stingray. OK Street Prepared? Nope they run Hoosiers. I did that on my FFR before we moved, but now half my AXs are 2 hours away, so either trailer or drive on Hoosiers. No thanks to either. So as best I can tell, I can run BS w/ one bar, SSP on Hoosiers, or CAMS. I am way outclassed in CAMS at the mod level I want to do to my car and it would be the same in SSP. Pretty disappointed at the limited options here. Maybe the stock front bar and Z51 rear bar if I don't end up way too loose. Does anyone have any ideas?

strano@stranoparts.com

you can't run in a street class in a configuration that wasn't available from the factory nor beyond the rules. In other words you can change one bar and one bar only. Pick an end. You cannot move to a z51 rear bar with some other aftermarket front unless your car is a z51. The exception to that would be if the stock rear bar was discontinued and the superseded part is the z51 bar, then that's okay.

also your shocks when you say you fabbed up amount that's all right too, but the shocks have to meet certain rules in terms of length and travel and stuff like that. A lot of times aftermarket shocks don't meet those rules. They have to be within one inch of overall length and they cannot have any less free travel then OEM to the bump stop. You can have more. You can remove the bump stop but you can't have less, and that all has to be done within 1 inch of overall length while also not breaking the shock because the links aren't right.

RacerRik

Craig,

The 2024 SCCA SOLO II rule book is out and it is official - C7 Stingray is now BS class. So you need to be in that class. Since the rules only allow you to change one sway bar, your only choice is to use the stock front bar and add the Z51 rear bar (or an aftermarket rear bar). I use the bigger (31mm) Z51 bar on the rear of my car. It is not too much. The car had so much understeer with the stock suspension that adding the huge rear bar works out perfect.

CraigStu

Sam, thank you for your experience. SCCA is SCCA I guess. Being allowed DA shocks w/ canisters but not allowed to add a swaybar to me is ridiculous. C7 ZO6 is in Super Street, C7 Grand Sport is in A Street, C7 Stingray is in B Street. They forgot about the C7 Z51 even though the "C6, base and Z51" is the next line down in B Street right under the C7 Stingray. Oh well.
Rick, that is the way I will be going I think. The stock front bar will be going back on soon. And 200 tires will be order soon also.

RacerRik

What 200TW tires are you going to use? My last three sets were RE71R and I am done with Bridgestone tires. They start out great - pretty much as grippy as you could want. Then about half way through the tread depth, the grip falls off massively. Probably due to heat cycling. But they wear fast also. I got about 4 events that were grippy and then I fought for traction and got poor results until I replaced them while they still had about 5/32" tread left. Not very good for the budget since you would go through two sets a year if you want to stay competitive.

Last year I switched to the RT660s. They do have slightly less grip but are still capable of top index finishes. After 6 events, they still have 6/32" tread left and there is no sign of grip going away yet. I have been very happy with these tires so far. We will see how much grip they have after sitting in the basement all winter. Our first event for 2024 is mid April. My goal is always to finish in the top ten places on the PAX index. I did that 4 out 8 events last year. And we have some very tough competition at our events.

I went with 295/35-19 rear and 245/40-18 front. I tried different widths with the RE71R tires and going wider (meaning somewhat pinched on our narrow wheels) did not give me better performance so I am back close to stock sizes now.

We also tried the A052 tires on my sons car and they performed well but wore out frighteningly fast. He did not make it through 8 events before they were down to the cords. Grip never fell off on those, but they are pricey and with how fast they wear, hard to justify on the Corvette for autox. Remember - this is supposed to be for fun!

.

CraigStu

Not sure which tires yet. I started making a list several months ago and need to go back and redo that. Thanks for your comments. I definitely don't want tires I wear out quickly. Pretty much any 200 will be better than my 300 Michelins. Tire Rack has good info and so does Grassroots motorsports so I will combine them. Also I need to decide whether to go 19/20 on my OE wheels (where the 300 Mich are and still have 1/2 tread) or 18/19 on my American racing wheels where my Conti DWS are with rears down to 4/32 but fronts more like 6-7/32. I remember some tires don't have 20s so that could be the decision maker.

l98tpi

If youre wearing out AO52's in 8 events something is not right with your alignment or suspension. I run just about every weekend from April to November and go through 1.5 sets of A052's/year. Even wear across the tread as well. And I run on a mix of concrete and asphalt. Could be why you're wearing out your Bridgestones too. Verify your alignment. Hope this helps.

RacerRik

My alignment is perfect. I adjust the alignment frequently as needed to get best grip / best wear out of the tires. But I also drive the car to the absolute limit of its capabilities in order to get competitive results in a tough club. Maybe your tires last a along time because you are not driving it hard enough to win. Where do you typically finish on the index and what cars are you competing against?

strano@stranoparts.com

I've been busy for the last few days in trying to get everybody set up with their parts for the year. Rt660s are not speed wise equal to the Bridgestone or the Yokohama. I did a bunch of testing last year I even took some to SCCA Nationals with me. An event I won for the second straight year in my current class for the 10th time since 2002, so I know I'm going fast enough. And I can tell you that almost every time I ran 660s against the re71rs, it was about .1 slower per 10 seconds.

now I'll have to go back and read some of the other posts. I'm not sure what's really been discussed. Like I said I've been busy.

strano@stranoparts.com

let's not do that. This scca is going to scca thing. A C7 z51 is a stingray. Z51 is simply an option on a stingray. Your car is B Street. If you read the rules. I'm pretty sure you can add a rear sway bar as long as you don't do anything to the front. It's one bar and one bar only. Now you can write for a clarification because admittedly I can't say that with 100% certainty, because they're so cars that come missing a sway bar at one end these days.

RacerRik

Sam,

Craig's car is a standard Stingray, so it does not come with a rear bar at all. He added a rear bar plus he put on a bigger than stock front bar. The rules only allow changes to one sway bar so he has to put the stock front bar back on since he has to have a rear bar to make the car turn.

BTW - I think your assessment of the time difference between the RT660 and the RE71R is spot on. For some of us, that difference in time is worth it to get tires that last twice as long.

Midwayman

Can't you just retrofit the z51 option in its entirety? That would be your new starting place for what to mod.

RacerRik

Per the rule book, you can do that. But at what cost? It would be a lot less cost to sell the car and buy a Z51. Retrofitting the complete package means swapping engines, swapping transmissions, installing the ESD, swapping exhaust, sway bars, springs, shocks, rear spoiler, etc. That would likely cost $25,000 or more and you have to get into computers that control ESD and maybe the ECU. The Z51 package was a good deal but building it piece part is certainly not.

l98tpi

I typically run CAMS in SCCA and GTU or NLO in DriveAutoX Events. UMI events I run Super Late and previous Mid Muscle in my C4. Not the best shoe in the country but not the worst either. AutoX Challenge 1st Place in Mid Muscle in 2021, 2022 won TeamX with my C6, Finished 6th and 7th at SCCA Nationals in CAMS 2021 and 2022. Local; club is Cincy Region SCCA. If you have a nice lot your club runs on I could possibly come out and run with you guys and you can give me some pointers. Always something to learn.

RacerRik

I took a look at the 2002 Nationals results. You must be R.A. You took 610th place on the index which is decent. That is a tough crowd.

I saw Sam Strano got 73 index place in that event. Awesome job Sam and on the RT660s!

We had four guys that run in our St. Louis club there. They got 230th, 235th, 505th and 550th places on the overall index just to give you an idea of how you might compete in our club.

I am the driving coach and course designer for our club. We run on a huge blacktop parking lot near in St. Charles, MO. They just repaved the whole lot at the end of 2023 so it should be super nice. Our first event is April 15th. Let me know if you want to attend and I can give you more details. The only concern would be weather at that time of the year. It would be a long drive from Ohio and really suk if we ended up getting cancelled due to weather. We do have rain events, but if it is storming the morning of the event and they are predicting rain all day, we cancel.

l98tpi

I would be glad to travel as I typically do. For 6hrs I’d rather do a two day event. Does your club list events on MotorsportReg?

If you have the ability to travel there are a few Drive AutoX Events that are 2 day events coming up late March through June. It would be fun to compete and see what we have to offer.

Relative to index (PAX). I don’t see that as a true reliable measuring tool. It’s theoretical factors used to compute a number from raw times. Raw time is real and even beyond raw times it’s hard to consider true skills and ability unless running at the same time in the same heat. Air temps, surface temps, course design, OPR, and weight and tires are factors that can change so watching an index is unrealistic.

RacerRik

Sorry, we are not on Motorsport.reg. I agree that PAX is far from perfect, but that is what we have. Our club does not look at class results - we only use PAX and everyone gets compared for final results based on the index. In particular, I have consternation about CAM classes. They allow so many upgrades and the PAX indexes for the CAM classes do not reflect those mods if the owners take full advantage of the CAM rules. So the CAM cars tend to always finish high in our results. If those cars were moved to standard classes reflecting all the mods they have, the tougher PAX indexes would make them noncompetitive. But again, SCCA will be SCCA. By the way, our club is not an SCCA club. We follow the SCCA rules but are an independent club.

One area we differ from the SCCA on CAM classes is that we do not allow a car that is classed with an index higher than the CAM class to run in CAM just so they get a lower PAX index. One example is a car like the Camaro ZL1 1LE that is in SS class cannot just run in CAMC to get the lower index. And in what world does that even make sense that you can take a car in SS and mod the hell out of it and then get a lower PAX index?

l98tpi

I’ve thought about it for a while that if PAX is used, there should be some factor used for Run Heats and then breakdown by surface temps. Difficult to do but so is coming up with the PAX factors.

Just being straight honest, I’m not putting much effort into going to an event that’s based only on index.

Maybe we can meet up at a different type event. I do plan to go to Nationals this year and run either CAMS in my C6Z or AS in my C7 GS. Haven’t decided yet.

RacerRik

I totally understand not wanting to drive that far for an event that is not run how you would like it to be. I will say we have great courses and have a super fun time out there.

As far as PAX index, we have no way to change them from run heat to run heat. We don't use class because we are a small club and usually have around 60 drivers so we would have a lot of cars that would be the only car in their class. We get a lot of diversity in cars also so raw time is not a good way to compare results. It is not fair for me in a Corvette to compare raw times with HS and ES cars. We also have mod cars and even karts sometimes.

I have never been to Nationals as it is too big of a time commitment for me and my family. If I am taking a week vacation, it needs to be something for the whole family to enjoy. Nationals does sound cool though!

Midwayman

PAX always creates winners and losers, especially not at the national level. Its just so hard to make cars competitive across such a wide spectrum. I like the idea of the power to weight classes better. Like how nasa does it. It makes more sense than the patchwork of rules you get with SCCA solo classing. I don't know that it'll work any better for autocross though. It doesn't account for how important a physically small car is in autox. I guess you could run something like a handicap system where you're more running against a running average of your own last 3 finishes or something. It'd be a different sort of competition though.