Autocross/daily driver questions

[BlackPlague]

Ok guys, I'm new to the S550 world and have a few questions. I've perused the forums for a while and I've found some of the answers I'm looking for but I'd like to have them all in one place.

This was my third(ish) year of autocross. I started late 2019 and 2020 was a short season, all done with an old WRX.

I bought a 2020 GTPP1 in March and ran FS this season and did pretty well, but since I need good tires I'm moving to CAM-C. Go big or go home.

On to the questions: I'm planning to get RT660s, 305/30R19 square. Would 315s fit? They're not a ton more expensive and I'm going to get camber plates, really liking the Vorshlag option.
Eventually I plan to upgrade the suspension, I've been attracted to the Steeda dual rate with adjustable shocks.

What are everyone's thoughts on this? This is my daily driver, and I'll be running the stock PP1 rims and PS4S until autocross weekend, I'll likely do 15-20 events next season. Based on my FS times on PS4S and comparing to CAM-C, I think I'll do well with just tires and camber, but how long can I really be satisfied with stock suspension? I don't want to get my teeth knocked out by hitting a pot hole on the expressway, though. I really want everything to be adjustable so I (and my wife/kids) can be comfortable enough when we take it somewhere, but then I can get a more aggressive setup on autocross days, and I'm not looking to drop it much. Also, if I'm doing camber plates, would it be worth it to bite the bullet and just upgrade the springs and struts while I'm in there? That would be a little more difficult to budget.

Sorry for the long-winded post, but I know you all have a lot of knowledge floating around so I was hoping to give as much detail as I can.

It's been a dream come true finally getting my own mustang.

Thanks in advance

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[NightmareMoon]

315s will be tight. I’m sort of hoping to do them but the 660s run wide and I’m not quite sure. It would take more than an ARP stud and 25mm spacer, maybe evn to fit the 305s. Usually 305s on 11s ET52 fir with just a 1” spacer but with the Falken widths its a little different. 315s 660s fit on 11s fine at least.

I actually have had great success with 295/35R19 Falkens because they’re a but taller and that helps with gearing in 2nd gear.

The Steeda dual rates are awesome for sport use but the ride frequency is bouncy on the street with cheaper adjustable shocks. You really want a good monotube shock to tame spring rates like these. I had instant regrets in daily use the first days after mounting them but I don’t really think about it anymore. On course, and paired with the right swaybars and camber, they’re amazing. I would do it again, but I was ready for an aggressively sporty ride. The minimal drop is perfect for handling.

next step after the above would be CAMC legal aero. Thats when my car went from top 10% finishes to being able to win top PAX locally. Found a 2nd rear decklid - swapping trunks takes 10 minutes tops from start to finish.

 

[Dana Pants]

You are always welcome to mod your car, but keep in mind the goal/measuring stick should be top pax, not the local CAM crowd. I’m always like 2 seconds off top pax in FS. Sadly, a good portion of that is not the car.

You really do need to increase the spring rates and damping if you are going in there.

 

[kz]

For camber plates you're taking struts apart, dealing with spring compressors and all, would make sense to at the minimum upgrade struts (assume no mag ride ?), stiffer springs would make substantial difference as those cars are soft stock.

315 - not much diameter difference vs. 305 (26.5 vs 26.3") but with how tall 2nd gear is, lower is better - with 305 you get 72ish max speed in 2nd gear which is more than enough.

 

[07S281E]

It has been my experience in autocross it is better to get a second set of wheels and tires. A good set of autocross tires will make a huge difference.

 

[Steve68Cougar]

I've got RT660 305s and Vorshlag plates on my '18 Roush. The coilovers are different than what you have, so I don't have info on how a 315 would work. It's a tight fit, but the ET52 w/ 25mm spacer setup actually has more inside tire clearance than the 20x9.5 Roush rims (w/ 275/35-19s) the car came with (but not much). The tires made a huge difference on where I place with PAX times. I went from bottom 1/3 to top half at our local events. This last event I even managed 9th out of 37. There were a few people missing (like 2 national champs from this year), so I still take it with a grain of salt. It's nice to see progress, though. One person that runs some of our local events had a 2016 Mustang GT with 285 RE-71s all the way around with Konis. Until I got the bigger tires he ALWAYS beat me, and usually by a significant margin. Now I'm able to run slightly faster than he does (except now he just got a GT350R he'll be running next year). A well driven FS or (especially) BS car on autocross tires can often times outrun a good chunk of the CAM-C cars, at least at the events I've been to. I think changing out springs/shocks/struts while getting the camber plates installed is a good idea, but obviously budget constraints can play with that. You'll make more difference with the big/sticky tires than you would with just suspension, so I'd definitely go that route if you need to make a choice one way or the other.

 

[NightmareMoon]

I've got RT660 305s and Vorshlag plates on my '18 Roush. The coilovers are different than what you have, so I don't have info on how a 315 would work. It's a tight fit, but the ET52 w/ 25mm spacer setup actually has more inside tire clearance than the 20x9.5 Roush rims (w/ 275/35-19s) the car came with (but not much). The tires made a huge difference on where I place with PAX times. I went from bottom 1/3 to top half at our local events. This last event I even managed 9th out of 37. There were a few people missing (like 2 national champs from this year), so I still take it with a grain of salt. It's nice to see progress, though. One person that runs some of our local events had a 2016 Mustang GT with 285 RE-71s all the way around with Konis. Until I got the bigger tires he ALWAYS beat me, and usually by a significant margin. Now I'm able to run slightly faster than he does (except now he just got a GT350R he'll be running next year). A well driven FS or (especially) BS car on autocross tires can often times outrun a good chunk of the CAM-C cars, at least at the events I've been to. I think changing out springs/shocks/struts while getting the camber plates installed is a good idea, but obviously budget constraints can play with that. You'll make more difference with the big/sticky tires than you would with just suspension, so I'd definitely go that route if you need to make a choice one way or the other.

And to be frank, we all should know that a CAMC car should _never_ be beaten by an FS car (at least an FS mustang). With the open rules, big tires, and mods, CAM drivers should be faster. Period

Yes I did get beat in my CAMC car by a BS camaro at the ProSolo last weekend, but in my defense ... he was the course designer.

 

[kz]

I get regularly beaten by 1/LE driven by mutliple (FP) national champion - car is currently BS (and obviously CAM-C) legal. By beaten I mean a second and half raw time.

 

[Steve68Cougar]

And to be frank, we all should know that a CAMC car should _never_ be beaten by an FS car (at least an FS mustang). With the open rules, big tires, and mods, CAM drivers should be faster. Period

Yes I did get beat in my CAMC car by a BS camaro at the ProSolo last weekend, but in my defense ... he was the course designer.

I looked back at my first outing in Nebraska with my 660s back in July. I was about 1.6 seconds behind the BS winner (Gearz on here, in his GT350) and about 1.2 seconds behind the ZL1 that won CAM-C. I did manage to beat the FS winner (an '07 Shelby GT) by about .9 seconds.

 

[BlackPlague]

Ok, so I don't know how to quote so I'll reply the best I can for now.

I'm 100% doing a dedicated set of rims and tires for autocross. Tires are the first upgrade you should always do. I've decided to go CAM-C because it won't be long before I decide to make a change that will bump me from FS, and I don't want to buy wheels and tires again. I already have the 11 inch rims, the decision now is 305 or 315. I've found it's generally accepted that 305 will fit up front with a spacer (or proper offset but i wanna rotate tires). But while I'm at it, over the winter I really wanna upgrade the suspension.

NightmareMoon - What do you mean by good monotube shocks? Do you think the Steeda adjustable are not good enough? Or are there better ones? Also, i think the 2nd gear is taller on the 2018+ so the shorter tires will do me well.

FS to CAM-C is a change in PAX, but I bought the 'stang because that's what I wanted, and making it better for autocross is just a bonus . I want to do well, but it's just for me to enjoy the car. If I wanted to just win autocross I would get a civic Si or something

Steve - Are the Vorshlag plates as easy to change trackside as they advertise? I love the idea of two discreet camber settings.

 

[Steve68Cougar]

Ok, so I don't know how to quote so I'll reply the best I can for now.

I'm 100% doing a dedicated set of rims and tires for autocross. Tires are the first upgrade you should always do. I've decided to go CAM-C because it won't be long before I decide to make a change that will bump me from FS, and I don't want to buy wheels and tires again. I already have the 11 inch rims, the decision now is 305 or 315. I've found it's generally accepted that 305 will fit up front with a spacer (or proper offset but i wanna rotate tires). But while I'm at it, over the winter I really wanna upgrade the suspension.

NightmareMoon - What do you mean by good monotube shocks? Do you think the Steeda adjustable are not good enough? Or are there better ones? Also, i think the 2nd gear is taller on the 2018+ so the shorter tires will do me well.

FS to CAM-C is a change in PAX, but I bought the 'stang because that's what I wanted, and making it better for autocross is just a bonus . I want to do well, but it's just for me to enjoy the car. If I wanted to just win autocross I would get a civic Si or something

Steve - Are the Vorshlag plates as easy to change trackside as they advertise? I love the idea of two discreet camber settings.

I haven't actually changed the camber trackside yet. All you need to do is get the weight off of the front end, loosen the 3 top nuts and put the camber where you want it. That's how I got it set before getting the final adjustments done at an alignment shop. It was really pretty easy. I'm currently set at -2.7 degrees of camber and 0 toe. It's been on trips to Michigan and Idaho (I'm in Kansas) and have seen no abnormal wear. These trips were done with 275/35-20 BFG Comp 2 AS Plus tires. I need to figure out how much the toe changes if I add another half degree of negative camber, or how much adjustment it takes to keep 0 toe.

The local that gets top pax score whenever he shows up is running a 2021 Accord Sport. He won HS at Nationals earlier this year.

Sounds like you've got a pretty good plan going. Seems like the preparation level of the CAM-C cars is all over the place, so there's almost always someone that's pretty close. The main thing is to have fun no matter how fast you go.

 

[NightmareMoon]

No the steeda adjustables are not monotube, but they’re very very similar to the Konis that I’m running. They perform well enough for autox but they’re a bit bouncy with the dual rate springs on the street. Having ridden in a car with even stiffer front springs and higher quality monotube shocks, there is a very noticeable difference.

If you’re concerned about ride quality you can run the steeda adjustibles with lower spring rates (like the BMR handling springs or steeda linears) as a different option. For me, the sacrifice in ride quality made sense for a while, but I’m egar to get into some much nicer shocks soon.

 

[shogun32]

To get the steeda dual rates under control you have to be around 1/4 turn from closed. For street I back them off to half. The damping is just not optimal IMO.

One of the vendors sells ohlins R&T with revised internals and rates. That would be my choice doing this over again.

 

[BlackPlague]

No the steeda adjustables are not monotube, but they’re very very similar to the Konis that I’m running. They perform well enough for autox but they’re a bit bouncy with the dual rate springs on the street. Having ridden in a car with even stiffer front springs and higher quality monotube shocks, there is a very noticeable difference.

If you’re concerned about ride quality you can run the steeda adjustibles with lower spring rates (like the BMR handling springs or steeda linears) as a different option. For me, the sacrifice in ride quality made sense for a while, but I’m egar to get into some much nicer shocks soon.

I don't mind it being stiffer on the street, but I don't want it to be uncomfortable. Do you have any shocks in mind that you think would work better for the DR springs? Again, I think adjustability is key for my purposes.

"Having ridden in a car with even stiffer front springs and higher quality monotube shocks, there is a very noticeable difference"
-What specifically do you mean here? Better all around, or better on the street or autox? I have seen in the CAM-C thread that people think the DR front rates are too low, but I'm not really building a dedicated CAM-C car. It'll just fit nicely there, and I'll probably still get beat by our top FS guy.. He's good.

To get the steeda dual rates under control you have to be around 1/4 turn from closed. For street I back them off to half. The damping is just not optimal IMO.

One of the vendors sells ohlins R&T with revised internals and rates. That would be my choice doing this over again.

Man, you're really trying to get me to spend some money haha! Those Ohlins look awesome but they are pricey.

I've been under the impression that coilovers tend to take more maintenance than your everyday strut setup. This is my summer car but I still drive it every day, whether it's nice out or not. And it's probably gonna see some snow, because I still have some work to do on my cherokee to make it sea-worthy. Also it just snowed today but I didn't drive it. All this to say the Ohlins look perfect, but expensive and maybe unhappy with corrosive conditions.

 

[shogun32]

I've been under the impression that coilovers tend to take more maintenance than your everyday strut setup.

not at all true. A coilover ALLOWS you to do a rebuild every year or two instead of having to throw the whole damn thing into the trash. Unless the Coilover supplier's anodizing is total crap unlike the traditional strut which is heavily painted.

the Ohlins look perfect, but expensive and maybe unhappy with corrosive conditions.

The Ohlins use chromed sliders and have multiple seals and other weather coatings so corrosion isn't your problem. I would still run the mud/grime guards but you're blowing it way out of proportion.

I live daily with the DR springs and if all you use your car for is track/cross you should be plenty happy. For street use they are an acquired taste.

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