First Autox in the Mustang

[Arustik]

Avid autoxer here with 6 years of experience + (2 years of instructing experience).

Trying to get some of your thoughts on my run:

https://www.youtube.com/watch?v=OAv7ULP3xKA

I was slightly disappointed in the car after the amount of work we did:

Power - Exhaust, Intake, Tune
Brakes - Boss 302 Brembos + 14" Rotors
Suspension - Eibach R2 (600lbs front, 250lbs rear), MM CC Plates (-3.3 camber, max caster), Rear LCAs, Relo Brackets, Panhard Bar + Brace, FRPP Front Sway (full stiff), GT500 Strut Tower Brace, FRPP Front LCAs
Interior - Harness
Fluids - Full Synthetic Oil, Motul 600 Brake Fluid, 93 Octane Only

For tires I tried mounting my R-Comps (didn't fit I'm rubbing against the strut with my new Apex 18x10s and 275/35/18s Toyo RA1s). Had to run my streets (255 front 285 rear Goodyear Eagle F1 Supercars. Alignment was spot on and no issues.

Temp was around 50 degrees all day with on/off sunlight.

Suspension was dialed into full soft in rear and medium stiff in front.

I lost by over 3 seconds to a 2007 Shelby GT on Hoosier A6's (I know Hoosiers will be much faster, but not 3 seconds faster IMO).

Felt like the car was extremely tail happy (I hit cones every single run). Just trying to figure out if there's something I'm missing here.

 

[chilema]

I would lean toward the tires in this case. If the guy in the Shelby knew what he was doing, and you certainly look like you did, around 1-2 seconds on one of the better autocross-specific street tires is not that surprising. I think on the Goodyears 3 seconds is not that bad at all, and even if you're on the G2's it can be hit or miss depending on temperature.

 

[Arustik]

Thanks for the quick reply. The guy in the Shelby has been Autoxing that car for 2-3 years now, so plenty of "seat time". I do not need much time in a car to get comfortable in it. Would I trust it more after a few events? Yes, but not enough to make up another second or 2.

The car felt like it was fairly "all over the place" understeer into oversteer, I wasn't going crazy with the throttle either.

I looked at the TW of the tire and it reads 220 which is quite low so I expected it to perform better.

 

[Whiskey11]

I didn't see any glaring issues with line in the video you posted but that doesn't mean there weren't any issues. You have more experience than I do. What I DO think is that your tires are holding you back. The original Goodyear Eagle F1 Supercars were pretty well known to be awful. I've heard the second generation are significantly better (although I only know of one person who has considered running them in F-Street) but there are better tires out there.

I also wouldn't put much stock in treadwear rating when trying to compare tires for grip. I'm pretty sure the Michelin PSS has a higher treadwear rating and is probably faster than the original F1's.

I'd be shocked if your loose condition was because of suspension setup. It seems to me like you have that typical push-loose associated with staggered tire setups. Very easy to get it to understeer and the experienced driver will try and correct with throttle and then the tires give up under the lateral loads and the car gets loose. You can try and tweak damping settings some to see if you can't tame it but I wouldn't make significant setup changes until you get squared up for tires.

 

[cbass]

I've had a couple of tires from the F1 line, never really impressed, until I tried the original F1 Supercars. I was thoroughly impressed with how horrible they were. You probably had 2-3 seconds on better tires, 4 or 5 if they were the first gen S1's.

 

[Arustik]

I didn't see any glaring issues with line in the video you posted but that doesn't mean there weren't any issues. You have more experience than I do. What I DO think is that your tires are holding you back. The original Goodyear Eagle F1 Supercars were pretty well known to be awful. I've heard the second generation are significantly better (although I only know of one person who has considered running them in F-Street) but there are better tires out there.

I also wouldn't put much stock in treadwear rating when trying to compare tires for grip. I'm pretty sure the Michelin PSS has a higher treadwear rating and is probably faster than the original F1's.

I'd be shocked if your loose condition was because of suspension setup. It seems to me like you have that typical push-loose associated with staggered tire setups. Very easy to get it to understeer and the experienced driver will try and correct with throttle and then the tires give up under the lateral loads and the car gets loose. You can try and tweak damping settings some to see if you can't tame it but I wouldn't make significant setup changes until you get squared up for tires.

I'm hoping this is the case. The car felt great on the street - similar to an 'on- rails' feeling I've felt from some cars in the past.

You're correct about the TW rating although I just couldn't believe when I saw the 220 number. I know it doesn't mean much, but it definitely killed me when I saw it. I have another event on the 20th and I'm going to be running my Toyo's and will hopefully be happy. I guess I'm going to order the extended studded hud kit from AM. Any recommendation as to where to get the open ended lugs? Vorshlag?

I've had a couple of tires from the F1 line, never really impressed, until I tried the original F1 Supercars. I was thoroughly impressed with how horrible they were. You probably had 2-3 seconds on better tires, 4 or 5 if they were the first gen S1's.

These were definitely old tires and I wouldn't be surprised if they were the original F1 Supercars. If they're really worth that kind of time I will be pleasantly surprised.

The guy who runs the Shelby GT is a good friend of mine, offered to have me run his street setups Star Spec ZII 265 square, I declined as my back was already tweaked (previous injury) and from the amount of times I swapped back and forth from the stocks to the Apex's.

 

[JesseW.]

what offset are those apex wheels? 48? 50? my AMR wheels were really close and are 48. i solved with a 7/32(about 5 mm) plate spacer i got from carquest that day. made by mr. gasket http://www.summitracing.com/parts/mrg-2370/overview/

those goodyear f1's are close to junk.

 

[Arustik]

what offset are those apex wheels? 48? 50? my AMR wheels were really close and are 48. i solved with a 7/32(about 5 mm) plate spacer i got from carquest that day. made by mr. gasket http://www.summitracing.com/parts/mrg-2370/overview/

those goodyear f1's are close to junk.

The wheels are ET43 sqaure. The tires are 275/35/18.

What tires were you running?

I know I'm going to need the studded hubs from AM, but what size spacer?

 

[JesseW.]

+43 and your hitting the strut? are those eibachs that big? how much camber do you have in it? 295/30/18

 

[Arustik]

+43 and your hitting the strut? are those eibachs that big? how much camber do you have in it? 295/30/18

That's what doesn't make sense to me. The Eibachs are way smaller than the factory struts. Camber is set to -3.3 degrees which gives me plenty of clearance on the fender side. I wanted to run a 305/30/18 and was really shocked to see these 275s grinding away on the Eibach struts.

 

[JesseW.]

i'm not sure what to say about that. if you are running camber bolts, bring them back a bit to get the tire away from the strut, then try to get the camber back from the plates up top.

or wheel spacers. probably won't take much

 

[Arustik]

i'm not sure what to say about that. if you are running camber bolts, bring them back a bit to get the tire away from the strut, then try to get the camber back from the plates up top.

or wheel spacers. probably won't take much

I'm running Max Motorsports CC plates. Camber was "maxed out" even though I know the plates can get way more than 3.3 degrees.

So you think the mounting position of the struts is what's causing the rub?

 

[sheizasosay]

IMO, you have a lot of rate for the tires you ran on. I'm sure you planned on running the R comps with those springs. Might make it twitchy.

The 255/285 with the rates, bars and camber would seem like it shouldn't be over -steering anywhere except trail braking. That makes me want to ask what the rear LCA angle is. Maybe excessive roll-steer. Just a thought.

 

[dontlifttoshift]

The eibachs have a slotted hole to mount the spindle to, don't they? That may be your tire clearance issue.

Your performance issue is tires.

 

[csamsh]

The eibachs have a slotted hole to mount the spindle to, don't they? That may be your tire clearance issue.

Your performance issue is tires.

Exactly what I was going to post

 

[Arustik]

IMO, you have a lot of rate for the tires you ran on. I'm sure you planned on running the R comps with those springs. Might make it twitchy.

The 255/285 with the rates, bars and camber would seem like it shouldn't be over -steering anywhere except trail braking. That makes me want to ask what the rear LCA angle is. Maybe excessive roll-steer. Just a thought.

High rate, but I wanted the eliminate as much of the dip as possible. The R2s are double adjustable and I did soften them up a bit.

The eibachs have a slotted hole to mount the spindle to, don't they? That may be your tire clearance issue.

Your performance issue is tires.

I did not install them, had my tech do it. Do you suppose this could be an issue with the install? So he has to unbolt from the strut tower to realign the spindle?

 

[csamsh]

I did not install them, had my tech do it. Do you suppose this could be an issue with the install? So he has to unbolt from the strut tower to realign the spindle?

No, just the two large bolts that connect the strut to the knuckle.

 

[sheizasosay]

Don't lift and CS are right. They are slotted http://mustangsdaily.com/blog/2011/...-multi-pro-r1-coilovers-for-the-2011-mustang/

 

[Norm Peterson]

What everybody else is saying.

What needs to be done is loosen the strut to knuckle bolts enough so the knuckle can be moved outward at the upper strut to knuckle bolt. Then regain the lost camber at the camber plates and reset toe, which I expect may change slightly even if you end up at the same cambers.


Norm

 

[jmauld]

You don't want to adjust the camber between the hub and strut, you give up braking ability and the camber gain goes away with steering input. All of your camber adjustment should be made in the top strut mounts. Fix that first, it will probably also fix the rubbing issue that you have between the tire and the strut.

Also, like others have said, it sounds as if your spring rates are too high for those street tires. This becomes even more exaggerated if your tires are cold and you have difficulty getting heat into them.