Autocross for newbies

[Scott #321]

I'm finally starting to figure this car out on the autox course. Same setup as above but I am now under 1.5 seconds variation in my runs and Sunday was less than 4 seconds behind FTOD. Hard braking at turn in and off throttle turns make this thing feel like the rear end is on ice skates. Getting a little throttle in the turns to transfer weight to the rear end makes a huge difference over my previous driving style. I set up a camera to view the drivers rear this weekend and was initially terrified to see the tire moving left to right in the frame considerably. Someone at the course advised me that it was likely the camera image stabilization causing that and in a later recording was bale to pan in a little getting part of the cage in vies and it does not appear to walk. Slight camber change probably due to body roll and me being too cheap to upgrade to the newer rear subframe design which addresses these items. If I can't close the time to FTOD some by the end of the season by addressing the loose nut behind the wheel it may be time to pull the trigger on subframe upgrade and Hoosier A7's. (Just need to start saving now I suppose)

 

[Stretch2126]

I'm finally starting to figure this car out on the autox course. Same setup as above but I am now under 1.5 seconds variation in my runs and Sunday was less than 4 seconds behind FTOD. Hard braking at turn in and off throttle turns make this thing feel like the rear end is on ice skates. Getting a little throttle in the turns to transfer weight to the rear end makes a huge difference over my previous driving style. I set up a camera to view the drivers rear this weekend and was initially terrified to see the tire moving left to right in the frame considerably. Someone at the course advised me that it was likely the camera image stabilization causing that and in a later recording was bale to pan in a little getting part of the cage in vies and it does not appear to walk. Slight camber change probably due to body roll and me being too cheap to upgrade to the newer rear subframe design which addresses these items. If I can't close the time to FTOD some by the end of the season by addressing the loose nut behind the wheel it may be time to pull the trigger on subframe upgrade and Hoosier A7's. (Just need to start saving now I suppose)

The instant I got A7s I got FTOD. They are unreal. But learning on less than perfect tires is critical in my opinion too for anyone else looking to get into it.

 

[Rttoys]

The instant I got A7s I got FTOD. They are unreal. But learning on less than perfect tires is critical in my opinion too for anyone else looking to get into it.

What does FTOD mean?

That’s where I’m at. If I can work out all the kinks on this thing and make it the best it can be with less than perfect tires, when I upgrade tires, it’ll be a nice switch.

 

[Stretch2126]

What does FTOD mean?

That’s where I’m at. If I can work out all the kinks on this thing and make it the best it can be with less than perfect tires, when I upgrade tires, it’ll be a nice switch.

Fast time of the day. They definitely make a difference.

 

[Rttoys]

Ah. Ok. Thanks.

 

[Keckster]

The instant I got A7s I got FTOD. They are unreal. But learning on less than perfect tires is critical in my opinion too for anyone else looking to get into it.

A7s are amazing but if the course is anything less than 60 seconds I would just run street tires in XU to be competitive in pax. I've run A7s for two years and Yoke AO52 for 2 years and on the same lot and course the A7 is maybe 2 tenths faster on a 40 second course. while the pax difference is major between XU and EM. For example if someone runs a 60s time in XU, you need to run a 56.9 to beat them.

 

[Waterdriver]

You can mark the tire shoulder up to tires tread surface see how much it's rolling over. This can help find your camber and tire pressures.
Currently running -1.5 camber in the rear and -1.0 in the front.

 

[SmsDetroit]

So making progress with suspension set up changed. Corner balanced the car. Also lowered the rear by 1”. It was sitting about 1 1/2” higher in the rear. Hopefully they will help with rear traction in hard corners. We will see next weekend

 

[Keckster]

So making progress with suspension set up changed. Corner balanced the car. Also lowered the rear by 1”. It was sitting about 1 1/2” higher in the rear. Hopefully they will help with rear traction in hard corners. We will see next weekend

What tire are you on and what size?

 

[SmsDetroit]

What tire are you on and what size?

My race set are 245/40R17 r888r

 

[Stretch2126]

Just in case anyone is thinking about trying 300/400, the car gets more tail happy on lift off but seems to plant well on acceleration. The car was loose but I had zero understeer even in a bad surface.

 

[SmsDetroit]

I run 400 up front 300 out back

 

[Keckster]

Just in case anyone is thinking about trying 300/400, the car gets more tail happy on lift off but seems to plant well on acceleration. The car was loose but I had zero understeer even in a bad surface.

I also found I liked the 300 front 400 rear. Although I’m thinking of bumping it even higher all around

My race set are 245/40R17 r888r

I haven’t driven on the r888 myself but I know a lot of people in the autox scene that will die on the hill against them. I personally switched to the Yokohama a052 and they are amazing. I’ve seen a lot of buzz around the p1 but from reviews I don’t think the goblin is heavy enough for how much heat they want

 

[SmsDetroit]

I don’t have a good reference point. Haven’t raced on a lot of tires. Seemed like they were the best for the cost and some goblin guys were using them. I think when they wear out I’ll switch to something else

 

[Stretch2126]

I’ve heard and seen a lot of good things on the ao52s if you want to stick to 200tw. Last time I looked they didn’t make one wide enough for my 15x10s though.

 

[Keckster]

I’ve heard and seen a lot of good things on the ao52s if you want to stick to 200tw. Last time I looked they didn’t make one wide enough for my 15x10s though.

Yeah that’s true. I’m on 17x9 running 255s and if I want to go any wider which it seems like I need since the tire is overheating in 1 or 2 autox runs

 

[Markm]

I know nothing about auto cross but it definitely looks appealing. My question is this… if I use the z06 wheels I picked up the other day and go back with the 200 tw tires, would 265 front and 275 rear be too much? The wheels are 18” and those are the factory C6 tire sizes. I looked briefly at tires and didn’t see many options for 18” in anything other than 265 and 275. Next question is how much different would it drive on the street compared to the 225-17 she currently has?

 

[Stretch2126]

I know nothing about auto cross but it definitely looks appealing. My question is this… if I use the z06 wheels I picked up the other day and go back with the 200 tw tires, would 265 front and 275 rear be too much? The wheels are 18” and those are the factory C6 tire sizes. I looked briefly at tires and didn’t see many options for 18” in anything other than 265 and 275. Next question is how much different would it drive on the street compared to the 225-17 she currently has?

You drilled the hubs to 5x120?
I don’t think it would be terribly different on the street. Just remember that the wider tire with a 200tw is great when it’s warm but it won’t like a lot of water.

 

[Rttoys]

I know nothing about auto cross but it definitely looks appealing. My question is this… if I use the z06 wheels I picked up the other day and go back with the 200 tw tires, would 265 front and 275 rear be too much? The wheels are 18” and those are the factory C6 tire sizes. I looked briefly at tires and didn’t see many options for 18” in anything other than 265 and 275. Next question is how much different would it drive on the street compared to the 225-17 she currently has?

I’m on 275 rears, but 245 front. A 265 front might be a little big but you’ll be fine. Do you know how wide the wheels are?

 

[Markm]

I’m on 275 rears, but 245 front. A 265 front might be a little big but you’ll be fine. Do you know how wide the wheels are?

I’m not certain I haven’t measured them

You drilled the hubs to 5x120?
I don’t think it would be terribly different on the street. Just remember that the wider tire with a 200tw is great when it’s warm but it won’t like a lot of water.

i I figured since the vettes run a lot of backspacing I’d end up getting adapters