The r3v autocross video thread

[Ocell]

Thanks. I was pretty far down in the pack. My tires are pretty used up, but I think my technique has a long way to grow too.

https://axwaresystems.com/axorm/files/SPOKES/event1_raw.htm

[nyy e90]

15x8's with 205/50 shouldn't be a problem. It's usually 225 and above where you run into issues.

205's will fit on a 7 but will perform better on an 8 like wise 225's will fit on an 8 but perform better on a 9. General rule is 195's on a 7, 205's on an 8, and 225's on a 9.

Do you have anymore info on why a 205 will perform better on a 15x8 than a 225? (I heard there was a recent article about it on Grassroots Motorsports but couldn't find the link). There is a lot of other info out there that says get the wider tire size for your wheel.

Any info or articles/threads about it are much appreciated. I'm ready to pull the trigger on a new setup

Thanks

[Wh33lhop]

Do you have anymore info on why a 205 will perform better on a 15x8 than a 225? (I heard there was a recent article about it on Grassroots Motorsports but couldn't find the link). There is a lot of other info out there that says get the wider tire size for your wheel.

Any info or articles/threads about it are much appreciated. I'm ready to pull the trigger on a new setup

Thanks

Basically if you put too wide a tire on a wheel the sidewalls won't be reinforced as well by the wheel and the tread won't stay flat on the ground. The slight stretch of a 205 on an 8" wheel will box the sidewalls in better and give the tire a more solid structure. Also with a wider tire you tend to pick up a bit of extra unsparing mass and rolling/wind resistance that doesn't matter THAT much but does matter. IIRC the 205 wasn't much faster, but going up to a 225/45 rival on a 15x8 doesn't seem to have an overall performance benefit over a 205/50.

[klodkrawler05]

My first auto-x in the e30 was our last one of the year in November, I'm looking forward to running it more this year on 275/35/15 hoosiers and 10" wide wheels vs the 8.5" wide with 225 wide kumho all seasons:

[Wh33lhop]

My first auto-x in the e30 was our last one of the year in November, I'm looking forward to running it more this year on 275/35/15 hoosiers and 10" wide wheels vs the 8.5" wide with 225 wide kumho all seasons:

Terrible first run, lol. Last two were much improved though. Wish we had big-ass courses like that around here.

What is the car sitting on? That's a lot of body roll for all-seasons, it'll only get worse with man tires.

[Bullet Ride]

I guess I can contribute. Here are a couple of runs from an event I did last year on the old Mosport DDT track, it's since been demo'd and rebuilt into a longer and wider road course. I never did get any interior shots of my runs...

[klodkrawler05]

Terrible first run, lol. Last two were much improved though. Wish we had big-ass courses like that around here.

What is the car sitting on? That's a lot of body roll for all-seasons, it'll only get worse with man tires.

Indeed, it'd been a long summer getting it running and after driving a ES miata all year having some power took a bit of adjustment :o

it was on Koni yellows, with ground control coil conversion (thanks PO) and crappy ebay springs that said 300lb front and 227lb rear (curse you PO) with no sway bar front or rear.

This season in addition to the wider rolling stock I've picked up 513lb front and 650lb rear eibach springs, as well as a 22mm front sway bar so the roll stiffness should now match the grip levels ;)

[tinkerputzer]

Basically if you put too wide a tire on a wheel the sidewalls won't be reinforced as well by the wheel and the tread won't stay flat on the ground. The slight stretch of a 205 on an 8" wheel will box the sidewalls in better and give the tire a more solid structure. Also with a wider tire you tend to pick up a bit of extra unsparing mass and rolling/wind resistance that doesn't matter THAT much but does matter. IIRC the 205 wasn't much faster, but going up to a 225/45 rival on a 15x8 doesn't seem to have an overall performance benefit over a 205/50.

Well put. I think the 205 and 225 had the same average lap time but the 205 had much sharper and precise handling characteristics. Basically over tiring a wheel gains you nothing but numbness.

Nyy e90, it's pretty hard to find grm articles online unless someone has taken the time to scan them. Grm is a worthwhile magazine to subscribe to plus you get access to all the archived issues online. The miata guys have beat this subject to death. Should be able to find some good threads from them.

[nyy e90]

Basically if you put too wide a tire on a wheel the sidewalls won't be reinforced as well by the wheel and the tread won't stay flat on the ground. The slight stretch of a 205 on an 8" wheel will box the sidewalls in better and give the tire a more solid structure. Also with a wider tire you tend to pick up a bit of extra unsparing mass and rolling/wind resistance that doesn't matter THAT much but does matter. IIRC the 205 wasn't much faster, but going up to a 225/45 rival on a 15x8 doesn't seem to have an overall performance benefit over a 205/50.

Thank you both, that makes perfect sense. Very helpful...

I went ahead and pulled the trigger on that setup. Will report back after the next HPDE or at the next autocross

Sorry to hijack the thread, carry on

[Gary Horneck]

Our season started yesterday with a Test n Tune event. I got 20 runs in 3 hrs, my times were all identical once it warmed up into the 60's.



Then I went home, swapped wheels and took the car to our first Rallycross of the season today.

[Wh33lhop]

Nice! I've always wanted to rallycross but can't bring myself to put any of my cars through that at the moment. :(

Did a really tight course with the moosestang today, fun. You can hear me swear when I hit a cone 2 seconds into the run in this one, lol. Super clean and tidy the whole day until the third cone on my fastest run. Wound up losing by 5 hundredths to my codriver. Can't win em all!

Here's the scratch run

[agent]

I'm jealous seeing these courses that are not set up specifically for Miatas and Boxsters.

[tinkerputzer]

Our season started yesterday with a Test n Tune event. I got 20 runs in 3 hrs, my times were all identical once it warmed up into the 60's.

Nice! Jealous you get that many runs in!

Did a really tight course with the moosestang today, fun. You can hear me swear when I hit a cone 2 seconds into the run in this one, lol. Super clean and tidy the whole day until the third cone on my fastest run. Wound up losing by 5 hundredths to my codriver. Can't win em all!

Nice square waves :) Wow, that tall gearing and low end grunt looks like a blast!

I'm jealous seeing these courses that are not set up specifically for Miatas and Boxsters.

What makes a course specific to miatas and boxters? A little on the tight side?

[Ocell]

I love that rallycross video! That looks like so much fun.

I stuck my GoPro on my helmet this weekend. This wasn't my quickest run, but it was probably the most fun. We had a cold front drop the temp about 40 degrees during the event, and it rained during the first heat, so grip was a bit of an issue.

[matthugie]

I tried to take some video from the season's 1st autox Saturday, but didn't notice that my GoPro was set to photograph rather than video so I just got random pictures at the start and finish lines... I'll make sure I get some videos up of the next one, we have some good courses around here.