Got a track related question? I'll try to answer.

[Azzudien]

Originally Posted by DocWalt

I went from the stock 215 Primacies to 245 RE-71Rs and exited the final corner of a local track 10mph faster. I got to the other end of the straight and was only 1-2 mph faster than the 215s. That's a huge amount of speed to give up on every straight.

But you gained a lot of speed in the corner. These cars are definitely momentum cars, so the more speed you can carry out of the turns the better.

Did your lap times on that track decrease with the tire upgrade?

[DocWalt]

Originally Posted by Icecreamtruk

Do you recall how long was that straight?

I was full throttle for ~2000 ft.

Originally Posted by Azzudien

But you gained a lot of speed in the corner. These cars are definitely momentum cars, so the more speed you can carry out of the turns the better.

Did your lap times on that track decrease with the tire upgrade?

They sure did (I also did coilovers, so who knows how much the tires gained), but that wasn't really my point. I was just saying that wider tires definitely make a measurable difference on straight line speed. There's a balance for every track of what works best at some given power level, I'm sure. If you're stock power and on a big wide open track like Spa I guarantee the wide 245s would be slower.

FWIW I likely could have set faster lap times with a bit narrower, but stickier tires. RE-71Rs are 200 treadwear street tires... not R comps.

[Icecreamtruk]

Originally Posted by DocWalt

I was full throttle for ~2000 ft.

Thanks for the info.

Originally Posted by DocWalt

RE-71Rs are 200 treadwear street tires... not R comps.

They might not be, but they stick just as much, they just dont handle prolonged heat. Besides the point I know, just saying.

[CSG Mike]

Originally Posted by DocWalt

I was full throttle for ~2000 ft.



They sure did (I also did coilovers, so who knows how much the tires gained), but that wasn't really my point. I was just saying that wider tires definitely make a measurable difference on straight line speed. There's a balance for every track of what works best at some given power level, I'm sure. If you're stock power and on a big wide open track like Spa I guarantee the wide 245s would be slower.

FWIW I likely could have set faster lap times with a bit narrower, but stickier tires. RE-71Rs are 200 treadwear street tires... not R comps.

You might be shocked if you go from "200TW" 71R to a "100TW" R-comp...

[DocWalt]

Originally Posted by CSG Mike

You might be shocked if you go from "200TW" 71R to a "100TW" R-comp...

I know guys, I know. Sorry, it was kind of a joke

I have never driven a "proper" R comp, but everyone that's ridden with me assumed I had R comps until we got out and looked at them.

Also, yes, the RE-71Rs get greasy towards the end of sessions. Meh. The BRZ is light and even at 10/10ths in ~80 F heat they were fine for ~20 minutes of a 30 minute session. Granted, narrower tires wouldn't handle the heat as well

[redlined600]

Is there any consensus on adding a wing and splitter to a n/a car(180-200hp range)? Is the increased cornering worth the straight line hit? I understand it will be track dependent but in general?

[lutfy]

Originally Posted by redlined600

Is there any consensus on adding a wing and splitter to a n/a car(180-200hp range)? Is the increased cornering worth the straight line hit? I understand it will be track dependent but in general?

I put the Apr 200 wing and front splitter. Luckily I gathered data at Summit Point. The car felt planted and pinned post spolier but I was stunned I gained 1/10 of a sec. the speeds at the straight was compromised.

At VIR was able to stay floored at places it was not possible before.

In retrospect I find the car to be more fun and confidence inspiring and would do it again.

Hard to say if it's a win win but certainly track dependent.

Lutfy


Sent from my iPhone using Tapatalk

[redlined600]

Any other experience with wings on an/a car?

[Tofurky]

Would there be any noticeable difference in handling feel in a 245/45/17 and a 245/40/17. If yes, how would you describe it?

[FirstWinter]

Originally Posted by Tofurky

Would there be any noticeable difference in handling feel in a 245/45/17 and a 245/40/17. If yes, how would you describe it?

Softer sidewall with the 245/45 so a little more flex. Your gearing would be affected as well slightly.

[CSG Mike]

Originally Posted by Tofurky

Would there be any noticeable difference in handling feel in a 245/45/17 and a 245/40/17. If yes, how would you describe it?

You want the 40 profile.

45 will have a taller sidewall, but more importantly, have a SOFTER sidewall with a lower load rating.

It'll feel squishy and less responsive.

[Lunatic]

Originally Posted by redlined600

Any other experience with wings on an/a car?

I had a cheap cosmetic wing break in half going into turn 8 at Willow Springs at !20 MPH. Boy was I surprised how well it was actually working!

[Jamestl]

Spent the weekend at Gingerman and had a great time. The group of twins didn't fair so well... One grenaded the block (engine internals was visible and a decent chunk of metal was found...), one wore brake pads down to the backplate (Ferodo 2500 -- apparently only lasted 4ish track days), one corded the tires and had to get crappier tires for the second day, and I had an ignition coil CEL. Thankfully I brought an extra coil just in case, and since it was #2 I was able to replace during lunch without losing a session...

Onto the question - there were a lot of hard right handers at Gingerman and the right left is worn pretty good. Looking at the pictures you can see that the first one is driver rear and driver front (L to R). The second picture shows the passenger side front and read. The last picture shows all together. You can see the edges of the driver front is worn so my question is what i should do with the tire. It looks like I should still be able to get a few days out of the tire, so should I have them remounted and just go swap left with right? Will that pose any safety risk? Thanks!!

[86Craze]

Someone please recommend some video or reading material on autocross driving. Theory, technique, selecting proper driving line for any track, etc etc. Thanks.