AutoCrossing a 997.1or.2 C4S
06-21-2011, 11:50 PM
#46
So, my dad has been looking more and definately likes the option of the 40th 996, but one of the questions I have is the wheel sizes. Since, the 40th was a set package, were there actually any options in the wheels? The 911 is nice with wheels since so many different options are available from factory that you could normally pick from within the rules. With the 40th are you stuck to the 18X8s and 18X10s? Or can you go to the wider 9s and 11s?
Thanks. This has been helpful so far. Now just finding a good used car out there is the hard part. Some people are listing them quite high.
Thanks. This has been helpful so far. Now just finding a good used car out there is the hard part. Some people are listing them quite high.
https://rennlist.com/forums/autocros...autocross.html
The factory order guide for the 996 40th does not list any wheel options for the 40th.
06-22-2011, 12:12 AM
#47
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The 40th is stuck with 8", 10".
https://rennlist.com/forums/autocros...autocross.html
The factory order guide for the 996 40th does not list any wheel options for the 40th.
https://rennlist.com/forums/autocros...autocross.html
The factory order guide for the 996 40th does not list any wheel options for the 40th.
06-22-2011, 01:23 AM
#48
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I believe all the options for the C4S were 18x8 / 18x11. The Sport Techno wheel was weird in that it had a ET63 offset with factory 17mm spacer, making the end result only 1mm different than the normal or GT3 wheel. I think the C4S default wheels were solid turbo twists.
The C4S does have a little advantage in having 1" wider rear wheels, but the fronts are the same width. More important might be possible differences in how much tire could be stuffed in the fronts given the slightly different front suspension setup. I also think the 40th's LSD trumps an extra wheel inch, plus that width comes at the expense of ~2.3" of overall body width. That may improve handling in general, but for pure autocross you want a lot of benefit for any additional car width.
The C4S does have a little advantage in having 1" wider rear wheels, but the fronts are the same width. More important might be possible differences in how much tire could be stuffed in the fronts given the slightly different front suspension setup. I also think the 40th's LSD trumps an extra wheel inch, plus that width comes at the expense of ~2.3" of overall body width. That may improve handling in general, but for pure autocross you want a lot of benefit for any additional car width.
06-23-2011, 08:11 PM
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I believe all the options for the C4S were 18x8 / 18x11. The Sport Techno wheel was weird in that it had a ET63 offset with factory 17mm spacer, making the end result only 1mm different than the normal or GT3 wheel. I think the C4S default wheels were solid turbo twists.
The C4S does have a little advantage in having 1" wider rear wheels, but the fronts are the same width. More important might be possible differences in how much tire could be stuffed in the fronts given the slightly different front suspension setup. I also think the 40th's LSD trumps an extra wheel inch, plus that width comes at the expense of ~2.3" of overall body width. That may improve handling in general, but for pure autocross you want a lot of benefit for any additional car width.
The C4S does have a little advantage in having 1" wider rear wheels, but the fronts are the same width. More important might be possible differences in how much tire could be stuffed in the fronts given the slightly different front suspension setup. I also think the 40th's LSD trumps an extra wheel inch, plus that width comes at the expense of ~2.3" of overall body width. That may improve handling in general, but for pure autocross you want a lot of benefit for any additional car width.
07-10-2011, 11:29 PM
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Well thanks for all the help guys. My dad got a 996 40th and took it out to its first autox today and I co-drove it with him. It was a blast to drive and a fun departure from my usually STR MX-5.
A few points I noticed:
I did not find the car that difficult to drive fast as everyone makes it seem. I also found it quite easy to correct the rear coming out. My MX-5 was much worse on both accounts with stock suspension.
The car was rather difficult to really feel the limits, but I got most of the way there with trial and error.
The PS2s didn't impress me. They seemed to have a lot less grip than the Hankook RS3s, but a MX-5 to 911 is apples to oranges as 225 just isn't enough front tire for the 911. The PS2s would just squeal like crazy the entire run.
The LSD worked great. I drove it once with the PSM on and couldn't stand it. An unhindered car with an LSD is the way to go.
Finally my dad has spent too much time driving FWD and he needs more practice, but he did pretty well with the extreme change!
A few points I noticed:
I did not find the car that difficult to drive fast as everyone makes it seem. I also found it quite easy to correct the rear coming out. My MX-5 was much worse on both accounts with stock suspension.
The car was rather difficult to really feel the limits, but I got most of the way there with trial and error.
The PS2s didn't impress me. They seemed to have a lot less grip than the Hankook RS3s, but a MX-5 to 911 is apples to oranges as 225 just isn't enough front tire for the 911. The PS2s would just squeal like crazy the entire run.
The LSD worked great. I drove it once with the PSM on and couldn't stand it. An unhindered car with an LSD is the way to go.
Finally my dad has spent too much time driving FWD and he needs more practice, but he did pretty well with the extreme change!
07-11-2011, 03:23 PM
#51
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Congrats on the purchase, and you got the 40th for less than I paid for my C4S (admittedly mine had 20k miles when I bought it, and I now know I overpaid some). Glad to hear you're autocrossing it and that it was fun to drive.
Having driven my old 96 stock Miata and my Subaru STi at the same event, way back when, they're totally different beasts just because of the massive weight and power differences. Not to mention that the course looks different from a foot closer to the ground. After driving the STi for a while, during one of the short straights with the Miata I literally looked down to make sure my foot was pushing the throttle all the way down. Plenty of time to precisely place the car where I want it, and not much braking due to (1) lower speed, and (2) 1000 fewer pounds. The old 1969 911 I autocrossed at one event was similar.
New tires wouldn't hurt, either race tires or a better autocross street tire (e.g. RS3 or AD08).
I wish I had an LSD in mine. I haven't been troubled much by PSM however, the times I've run with it on, either not feeling it at all or just once very briefly during a run. Nothing like the 350Z that was in your face non-stop even when just doing a slalom. It reminds me most of the Z06's 'Competition' mode which lets you get the car fairly wild before it'd rein things in (a Z06 on street tires is ridiculously easy to get wildly out of shape in). The last 4 to 5 events I've had it off every run so can't compare. I also suspect that PSM may not be identical across all models and years of 996's.
Having driven my old 96 stock Miata and my Subaru STi at the same event, way back when, they're totally different beasts just because of the massive weight and power differences. Not to mention that the course looks different from a foot closer to the ground. After driving the STi for a while, during one of the short straights with the Miata I literally looked down to make sure my foot was pushing the throttle all the way down. Plenty of time to precisely place the car where I want it, and not much braking due to (1) lower speed, and (2) 1000 fewer pounds. The old 1969 911 I autocrossed at one event was similar.
New tires wouldn't hurt, either race tires or a better autocross street tire (e.g. RS3 or AD08).
I wish I had an LSD in mine. I haven't been troubled much by PSM however, the times I've run with it on, either not feeling it at all or just once very briefly during a run. Nothing like the 350Z that was in your face non-stop even when just doing a slalom. It reminds me most of the Z06's 'Competition' mode which lets you get the car fairly wild before it'd rein things in (a Z06 on street tires is ridiculously easy to get wildly out of shape in). The last 4 to 5 events I've had it off every run so can't compare. I also suspect that PSM may not be identical across all models and years of 996's.
07-11-2011, 03:27 PM
#52
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No real shocker there. The PS2 is not in the same league as the RS3. I'm running a set of RS3s on my GT3 currently (because RE11s were back-ordered). They're nice, but I miss my RE11s.
07-11-2011, 06:58 PM
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I didn't think Hankook made any of the right sizes for the 911s. What are you running?
07-11-2011, 07:09 PM
#54
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You can get the Hankook EVO 112 as well as the Hankook RS-3 in 997 sizes. I've got the RS-3 currently.
The PS2 is just a run-of-the-mill street tire. Nothing special other than Michelin have paid/arranged to have them tested for Porsche's "N Specification."
The Michelin Pilot Sport Cup (factory fitment on the GT3 along with the Pirelli Corsa System tires) is their more track-focused tire that's closer to an R Comp. I'm not a fan of the MPSC either, but some people seem to like them.
The PS2 is just a run-of-the-mill street tire. Nothing special other than Michelin have paid/arranged to have them tested for Porsche's "N Specification."
The Michelin Pilot Sport Cup (factory fitment on the GT3 along with the Pirelli Corsa System tires) is their more track-focused tire that's closer to an R Comp. I'm not a fan of the MPSC either, but some people seem to like them.
07-11-2011, 08:05 PM
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The C4S is a little harder to fit because the 11" rear wheels really would prefer a 295 or larger tire. With 10" wheels you have a lot of choices, including in theory running 285/30-18's V710's all around (I think you'd have a bear of a time getting them in the front, but it's been done). Most of the street tires come in 275 or 285 widths which will fit your 10" rears well. The R-1R I believe maxes out at 265/35-18 which is pretty skinny. On the other hand, Hankook R-S3s in something like 285/35 rear - 245/40 front would seem like a decent choice (with arguments about 235 vs. 245 vs. 255 vs 265 for the fronts).
You can find a fair number of threads online as well as look at places like Grassroots Motorsports for tire ideas. There are quite a few tires that come up a lot, and a lot of tires that nobody ever tests. Now the latter may be because of size availability or price, but for high end autocross I really doubt price would stop everyone from running a tire if it were actually faster. I was listening to the Lincoln national tour audio one weekend and heard "Since it started raining, everyone in ST has put on the Toyo [R-1R] tires. [...] It looks like the water is clearing up for this heat, and it seems most of the 70+ drivers are putting their Hankook's [RS3] back on." It's pretty clear what they think the fastest tires are.
Just a guide, other people will have different opinions, you can find lots of tests, reviews, and comparisons. I've personally autocrossed on PZeros, Hankook RS2s, Yokohama AD08s, Toyo RA-1, Kumho Ecsta and V710, Hoosier A3S04, Falken Azenis, Michelin all-seasons, and various Bridgestones. There are lots of tires I've not driven.
Hankook RS3 - seems to be the street tire choice this year
Toyo R-1R - a bit faster in the wet, a bit slower in the dry
Bridgestone RE-11 - a good all-around tire
Dunlop Star Spec - popular last year, not so much this year. Still a good tire.
Kumho Ecsta XS - arguably the fastest tire in the hot and dry, lots of sizes. Horrible in the wet or cold, based on comments from people who have driven on them and know what that means.
Yokohama AD08 - expensive, a good compromise tire (good at everything, but beat by another tire in any one area)
Pirelli PZero - expensive and I've never seen it in an autocross tire test nor seen anyone intentionally use them for autocross
Michelin PS2 - ditto. I'm sure it's a great street tire. (See this Car and Driver test for some more info)
Michelin Pilot Super Sport - too new. Probably a great street tire, expensive, and probably not a top 5 autocross tire
Sumitomo HTR ZIII - cheap! Supposed to be a good summer street tire. Not an autocross tire.
Hankook V12 Evo K110 - ditto above
Toyo RA-1 - an R compound, not an autocross tire but should be quite a bit better than any of the street tires (debatable given the RA-1's age, but I think still true). Really, really bad treadwear for street use
Toyo R888 - similar to above but the treadwear looks scary in the rain.
Nitto - similar
Edit: in case it isn't obvious, Hoosier A6's and Kumho V710s are the only two tires to consider to be maximally competitive. Anything else is giving up a non-trivial amount of time unless it's raining. 1.5-2 seconds per 60 seconds is about the difference between the A6/V710 autocross tires and a good street tire like the RS3. A good street tire like the RS3 will probably be 1-2 seconds faster than a mid-range tire like the PS2 though that's much more debatable (also consider if the PS2's are just worn out). Those are my personal experiences switching tires, what I've seen from others when they switch tires, internet lore (often dubious), and the race-tire vs. street tire difference has been studied pretty extensively by Rick Ruth as well as others with the number derived from data early this year equal to about 1.5s / 60s for R comps (A6) vs. street (RS3 etc.) tires.
You can find a fair number of threads online as well as look at places like Grassroots Motorsports for tire ideas. There are quite a few tires that come up a lot, and a lot of tires that nobody ever tests. Now the latter may be because of size availability or price, but for high end autocross I really doubt price would stop everyone from running a tire if it were actually faster. I was listening to the Lincoln national tour audio one weekend and heard "Since it started raining, everyone in ST has put on the Toyo [R-1R] tires. [...] It looks like the water is clearing up for this heat, and it seems most of the 70+ drivers are putting their Hankook's [RS3] back on." It's pretty clear what they think the fastest tires are.
Just a guide, other people will have different opinions, you can find lots of tests, reviews, and comparisons. I've personally autocrossed on PZeros, Hankook RS2s, Yokohama AD08s, Toyo RA-1, Kumho Ecsta and V710, Hoosier A3S04, Falken Azenis, Michelin all-seasons, and various Bridgestones. There are lots of tires I've not driven.
Hankook RS3 - seems to be the street tire choice this year
Toyo R-1R - a bit faster in the wet, a bit slower in the dry
Bridgestone RE-11 - a good all-around tire
Dunlop Star Spec - popular last year, not so much this year. Still a good tire.
Kumho Ecsta XS - arguably the fastest tire in the hot and dry, lots of sizes. Horrible in the wet or cold, based on comments from people who have driven on them and know what that means.
Yokohama AD08 - expensive, a good compromise tire (good at everything, but beat by another tire in any one area)
Pirelli PZero - expensive and I've never seen it in an autocross tire test nor seen anyone intentionally use them for autocross
Michelin PS2 - ditto. I'm sure it's a great street tire. (See this Car and Driver test for some more info)
Michelin Pilot Super Sport - too new. Probably a great street tire, expensive, and probably not a top 5 autocross tire
Sumitomo HTR ZIII - cheap! Supposed to be a good summer street tire. Not an autocross tire.
Hankook V12 Evo K110 - ditto above
Toyo RA-1 - an R compound, not an autocross tire but should be quite a bit better than any of the street tires (debatable given the RA-1's age, but I think still true). Really, really bad treadwear for street use
Toyo R888 - similar to above but the treadwear looks scary in the rain.
Nitto - similar
Edit: in case it isn't obvious, Hoosier A6's and Kumho V710s are the only two tires to consider to be maximally competitive. Anything else is giving up a non-trivial amount of time unless it's raining. 1.5-2 seconds per 60 seconds is about the difference between the A6/V710 autocross tires and a good street tire like the RS3. A good street tire like the RS3 will probably be 1-2 seconds faster than a mid-range tire like the PS2 though that's much more debatable (also consider if the PS2's are just worn out). Those are my personal experiences switching tires, what I've seen from others when they switch tires, internet lore (often dubious), and the race-tire vs. street tire difference has been studied pretty extensively by Rick Ruth as well as others with the number derived from data early this year equal to about 1.5s / 60s for R comps (A6) vs. street (RS3 etc.) tires.
Last edited by Yomi; 07-12-2011 at 10:39 PM. Reason: Add Car and Driver test link, add last paragraph
07-11-2011, 09:57 PM
#56
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Thats interesting. The RS3s have some tires that would work, but they you would be increasing your tire OD by 2-3%. Not a huge deal, I guess thats about what I ended up doing in my MX5 anyways.
My dad will have to decide what he wants to do with tires. Based on everyone agreeing that the PS2s aren't that good, I'm pretty happy with what I got out of the car. If he decided to spring for hoosiers, I don't doubt that it would be very competitive. First hes got to learn how to drive faster.
Again, thanks for all the help directing us to that car. Its quite a bit of fun and hes very happy with it so far.
My dad will have to decide what he wants to do with tires. Based on everyone agreeing that the PS2s aren't that good, I'm pretty happy with what I got out of the car. If he decided to spring for hoosiers, I don't doubt that it would be very competitive. First hes got to learn how to drive faster.
Again, thanks for all the help directing us to that car. Its quite a bit of fun and hes very happy with it so far.
07-16-2011, 10:44 AM
#58
Hankook RS3 - seems to be the street tire choice this year
Toyo R-1R - a bit faster in the wet, a bit slower in the dry
Bridgestone RE-11 - a good all-around tire
Dunlop Star Spec - popular last year, not so much this year. Still a good tire.
Kumho Ecsta XS - arguably the fastest tire in the hot and dry, lots of sizes. Horrible in the wet or cold, based on comments from people who have driven on them and know what that means.
Yokohama AD08 - expensive, a good compromise tire (good at everything, but beat by another tire in any one area)
Pirelli PZero - expensive and I've never seen it in an autocross tire test nor seen anyone intentionally use them for autocross
Michelin PS2 - ditto. I'm sure it's a great street tire. (See this Car and Driver test for some more info)
Michelin Pilot Super Sport - too new. Probably a great street tire, expensive, and probably not a top 5 autocross tire
Sumitomo HTR ZIII - cheap! Supposed to be a good summer street tire. Not an autocross tire.
Hankook V12 Evo K110 - ditto above
Toyo RA-1 - an R compound, not an autocross tire but should be quite a bit better than any of the street tires (debatable given the RA-1's age, but I think still true). Really, really bad treadwear for street use
Toyo R888 - similar to above but the treadwear looks scary in the rain.
Nitto - similar
Edit: in case it isn't obvious, Hoosier A6's and Kumho V710s are the only two tires to consider to be maximally competitive. Anything else is giving up a non-trivial amount of time unless it's raining. 1.5-2 seconds per 60 seconds is about the difference between the A6/V710 autocross tires and a good street tire like the RS3. A good street tire like the RS3 will probably be 1-2 seconds faster than a mid-range tire like the PS2 though that's much more debatable (also consider if the PS2's are just worn out). Those are my personal experiences switching tires, what I've seen from others when they switch tires, internet lore (often dubious), and the race-tire vs. street tire difference has been studied pretty extensively by Rick Ruth as well as others with the number derived from data early this year equal to about 1.5s / 60s for R comps (A6) vs. street (RS3 etc.) tires.
Toyo R-1R - a bit faster in the wet, a bit slower in the dry
Bridgestone RE-11 - a good all-around tire
Dunlop Star Spec - popular last year, not so much this year. Still a good tire.
Kumho Ecsta XS - arguably the fastest tire in the hot and dry, lots of sizes. Horrible in the wet or cold, based on comments from people who have driven on them and know what that means.
Yokohama AD08 - expensive, a good compromise tire (good at everything, but beat by another tire in any one area)
Pirelli PZero - expensive and I've never seen it in an autocross tire test nor seen anyone intentionally use them for autocross
Michelin PS2 - ditto. I'm sure it's a great street tire. (See this Car and Driver test for some more info)
Michelin Pilot Super Sport - too new. Probably a great street tire, expensive, and probably not a top 5 autocross tire
Sumitomo HTR ZIII - cheap! Supposed to be a good summer street tire. Not an autocross tire.
Hankook V12 Evo K110 - ditto above
Toyo RA-1 - an R compound, not an autocross tire but should be quite a bit better than any of the street tires (debatable given the RA-1's age, but I think still true). Really, really bad treadwear for street use
Toyo R888 - similar to above but the treadwear looks scary in the rain.
Nitto - similar
Edit: in case it isn't obvious, Hoosier A6's and Kumho V710s are the only two tires to consider to be maximally competitive. Anything else is giving up a non-trivial amount of time unless it's raining. 1.5-2 seconds per 60 seconds is about the difference between the A6/V710 autocross tires and a good street tire like the RS3. A good street tire like the RS3 will probably be 1-2 seconds faster than a mid-range tire like the PS2 though that's much more debatable (also consider if the PS2's are just worn out). Those are my personal experiences switching tires, what I've seen from others when they switch tires, internet lore (often dubious), and the race-tire vs. street tire difference has been studied pretty extensively by Rick Ruth as well as others with the number derived from data early this year equal to about 1.5s / 60s for R comps (A6) vs. street (RS3 etc.) tires.
Just a couple of items to add to the discussion:
GRM just did an autocros street tire test last month, and the RS3 was significantly faster than all others. I wonder if they changed the compound recently?
I would be wary of any tire calculators. Many manufacturer's use huge numerical rounding (or stretch the truth) in designating a tire size. CAse in point: AD08's are well known to run wide for the size that is specified on the side wall. Tire Rack has specification tables showing detail dimensions on all of the performance tires they sell, and I would use that for checking tire dimensions.
