Kirk180

Hi guys. First and foremost, admittedly I'm no gear expert, but I have searched the forums. Lol. Anyway, I wanted to pose a particular question here for any local track guys to give me their feedback about their experiences on the two tracks I most frequent, PIRC & Mid-Ohio, regarding using different gears. I was wondering if any of my fellow local track guys were running a 4.57 or a 4.44 on an aP1 at PIRC and/or Mid-Ohio? Not really interested in a 4.77. There's two turns at PIRC where I'm in gear trouble to where I'm thinking one of those two would help. However, I'm uncertain if they would only cause a problem elsewhere on the rack. either way it would have to be quicker, no?

Also, if you are running a 4.44 or 4.57 , how is it at Mid-Ohio? I don't want gears to hinder. Or isn't there a downside? Is the pay off worth it?

Finally, I'm probably leaning more toward a 4.44 right now. Thoughts on either?

TIA for any insight.

Singh_snisen

If u think u r good at shifting and are NA go for 477. 477 wount be fun on streets either. Iv tried the 477 and its to short for me. FI I would recommend OEM. 444 is good if u wana build a NA machine that can be driven on track and streets.

bgoetz

Not sure if you have seen this, but it has been tempting the crap out of me since it was posted. I think it might solve your dilemma and mine because I will no longer be tempted.

https://www.s2ki.com/forums/member-s...-diff-1166725/

BlueBarchetta

Which corners are causing issues? Do you have any data, times, corner speeds, etc?

im not real big on changimg to a 4.57. That's a big difference. A cheap way to gain gearing is to run 235/40/17 tires

BlueBarchetta

To further expand on above, 4.10 vs 4.57 is a little more than 10% shorter final drive
4.10 vs 4.44 is around 8%

you can gain 2.5% shorter final drive by using 235/40 tires, vs the 225/45 or 255/40 (prob 2 most popular track sizes).
Trust me that little bit can make a difference. I ran 235/40 BFG R1 at Road America, and HATED them. Too short gearing in corners really killed my times. I switched to a 255/40 NT01 (glorified street tire), and was more than 4 sec a lap faster. The opposite could be true for you at a different place, and considering AP1 vs AP2

FWIW, I think I still have 3 older unused 235 R1 in my basement, I'd nearly give to you if you wanna try that idea.

Kirk180

Correct Blue. I believe the difference is in the point that I drive an AP1. FWIW, my buddy I went to PIRC pro ably 4-5 times with last year tracks an AP2 and he doesn't have that same problem due to different gearing. And after more thought and reading, I wouldn't go 4.57. The only option for me would be a 4.44. But it's not something that's happening by season start. I have too many things to put on and do as is. Anyway, back to the story. My friend runs PIRC maybe a second faster than me sometimes. But we're close to even for the most part. One of the locations at PIRC for me is as you go down into the sink hole on the new south track. If I keep it in third, the rpms are too low, and I'm well out of vtec and then I have to start climbing back up the hill. It sucks that way and my rpms are too low. . But if I go to 2nd then it's pretty high into vtec and I need to shift into third as im finishing the turn and getting ready To start climbing the hill, which kind of dogs it, but not too bad. It's more of a nuisance having to go to 2nd for a whole 2-3 seconds there. And the other location is after the back straight entering the final turn around right hander. I find myself with the same dilemma before you head back up toward the pits and the front straight. Figured a 4.44 closer gear ratio would give me the ability to stay in third there (due to 8% change in gearing), as well as give me a little more push to climb back out of those two spots. Am I making sense? In theory it sounds correct to me. But I haven't tried it.

And as far as the tires go, that's really kind of you to offer. Thanks. I'll have to keep that in mind. However, my fenders are rolled and pulled for these 17x9 rpf1's hauling around 255's. My new Hankook RS4's came in and I'm really eager to try the new rubber. If you still have them after I run through these, I just may take you up on it. Although I'm uncertain if a 235 is good on track with a 9" wheel, and my wheels are 9". What's your thoughts on the wheel size with a 235?

Any feedback is appreciated. Thanks.

Kirk180

Right. Theirs are nice. But I've since ruled out the 4.57. Especially that one if it's louder than the normal noise they make. 4.57's are hit and miss in the noise dept. 4.77's are always louder, I believe. But 4.44's never make noise. Or at least I haven't heard of one yet, and have read that they don't. There's a nice pull video on YouTube that shows a 4.44 from a stock 4.10's final ratio as they race from a rolling start Down the street. 4.44 seems good to me. Looks like it puts a couple cars on him in approx. 1/4 mile.

let me see if this works:


https://www.youtube.com/shared?ci=sjMPK1Uqssw

BlueBarchetta

Any chance you have some video? I do understand the corners and the issues. I have some spare go pros you could try out if you want. Some video from basically over your shoulder, showing speedometer and tach, along with view outside can tell us a lot. I'm not saying it's your driving technique, just that video and data can give us some idea of the extent, speed and tach wise that gearing could help. I haven't had my S on the new course yet, only had the E30 endurance car on it. I do think I have video of the endurance car full course, and also my S on the old course (including TTC lap record). We could do some comparisons.

Do you have any issues at Mid Ohio, if so which corners. I ask these questions, cause gearing is a BIG step, and you wanna get it right the first time.

The 235 tires I have are BFG R1. They are R comp tires. Generally the size ratings of most R comps have no real relation to their actual size. Those 235 tires on a 9" rim will be as wide as your 255's. In my garage I have 4 NT01's on 9" rims stacked up. Right next to them are 4 Hoosier R7, 225's on 9" rims. The stacks are exactly the same height.

If you wanna feel better, you should go to Gingerman in Michigan. AP1 there is much easier to drive. You only shift like 4 times on the whole course, vs like 14 for AP2.

Kirk180

I have a GoPro; which reminds me, I need to restore the software on it. It went rogue on me halfway through last season. GoPRo was aware fo the issue, but it wasn't going to be resolved for a while, so I just quit using it. Regardless, I don't have any good footage now. But I'll be recording again this season. Then again, before I get too wrapped up on those turns, perhaps the new squared set up with RS4's and such will help me carry higher speeds in those areas, those not making it such an issue anymore. Guess I'll know more on how the car now handles those areas, after my May 1st track day there. Thanks again for the feedback.

ajohnson

Ap1 gearbox with 4.77 rear is perfect for mid Ohio. I've got video here. Not my best session but this is only my 3rd session in the car.

https://youtu.be/oYIJzoi9KA8