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I know you are, but what am I?

still driving, still in that pointless pursuit of lower laptimes... 🤣

The RT660 is an outdated compound in 2024; it has also shown to suffer from alarmingly severe cases of delamination under track use. I would strongly recommend you consider better 200TW autox/track tires like the Bridgestone RE71RS, the Kumhos V730, and the Nankang CR-S v2. The Advan A052 remains a top contender if you want maximum speed / grip and don't mind how much the tires cost and how fast they wear. All of the fastest current-gen 200TW tires are significantly oversized compared to their listed width. The 255/40 RT660s I ran on 9.5" wheels required significant fender rolling front and rear and they still rubbed under certain conditions.

@@panda_exprs Good to know about the RT660s! Is there a wheel / tire combo that you'd recommend for my 1998 m3? I'm looking for a 200tw tire on Kosei k1 8.5s (but I'm open to other wheel options). I do about 4 -6 HPDE weekends/ year. The car would pretty much be only driven back and forth to the track with possibly some nice weather mountain driving. Probably 245/40/17s square, but just want to be prepared to know the right sized spacers I'd need (if I would need them) with the 245s.

Can't remember what spacers I used (the car is gone) and the exact offset needed will depend on camber, caster, how well you've rolled/pulled the fenders, the exact tire you're running (different brand tires in the same nominal size aren't the same size IRL), your ride height, your spring rate, your offset bushings, etc etc. Buy or borrow a bunch of 3mm, 5mm, and 10mm 5x120 spacers and be prepared to experiment

@@panda_exprs Super helpful (especially about having the variety of spacers on hand), thanks!

Appreciate the feedback! I try to remember that right line > using more throttle, but with a higher-horsepower car, the urge to use the right pedal injudiciously is strong for me...

Glad you enjoyed it. While driving the car on track, my attention is otherwise occupied, so having recorded this video with the close-micced exhaust sound is really enjoyable for me to be able to hear too, especially since I no longer own the car. ☹️

stock cam

295/35-18 will fit up front w OE dampers on 10.5" +20 wheels 3 deg. camber, but the issue is the 295/35 size is tall, so the tire will rub the fender liners badly when you try to turn. I've extensively reshaped the fender liners (heat gun) to gain clearance plus trimmed a little metal behind them on the back side (toward the passenger compartment) to get very tall and wide tires like 305/30-19s (mostly) clear while turning.

@@panda_exprs thanks for the reply. Do you have ig. Would love to follow to Get some advice on building my car.

@@joellafortune2889 @panda_exprs

No, each O2 sensor has its own connector.

@@EGbeater Got it. Found all 4 connectors( upstream and downstream). Now I have to replace bank 2 upstream sensor as the dealer tested it and it is faulty. This explains why I am getting an error code of Bank 2 too lean and the 4/5/6 plugs are fouled. The bank 2 is getting too much fuel due to the bad O2 sensor.

Thank you. Hoping to get into the 1:55s with a fresh set of 200TW tires and a on cool day...

The A052 is softer and stickier than the old (now discontinued) RE71R, but there's no free lunch; the A052 wears faster and overheats easily. The A052 doesn't have the precision and steering feedback of the old RE71R though. The RT660 works well overall but isn't as fast as a fresh, cool A052. The new Bridgestone RE71RS looks very promising, but I haven't seen tests that prove that it'll be as quick as the A052... but people running the RE71RSs at local autocross events recently are very fast on them.

Good question about the mounting location of the Qstarts GPS... I don't remember, but it might have been duct-taped to the roof or exterior glass. These days, I use an Arkon BT010 universal suction platform and mount it inside the windshield: www.arkon.com/product/BT010-radar-detector-ez-pass-suction-mount.html

Who?? I don't recognize you.

That's because we all look alike. :)

It's a lot easier to get on those apexes/curbing on four wheels than on two, like you used to do!

Thanks, this was my first time on this set of tires and I left a lot out there being a little cautious... then conditions got worse (hotter, windier, greasier) later in the day and I never dropped the full second I'm convinced is possible.

On 275/35-18s on a heavy car (mine is about 3800-3830 w me in it, 5/8-full tank of gas, depending on the wheel & tire package) I think 36-38 psi F and 34-36 psi R fully hot is good. With wider wheels and tires, say 295/30-18 F and 295/35-18 R, the larger air volume inside the tire allows you to run less pressure with still-adequate load capacity, which makes the contact patches a little bigger... aim for 34.5-36.5 F, 32.5-34.5 R hot. Note that tire pressures typically rise after a track session from dead cold before hitting the track by 6-9 psi. Useful website for considering specific tire sizes, tire pressures, and load capacity: tirepressure.com/tire-sizes

@@EGbeater Thanks will give it a shot. What groups do you run with? I'm planning on a few days this year with BMWCCA and PCA. Maybe see you out there one of these days!

@@coureurdecourse I instruct with BMWCCA and NASA but also run Time Trials with SCCA, and I am at HPR for the random open lapping day as well. But, as always, my track driving is budget (tire and brake pad)-limited...

Thanks for sharing your clip; your Tesla has some very impressive cornering grip/min speeds in corners for a 4300-lb car and only being on 255 Nankang AR-1s! For example, in T5 of your lap 3 (1:42.99) your data shows min speed is 76 mph; for me on the RE71Rs (2019 date code, pretty heat cycled) I drop all the way down to 69 mph in T5... even on Hoosiers last year (even more ancient, lol) in T5 I still dropped to 72 mph. I need to carry a lot more speed through the faster corners to go faster. Here's the video with NASA on Hoosiers... a lot more exhaust noise because that event I ran an external mic on the back bumper: ruclips.net/video/Wb9cs9Hp7V4/видео.html

@@EGbeater Thanks! I've been looking at changing to wider tire/wheel setup. I think it definitely needs it. 5 and 6AB is definitely my favorite part of the track. It looks like you get the line pretty well though. You may be turning into 5 just a tad early causing you to causing you to come out of compression at the wrong time. When you end up on the left at the perfect spot you know because the car is more settled when you turn in for 6AB where you pretty much just hold the wheel at same angle through them.(if that makes sense) It's too bad I'm moving out of state at the end of the month or I'd say we should hit up an open lap day. Would be fun with such similar times.

HPR is a really fun (and safe!) road course. We in Colorado are fortunate to have such a great racing facility.

Doesn't help having bald rear tires and 500 lb-ft torque that hits all at once when the turbos spool... the only thing I've gotten good at after decades of track driving is making excuses for my poor driving.

@@panda_exprs no doubt - took me almost all of driver’s school to not spin out there (with ~1/10th yer power)

Similar... C5 Z06 is substantially smaller displacement V8 though, so probably less deep of a sound... 5.7L (LS1) vs 7.0L of the C6 Z06's LS7

It might sound kinda familiar with the same setup but the C5 has a completely different engine than the C6 Z06. C5 has the 5.7L LS1 and the C6 Z06 has the 7L LS7

Thanks; in 2021, my best lap time at HPR was 1:57.6... that's this video: ruclips.net/video/232oQ3zscqE/видео.html In 2022, I'm making major suspension changes and hope to shave several full seconds off that PB.

Sorry there wasn't more viewing of your lines... that's where the GoPro truncated the video segment and I was running into traffic so didn't see the point of splicing it together with the next segment. This video showcases a lot of not-great driving by me, but then again, I've never managed to record me doing a great lap from start to finish, so sure, I'll share this clip too. :)

If you watch from 0:23 to 0:30, you can see the silver C7 Vette entering the track via the pit-out road... it's on the left, between turns 1 and 2. So the C7 was on cold tires whereas I'd been lapping and had heat in mine. On big wide tires that take some time to build heat, I definitely take my first lap or two at only 6 to 8/10ths, until I can feel the tires come in. Also, this was an Emich-sponsored open lapping day, where a wide range of drivers come out to play... certainly possible this day was this driver's first time on track, whereas I've done many hundreds of laps at HPR.

The thin darker patch wrapping around T2 used to be noticeably less grippy than the existing pavement (in that I felt a little change crossing it and heard my tires squealing when on it)... but now it seems the same as the surrounding pavement. The rest of the much larger repaved areas (at T8, at 9a) seemed fine, but TBH I was on old/partially corded tires this weekend and the track felt a little slippery everywhere to me... another driver reported the grip of the new asphalt in T8 is much better than it was previous. Check out me exiting T8 @ 4:30... that's with 15% peak torque reduction via my BM3 tune... didn't feel grippy to me.

Fix the cylinder heads..

Don't mess with it. This car is stock.

Yeah me too.

The cameras are super old-school GoPro Hero2 and Hero3... after the Hero2, GoPro discontinued having a separate 1/8" external microphone jack (with the later models, you lose the ability to have a power cord feeding the camera power while using an external mic). The data/map comes from the TrackAddict timing app, and for higher accuracy, you need to feed the app faster than 1hz (all most phones' built-in GPS can do) data... I use the old Qstarz 818XT which connects to the phone via Bluetooth. BUT, I've been having issues with weird/inaccurate map traces and speed data (you can see it in this video too, with how fast the speed changes). Something's not working correctly and I haven't figured out what the issue is (is it the app? My phone's memory being too full? The BT GPS unit is failing/dying?)