04-04-2022, 06:31 PM | #1 |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
Posts: 2,343
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305 45 17 MT et street R air pressure question
With 305 45 17 MT et street R with a 17x10 wheel on a 2021 LT1 with 440 rear wheel horse max and a 10 speed auto trans, what air pressure (warm) should I be running on a average prepped track on a sunny 60 degree day, 70 degree day, 80 degree day ?. I would like to flat foot the car off idle and want it to dead hook. I have removed the front swaybar and have had a 4 wheel alignment to have 0 degrees toe front and rear along with the least amount of negative camber possible in the rear for a flatter rear footprint. On street tires I usually have a full tank of fuel for rear weight, but my thoughts with these MTs I am leaning toward a half tank instead to save 50 or 60 lbs
Last edited by lt4camaro; 04-04-2022 at 11:04 PM. |
04-04-2022, 08:08 PM | #2 | |
Drives: '20 ZLE Join Date: Jun 2020
Location: Mile High
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'20 ZL1 1LE A10,
OEM short block, LME heads/valve train, E2650. 100+ octanes, no eth, no meth, no N2O. 2/23 - 1031/1004 wheel. 4/23 - 1.41/9.61/145 at DA 7000 ft. (only made five passes). 2/24 - LME 390, E2650, FBO, 100 oct.; 1116hp/ 1063tq; 109 oct. dyno next. |
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04-04-2022, 11:02 PM | #3 |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
Posts: 2,343
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04-05-2022, 12:27 AM | #4 |
Drives: like an old lady Join Date: Jun 2012
Location: indiana
Posts: 2,396
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given those circumstances id start at 24 cold. i managed a 1.60 60' in a full weight m6 1LE on a 275/40. i had 24 cold in mine and the track wasnt even prepped. id like to think an auto car setup like yours would have no trouble hooking.
edit: 58*, 900' da. car made 441.
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2016+ camaro: everyone’s first car
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04-05-2022, 06:20 AM | #5 |
Drives: 2024 Toyota Camry XSE Join Date: Sep 2017
Location: South Texas
Posts: 155
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What he said. Don't overdo the burnout. Not a recommendation but what I did: Bought a really good pressure gauge 0-30 with 1/4 lb. graduations. M/T says best results are with tire temp within 15 degrees of track temp (yes, used a infrared thermometer; checked tire temp asap after every run). As for your question of ambient temperature variations; checking tire temp and adjusting psi will account for that. Checked psi in pits after first run, always needed to lower pressure. After first run, started in pits 1-2 psi lower than what I wanted on the line, i.e. 16-17 lbs. in pits (experimented and documented). Recorded both rear tires temp and psi before and after every run. Removed front sway bar and pulled links from rear sway bar. Stabilized the rear sway bar with a 1/4" x 1" x 8" metal strap bolted to the frame and a couple of zip ties. 1" lowering springs in rear took .1-.2 seconds off the 60'. I did everything you did on the alignment (and more) and DID NOT DRIVE THE CAR ON THE STREET. Fuel issue - my thoughts are,for drag racing, remove weight anywhere you can, front, rear, middle, liquid or solid (drain the windshield washer tank -8 lbs). At the track, I start with 1/8 tank and add a gallon or two when the low fuel warning comes on.
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2016 1SS - Bought: 8/2017 Sold: 12/2023
Last edited by Yosh6; 04-05-2022 at 08:15 AM. |
04-05-2022, 10:05 AM | #6 |
Drives: 2022 Lt1 A10 Join Date: Nov 2015
Location: clark, mo
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I ran 18 to 20 depending on the track and prep. Best 60ft was 1.35.
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2022 Lt1 6.2 A10, Maggie 2300, THPSI Port Inj/10 rib, Rotofab, E, Nickey, SCOL, Griptech, RC Bandits, Hoosiers/MT 9.80@142.96 1.44 60ft, 6.34@112 707/669 RWHP/TRQ. 16SS Maggie 2650 9.41@147 1.35 60ft, 5.99@119. 16 C7 A8 10.90@128 Bolt on stuff
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04-05-2022, 10:10 AM | #7 | |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
Posts: 2,343
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04-05-2022, 10:13 AM | #8 | |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
Posts: 2,343
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04-05-2022, 11:13 AM | #9 | |
Drives: 2024 Toyota Camry XSE Join Date: Sep 2017
Location: South Texas
Posts: 155
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This was a dedicated track car for three years so I did a lot to it that I would not do to a street-driven car. Now, most of what I took off is back on and I drive the car on the street and go to the tract from time to time. I pull the seats, change the wheels and tires and disconnect the sway bars for the track. So, when the car was track only, it was considerably lighter (3,320 lbs.) There is a convenient stud or bolt (10mm) on the back corner of the carriage on both sides. Removed the nut and bolted the brace to that on one end. The other end is fairly close to the wheel/tire, 1" -1.5" away. Let the sway bar sit on top of the brace and zip tied just to keep it from bouncing around. I did it on just one side, but both sides wouldn't hurt. I have no idea how pinching or clamping the rear springs would work. Understand the concept; used to drag race motorcycles with a strap on the front that compressed the front suspension to prevent (to some degree) wheelies. I've weighed some of this and some is by consensuses: Pass seat- 55 lb, rear seat - 30 lb. Sway bars 15 lb. each, muffler replaced with straight pipes 30-35 lb. Aluminum belly pan under engine and plastic panels/covers - 15 lb. Engine covers - 11 lb. Trunk panels and floor - 10 lb. Anti-gravity Lithium battery saves 40 lbs. Skinnies save a lot in tire weight plus use light weight wheel ( I used Bogart 14 lb. each). Used Bogart in rear also (21 lb). Hoosier DBR 10.5' X 28' R-17 is 8 lb. lighter (each tire) than M/T 305 Street R, but is a slick not a DOT tire. Probably a lot more can be found and keep it streetable. Happy hunting.
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2016 1SS - Bought: 8/2017 Sold: 12/2023
Last edited by Yosh6; 04-05-2022 at 11:47 AM. |
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04-05-2022, 12:22 PM | #10 | |
Drives: 2021 LT1 10 speed auto Join Date: May 2013
Location: Connecticut
Posts: 2,343
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04-05-2022, 12:31 PM | #11 | |
Drives: 2024 Toyota Camry XSE Join Date: Sep 2017
Location: South Texas
Posts: 155
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2016 1SS - Bought: 8/2017 Sold: 12/2023
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04-05-2022, 05:35 PM | #12 |
2Spdsy
Drives: 2021 Camaro LT1 A10 Join Date: Mar 2016
Location: Mission hills
Posts: 122
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Yep, what Yosh said , 17 to 18psi at the pits . Remove front swaybar and pan . With the burnout it will go up to 20psi and the car should hook off of idle . Your best 60ft will come off idle as well. Never heard of removing the rear swaybar on an IRS car , but it’s worth a try . I thought you keep to plant the tires better and keep the car launching straight .
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04-06-2022, 02:45 PM | #13 |
Drives: '20 ZLE Join Date: Jun 2020
Location: Mile High
Posts: 3,560
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I assume you were foot braking it. Did it 60 ft. better in Tour, Sport, or Track?
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'20 ZL1 1LE A10,
OEM short block, LME heads/valve train, E2650. 100+ octanes, no eth, no meth, no N2O. 2/23 - 1031/1004 wheel. 4/23 - 1.41/9.61/145 at DA 7000 ft. (only made five passes). 2/24 - LME 390, E2650, FBO, 100 oct.; 1116hp/ 1063tq; 109 oct. dyno next. |
04-06-2022, 02:51 PM | #14 |
Drives: '20 ZLE Join Date: Jun 2020
Location: Mile High
Posts: 3,560
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In every video I've seen, the Camaro driver pulls through the water in manual, stops on the other side, gets the tires spinning in 1st, shifts to 2nd, floors it for a second or two, and rolls forward.
I can't help but believe these big ass OEM tires don't leave a bunch of water on the track. If you burn through it, fine, if not . . . Not sure Bandimere will let me drive around the box and back into it.
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'20 ZL1 1LE A10,
OEM short block, LME heads/valve train, E2650. 100+ octanes, no eth, no meth, no N2O. 2/23 - 1031/1004 wheel. 4/23 - 1.41/9.61/145 at DA 7000 ft. (only made five passes). 2/24 - LME 390, E2650, FBO, 100 oct.; 1116hp/ 1063tq; 109 oct. dyno next. |
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