pulling the trigger on a drag pack

[Jayjellyfish212]

Originally Posted by redmuddman

Thanks Jelly. I ended up ordering a set of polished Racestars for the rear. Good idea with the sand in the paint. I may try that if it's a problem. I'm not worried about chips or scuffs on a track wheel. I'm anxious to head to the track Friday night and see how they do.

You betcha man! Have fun buddy that’s really what matters the most. On the polished wheels your probably best to do the scuff method on inner wheel lips before mounting tires.

[redmuddman]

got my wheels and tires. when i put them on and drive about half mile down the street i get service stabillitrac, ABS and TC lights ? is that due to tire height change ?

[Chris49066SS]

Originally Posted by redmuddman

got my wheels and tires. when i put them on and drive about half mile down the street i get service stabillitrac, ABS and TC lights ? is that due to tire height change ?

Yes. A 315/35/17 has a tire height of 25.6", which is well outside the ~1" area of wiggle room/tolerance. A 315/45/17 would be the tire needed to keep it at 28.1" tall. But nevermind that. Keep the tires, get a speedo recalibration, and you have yourself a lot more launch..even if a tire that short does look funny, it still fits, and is gonna make you money off the line and give you some more rpm on the back end.

[Joe M 2012 2SS]

Pull fuse #40 and relay #43. You will still have an ABS and a BRAKE light on the dash, but no stabilitrac , car will run fine. All the nannies will be off so you won't have to worry about the button.

[Chris49066SS]

Originally Posted by Joe M 2012 2SS

Pull fuse #40 and relay #43. You will still have an ABS and a BRAKE light on the dash, but no stabilitrac , car will run fine. All the nannies will be off so you won't have to worry about the button.

You're right Joe.

But OP you will still need that speedo calibrated or your odometer is going to read incorrectly, as well as your speedometer, and when it comes to tuning, you want them to tune with your tire height that you're running since the shorter tire will affect shift points.

[Joe M 2012 2SS]

Originally Posted by Chris49066SS

You're right Joe.

But OP you will still need that speedo calibrated or your odometer is going to read incorrectly, as well as your speedometer, and when it comes to tuning, you want them to tune with your tire height that you're running since the shorter tire will affect shift points.

That's true, shift points and speedo will need adjusting. I'm so glad I bought the SCTX4 from Dynosteve @ RDP, I never have to pay for tunes!

[redmuddman]

got the wheels mounted up and the weights hit the calipers. i removed the weights and they shake like crazy at 80 mph so i didn't go to the track. now i'm second guessing myself and wondering if i should go with 28'' inch tires. are the 26'' tires much of an advantage ? i have 3.91 gears, headers, cai and a tune. A6

[Jayjellyfish212]

Originally Posted by redmuddman

got the wheels mounted up and the weights hit the calipers. i removed the weights and they shake like crazy at 80 mph so i didn't go to the track. now i'm second guessing myself and wondering if i should go with 28'' inch tires. are the 26'' tires much of an advantage ? i have 3.91 gears, headers, cai and a tune. A6

Hey on my Racestars the guy did balance mine and he put the weights on the inner lip edge. I forgot what he called it . Something like a static balance I believe. I had mine well over 100 many times and feels no different than my stock Zl1 wheels did going straight. I can add a picture for you if you need. I’d go back to the person that balanced them and tell them you need it balance with weights on far inside area of wheels

[Jayjellyfish212]

The 26” tire has a very slight advantage over the 28”. Looks a little odd but it’s said and known to squeeze a tad better ET. If you are not entering any track events or anything and just learn things out and getting the car and driver well connected I don’t see any reason to switch from 28” to 26” yet until you burn up the 28” tires first. I’m running a 28” and when these are shot I’ll probably try out a 26” myself.

[hillshooter]

26?! I would be going to other way, get a 29.5 to fit and you are talking. personally the best tire I have ran is Mickey Thompson 30551.

[zlathim]

Originally Posted by redmuddman

got the wheels mounted up and the weights hit the calipers. i removed the weights and they shake like crazy at 80 mph so i didn't go to the track. now i'm second guessing myself and wondering if i should go with 28'' inch tires. are the 26'' tires much of an advantage ? i have 3.91 gears, headers, cai and a tune. A6

I had the same problem. Here's a pic of my buddy smoothing down the caliper for clearance:





It provided just enough clearance.

[Chris49066SS]

Originally Posted by hillshooter

26?! I would be going to other way, get a 29.5 to fit and you are talking. personally the best tire I have ran is Mickey Thompson 30551.

An almost 30 inch tire on a 3800+ lb car? I respecfully disagree, sir, if he's NA

There are multiple factors going into the proper selection of tires. Lets look first at the transmissions. The manual and automatic transmissions both have different final drive ratios, as well as 1st gear ratios. The auto has a very aggressive 1st gear compared to the manual. With the manual, you don't have that more aggressive 1st gear, but you do have the drivetrain shock that comes hand in hand with the manual, that us auto guys don't have to deal with.

Next you have to look at power level. In a boosted application with gobs of torque, a taller tire is fine, but especially with a NA setup, a manual car is going to need all the gear it can get. And again, it depends on a bunch of factors;

Are you an auto or manual
How much power do you make
What wheel and tire are you using
Do you have stock gears and transmission
Hows your wheelhop

I have 3.91 with an auto, and my 60' is 1.5, Andrew Cammer (The Gear Guru) will tell you the same thing. Sticks need more gear. Autos not so much, but I am telling you, there are more than a couple factors that need to be taken into consideration


Going with a shorter tire, you're getting out of the hole quicker and gaining more RPM on the back end.

[Tajefe Couple]

Originally Posted by redmuddman

got the wheels mounted up and the weights hit the calipers. i removed the weights and they shake like crazy at 80 mph so i didn't go to the track. now i'm second guessing myself and wondering if i should go with 28'' inch tires. are the 26'' tires much of an advantage ? i have 3.91 gears, headers, cai and a tune. A6

Maybe this will help

Effective Ratio shows your adjusted gear ratio if you choose to keep your original gears.

Tire Size Change
New Tire Diameter:
26
Old Tire Diameter:
28
Current Gear Ratio:
3.91:1
Effective
4.21:1

[acammer]

Originally Posted by Chris49066SS

An almost 30 inch tire on a 3800+ lb car? I respecfully disagree, sir, if he's NA.

Chris is right on point - these cars need gear! I'll give you a quick example with my own car. N/A cam only near 500whp, 4160lbs race weight M6 car - 4.10 gears. Right now I have 305/45/18 NT05R's on the car, a 28.8" tall tire. It traps pretty consistently in the 117-118mph range right now, which is about 5600rpm in 4th. My car makes peak power at 6500rpm, and the best of the horsepower doesn't even come on till 5500rpm or so, and it carries out well past 7000rpm (I shift at 7300 and it's barely rolling over by then).

Switching to a 25.6" tire (a 275/40/17) would be an 11% increase in final drive ratio. At the same 118 mph I would now be at 6350rpm. The net effect would be that the car would be much more into it's power band throughout the entire run, but especially down the back half of the track - us stick guys with 4.10s are into 4th just after the 1/8th mile and just cruising from there. Result - the car would trap with more MPH and better ET.

Also, it helps (you read that right) on the launch - if you have a good track. Where I run we always have fantastic prep and a very tight track - I launch as high as 6400rpm and have no significant wheelspin - never more than just a squawk as I complete my clutch release. A shorter tire would actually be helpful down there in the 60' as well, as the car would climb into the power quicker. There definitely comes a point where you could have too little tire and/or too much gear - but these big heavy cars will go quite a ways in that direction and still leave nicely if you can drive. If you're a "dump and run" guy then the 5th gen Camaro (without some super expensive driveline upgrades) isn't the car for your anyways - these cars need a quick but well modulated clutch release.

No - it doesn't look cool at all. Those short tires on these big cars look funny. In a perfect world we'd have somebody offering us a strong and quiet (I realize those two terms are opposed - I said perfect world!) 4.56 gearset. Then we could accomplish the same things on the 29" tires, which look great under these cars. But, for the guys that wanna go the fastest all motor, you need to keep these big cammed LS motors singing - and that means getting all the gear you can in the rear, and getting on the shortest tire you can still get down the track with.

Boosted cars - totally different story. Once you've got something that's going to trap in the 130-140mph range you can forget about the short tires, they won't stick the power off the hit, and they don't need 'em on the big end anyways.