TIRES: How tall is too tall.....how wide is to wide?

[Ridiculous5.0]

Recently puchased some dark stars 15x8s with 275/60r15 Mickey thompson et streets and when I ran my 1/4 mile it felt like the tires were either too tall or too wide. Car launched great but it seemed to lag on top end even when I power shifted I managed to squeese out an 11.62. Any suggestions on what's going on? Really trying to hit a 10sec 1/4 mile......going back in a month.

 

[dirtyd88]

What gears do you have? And are you a manual or auto?

 

[scotmach]

when I power shifted

What gears do you have? And are you a manual or auto?

I'm going to go out on a limb and say he has a manual.

 

[dirtyd88]

I'm going to go out on a limb and say he has a manual.

Missed that in his posts. Thanks.

It may be an issue of what size OD tire you have versus the gears you have.

 

[orange_whiner]

There are so many factors.. and with you saying it launched great but felt laggy up top seems backwards for a tire that's too tall. What was your 60' and are your mods?

 

[Ridiculous5.0]

I have 3.73 gears supercharged 640hp 506tq........i think it is the gear ratio because i have to shift from first to 2nd maybe right after the 60ft and soon sfter that i have to shift to 3rd right away my trap speed is kinda low too like 120mph

 

[Voltwings]

120 is very low for a supercharged car i feel ... 28" tire is like 2" over stock though, and a slick is going to expand as you go down the track. A taller tire would essentiall be giving you more gear, so something <3.73, and should allow you to be holding each gear longer... what are you shifting at?

 

[SignalZero]

With a 28" tall tire, 3.73's and @ 7000rpm (without adjusting for tire growth) top speed in 4th gear is ~118 mph. With 3.55's it goes to ~124mph and with 3.31's it goes to ~133mph.

(@ 7400 3.73's are ~125mph, 3.55's are ~132mph and 3.31's are ~141mph)

I would say op should have a ~3.31 gear installed if he wants to be happy. Would also keep him from going to 5th unless he shifts ~7400 in which case I'd go 3.55's.

 

[Voltwings]

Oh my god haha I have datalogs of my 3rd gear going to 113 at 7800 rpm, I love my 3.31's. I need a 28" tire so I can finish the 1/4 in 3rd instead of the middle / bottom of 4th -_-