26"x11.5" ET Street vs 28"x12.5" ET Street

I recently added a new rearend to my car and now I am concerned I didn't have enough gear put in it. Besides the obvious cost of new gears, I really don't want to change out the gears because mine are very quite so far.

I am getting ready to order some ET Streets. I was looking at the chart with the information concerning the two tires. Below is the tire information.

Tire Size Rim Tread Section Diameter

26x11.5 10" 9.8" 12.0" 26.3"
28x12.5 10" 9.9" 12.5" 28.2"

They are very close in size besides the diameter. Will they hook and run out on track very similar? Am I giving up a lot of hook going with the shorter tire?

The shorter tire more close matches my gearing. My setup should be good for low 11s / high 10s motor and then will get a 200-300 shot and see where that takes me.

Thanks,

Dave

Im getting 4.10 gears for next year .. and i figuered @ 7000 rpm .. u will trap 132 with 26" and 142 with 28" tires

my only concern is fitting 28 tires in the wheel wells without major surgery ...

I switched partway through last season from 26" x 11.5" x 15" top 28" x 12.5" x 15".

I switched becasue I needed to slow myself down just a tad and I wanted a longer rollout at the start so I also changed fronts to matching 28" size.

My sixty foot times slowed between .02 and .04 consistently. My top end speed increased by about .5

I did all the body work I needed with a hacksaw in about 20 minutes. I like the taller tires.

what did you have to do to get the 28" to fit? Are they on a 15x8 or 15x10? And what back space?

tnt: by slowed down, u mean improved right :) ?

im also intersted to know what mods u have to make to get them to fit

and pics would be great :)

i'll be purchasing new slicks and need to make up my mind

if you dont have any gear in your car, your going to want the shorter tire to go faster. the taller the tire, the more gear youll need if you want to go faster.

EX- i ran a 12.7 @ 110 spinning on radials (about 25 in. tall). my buddy lets me use his slicks to make a pass, but they are 28x10.5. i ran a 12.7 @ 107. so obviously it had more in it, but the taller tire slowed me down. i have 2.73 gears, so to optimize my performance with the stock gears im gonna need a shorter tire.

for a 28in tall tire, i would recommend no less than 3.73s.




jon

I mean slowed down.

The cutoff for Street Et is 12.00 flat. I can deal with a car capable of running 11.98 and dialing 12.00, but not a car that is capable of 11.8's or quicker and having to dial 12.00. At least not with the level of competition at my track.

My sixty foot times went from generally 1.58's to generally 1.61-1.62 and that was enough to keep me over the 12.00 cutoff as long as I ran it with a stifled up exhaust (really rich).

I need to run a predictable number each time and could care less about how quick that is as long as I am reasonably close to the class cutoff, at either end.

I plan on running top this year too and since many of those guys need chutes to stop I will be as hard for them to judge as they will be for me...

i'll be running 4.10s .. with enough power to trap in the lower 130s ... so i figuered 28" tires would suite me better .. dont wanna have to ride the limiter thru the traps ...

I have a 3.70 gear. Can't remember my logic in picking it over a 3.89 at the moment. I am wanting to trap in the high 130s. Right now I show the 26" ET Street allowing me to trap around 137 at around 7000rpm and would be much better for naturally aspirated performance.

But if a 26" will not hook as well as the 28" it really won't matter what it runs out the big end. I was hoping MT would come out with a 27" ET Street and from their website they did...but only 10" wide. Preferably if they came out with a 27" 12.5" I would be all over it. Not sure about running a Hoosier as an alternative as a guy I know locally has them and I am not too impressed with how they hook.

Dave

tnthub, what bodywork did you need to do to make the 28" tire fit? any pics? is it just trimming the inner qrtr flare? or did you have to cut the rear bumper cover too?
chris

FYI

A rep from MT got back with me. They will not be offering any other 27" ET Streets for a 15" rim other than the 10" width they currently have listed on their webpage.

Dave