Going from 275radial to 30x9 ?

Tex013 · 07-21-2014, 02:22 AM

hi,
long time watcher from Australia with a tyre question
Is there much to be gained (or lost) from going from a 275/60R15(28") Hoosier to a 30x9 Radial ?
Bit less sixty foot , more MPH ?
Better footprint for traction ?
I have a 68 Satellite with a 440+0.055,TF727,5000 stall , 4.10 geared Strange 60 . Caltracs,Rancho rear shocks,QA1 front shocks . Average sixty is 1.52/3, best of 1.50. Car weighs 3657lbs with me in it .Ran 10.965@115 on the brakes on Saturday.Car is a daily driver street car .Car is foot braked , at least for the time being
Your cars are the nearest to how I like to run mine though I run Super Street , 11.00-12.99 DYO, no Stock /Super Stock like you here plus my wallet isn't that deep

Any thoughts appreciated
Tex

Michael K · 07-21-2014, 12:52 PM

Is 4.10 going to be enough gear when going to a taller tire...Hoosier 18210C07?

Bimbo Jones · 07-21-2014, 02:21 PM

I would guess ET may be quicker by a few due to a harder hook and mph will decrease a few due to less wheel speed at the hit.

Tex013 · 07-21-2014, 05:52 PM

thanks for the replies ,
I was looking at either the 18209C06 or 18210C07 tyre
I may not quite get 18211 or 18212 into the stock wheel well
thanks,

Tex

Dave Noll · 07-23-2014, 01:00 AM

Assuming good traction, a change to a 30 inch tall tire would require roughly a 4.4 gear to turn the engine the same RPM, so if you can take a little more RPM a 4.56 gear should work nicely. & be quicker. (depending on your powerband)

Tex013 · 07-24-2014, 05:56 PM

thanks Dave,
funny as it seems I only shift at 6000,trap around 63/6400. not sure of pulling harder with the rods(ly with ARP bolts),peak power on chassis dyno is around 5500 but pulls happily to 6500 never went past here
I did used to run 3.9 gears with the 28"
as to quicker with more gear - car is able to run faster than the class

Tex

07-21-2014, 02:22 AM	#1
Tex013 Junior Member Join Date: Oct 2012 Location: Sydney , Australia Posts: 97 Likes: 23 Liked 43 Times in 25 Posts	Going from 275radial to 30x9 ? hi, long time watcher from Australia with a tyre question Is there much to be gained (or lost) from going from a 275/60R15(28") Hoosier to a 30x9 Radial ? Bit less sixty foot , more MPH ? Better footprint for traction ? I have a 68 Satellite with a 440+0.055,TF727,5000 stall , 4.10 geared Strange 60 . Caltracs,Rancho rear shocks,QA1 front shocks . Average sixty is 1.52/3, best of 1.50. Car weighs 3657lbs with me in it .Ran 10.965@115 on the brakes on Saturday.Car is a daily driver street car .Car is foot braked , at least for the time being Your cars are the nearest to how I like to run mine though I run Super Street , 11.00-12.99 DYO, no Stock /Super Stock like you here plus my wallet isn't that deep Any thoughts appreciated Tex

07-21-2014, 12:52 PM	#2
Michael K Member Join Date: Nov 2012 Location: Minnesota Posts: 101 Likes: 89 Liked 62 Times in 17 Posts	Re: Going from 275radial to 30x9 ? Is 4.10 going to be enough gear when going to a taller tire...Hoosier 18210C07?

07-21-2014, 02:21 PM	#3
Bimbo Jones Member Join Date: Nov 2008 Posts: 109 Likes: 0 Liked 0 Times in 0 Posts	Re: Going from 275radial to 30x9 ? I would guess ET may be quicker by a few due to a harder hook and mph will decrease a few due to less wheel speed at the hit.

07-21-2014, 05:52 PM	#4
Tex013 Junior Member Join Date: Oct 2012 Location: Sydney , Australia Posts: 97 Likes: 23 Liked 43 Times in 25 Posts	Re: Going from 275radial to 30x9 ? thanks for the replies , I was looking at either the 18209C06 or 18210C07 tyre I may not quite get 18211 or 18212 into the stock wheel well thanks, Tex

07-23-2014, 01:00 AM	#5
Dave Noll Senior Member Join Date: Nov 2007 Location: Div. 6, Eastern, WA Posts: 710 Likes: 2,671 Liked 240 Times in 112 Posts	Re: Going from 275radial to 30x9 ? Assuming good traction, a change to a 30 inch tall tire would require roughly a 4.4 gear to turn the engine the same RPM, so if you can take a little more RPM a 4.56 gear should work nicely. & be quicker. (depending on your powerband) __________________ Dave Noll, EF/S ,?/SA 6526

07-24-2014, 05:56 PM	#6
Tex013 Junior Member Join Date: Oct 2012 Location: Sydney , Australia Posts: 97 Likes: 23 Liked 43 Times in 25 Posts	Re: Going from 275radial to 30x9 ? thanks Dave, funny as it seems I only shift at 6000,trap around 63/6400. not sure of pulling harder with the rods(ly with ARP bolts),peak power on chassis dyno is around 5500 but pulls happily to 6500 never went past here I did used to run 3.9 gears with the 28" as to quicker with more gear - car is able to run faster than the class Tex