HRP opening night was Friday, so I went to see what I could get out of the truck with the MP112. First run was a 16.52@97.97mph . Temps where in the low 40's and the track had just been redone. Long story short I got my times down to 14.13 @ 102mph by the end of the night. Needless to say I could not hook up out of the hole. I took my tire pressure down to 25lbs on the stock tires and was still spinning them .

What tires would be of good use at the track as I plan on going back soon .
I was looking to see what I could find for the stock 20" rims and found that nitto has a 275/40r-20 and a 305/35r-20.
Any advise would be helpful as long as it's helpful advise

 

how was it there friday ? i was gonna go but ended up not able to. allot of trucks show up ?

 

On stock tires I never got better than a 14.8 on my 20's. I spun almost the whole way down the track. You need some slicks.

 

I would say maybe about 20 trucks.

 

You need slicks for sure, probably about a 28x10....

Get rid of those wheels in your sig for the track and watch the times fall...

 

what was you 60' and 1/8 mile times/mph?

 

275 40 17 mt drag rads. For the truck running less than 12.00 this is perfect.

it lets you go thru the traps at the right rpm.

Now your truck has the 4l60e which is 1.1 in 3rd.

Your running thru the traps at 97 mph honestly id do rear end 3.73 gears and a 28 inch tall drag rad or 3.73 and the 275 40 17s.

Here is a vid of my wifes BONE STOCK tbss only thing i chaged was rims. rear im runnign 17x8.5 with 275 40 17 and the small tires help sooooo much that and i havre 4.10 gears stock and with these tires makes it like a 4.97 gear ratio

http://www.youtube.com/watch?v=6ya_6cxFN2g




now lets compare a few things here

Lets say you have 3.23 gears redline is 6000 rpms
with 275 40 17 top speed of 3rd is 140 mph
with 305 35 18 top speed of 3rd is 145 mph
with 295 45 17 top speed of 3rd is 152 mph
with 345 35 18 top speed of 3rd is 152 mph (28 inch tall tire)
with 305 45 18 top speed of 3rd is 159 mph (29 inch tall tire)

Lets say you have 3.42 gears redline is 6000 rpms
with 275 40 17 top speed of 3rd is 134 mph
with 305 35 18 top speed of 3rd is 138 mph
with 295 45 17 top speed of 3rd is 143 mph
with 345 35 18 top speed of 3rd is 143 mph (28 inch tall tire)
with 305 45 18 top speed of 3rd is 150 mph (29 inch tall tire)


Lets say you have 3.73 gears redline is 6000 rpms
with 275 40 17 top speed of 3rd is 123 mph
with 305 35 18 top speed of 3rd is 126 mph
with 295 45 17 top speed of 3rd is 131 mph
with 345 35 18 top speed of 3rd is 131 mph (28 inch tall tire)
with 305 45 18 top speed of 3rd is 138 mph (29 inch tall tire)


Now lets say you have 3.90
with 275 40 17 top speed of 3rd is 117 mph
with 305 35 18 top speed of 3rd is 120 mph
with 295 45 17 top speed of 3rd is 126 mph
with 345 35 18 top speed of 3rd is 126 mph (28 inch tall tire)
with 305 45 18 top speed of 3rd is 132 mph (29 inch tall tire)


Now lets say you have 4.10s
with 275 40 17 top speed of 3rd is 112 mph
with 305 35 18 top speed of 3rd is 115 mph
with 295 45 17 top speed of 3rd is 120 mph
with 345 35 18 top speed of 3rd is 120 mph (28 inch tall tire)
with 305 45 18 top speed of 3rd is 125 mph (29 inch tall tire)

before you do anything id invest in hp tuners so you can change the tire heights for your truck..

Are you even running a 3.73 rear end gear?


What is your redline of the truck?

 

Thanks for the info NORCAL ,
I have the 3.42 rear end as this is my daily driver to and from work.
60miles to and 60miles from so I am trying to stick with them for the daily use and gas mileage.
I do have HPTuners pro , so a tire change would not be and issue. I was asking about the nitto 20's because I have my stock rims and would like to use them, can you include them in your formula.
I am open to going with the 3.73 but only if I have to but I think I would do the 305/18 first. I have the red line bumped up to 6200rpm.

 

3.73 Gears wont hurt much at all done many swaps like this.

honestly with 3.42 gears id get the shortest tire you can. 17x8.5s are like 60 each at discounttiresdirect.com and put 275 40 17 and trust me you will drop at least 5/10s.

do you have a posi in the truck?>

 

btw lets say 70 mph with 3.42 gears and 275 40 17. at 105 mph your only doing 4704 rpms. now 3.73 gears with 275 40 17 at 105 mph your doing 5130 rpms. See still way below what you would want to go thru the traps. with your maggie for best results you would want 5500 going thru the traps.

now lets say you had 285 50 20 tires on the truck this is whats killing you.

wiht 285 50 20 at 105 mph in 3rd your only at 3800 rpms which is why your time is so low. now with 3.73 that would be 4120 rpms still way to low.

If you want to do the best thing for that truck i would get the smallest tire you can find because your truck is not going thru the traps at a good rpm at all which is making your times slower than what they should be.

also going from 3.42 to 3.73 at 75 mph is 300 rpms more. Its not that much difference at all and many of the customers said that in the city they have better mileage and on freeway the most lost was 1 mpg. From 3.42 to 4.10 swap the guy said he did 45 miles less on one tank.