Drag Tire Problems & Suggestions

[precisiondyeing]

Here's the dilemma:

I own an 05 QC SRT-10. I want to put drag radials on the truck, but nobody makes a 22" drag radial. So I found a replica of the SRT wheel in a 20"x9" size. This rim will accomodate the Nitto 555R 275/40/R20. I was going to compliment the front axle with the Nitto Invo in the same size.

Sounds good so far, right? Well according to Discount Tire this truck needs a tire of 114XL weight rating, which at 32psi will carry about 2,250lbs. However this 555R is only rated at 102 which at 33psi is about 1,750lbs. The front Invo's are 106's and carry about 2,175lb at 42psi.

So the question is, how much of a risk am I taking running this combo? Aside from going to 18" rims I don't know of any other viable solution. I encourage anyone who has a working knowledge of tire load and physics to reply. Thanks in advance.

Michael Teer
[email protected]

 

[viperhauler]

we don't do physics...

just put them on and go...

then report back with you're findings

 

[TNVIPER]

This is what you need............

http://www.mandhtires.com/store.php?crn=70&rn=295&action=show_detail



..

 

[Fahrenheit]

I have 17" Eagle 058's with M&H 390/40 17's on it, they are great! The only thing if you are drag racing is you need to keep it in "tow haul" mode or the computer will shift into OD about 60' to the end of the track. If you want something to cruise the streets the tire and rim combo are almost the size of the 22's, you would have to adjust the air pressure between track and street. Nittos and M&H will be two different animals, the M&H's are really soft....like I can mash the tread really good with my finger....I really dont know how much harder the Nittos are.

 

[precisiondyeing]

TNVIPER: I really don't want to go with 17" rims.

Dan: Just strap them on and go, huh? Easy for you to say when you're not the one risking your prized truck and own health, lol!

Michael

 

[viperhauler]

i'd do it...

seriously, tho...

if i understand your post correctly...mathematiclaly, the numbers work...you won't be over 6k lbs, and less than half of that will be directly over the rear axle...

now...how much each wheel is carrying, you'll have to put it on a scale to find out....

but i've been drinking...so what do i know...

 

[moparracing]

I really don't want to go with 17" rims.

Michael

i curious why not ?

there's no grinding involved & the more side wall the better for drag racing. :rock:

 

[TNVIPER]

i curious why not ?

there's no grinding involved & the more side wall the better for drag racing. :rock:

...:withstupid: ..........dang..I think this is the second time I had to agree with you..............the M&H shaved 7 tenths off my qtr mile...and like Mopar said they are plug & play..

 

[moparracing]

...:withstupid: ..........dang..I think this is the second time I had to agree with you..............the M&H shaved 7 tenths off my qtr mile...and like Mopar said they are plug & play..

actually, i think it's the third time, but who's counting......

 

[precisiondyeing]

Honestly, I don't want to go with 17's for cosmetic reasons. I am worried it will severely detract from the curb appeal. It has a custom paint job and I really want to keep bigger, possibly factory wheels on it for car shows. I know...I want my cake and to eat it too, but who doesn't?!

Michael

 

[moparracing]

Honestly, I don't want to go with 17's for cosmetic reasons. I am worried it will severely detract from the curb appeal. It has a custom paint job and I really want to keep bigger, possibly factory wheels on it for car shows. I know...I want my cake and to eat it too, but who doesn't?!

Michael

ya only put the drag radials for the track, stocker's on 22's for daily drivin'......

 

[precisiondyeing]

Good answer. But here's what I've come up with:

Most passenger truck tires are load ratio C and the load weight is calculated at 50 psi. For example, the OEM tires are a 114 load rating and can carry a max weight of 2601lb at 50psi. According to the GAWR, front is 3700 and back is 3900. This compensates for an extra 1000lb for passengers or cargo.

According to a chart published by Goodyear that measures load weight of a tire vs it's pressure -

Generally speaking, a C ratio tire can support approx 75-80% of max load at 35psi and roughly 50% at 15psi (drag radial pressure)

The Nitto 555R is a C 102, which at 50psi has a max weight of 1874lb. After correcting GAWR for passengers/payload, I have my
truck weighing in at 3430lb front and 3620 rear. (I plan on verifying this at a Cat truck scale in the morning) Given Goodyear's calculations, this tire
can take 1500lb @ 35psi and 940lb@15psi.

Likewise the front tires, Nitto Invo's are C 106 rated, which is 2094lb max. And at 35psi is roughly 1675lb.

From here, do the math .....I'll report back tomorrow on the
vehicles true weight.

-Michael

 

[VIPER]

TNVIPER: I really don't want to go with 17" rims.

Dan: Just strap them on and go, huh? Easy for you to say when you're not the one risking your prized truck and own health, lol!

Michael

i guess you dont want to go fast - and get your 1/4 time down......

 

[VIPER]

i use slick's, 28x12.5x16LT M/T ET Street Slicks

and i have two 11 sec passes on them...

http://www.vtcoa.com/forums/showthread.php?p=764907#post764907

just remember pretty dont make you go fast !

dont worrie about all the math, and the calc's ect... just get some tires and go have fun....

 

[SANTEEN]

Here's the dilemma:

I own an 05 QC SRT-10. I want to put drag radials on the truck, but nobody makes a 22" drag radial. So I found a replica of the SRT wheel in a 20"x9" size. This rim will accomodate the Nitto 555R 275/40/R20. I was going to compliment the front axle with the Nitto Invo in the same size.

Sounds good so far, right? Well according to Discount Tire this truck needs a tire of 114XL weight rating, which at 32psi will carry about 2,250lbs. However this 555R is only rated at 102 which at 33psi is about 1,750lbs. The front Invo's are 106's and carry about 2,175lb at 42psi.

So the question is, how much of a risk am I taking running this combo? Aside from going to 18" rims I don't know of any other viable solution. I encourage anyone who has a working knowledge of tire load and physics to reply. Thanks in advance.

Michael Teer
[email protected]

Bro, you just have to make up your mind. Either you want to hook at the track or look good at the track without hooking well. I dont think 20" DR's are going to have enough sidewal flex to hook well on a vehicle with 500 ft/lbs of torque. Get the 17" DR's for the track, you wont regret it.

 

[VIPER]

Bro, you just have to make up your mind. Either you want to hook at the track or look good at the track without hooking well. I dont think 20" DR's are going to have enough sidewal flex to hook well on a vehicle with 500 ft/lbs of torque. Get the 17" DR's for the track, you wont regret it.

yep, :rock: :rock: :rock: :rock: :rock: :rock: :rock:

 

[precisiondyeing]

Total Weight 5620lb
Front Axle 4720lb
Drive Axle 900lb

Per CAT scale. Does this sound right?

 

[VIPER]

Total Weight 5620lb
Front Axle 4720lb
Drive Axle 900lb

Per CAT scale. Does this sound right?

dude you over thinking this.......

wow - did i just say that ?!?!?! " im an engineer "

just get the slick or DR's and go have fun bro !

 

[FATJACK]

Total Weight 5620lb
Front Axle 4720lb
Drive Axle 900lb

Per CAT scale. Does this sound right?

Why hell no, not even physically possible....

 

[VIPER]

TNVIPER: I really don't want to go with 17" rims.

Dan: Just strap them on and go, huh? Easy for you to say when you're not the one risking your prized truck and own health, lol!

Michael

if this is what you are thinking than maybe you should not be on the race track.....