Contour Enthusiasts Group Archives Forums Modifications Wheels & Tires Proper Tire Pressure?

I was just wondering, I JUST bought 4 Centerline Rpm (polished-15lbs a piece) 19s...and have a 225/35/19 tire, NITTO 555s..what is the proper tire pressure or should I say max? They have them set at 35 (Discount Tire Co.)..I was reading the Centerline paper that comes w/ the rims and they show several different times a max of 40psi, but was worded differently...wasnt sure if someone could help me out or not..Most 45 and lower series tires I thought ran at a higher psi..Thanks in advance for any help that anyone can give me.

-Ken

P.S. I will be posting pics tomorrow-Mon...they will be put on the car Monday b4 I go to dyno tune the car FINALLY!

Depends on the tire usually. With 35 series tires on some 19s, I'd say leave it at 35 or a little higher. What does the max say on the tire?
Edit: You should leave the stockers on the car while you dyno it...You're most likely going to lose some hp through the larger wheels, if you want bragging rights, just dyno with the stockers....or hell, dyno with both setups to see for yourself.

I honestly dont think that .3" is going to make a whole hell of a lot of difference considering each wheel is more than 6 lbs lighter than the stockers. I would imagine that it would actually be more beneficial w/ those rims.

Thank you for your help w/ the psi. Just making sure that I wont have any problems w/ the tires at the pressure they had it at. Centerline themselves also said no more than 40 so I will just leave it.

Thanks again,
-Ken

Rule of thumb is to always go with whats on the tire

So if a tire reads a max. of 55 psi, then i should go w/ 55psi? LOL

Are you referring to the .3" diff there is between the two tire/wheel combos or just wheels. Wheels are a full 3". I'll just tell you that I lost a consistent 1 mph in trap speed when I switched to 3 lbs. lighter, yet 1" larger (17") wheels. I say dyno both and you'll see for yourself, all you have to do is replace the drive wheels in between runs. That should about end this neverending debate on wheel size vs. weight that we've had going on for a while now. Pleeaassseeeee....

np, the only thing is this is a dynoTUNE..so there will be inconsistencies for a lil while. However I am referring to .3"overall from bottom of tire to top of tire...besides I dont drag race...not what the car was built for, so pretty friggin pointless, however, for the sake of having a lil competition..I am going to run the car one day just to see how I "size" up w/ the rest =P.

So if you take the 225 = 9" multiply by .50 you get 4.5...multiply that by 2 and add 16 and you get 25"

Then take 225 = 9" multiply by .35 you get 3.15" multiply that by 2 and add 19 and you get 25.3"

Not a big difference that is going to be noticed...but will still check when dyno is consistent, to try and settle the "age old argument".

-Ken

I completely understand, if you read some of the older posts about the subject, you will see what I'm talking about. The problem is more mass away from the center of the wheel to turn, not the overall diameter of the combo, as I used to think. I believe somebody said Sean Hyland tested it once, testing between 2 different wheel sizes, virtually the same weight and overall diameter, but still lost more than 5whp. It doesn't only apply to drag racing either, but the turbo setup should be plenty of power to sacrifice a few hp to look pretty.

LOL, right (as far as your turbo statement)

The problem I am having a problem getting around is the fact that there WONT be MORE mass...they are well over 6lbs lighter than the factory wheel (each), so maybe I am misunderstanding but I dont see the added mass.

If I am truly missing something, PLEASE let me know...b/c then I maybe blind

-Ken