ok first time going, where im actually racing, i have 315 555r's what's the best PSI. they are also daily drivers so i dont plan on lighting them up. also where should i shift, i can go higher because my MSD keeps the power more constant.

 

You have do a burnout to get them heated up. Most people inflate them to somewhere between 16-20 PSI.

 

are they drag radials or just the regular tires? If they're drag radials then you have to heat them otherwise you probably better off just running a normal street tire. As for how high you should spin the motor, I wouldnt go past 5800 because your cam dictates your power curve a whole lot more than your MSD. You would be wasting your time if you try to over spin it, I gained 3mph from my 5.0 shifting at 4900 rather than 5300 (stock longblock then).

 

i know how the power curve works, im just referring to the way lt1's seem to really drop off at the top of the rev due to poor spark. i know for a fact that i pull harder at the top than other lt1's. i raced this TA and it seemed equal on the first half of the rev, then i pull ahead, i shift and im not pulling anymore, then again i start to pull.

yes they are drag radials, but i dont have a lot of money so i dont really feel like spinning them. i understand that hot tires=good traction but doesnt that apply the same for any tire?

 

no they dont. most street tires run better cold while dr's pretty much are ZERO advantage cold, if anything probably a disadvantage. your probably pulling better up top from the headers. a friend of mine has headers and had the same trap speed no matter where he shifted (5300-6000). Your just gonna have to find out for yourself what is the best shiftpoints, which can take a few trips.

 

another reason you might be pulling on other LT1's is cuz you have more mods OR the people you're racing are shifting too early or too late.

 

If you're not willing to heat up your drag radials then you wasted your money. Just buy regular radials next time.

 

I have the same tires(315/35/17 Nitto Drag 555R's) and I run them at 18-20 PSI. Make them SMOKE for about 5 solid seconds after going thru the water box. Best way is to back into the wayer, roll forward and procede to spin them. The burnout doesn't wear the tire out as much as you think considering the water is there taking a lot of the friction away. As far as launching with 3.73's, I'd start with a 3000rpm clutch dump with a quick applocation of the throttle. It should hook at a good track.

And NO it's not the same for all tires. A normal street tire is not meant to be heated up and raced. It's meant to wear well and last for 20,000+ miles. Your drag radials are made of a different rubber and once heated, they become a lot stickier. You bought them because you need traction I'm assuming...So use them I will get over 10K miles out of mine and I have about 60 track passses on them already, each including a PROPER 5+ second burnout. I even autocross on these tires and they do extremely well. Goodluck!

 

yea i agree.....if you dont want to spin your drag radials....theres NO point to having them. in my experience cold drag radials are WORSE than warm street tires....believe me my Z is a daily driver and i beat the **** out of my drag radials...you get pretty decent life out of them....believe me I KNOW, I HAVE THEM.....dont listen to people who say burning your drag radials out once in awhile make them useless after like a couple thousand miles...im at 8000+ miles on mine and they still ave plenty of tread, plus they HOOK BIG TIME when their broken in....also i only havve 275/40/17 nittos.... 315s will last you just fine....BURN THEM GOOD.....when you see smoke in your mirrors, count to 6 or 7 and release the brake...theres really no other way to use drag radials...

BTW 18 PSI works best for me...

 

LOL you should probly release the gas too.

 

i usually dont, i let off the break and ride the burnout up to the tree...

 

In my experience the Drag radials need to be well heated to be of any good. I never run less than 20 psi, it seems to hurt my mph if I go lower (and somewhat the ET).
I did notice that anythin less than 16 psi cold before the burnout and it gets squirrely up top.
You could also be pulling away up top because youre a stick and they are autos with stock or simular mods.

 

You come asking for advice... then you don't listen to any of us.

What did you buy DR's for? If you "dont' have alot of money" you bought the wrong kind of tire. If you're not going to heat them up, they'll be the equivalent of a street tire that wears out quicker. You just wasted money right there.

"Fact" that you can rev higher b/c you have more spark? Get real, obviously you have no clue how a powerband works. I have 100% stock ignition and rev my cam'd Z to 6300... obviously it runs pretty well.