Droptopp

Good Morning,

I picked up a set of Nitto Drag radials 345 30 19 for use on my corvette zr1 conversion. 630 rwhp. I have about 100 miles on them and used them at the track last night and just could not get them to hook up. Quite dangerous actually. Rather surprising as the reviews from other corvette owners are these things hook.

What psi should these be put at at the track? On the street I use 32 lbs and they seem to hook up reasonably well. I tried 20 at the track and Broke up all down the track and would not hook out the hole at all.

Any thought? Is there a mold release used that could cause this?

Best Regards,

JUIC3D

Did you heat cycle them properly before going to the track? My buddy just bought a brand new set of Mickeys, and drove straight to the track. His tires were so shiny from the oils coming out of the sidewalls when they heated up.

In short, you need to heat cycle drag radials before going to the track with them. Heat cycling consists of bring them up to temp, then letting them cool for 24 hours. Bring them up to temp again and let them cool for 24 hours. Bring them up to temp again and then they should be ready to go.

FRDnemesis

I'm not saying you're wrong, but I've never heard of that for a Drag radial and I've been using DR's for 12 years. However, I have heard of that for road race compound tires.

OP, a lot of your tire pressures for the track are going to have multiple variables: launch technique, track prep, humidity in the air putting moisture on the track (if at night), weight transfer capabilities of your car, heat of the track, heat in the tire and of course air pressure in the tires. Most even run 1/2-1psi more in the right rear than the left rear.

Radial tires can be much more finicky than a bias-ply tire. But, once you get them figured out to what works for your car and your launch technique, its all fine-tuning from there.

-jeff

JUIC3D

The heat cycle I described was recommended to me by Spinmonster and after doin my own due diligence with what other people were doing, it all coincided.

Sure, if you just want a sticky tire that beats a street tire, you might not need to take the extra steps to make sure they're heat cycled properly. But if you're like me, and chasing every last .01 and .001, everything matters and I make sure to follow the recommend protocol.

jsnolan

don't know where you got the Nitto's, but I got mine from Discount Tires Direct, and they recommend a heat cycle. Of coarse they are happy to offer it for just $15 per tire.
I don't know if it is necessary, but I know once mine are heated up I don't have a problem. but then again, I don't have 630 RWHP either.

turbotuner20v

Is your tread 'peeling'? Almost looks like someone took a cheese grater to it?

I had a bad batch of nt05r's that I sent back, they went to **** in under 200 miles and wouldn't hold 560whp.

The replacements have lasted me thousands of miles, a few track days and still hook well when warm at 630whp.

antman69

14 psi after good burnout works well @ 652 RWHP for me. Run them everyday (except of course in rain)

FloydSummerOf68

How long of a burnout? How much smoke?

I've never heat-cycled a drag radial either and never had a problem and I've run 5 different sets from nitto, MT and BFG. That's not to say a heat-cycle isn't a good idea though, I've just never had problems hooking up in a car without doing it.

camirocz

You dont need to heat cycle the tires ,thats b.s .You should be hooking up very well given your h.p.Clean them when exiting the water until you feel them grabbing.Its that simple

dennis50nj

with Justin, i have tried with many brands and sizes and if heat cycled before the track they hook with a short burnout first pass, if new it takes 5-6 passes of long burnouts the first day then long burnouts the whole life of the tire to hook

Crowhater

I go to the track pretty often and I can't remember seeing anyone get real traction from a 19" tire. I sure you could make it work if your setup was tweaked for it but what a nightmare. There is just no sidewall on a 19" tire. I can hook a 275-17 Hoosier like glue, 1.45sec 60' and run a low 10 with ease.

I have run a real ZR1 down the 1/4 mile and it was hopeless until the end of third gear.

FloydSummerOf68

That ZR1 also wasn't on a drag radial :P

The 19" NT05Rs have gone 1.4s and plenty of people run them into the 1.6s

Justasheet

Did he say this was a NT05Rs? I had Nitto 555's and they never stuck once I added a cam let alone we're talking about a ZR1 in this case.
Jeff

RichieRichZ06

I run them and have over 50 passes on them with good results. Once I got the pressures and launch technique figured out, I was able to consistantly lay down 1.5x and low 1.6x short times. I usually run them at 16.5-17.5 PSI and they will hook if the track is prepped decently.

Justasheet

Are you running 630 hp like the OP?
Jeff

stanger383

when I put my new DRs on late this spring I did a huge burn out on my way to work(on a closed course) and then parked in the air conditioned shop all day. When I went to the track that night I dead hooked to a 1.42-60' If I remember right. That same set of DRs netted two 1.32s friday MIR. These are 275-40-17s so it's not the same tire but that's the process I used.

Justasheet

I think that is the preferable setup to these Nitto 19's.
Jeff

FloydSummerOf68

Yes, just not directly

Also, just to clarify, a nitto 555 is a lot different than a 555R as well.

I run a 275 nitto 555R and have run them down to 1.60s and went 11.2s only limited by power. I know they'd easily take me into the 10s now that I have the blower on the car although I know they wouldn't hold all of the power.

Justasheet

I see what you mean, NT05R is for a 19" rim in that size. I had the Nitto555R and they wouldn't stick as soon as I added my cam. I ordered a set of MT's and they stuck like glue. I'm glad you had better results.

FloydSummerOf68

No doubt the MT's are way stickier.

The 555Rs take a LOT of heat to hook. A strong 8 second burnout and they hooked up pretty well, but it was also dependent on track prep.