Iam thinking of buying a set of drag radials for the track. On a 03 Z with a Blackwing should I be concerned about breakage of the rear and clutch. I only plan on going to the track about 6 times a year. Thanks.

 

Yes, anything can happen. To reduce your risk start with the tires around 20-24psi and slip the clutch and try and keep the launch rpms below 5000. After you start maximizing your setup then, on a cool night I would try a few all out runs at different psi's to see what you can muster up.

 

I usually run mine at 16 to 18 PSI and launch at 3500RPM. Works for me!

 

I run mine at 16 PSI and launch at 3000RPM. M/T Street radials stick and go. Havent had a bit of problems.

 

what are you guys using for longer studs? you all have an arp part number?

 

If you choose wheels with the correct offset for your car, the stock studs will work perfectly.

Ranger

 

yea i kinda guessed that but incase i grab some grand sport wheels i may need to get longer ones. i may stick with a set of z fronts and thow them outback with some mt radials. i could try the bfg's drags on my stockers but its still a toss up right now. going to do a clutch and left shaft before i start stressing the rear case or spin the clutch and get stuck on the other side of the island at the track.

 

C5Z front wheels with MT ET Street Radial is a good approach. Properly heated, they hook well enough to require 600-1000 higher launch rpm than BFG DRs on the same wheel. That makes for better 60' but at the expense of higher wear on the clutch. ET Radials on a C5Z need 20-24 psi. Don't listen to the folks saying 12-16. Its way too low for this car. But if you're spraying off the line, you might experiment starting high and dropping slowly as you learn them.

Ranger

 

Ranger, what is your opinion/insight on the ET Streets vs ET Radials? I have heard that they are real close in performance. I will be spraying up to 150hp shot out of the hole, at about 5500rpm (torque will be 5xx). I am trying to get 1.4xs, and do know that some get into that area on the ET Streets (Rob Z). I will also be running the stock Z06 front tire, and am wondering how loose it will get with the bias ply on the rear. The rear set-up will be on 17" front Z06 wheels. Thanks in advance.
Robert

 

Hi Robert.

(1) Performance. The nod should go ...slightly to the ET bias because its sidewall will wrinkle to help absorb launch shock. The ET radial won't wrinkle. So the bias should do a better job of capturing the inertia of the flywheel on a high rpm launch. Robz is pretty much the champ at that but was using 5500-6000 range when I watched him in Nov-Dec 2004. Others do "on the limiter." Robz launches lower with better resullts.

That's said, however, with the understanding that the fast crowd settled on the ET bias because there was no alternative. So a true widespread comparison between the two tires has not been done. MT staff did a compro and said the ET radial gave a faster 60' but some saw that as hype for the new radial's sale's release. Stealth has run ET radials on his 9 sec FI car and gotten low 1.4x. His ride is an automatic now.

(2) Safety
Radial front + radial rear = safe
radial front + bias rear = squirrelly at speed

Some guys manage to mix radial and bias and deal with the squirrelly handling from the 660' on. But, for me, I'd rather focus on staying in the groove rather that fighting to keep control at 12X mph. Dr Ron and others have successfully done the mixed tires, saying they got used to it. I wouldn't personally take that risk.

Good luck either way.

Ranger

 

Ranger makes some great points.
Here is some additional info that may help.
I usually run 10-12 psi @5500-6000 rpms MT et streets 26x11.5x16.

I will be experimenting with others tires soon.

1)MT et street radial in 16" (stealth has cut 1.3x's high w/auto/turbo)
2)M&H 12x16 (guys have cut 1.3x high with auto/drag shocks/stroker)
3)M&H 11.5x26x16 (ErnieK uses these cutting the same 60's as et streets with more psi)

So, it has been proven that most all of these tires are capable of a high 1.3x but can it be done with a Manual with stock suspension and a 346 n/a ? I think so, but just not sure what tire will make it easiest.

I have taken 2 passes only with mt et street radials in 17" inch at 16-18psi in my friends car with about 450rwhp.(simpleman) He had street tires up front and the 60' were 1.51/1.52. I would have been able to break into the 1.4x's for sure with a few more passes but I noticed the tire would skip very slightly at the latter part of the 60' which definitley hurt. Not sure exactly why but it was tire slip. Hooked good off the line then a slip. That same day I was able to cut low 1.4x's with mt et streets on my car.
So, I believe the 16" et streets(cheater slicks) are slightly better for hooking at the launch particularly for manual cars. Auto's might be a slighltly different story. And, I believe the 16" MT et street radials hooks better than the 17" Mt et street radial.

As for squirliness, I have run my 16" et streets(10-12psi) a few times without skinnies and notice at 124 mph+ it gets pretty hairy. The more pressure you run the less squirly but for the most part if your running 16" tires out back then get the skinnies.
As for the 17" mt et streets(cheater slicks), they are less squirly than the 16" tires and can be pushed more at high mph.
The reason guys like Ronnie have not had top end instability are with 17"et streets and stock tires up front are:

1) He runs higher pressures (18-22)
2) He is not trapping so high (116-122mph)
3) The 17's are more forgiving on the high end

I have seen autos run 9.9's with 17" mt etstreets and stock tires up front. (I believe the tire pressure was around 12 psi). So, it can be done but manual cars tend to break traction more easliy IMO and it's better to err on the safe side.Skinnies are the safer route.

IMO, If you plan on running MT et streets(cheater slick) in size 17" with stock tires up front you should be aware of a few things that will make this setup more unstable on the high end:
1)Tire pressure in rears below 14psi
2)If your trapping 128+
3)Cold track/cold ambient temp/poor prep.
With 150 shot you will likely want the tires in the 12 psi range and you will likely trap over 128mph so be careful.
I believe either tire will get you in the 10's convincingly just make sure you do it safely.
My advice:
Take it slow with the Nitrous and make sure your comfy on the high end before you lower the rears too much in search of that great 60" time. Goodluck!

 

I have exactly what you need

http://forums.corvetteforum.com/show....php?t=1409208

 

robz - Why would running skinnies up front make the bias tires (at what might be considered low pressure 10lbs) more stable. I understand both would then be bias so you aren't mixing types and that helps but is there anything else to that?

 

Yes, the skinnies input very little on steering/handling which keeps the car from jutting back and forth. You may notice that on your street setup at high speeds on crowned roads the car will dart around.
They also don't drag water, rocks and debris as much.

 

Thanks, robz for the great perspective on the MT options. Excellent write-up.

Just what Robert56 needed.

Ranger

 

What kinda hp is your car making on the juice?

 

Currently 485rwhp and 510torque, however, the shot is going to be boosted, with 150 out of the hole, then another 50 coming on in 2nd gear.

Thanks Ranger and Rob Z, some good input/info..
Robert