So as some of you know I recently finished my LS1/TH400 swap on my Z. I am starting to prep my car for the track in spring and on my long list of things to do is slicks and wheels. Below is a link to the wheels I am going to buy.

http://www.summitracing.com/parts/SUM-571-5866PS/


My car is 322whp right now through the TH400. This winter I am spending the majority of my time lightening the car. I will be doing some additional work such as a fuel cell, differential brace and a 75-100hp wet shot of nitrous. Suspension will remain stock for now. I am also running a 3600rpm stall and no trans brake just yet. Solid motor mounts.

I am not planning on running the nitrous until I get the car dialed in properly. However, I want to make sure that the tires I buy can handle launching with the nitrous off the line but aren't overkill. Below is some information and calculations on my drivetrain.

Specs
1st Gear Ratio: 2.48:1
2nd Gear Ratio: 1.48:1
3rd Gear Ratio: 1.0:1
Final Drive Ratio: 3.538:1

Speed Calculations
Tire Diameter: 27.0"
Redline: 6,000rpm's
1st Gear: 55mph
2nd Gear: 92mph
3rd Gear: 136mph

Tire Diameter: 28.0"
Redline: 6,000rpm's
1st Gear: 57mph
2nd Gear: 95mph
3rd Gear: 141mph

There isn't a huge difference in mph so I am leaning towards the smaller tires. I am looking for slicks that I swap on at the track.

Can anyone recommend a specific tire that would suit my setup? Maybe even a 26" diameter(?).

 

I used a 275/50/15 MT DR on the same size wheels....plenty of stick (perhaps too much) at 280/260. Be plenty of tire for you with a good burnout. The 275/60 is also an option, but I wouldn't at your hp level without the giggle gas.

Edit because pics are best...
275/50/15 on stock suspension:

 

You did lots of homework. I think this will work out well.

27.0 inch tires. No way will 322 horsepower plus nitrous reach 136 MPH. You will have plenty of room at the top.

http://www.wallaceracing.com/et-hp-mph.php

Did you run numbers for 26.0 inch tires?

ET street or slicks and width. This is generally a class question. If you run in a DOT class than you must run DOT tires. If you run in a 10 inch slick class than maximum tire width is 10.0 inches.

 

Tire Diameter: 26.0"
Redline: 6,000rpm's
1st Gear: 53mph
2nd Gear: 89mph
3rd Gear: 131mph

I might as well go with a 26" tire since I should be able to run mid tens with that mph through the TH400 (and additional HP of course). I can always raise my redline after I do the valve train in order to adjust my top mph. 26" with a 6800 rpm redline would top out at 149mph which is way more than I need.

I don't really have plans on running in a class. Just "fun racing", so there is no tire requirements.

What about these tires?
http://www.summitracing.com/parts/HOO-18120D06/
http://www.summitracing.com/parts/MTT-3052/

 

26.0 inches and 131 MPH is good. You still have room at the top to spare.

Either of the slicks that you listed is good. For “fun racing” you may want to have a couple of spare rear axles in the garage.

 

I thought 131 was acceptable also. Like I said, I can adjust redline to suit my car as I increase power.

I plan on scoping out some junk yards for some spares axles soon.

 

The gearing is wayyyy to long in that setup IMO

Ideally you want to be near peak power as you cross the line, from reading those tire diameters you will barely be into 3rd gear and thats no bueno.

Of course the N20 setup will be better, but Id honestly go 26" in your case.

 

I'd agree that his gearing isn't ideal for the 1/4, but given that he has a th400 he will need to concede a little if this is going to be street driven. With 320 through that power robber.....he should still trap 110-113 easy on the motor.

Also, Quamen, I would go with the 26x10.5. The 8.5/9 is way too narrow.

 

I agree that the gearing is way to long right now. I could put a 3.9 in the back but then my top speed would be 119 which would be good for a while.

My peak power is at 5500 rpm's FYI. With the stock gearing, 26" tires and no nitrous I think I will only be 500rpm's short of peak power in 3rd gear based on my calculations assuming I trap 109.

 

If that is the case then that is perfect!

Good luck Im curious to see what your new setup can do. Id think mid 12's easy NA

 

Anyone else have input on width?

 

I'd go lower than that....I think 12.0-12.1 at 320whp through a th400. He should be able to pull 1.6's even through the IRS rear with his tq and gearing. I'll say 12.10 at 111 with a high 1.6. That 3600 stall is pretty ideal as well.

 

So you think I should run something more like these:
http://www.summitracing.com/parts/MTT-3053/
http://www.summitracing.com/parts/HOO-18131/

I would go with the MT's most likely since they are slightly smaller in diameter.

Any comments on compounds?

 

Anyone?

Should I be using 8", 9" or 10" slicks?

 

With an 8" wheel....26x10.5" Slick. Both hoosier and MT make a a perfect tire for you. It is personal brand preference. We don't have a particularly large drag racing community....if you want some additional opinions I would look at some other platform websites. Good Luck.

 

Hate to say it bud but those rims from summit really blow a$$. Although they are cheap for another 40 bucks per wheel you can get welds.They are a solid rims (which you can for sure notice when you look at the wieght). I had a set (of the summit rims)for my frontrunners and practically gave them away to get rid of them. But anyways I run 9.5 weld magnums in the rear. the spec of the rim are 15x 9.5 with 5.5 backspace. The tires i run are 275 50 15's. I want to say i run around a 26.8 diam. Anyways hope this helps. Talk soon mike

 

Those wheels are $$$

Look sick though!

 

I never heard welds going for cheap but he said like another 40 bucks? Ima check em out... I too have an interest in this....

 

U meant another $400 bucks.....I jus checked and saw nothing that cheap..


Link to low price weld magnum wheels or I call bs.....lolzzzz seriously!

 

I didnt say that weld magnums are anywhere near cheap guys. What i was saying is that the summit style wheel pictured at the top of this thread (which is identical looking to a weld wheel) is a solid rim. Welds are a 2 pice and some time 3 piece constructed wheel. And for 40$-60$ more you can get the real draglights. I had them before the magnums and made the mistake of powdercoating them black (stealth) but in turn it looked like i had 4 spares on the car. Hope this helps guys. Tried to find the weight comparison for the rims but no dice later mike





http://www.summitracing.com/parts/SUM-521-5166PS25/
vs
http://www.summitracing.com/parts/WLD-90-510350/