Tire issues

Scufty · #1 (**permalink**) 08-11-2008, 05:19 PM

Ok I have a butler with MT Competitors 315/50-15's I am having a hell of a tough time matching these up ..I would like to go MT again or maybe Gpood Year but my issue is just sizing the darn things ...how much wider will a 325/50-15 be? I dont have alot of room for a wider tire I dont think?
anyone else running these and if so where can I get that same size tire ...arghh

vanoochka · #2 (**permalink**) 08-11-2008, 06:23 PM

Your 315/50/15's are about 12.4" wide, sidewall to sidewall, and 27.4" in outside diameter.

The 325/50/15's are about 12.8" wide, sidewall to sidewall, and 27.8" in outside diameter.

Scufty · #3 (**permalink**) 08-11-2008, 06:54 PM

Thanks alot ...so very little difference really
anyone tried the MT street radials ..what ya think

vanoochka · #4 (**permalink**) 08-11-2008, 07:43 PM

I just ordered a set this weekend to replace my old, slippery Goodyears (not BB's). I've been exchanging PM's with some Cobra owners who run them and concluded they are the best choice for me.

Avons are clearly superior, but I would never push them enough to realize their benefits, so why kid myself and pay almost twice as much?

I'm moving from 275/60/15 to 325/50/15 on the rears, and keeping the fronts at 255/60/15. I'll pick up almost 2" in width and lose only .2" in diameter. Can't wait to finally experience what it feels like to hook up the tires.

Good luck with them.

Got the Bug · #5 (**permalink**) 08-11-2008, 10:23 PM

Hey Chuck,

Did you go with the MT Sportsman Radials (http://www.mickeythompsontires.com/s...em=SportsmanSR ) or the MT ET Street Radial (http://www.mickeythompsontires.com/s...ETStreetRadial)?

vanoochka · #6 (**permalink**) 08-11-2008, 11:12 PM

Quote:

Originally Posted by Got the Bug

Hey Chuck,

Did you go with the MT Sportsman Radials?

Hey Doug,

That's a timely question. About 30 minutes ago, I read another post on the topic of MT E/T's in a different thread and had one of those moments of clarity. The post questioned the sanity of putting tires made for the rear of a drag car on the front of a Cobra.

I thought that was a pretty good point.

So, although I had originally ordered the E/T's, I just cancelled them and went to the Sportsman S/R's. The Sportsman tire chart uses a non-metric sizing convention, so I am now getting 28x10.00R15LT on the front and 28x12.00x15LT on the back.

The fronts are basically the same as I now have. The rears will be over 1" wider than what I now have, but about 3/4" less than what I was going to.

The rear diameter will be the same as now. The front will be 1" greater, so the car will sit about 1/2" higher in the front. Seems a fair trade.

The Sportsmans will be much better in the corners. Although I don't track, it's worth a few extra bucks for the safety factor. As you know, my current tires let go totally without notice, which is getting tedious.

AND I noticed the Sportsmans are 6 lbs. ligher per tire than the E/T's!

Chuck

Got the Bug · #7 (**permalink**) 08-11-2008, 11:29 PM

Chuck,

Some people swear by the ET street radials, but for all around driving (i.e. slightly wet mountain roads) it makes a lot of sense to put the Sportsman tires on all four corners. Here's a picture of Tom Howland's cars with the tires....they look nice and sticky.

You're gonna be happy with those.

vanoochka · #8 (**permalink**) 08-12-2008, 10:15 AM

Thanks Doug,

Nice!

They are going to look even better with yellow lettering!

Chuck

Scufty · #9 (**permalink**) 08-12-2008, 05:01 PM

isnt the 325/50/15 about 13.5 inches wide and the 28 12.0 about 12 inches wide

big difference no?
what size rims ...I have this ..what are the suggestions ..cripes now Im comp[letely confused
I have
255/60/15-front
315/50/15-back
Need a size thats damm near the same on front and back
I have very little room to go wider due to a suspension part on the back

Scufty · #10 (**permalink**) 08-12-2008, 05:19 PM

ok I think I have this figured ..Ithink you are pretty much bang on Chuck for me too
I think I will go with 28-12-15 for back and 28-10-15 front...the only thought I have is that the present 255/60/15's are 27 tall....do I go with the 28 tall or a 26 tall?
hummm

Scufty · #11 (**permalink**) 08-12-2008, 05:27 PM

I think the ass sits a little low now as it is so maybe the 26's would be better?

vanoochka · #12 (**permalink**) 08-12-2008, 05:38 PM

Scufty,

All the different sizing conventions do make it confusing. Let me give it a try...

A straight conversion of your current, 315/50/15 would be 27.4x12.4/15.

Now, if you compare your current tires to the 28x12.00x15LT Sportsman S/R tires it's easy to see that the Sportsmans are .6" greater in outside diameter (28-27.4) and .4" narrower from sidewall to sidewall (12.4-12).

A straight conversion of 325/50/15 is 27.8x12.8/15. So, the Sportsmans are .2" greater in OD (28-27.8), and .8" less S2S (12.8-12).

The S2S on the Sportsman fronts is basically the same, but they are 1" greater in OD than your current, so you car will sit about 1/2" higher in the front.

So, not too different all around from what you are currently running, but almost 1" less width on the rears than what you were planning on going to.

Keep in mind there are plenty of people on this site who absolutely swear by the E/
T's, so please don't let my decision to swithch knock them out of the box for you.

If you really want those wide tires on the back, an option is to run the E/T's on the back and the Sportsman S/R's on the front. M/T approves of this setup.

Good luck.

Chuck

RedBarchetta · #13 (**permalink**) 08-12-2008, 06:30 PM

If any of you guys are interested in buying my complete set-up, send me an e-mail. Look in my gallery for pics on how these bad boys fit nicely on an SPF.

The rear Trigos have been widened to 10.5" (new inner half using an automatic wheel welder...the best equip and done pro) and machined (to clear the caliper if you eliminate the 1/2" spacer on the Trigo adapter). The front Trigos are stock. All are five pin factory SPF. I have pics in my gallery of the bare rear rims after they were widened/machined.

Tires are MT ET Drag Radials. 255/60-15 on front and 325/50-15 on back. Tires have about 600-700 miles on them and have NEVER (God as my witness) experienced any form of burnout. I'd snap half-shafts otherwise. You can shoehorn a 325 on a stock 9.5" rim, but it will bulge the sidewalls and the tires won't "settle" as well. The extra inch makes a big difference. These tires grip like mad...no more wheel spin on hard 1-2 and 2-3 shifts.

I have a complete set of new Trigos that I want to mount Goodyear Billboards on. So something has to go (I really do love my wife...I really do!) and I've decided to see what I can get for the rolling stock on the car at the moment.

-Dean #747

Got the Bug · #14 (**permalink**) 08-12-2008, 09:05 PM

Dean,

I saw your car flash by as a featured ad this afternoon. I looked tonight and it was listed as "SOLD!" That was fast! New project?

Scufty · #15 (**permalink**) 08-12-2008, 10:12 PM

alright why on MT site does it state that the ET street radials in a 325 50 15 have a width of 13.5 inches or actual width of 13.1 ..I thought 325 50 15 translated to a 12.8 wide tire?

vanoochka · #16 (**permalink**) 08-12-2008, 11:46 PM

I've been told, and have read - but don't know this for certain - that there is up to a 3% variation, from manufacturer to manufacturer, within each size. That's why I used the word "about" when describing your tire size in my 1st reply. The 13.1" sidewall to sidewall width falls within that 3% tolerance, relative to 12.8" and only extends the outer sidewall of the tire by .15" compared to a 12.8" tire. Mouse nuts.

The graphic below gives you an idea of the different elements that can be measured. The 13.5" from MT can only refer to the overall width. The overall width of you current tires is also wider than your current sidewall to sidewall width, so don't worry too much about it; it's relative.

The 12.8" or 13.1" or 325mm measures the sidewall to sidewall width, aka section width in the graphic below.

BTW, the section width of the tire on your car could be different than stated by MT if your rims are a different width than the measuring rim. I checked the MT chart and the measuring rim they used was 10". Don't worry too much about that. I just tossed it in to get you even more confused.

Bottom line: if you had clearance for the 12.8" tire, you have clearance for the 13.1"/13.5" tire.

bret a ewing · #17 (**permalink**) 08-13-2008, 07:51 AM

Your right, check the Tirerack, it will show the tire specs of many different models.

Scufty · #18 (**permalink**) 08-13-2008, 09:10 AM

well heres the consensus. I talked to our local speed shop and he says the Sportsman S/R will be the best tire for my need and can have what I need in 2 days. I drive my car on the street not the track and I think that will be the way to go for me
28 10 15 front replaces 255/60 15
28 12 15 rear replaces 315/50 15

sounds right ?

bret a ewing · #19 (**permalink**) 08-13-2008, 09:14 AM

You bet Scufty,

Check your sizes, make sure they will fit. I could not fit those sneakers on my car without some rubbing.

F: 245
R: 295

Bret.

vanoochka · #20 (**permalink**) 08-13-2008, 09:22 AM

Scrufty,

Those are exactly what I ordered, so I hope they work out great for you! My local speed shop will match summitracing.com prices, which saved me more than a few bucks. Ask if your shop has the same policy.

Good luck with them,

Chuck