305/45R18.. will it fit?

[471_Magnum]

A little background first:

I've been relatively pleased with the 17" rolling stock on my car, but there has been one area that leaves something to be desired: straight line traction. These hard Nitto NT450s just won't hook behind 4.10 gears and 500+ lb*ft. I've got to pedal it through first and second gears. WOT isn't an option, even from a roll. Fun, but at the same time, frustrating. It's something I need to get a handle on.

Previously I ran 15" Nitto 555R Drag Radials and was very pleased with them as a dual purpose tire. Unfortunately, these aren't produced with a 28" diameter for a 17" rim. M&H makes a 275-50-17 that is perfect size-wise, but they aren't streetable.. at least not to the level I require. Everything else out there is 26" tall, which is too short, both for appearance and gearing.

So I'm facing a delima. Go back to 15" rolling stock, or... Nitto makes the 555R in a 305-45-18, which measures 28.78x12. With the 45 aspect ratio, it's got a reasonable amount of sidewall (~5.5"), so it won't look dorky, and it should hook reasonably well. But will it fit?

I've got a line on some 18x10 wheels with 5.25" back space. Not sure if that would be enough back space. That's about 1/4" negative offset. I know zero offset, or up to 1/2" positive offset would be better.

I ran negative offset (15x8.5 w/3.75 BS) with the 275-60-15's I previously ran, with only minor rubbing on BIG bumps. The 1/4" negative offset with the 305-45-18 should put the outboard edge in about the same spot, theoretically about 1/4" closer to the lip. Inboard side should be fine.

Budget is a big constraint here. This isn't a cost-no-object project. Buying new custom offset wheels is not an option. I'm trying to take advantage of an opportunity here that would result in minimal expense (assuming I can sell my old wheels and tires).

Anybody else running this much tire on a  2nd Gen Charger? NYCMille?

[firefighter3931]

There's plenty of room for a 29x12 in tire back there. A 295/65/15 will fit (29.5in tall x 12.5in wide) so i don't see you having any problems.

I tried a 30in et street on mine awhile back and it was a no go.....29.5in is pretty much the limit for diameter before you have to cut the wheelwells.

Fwiw a 325/50/15 wll also fit with a 15x10 wheel with 5.5in backspace. Those are over 13in wide at the section.


Ron

[471_Magnum]

Thanks!

The deal on the 18's fell through, but I won't rule out the combination for future consideration.

I figure the 325-50-15 combination would be REAL tight... too tight. I pretty much ruled it out as an option.  I'd like to see a car running this combo.

[firefighter3931]

Jim, there's a member here who runs that tire (325/15) on his second gen Charger....can't remember his name off hand but he's posted about it before.

Groove Daddy over at Moparts runs a tire shop in Michigan and has that tire on his car with 15x10 prostars (5.5in backspace) and no problems. He's sold plenty of those to his customers.....maybe contact him for some feedback. I beleve he manages a shop called Harlow Tire in the Detroit area.

R2 on this board used to run the 325's before he switched to the 295/65/15's on a 15x8 with 4.5 backspace and they also fit nice on that wheel as well. The 325's are 28in tall in case you were wondering.

Ron

[471_Magnum]

I did a search and found some pics. The tire were bias plys, but it proves the point. Wouldn't mind seeing some others though.

Now to find some 15x10 rims...

[firefighter3931]

The new MT drag Radials are supposed to be awesome....much better than the BFG equivelant D/R. I'd think those would solve your traction issues. Member Blown71X at Moparts ran a 275/60 on his car well into the mid 10's and said that they hooked better than anything he'd ran before....slicks included....and felt more stable at the big end due to the car's weight (4100 lbs). Tony with the 470 SR headed stroker wagon also runs 10's with the same tire & xhd springs. 

That's impressive for a relatively small tire, inmo. I just figures that i've got a brand new set of BFG 295's waiting to be mounted....and now these MT's come out !  Oh well....once they're finished i know which tire i'll go to next. 

I've also read that certain events won't recognize the MT street radial as a legitimate street tire because it hooks so hard. Imagine, a DOT stiiffwall radial tire banned from racing in the class it's designed for because it works too good ! 

Ron

[471_Magnum]

I can appreciate the potential of the MTs. Remember though, this is a stick shifted car. I don't want to hook too hard. I still want the tires to be the engineered weak link.

[firefighter3931]

I can appreciate the potential of the MTs. Remember though, this is a stick shifted car. I don't want to hook too hard. I still want the tires to be the engineered weak link.

I'm sure there'll still be some spin on the street....big difference from a prepped track.  I agree....the dead hook will eventually hurt something in the drivetrain....but i don't see any street tire dead hooking on the ashphalt....you'll still get some spin, i would think.

Ron

[Rolling_Thunder]

here you go -  325/50/15...      15X10 with 5.5" backspacing and stock leaf spring location

[471_Magnum]

Looks good from that angle.  Any other shots?

Problem with the 10" rims is that I want something "retro". All the retro stuff has limited back space, with the exception of Magnums. Torq Thrusts are what I've got envisioned at the moment

[Rolling_Thunder]

that pic was posted on the old board...     I dont have any other shots of it - sorry ...       torque thrusts ?   hmmm   

[Blakcharger440]

here you go -  325/50/15...      15X10 with 5.5" backspacing and stock leaf spring location

It doesnt look like that car is at stock ride height in the rear. He must be running super stock springs as those
make the car sit a little higher. Nice Charger tho.

[Silver R/T]

nice setup, I want to go with 325/50/15 in future