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Topic: Anybody get 275 tires on the front? (Read 1577 times) previous topic - next topic

Anybody get 275 tires on the front?

I am looking at getting a new suspension and tire setup for autox for next year.  I am considering getting some coilovers(are the ebay ones worth anything or what brand should I get(have bilstiens struts right now) and am also trying to get some 275/40/17 hoosier autox tires on the front and 295/35/17 tires on the rear.  What kind of issues am I going to run into running 17x9 wheels w/20mm offset(5.71"+2mm backspace) and 17x10 w/25mm offset(backspacing is wierd on these where I'm lookinghttp://www.latemodelrestoration.com/wheelpit?l=4&c=&d=17&f=&b=&w=10.00&o=&bs=&k= )  I havent been able to find much in the way of fitting this big a tire anywhere but then again people seem to be having trouble with rubbing with 245's.  I was running 245/50/15's all season this year, and had no problems whatsoever, and it seemed like there was still decent clearance to the strut.  This was with 15x7 wheels, but dont know what backspace those wheels have right off hand(old american racing forged aluminum mesh wheels)

88 t-bird tc - 14.97 @ 90  IHI 18 psi + k+n filter...so far - NOW HX-35 @25psi - 12.75@112    348rwhp/395rwtq
78 F-150 - 11.61@120 on 175shot N20 - 12.55@110 on motor - 5200# race weight:hick:

Anybody get 275 tires on the front?

Reply #1
Yeah, my 245/45/17's on 17x9's  (25mm offset) clear the strut by 1/4" and you can see that they are about flush with the fender lip. Perhaps someone else has fit larger - you gain a bit due to the 20mm BS, but the tire may stick out a bit - especially a 275. You'd probably need to stay at stock ride height or find a very round sidewall tire with less tread width.

11.96 @ 118 MPH old 306 KB; 428W coming soon.

Anybody get 275 tires on the front?

Reply #2
I've got 265R35 +20 offset 18x9s up front, 275R35 +40 offset 18x9s in back.  There's room in the back for a little more but not the front.  You might consider going with a larger diameter up front, you'll get a little more clearance on the backside.

Or you can go old school, run plenty of offset with short tires and not worry about keeping the outside tucked.  Just be careful of the cones. That extra inch or so on each side really makes the car seem wide between gates.
__________________
Twin '85 TCs
White/ Grey 2-tone
#1 (left): undergoing top-to-bottom rebuild     
#2 (right): DD, power everything (sorta)
[SIGPIC][/SIGPIC]

Anybody get 275 tires on the front?

Reply #3
actually my 245's stuck out but when they went up they also went in, so I dont care if they stick out, but I will have to find a good spring that wont allow the car to body roll as much.  I have the biggest sway bars I could find on the car already(1 3/8" front and 1" rear).  I'm looking for wider tires because the car still wants to push through the corners.  I'm aiming to be really close to the local national street modified champion in his civic hatch, but it is becoming difficult to make a decision on what to do suspension wise

88 t-bird tc - 14.97 @ 90  IHI 18 psi + k+n filter...so far - NOW HX-35 @25psi - 12.75@112    348rwhp/395rwtq
78 F-150 - 11.61@120 on 175shot N20 - 12.55@110 on motor - 5200# race weight:hick:

Anybody get 275 tires on the front?

Reply #4
255 is about as big as you can get in there without it chewing up the fenderlip.

To get the car to stop pushing you need a lot of spring up front because 'birds are heavy. Something in the 1,000 lbs/inch range. Also run as much negative camber as the rules will allow.....at least 2 to 2 1/2 degrees and toe it out.....this helps a lot in slower speed slalom type, parking lot racing. Stiffer sway bars won't alleviate the problem as the bars you have are huge as it is. It's far better to control roll with spring rates than giant swaybars. Ever look under a Vette and look at their swaybars? They're tiny in comparison.

Anybody get 275 tires on the front?

Reply #5
well, thats kinda why I was considering going to coilovers so that I could put a stiff spring on it and raise the car if I have to to keep it off the tires.  I have MM C/C plates that I flipped over to get more camber and caster which gave it a noticable toe out, and it helped for that first day but it seems to have gone back to pushing bad again.

88 t-bird tc - 14.97 @ 90  IHI 18 psi + k+n filter...so far - NOW HX-35 @25psi - 12.75@112    348rwhp/395rwtq
78 F-150 - 11.61@120 on 175shot N20 - 12.55@110 on motor - 5200# race weight:hick:

Anybody get 275 tires on the front?

Reply #6
What have you done to the suspension?
__________________
Twin '85 TCs
White/ Grey 2-tone
#1 (left): undergoing top-to-bottom rebuild     
#2 (right): DD, power everything (sorta)
[SIGPIC][/SIGPIC]

Anybody get 275 tires on the front?

Reply #7
I myself havent done anything to it other than swaybars, but I think its on stock replacement springs and bilstien front struts and MM c/c plates, rear monroe sensatrac shocks, previous owner went through and replaced all bushings, but I plan to replace at least the front with polyurethane, and I put on stainless braided brake lines and new semimetallic pads.  Other than that, I dont know what else has been done.

Dad had a new set of 315/35/17 hoosier tires sitting there so I test fitted them and there is no possibility of those EVER going on.

88 t-bird tc - 14.97 @ 90  IHI 18 psi + k+n filter...so far - NOW HX-35 @25psi - 12.75@112    348rwhp/395rwtq
78 F-150 - 11.61@120 on 175shot N20 - 12.55@110 on motor - 5200# race weight:hick:

Anybody get 275 tires on the front?

Reply #8
I don't have much seat time in the 87-88s but my experience is that TCs are a little tail happy, so it's surprising to hear your car's plowing.  I'd suggest that you try these steps individually until it handles the way you like
1) get it aligned so you know what the settings are
2) get a uniform set of shocks/struts (I'd suggest adj Konis),
3) put the stock front bar back on it

Independent of those steps, definitely install the ss lines and move the battery to the trunk.
__________________
Twin '85 TCs
White/ Grey 2-tone
#1 (left): undergoing top-to-bottom rebuild     
#2 (right): DD, power everything (sorta)
[SIGPIC][/SIGPIC]

Anybody get 275 tires on the front?

Reply #9
Put a smaller  sway bar in the front.  If you're pushing hard (understeer) this will actually help a bit.
-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

Anybody get 275 tires on the front?

Reply #10
I know my car is not a mustang, but I wish I knew what suspension and tire setup this guy is running

88 t-bird tc - 14.97 @ 90  IHI 18 psi + k+n filter...so far - NOW HX-35 @25psi - 12.75@112    348rwhp/395rwtq
78 F-150 - 11.61@120 on 175shot N20 - 12.55@110 on motor - 5200# race weight:hick:

Anybody get 275 tires on the front?

Reply #11
:bowdown:
home ported E7's, HO intake, 93 Tbird cam, 65mm tb, Shorties, dynomax lers, TC 3.73 rear, Mach 1 springs, Bauman shiftkit, epoxy mod, SD, 3G alt, black magic fan

 

Anybody get 275 tires on the front?

Reply #12
Well, I ended up ordering some motorsport c springs today.  See how much work it is to get them to fit right on the back, lol

88 t-bird tc - 14.97 @ 90  IHI 18 psi + k+n filter...so far - NOW HX-35 @25psi - 12.75@112    348rwhp/395rwtq
78 F-150 - 11.61@120 on 175shot N20 - 12.55@110 on motor - 5200# race weight:hick: