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#1
05-31-2013, 12:34 PM
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MT ET 255/60 15's Radials
If someone is running these could you take a quick tire height measurement please? Just a quick look with a tape measure and note weather they are on the car or off and rim width please. I’ve read the advertised numbers but they are just that, “advertised” in some cases. My BFG’s of the same size are considerably shorter than 27.1" on my 7” Rally II’s. Thanks.
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 68 Firebird, trying a q-jet now. 434/10.5:1/997's/240-242 HFT/4L80E/2800 Yank/3.42's/ Vintage Air/ 13.0 @105 mph 70 Lemans, 350/350, A/C, mostly stock 14 Ram CC, 5.7 Hemi, 8-speed, 3.92 lsd 97 Trans Am, HPP Aug 2012 http://www.highperformancepontiac.co...tiac_trans_am/ ***Sold*** |
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#2
05-31-2013, 12:38 PM
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With weight sitting on them I'm seeing 26" tall with the tape measure. They are completely worn down so the grooves are just about non-existant. They may "grow" to 27" on the run, not sure?......Cliff
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#3
05-31-2013, 01:23 PM
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Thanks for the quick reply Cliff, I really appreciate it.
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68 Firebird, trying a q-jet now. 434/10.5:1/997's/240-242 HFT/4L80E/2800 Yank/3.42's/ Vintage Air/ 13.0 @105 mph 70 Lemans, 350/350, A/C, mostly stock 14 Ram CC, 5.7 Hemi, 8-speed, 3.92 lsd 97 Trans Am, HPP Aug 2012 http://www.highperformancepontiac.co...tiac_trans_am/ ***Sold*** |
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#4
05-31-2013, 03:05 PM
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mine are 26 1/4 and 9 wide on car off car my other set are 27 1/8 9wide off car these are on 7inch rims
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#5
05-31-2013, 03:35 PM
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Mine are also on 7" rims, and have 8" of good tread on the ground with 18psi in them.
They are able to hold over 550ft lbs torque on the starting line, require a lot of heat and a good track, and are rock solid on the run. Negatives are they don't last much longer than it took me to type this. I get about 40 good runs till the grooves are just about gone, then 20 really good runs till the cords start showing. Pretty expensive racing for 60 runs tread life. I do run them on the street some in between, couple of short outings a month, and drive the car 20 miles round trip back and forth to the track.....Cliff
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#6
05-31-2013, 03:52 PM
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I'm trying to decide between these or a 275/50. They will go on an 8" rim. I had 275/60s and they were more tire than I needed. They were also considerably taller than my BFG 255/60 street tire mentioned. This noticeably threw off the speedo and it 'seemed' like I could tell the car was a softer on take off.
I'm leaning towards the 255's. I'm sure they'll do the job from what I've read here and I'm afraid the 275/50 might look a little 'squatty'? 
__________________
68 Firebird, trying a q-jet now. 434/10.5:1/997's/240-242 HFT/4L80E/2800 Yank/3.42's/ Vintage Air/ 13.0 @105 mph 70 Lemans, 350/350, A/C, mostly stock 14 Ram CC, 5.7 Hemi, 8-speed, 3.92 lsd 97 Trans Am, HPP Aug 2012 http://www.highperformancepontiac.co...tiac_trans_am/ ***Sold*** |
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#7
06-01-2013, 07:03 AM
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I'm hooking up a 455 cid engine with 11 to 1 compression and 3500rpm stall converter with "stock" suspension on the 255/60-15's on a stock 7" Ralley wheel. No need to go to a wider tire, IMHO.
I would add that I wore out two sets of the 275/60-15's before going to the smaller tires. On the same 7" Ralley wheels they didn't put any more tread on the track than the smaller tires and required less air in them for best results. I think it was Darby Otto who recommended going to the smaller tires, and he was correct, they work equally as well as the 275's, even at my power level......Cliff
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#8
06-01-2013, 03:53 PM
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255/60's are on the way.
 Went ahead and pulled the trigger yesterday.Check out how short these BFG's 255/60's are.  Looks like 25 1/8". I have no idea why they measure so short.
__________________
68 Firebird, trying a q-jet now. 434/10.5:1/997's/240-242 HFT/4L80E/2800 Yank/3.42's/ Vintage Air/ 13.0 @105 mph 70 Lemans, 350/350, A/C, mostly stock 14 Ram CC, 5.7 Hemi, 8-speed, 3.92 lsd 97 Trans Am, HPP Aug 2012 http://www.highperformancepontiac.co...tiac_trans_am/ ***Sold*** |
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