Well, the Turbo Regal guys down here would probably disagree with that. The only ones that run the 275/60s are the ones with taller gears than 3.42 or guys who are running out of RPM in the traps because of so much HP. The vast majority of the stock 3.42 guys are running 275/50s and say they hook best. These guys are guys running all the way down to the low 11s. Here's my first time slip in the 11s with me WE4. 275/50 x 15 MTs.
I think their main consideration is gear ratio. I would talk to a variety of Buick Racers and get their opinion. Rob Chilenski is the one who told me the 275/60 would be a better choice for traction. Hopefully, others will weigh in.
1.63 60 ft three times back to back, and frequent dead hooks on a blacktop road. If you would like that, here's what I did. I installed: 1. Hellwig anti sway bar. 2. TA nohop bars. 3. Viking double adjustable rear shocks. .4 Put a .75 second diaphragm on my Ruggles quadrajet 2nd(recipie). Whole new world! I swapped my 3500 jw converter to a 4000 stall Coan, and it planted the tires even harder!!! My 67 GS will instantly go up to 5000-5500, stay there and tickle my tummy till I let off!
1.80 60ft is easy to hook....when you get down to 1.60 or better everything is more critical. I think the Hoosier 275/60-15 is best track drag radial right now....I've run 1.37 60ft on 10in wheel
And 275r60 mt radials, good fuel pump, half inch fuel line into the tank or you will outrun the gas. 1.66, 7.52 at 92mph eighth mile (with 3500 stall jw). 3.73 gear. Will test the 4000 Coan soon. Its already hooking hard on blacktop at home.
Found this on a Corvette Forum, https://www.corvetteforum.com/forum...taller-sidewall-heights-for-drag-radials.html I believe even though the 50 series tire contact patch is wider, it is also shorter in length. The taller 60 series tire will have a longer contact patch.
How fast is fast? Score yourself. Just pick a number somewhere between 220 and 175. I shoot for 180 as a goal. 175 is exceptional. Example: 180 divided by 116.85 mph =1.54 for your 60 ft time. 175 divided by 116.85 mph =1.497 !! Kramer, this my formula to know how good my hook and launch is going. Anyone can do this to test traction efficiency. Try this out with your time slips and see how your doing Kramer your at 212 right now, shoot for 180. 60 ft x mph: (1.815 60 ft x 116.85 mph = 212) Score number divided by mph: ( 180 รท 116.85 mph = 1.54 60 ft.) 1.75 is hard to do, but 180 is more realistic.
How much air psi are those turbo Buicks running in the 275r50 tires? Psi choice is critical. (And hot vs cold)
I used to run 19-20 psi. Most serious GN/TType guys are in the 16-20 psi range. I never cared to launch hard enough to get into the 1.60 60 ft. range. I was pretty consistently in the 1.75 to 1.82 range because I didn't want to break rear end parts. I only raced 3 or 4 times a year. When I sold my '87 WE4, it had over 178,000 miles on it with over 200 passes over 20 years. The original 3.42 posi was still in it and never broke.
No argument there, Larry. But, keep in mind that I'm not interested in maximizing 60 ft times. If the shorter sidewall will give me consistent 1.75-to 1.8 times, I'm good with that. I can keep the same tire diameter front to rear and my speedo will continue to be accurate in addition to putting less strain on parts. I think I'm talking myself into either the 255/60s or the 275/50s. Still working on it. My wheels don't get here until next week anyway. See my answer to Gary above for more.
Now, I'll throw another twist into the traction thing. Someone said I should consider the Coker repro G60 Poliglas tires if I wanted the 275/50 DRs. Will those tires properly inflated compete with drag radials?
The 8.5 ten bolt is good for 1.60 60 foot times forever. For 1.50 60 foot time, get a true track posi. It eliminates the weak spider gears problem, and can handle 750 hp. Next weak link is axles and you aren't trying to break into the 10 second zone.
Good to know, Gary. Thanks. How about tranny yoke, driveshaft and universals? I'm running one of the TSP 9.5 converters.
All good except...if your u-joints have grease zerks, make sure the rotation is pushing on the zerks, never pulling them. You will RIP them apart, and the consequences can be disastrous! I dont like stock rubber dampened driveshafts either. 50 year old rubber! Have a performance tube built for your big Buick u-joints and then,,, double check zerk position so you dont destroy the new stuff.
Thanks. If I had decided to run the Poliglas tires, I'd put them on all four corners. But, seems they don't match drag radials anyway.
Given what you want, I think you have your choices narrowed down. The 275/50's should give you a little more gear. I don't care what MT tells you, that tire is about 26" even according to the numbers. The 255/60's are 27", and you could use that size all the way around. I like the 275/60's on the rear of my car. The only concern I had was if I should get a flat on the rear tire, I would need a 28" spare to avoid destroying the posi. To that end, I bought a P235/70R-15 (28") Cooper Cobra and mounted it on a Buick Chrome wheel. That is the spare I carry in the trunk, and I can use it front or rear should I get a flat on the road. No they do not. I've driven cars with the Poliglas tires, and although they look killer, they ride like crap, and the car I drove was all over the road with them. They wander. I didn't like the experience. You get spoiled by the Radial ride and handling.
