Will I gain in ET and MPH if I go to a higher tire?

[evil666]

My question is should I switch my M/T DR 275-50-15 to M/T DR 275-60-15, and if I do so, will my ET drop and will I gain some MPH. If I go to a higher tire should I still lock my torque convertor in third gear or will it drop my rpm to much?

Thanks, Marco.

86 Grand National t-top
stock long block, stock suspension, 12 inch red stripe convertor (2800stall), te44, smc alk injection (95 % etanol), 25.5lbs boost, 94 octane, hooker cat back with dyno max ultra flow muffers, 42 ½ lbs 009 injectors, turbotweak alky chip, thdp, mease 24 row IC, Ron Custom max boost brake module, MT drag radials (275/50/15) 3835lbs race weight with driver. (Torque convertor locked only after car shifted in third), rjc power plate, rjc boost controller, zeitronix wideband, HR motor mounts, comp cam 980 valve springs.
BEST E/T
60FT=1.55
1/8= 7.34
1/4= 11.59
MPH=118
BEST 60FT=1.52

 

[JC'sGN]

Marco, what rpm do you go through the traps at now? At your level, if it were me I would switch the 28's ....

 

[forcefed3.8's]

118mph with the stock cam would probably want the taller tire.

 

[evil666]

Marco, what rpm do you go through the traps at now? At your level, if it were me I would switch the 28's ....

John I come in at around 5100 rpm with the convertor locked in third. I would maybe like to try to switch to the 28's but I am worried that the tires are going to rub to much because they already rub with the 26's when I hit bumps on the right fender molding. I am using custom made 8" gn mags with a 3 1/2 back spacing, and I would like to switch to weld draglites but they only have 3 1/2 or 4 1/2 back spacing and I think 4 " backspace would fit the best. I don't want to notch my frame or roll over the fender lip or cut it, which I think will cause a problem for me to fit a taller tire.

Thanks, Marco.

86 Grand National t-top
stock long block, stock suspension, 12 inch red stripe convertor (2800stall), te44, smc alk injection (95 % etanol), 25.5lbs boost, 94 octane, hooker cat back with dyno max ultra flow muffers, 42 ½ lbs 009 injectors, turbotweak alky chip, thdp, mease 24 row IC, Ron Custom max boost brake module, MT drag radials (275/50/15) 3835lbs race weight with driver. (Torque convertor locked only after car shifted in third), rjc power plate, rjc boost controller, zeitronix wideband, HR motor mounts, comp cam 980 valve springs.
BEST E/T
60FT=1.55
1/8= 7.34
1/4= 11.59
MPH=118
BEST 60FT=1.52

 

[JC'sGN]

Marco, my street wheels are 15 x 9 with a 4 1/2 back space with the 275-60's and they don't rub anywhere..

 

[evil666]

Will I gain or loose out by locking the convertor with a taller tire since the rpm will drop even lower?

Marco.

86 Grand National t-top
stock long block, stock suspension, 12 inch red stripe convertor (2800stall), te44, smc alk injection (95 % etanol), 25.5lbs boost, 94 octane, hooker cat back with dyno max ultra flow muffers, 42 ½ lbs 009 injectors, turbotweak alky chip, thdp, mease 24 row IC, Ron Custom max boost brake module, MT drag radials (275/50/15) 3835lbs race weight with driver. (Torque convertor locked only after car shifted in third), rjc power plate, rjc boost controller, zeitronix wideband, HR motor mounts, comp cam 980 valve springs.
BEST E/T
60FT=1.55
1/8= 7.34
1/4= 11.59
MPH=118
BEST 60FT=1.52

 

[JC'sGN]

You will gain, you may need to lock it up at a higher mph than before..