« previous next »
Pages: [1]   Go Down

Author Topic: top speed of 79mph? wth? rear end gears?  (Read 7176 times)

Offline 84scottsdale454

  • Newbie
  • Posts: 58
top speed of 79mph? wth? rear end gears?
« on: May 28, 2011, 10:47:43 am »
i have a stock 454 installed with a turbo350 trans, i cant look at my gears at this time......can someone give me an idea on what they will be? i think this rear end was custom built before i bought it! any ideas?????????
Logged

Offline Psycho71

  • Registered Users
  • *
  • Posts: 239
Re: top speed of 79mph? wth? rear end gears?
« Reply #1 on: May 28, 2011, 11:20:52 am »
what kind of rpm are you turning at 79mph, or 60mph, or whatever? Tire size will ploy a role in that as well. With both of those figures, and the 1:1 thrid gear of the th350, it's just math to get the rear end ratio.
Logged
There are two tools needed, duct tape and WD40. If it moves and shouldn't, use the duct tape. If it doesn't move and should, use the WD 40.

Offline 84scottsdale454

  • Newbie
  • Posts: 58
Re: top speed of 79mph? wth? rear end gears?
« Reply #2 on: May 28, 2011, 11:29:33 am »
unsure of the rpm, it was the max rpm because thats all it could take....i could not go 80mph! the tires size are the stock height
Logged

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19183
Re: top speed of 79mph? wth? rear end gears?
« Reply #3 on: May 28, 2011, 02:38:20 pm »
You have given nowhere near enough information for anyone to even venture a guess and at that all you will be getting are random guesses.
Logged
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline malibu795

  • Frequent Member
  • **
  • Posts: 336
Re: top speed of 79mph? wth? rear end gears?
« Reply #4 on: May 28, 2011, 10:30:53 pm »
Quote from: VileZambonie on May 28, 2011, 02:38:20 pm
You have given nowhere near enough information for anyone to even venture a guess and at that all you will be getting are random guesses.
yep
Logged
adam wildman
75 K25 383/400
79 malibu 454/T56 305rwhp/432rwtq 15.6@92.8mph
02 2500HD D-max/allison best time 13.77 @ 99mph 463rwhp/930rwtq

Offline slammed79

  • Senior Member
  • ****
  • Posts: 1367
  • Thou shalt not drive stock
Re: top speed of 79mph? wth? rear end gears?
« Reply #5 on: May 28, 2011, 10:34:50 pm »
Shove a $30 dollar tach in there and get a rpm reading. Then please report back with rpms and the actual tire size. Stock doesn't help in the slightest.
Logged
74 C10 Long bed 350/SM465 Lowered on 20's

Praise the lowered

Offline 84scottsdale454

  • Newbie
  • Posts: 58
Re: top speed of 79mph? wth? rear end gears?
« Reply #6 on: May 28, 2011, 10:50:57 pm »
your a smart man slammed79..... imma get a tach, me and the ol man pulled it out today, they were 4.56s! well thats what he says anyway! i appreciate your help! i dont know much when it comes to things like this! i wish i could get a pic on here, my truck is 1 of a kind! thanks again
Logged

Offline beastie_3

  • Senior Member
  • ****
  • Posts: 3170
  • Josh
    • My truck pics
Re: top speed of 79mph? wth? rear end gears?
« Reply #7 on: May 28, 2011, 11:31:26 pm »
count the teeth of the pinion and ring, then divide one into the other to get the gear ratio, but it should be stamped on the ring.
Logged

Offline malibu795

  • Frequent Member
  • **
  • Posts: 336
Re: top speed of 79mph? wth? rear end gears?
« Reply #8 on: May 29, 2011, 02:07:38 pm »
Why count it stamped in the ring gear tooth count
Logged
adam wildman
75 K25 383/400
79 malibu 454/T56 305rwhp/432rwtq 15.6@92.8mph
02 2500HD D-max/allison best time 13.77 @ 99mph 463rwhp/930rwtq

Offline beastie_3

  • Senior Member
  • ****
  • Posts: 3170
  • Josh
    • My truck pics
Re: top speed of 79mph? wth? rear end gears?
« Reply #9 on: May 29, 2011, 03:11:41 pm »
thats why I said it should be stamped....
Logged

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19183
Re: top speed of 79mph? wth? rear end gears?
« Reply #10 on: May 29, 2011, 09:55:48 pm »
driven over drive = :1

Logged
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: top speed of 79mph? wth? rear end gears?
« Reply #11 on: May 31, 2011, 05:27:25 am »
Your speedometer could be wrong if the rear end gears are different than stock. What type of phone do you have? If you have an android phone, download a gps speedometer and check your speed with that.
Logged
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline 84scottsdale454

  • Newbie
  • Posts: 58
Re: top speed of 79mph? wth? rear end gears?
« Reply #12 on: July 24, 2011, 08:37:44 am »
I used 2 diff speedometers on my droid phone! I'm sure any idiot could determine they were low,thanks for the reply "79"! Now I'm runnin 3.08s and they seem perfect! I can't still smoke the 22s at 20mph kickdown
Logged

Offline chevymanrob

  • Registered Users
  • *
  • Posts: 100
Re: top speed of 79mph? wth? rear end gears?
« Reply #13 on: July 24, 2011, 12:43:48 pm »
4.56s even with a 26" tire and 79 mph should be about 3800 rpm. if your engine wont turn past that you may have some MAJOR issues. i think the "buy a tach" advice was the best thing said to this point.
Logged
ex G-body drag fan. best was 11.86 on a 93 octane SBC street car.

Offline 84scottsdale454

  • Newbie
  • Posts: 58
Re: top speed of 79mph? wth? rear end gears?
« Reply #14 on: July 24, 2011, 10:42:29 pm »
i dont feel the need to buy on tachs look TACH-Y, i know how to blow a motor up and to keep from doing it. i solved the problem with 3.08s and my motor runs flawless and is practically new so maybe my phone is a turd or something! either way THIS MAN IS HAPPY LOL
Logged
Pages: [1]   Go Up
« previous next »