Transmissions and Drivetrain Need help with your trans? Problems with your axle?

What mph should I shift at?

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Old Apr 5, 2012 | 09:11 PM
  #1  
Slow87's Avatar
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From: Las Vegas
Car: 87 Camaro Lt
Engine: 350
Transmission: 700R4
Axle/Gears: 4th gen 3:42, posi, disc
What mph should I shift at?

700r4
10 bolt from 87 v6 with stock gears...3.23 or 3.27?
bone stock lg4 305.
225/65/15 tires

My car has no tach and the transmission refuses to ride through the gears during wot. For some reason it jumps into overdrive extremely early and just skips third completely. So When racing I manually run through the gears. Question is at what mph should I shift for each gear?
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Old Apr 5, 2012 | 09:18 PM
  #2  
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Re: What mph should I shift at?

At roughly the peak HP RPM... or looked at another way, at the RPM where the engine changes to the peak torque RPM after the shift.
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Old Apr 5, 2012 | 10:43 PM
  #3  
Slow87's Avatar
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From: Las Vegas
Car: 87 Camaro Lt
Engine: 350
Transmission: 700R4
Axle/Gears: 4th gen 3:42, posi, disc
Re: What mph should I shift at?

Originally Posted by sofakingdom
At roughly the peak HP RPM... or looked at another way, at the RPM where the engine changes to the peak torque RPM after the shift.
I have no tachometer. The speedometer is the only thing I have to gauge what rpm im at. What mph does your car shift at for each gear under full throttle is what I'm asking.
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Old Apr 5, 2012 | 10:50 PM
  #4  
ghost91's Avatar
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From: Woodbridge, New Jersey
Car: 1991 Camaro Z28
Engine: 305 TPI
Transmission: 700r4
Axle/Gears: 2.73
Re: What mph should I shift at?

Listen to the cars rpms would work lol... Mine does around 15, mid 20s, 35-40, and so on...at least for me..
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Old Apr 6, 2012 | 02:52 AM
  #5  
Slow87's Avatar
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From: Las Vegas
Car: 87 Camaro Lt
Engine: 350
Transmission: 700R4
Axle/Gears: 4th gen 3:42, posi, disc
Re: What mph should I shift at?

Originally Posted by ghost91
Listen to the cars rpms would work lol... Mine does around 15, mid 20s, 35-40, and so on...at least for me..
That sounds about right for daily driving, but im talking about racing and running each gear to about 5k rpms. Like I said I can't really listen to in when its just in overdrive because it skips the gears so I have to do it manually. When you floor it what mph does it usually shift at in each gear?
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Old Apr 6, 2012 | 08:21 AM
  #6  
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From: Woodbridge, New Jersey
Car: 1991 Camaro Z28
Engine: 305 TPI
Transmission: 700r4
Axle/Gears: 2.73
Re: What mph should I shift at?

I'll let you know later today after I drive it. Unless someone else comes up with a precise answer
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Old Apr 6, 2012 | 03:18 PM
  #7  
Slow87's Avatar
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From: Las Vegas
Car: 87 Camaro Lt
Engine: 350
Transmission: 700R4
Axle/Gears: 4th gen 3:42, posi, disc
Re: What mph should I shift at?

Originally Posted by ghost91
I'll let you know later today after I drive it. Unless someone else comes up with a precise answer
Thanks man that would really help me out!
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Old Apr 6, 2012 | 03:41 PM
  #8  
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From: Henrietta NY
Car: 1984 Trans Am L69
Engine: Sniper EFI Powered 355
Transmission: WC T5 w/ Steel Support Plate
Axle/Gears: 3.42 10 Bolt Posi
Re: What mph should I shift at?

An 87 V6 should have 3.42 gears.

With 3.42 gears and your tires and a 5000 redline my sim gives optimum shift points at

39 mph @ 5000 rpm
69 mph @ 4600 rpm
103 mph @ 4600 RPM

What are you racing with a 17 second car?

If you want to know what speed is 5k rpms in each gear go look up a gear ratio calculator with speed in gears.

https://www.thirdgen.org/gears

Last edited by midias; Apr 6, 2012 at 03:44 PM.
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Old Apr 6, 2012 | 03:53 PM
  #9  
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From: Pasadena, TX
Car: 1991 RS
Engine: 5.0
Transmission: 700r4
Re: What mph should I shift at?

[QUOTE=midias;5235213]
What are you racing with a 17 second car?

[QUOTE]

Hondas, school buses, old ladies on rascals.
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Old Apr 6, 2012 | 03:55 PM
  #10  
midias's Avatar
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From: Henrietta NY
Car: 1984 Trans Am L69
Engine: Sniper EFI Powered 355
Transmission: WC T5 w/ Steel Support Plate
Axle/Gears: 3.42 10 Bolt Posi
Re: What mph should I shift at?

[QUOTE=RS Chris;5235223][QUOTE=midias;5235213]
What are you racing with a 17 second car?


Hondas, school buses, old ladies on rascals.
You could keep it floored and old ladies in Buicks would still pass you on any freeway on ramp.
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Old Apr 7, 2012 | 11:52 AM
  #11  
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From: Woodbridge, New Jersey
Car: 1991 Camaro Z28
Engine: 305 TPI
Transmission: 700r4
Axle/Gears: 2.73
Re: What mph should I shift at?

i didnt even realize you were driving a 6..sorry, i cant really help then :/
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Old Apr 7, 2012 | 12:23 PM
  #12  
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Re: What mph should I shift at?

bone stock lg4 305
10 bolt from 87 v6
Some people just can't read, I guess.

No sense trying to wind that up to 5000 RPM; it'll run about 3 seconds quicker if you shift it at a more sensible rev down somewhere nearer the peak HP RPM, around 4200.

Fix the tach. Make sure it's accurate. Shift by RPM not mph.
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Old Apr 7, 2012 | 04:33 PM
  #13  
Slow87's Avatar
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From: Las Vegas
Car: 87 Camaro Lt
Engine: 350
Transmission: 700R4
Axle/Gears: 4th gen 3:42, posi, disc
Re: What mph should I shift at?

Lol, not a v6! I still imagine it to be roughly a 17 second car though. I just want to track it now while its stock so I can get before and after times with parts as I upgrade. There is no tach to fix, this is a rs with a 305 swapped in.

Thanks for the numbers though, those were exactly what I was looking for
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Old Apr 7, 2012 | 07:43 PM
  #14  
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: What mph should I shift at?

There is no tach to fix
Then install one.
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Old Apr 7, 2012 | 08:10 PM
  #15  
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From: Hurst, Texas
Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: What mph should I shift at?

Originally Posted by Slow87
700r4
10 bolt from 87 v6 with stock gears...3.23 or 3.27?
bone stock lg4 305.
225/65/15 tires

My car has no tach and the transmission refuses to ride through the gears during wot. For some reason it jumps into overdrive extremely early and just skips third completely. So When racing I manually run through the gears. Question is at what mph should I shift for each gear?
Governor pressure overcomes TV pressure to force an upshift. Either you have too much governor pressure, too soon or not enough TV pressure. Since your car has a different axle in it, that allows Governor pressure to rise quicker in regards to MPH than the stock axle, this is where I would check first. But for grins check the TV Cable to make sure it is properly adjusted first. 700r4s are also known to have SSS or Short Spring Syndrome on the throttle valve spring.
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Old Apr 8, 2012 | 09:27 AM
  #16  
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From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: What mph should I shift at?

Originally Posted by Slow87
Lol, not a v6! I still imagine it to be roughly a 17 second car though. I just want to track it now while its stock so I can get before and after times with parts as I upgrade. There is no tach to fix, this is a rs with a 305 swapped in.

Thanks for the numbers though, those were exactly what I was looking for
The tach can be removed from the cluster and changed to a v8 tach.

Before posting such things, you should really do some reading. We like hard to answer questions with lots of technical background.

This type of question is like "how do you eat with a spoon?".

-- Joe
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Old Apr 8, 2012 | 09:41 AM
  #17  
midias's Avatar
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From: Henrietta NY
Car: 1984 Trans Am L69
Engine: Sniper EFI Powered 355
Transmission: WC T5 w/ Steel Support Plate
Axle/Gears: 3.42 10 Bolt Posi
Re: What mph should I shift at?

^ i don't think he even had a tach to begin with he would probably need a new cluster right?
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Old Apr 8, 2012 | 10:32 AM
  #18  
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From: Central Texas
Car: GTA
Engine: 350 TPI
Transmission: 700R4
Axle/Gears: Aussie 9-bolt/3.27 posi
Re: What mph should I shift at?

Step 1. get tranny fixed (if it won't upshift at WOT then something is "broke" possibly just a vacuum line/piece or cable to TB)
Step 2. Install gauge cluster with tach (or aftermarket tack like an Autometer 5" but that might look funny with the stock cluster)
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Old Apr 8, 2012 | 01:27 PM
  #19  
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From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: What mph should I shift at?

Originally Posted by midias
^ i don't think he even had a tach to begin with he would probably need a new cluster right?
What is in place of the tach on an RS cluster? Or is it just idiot lights?

Either way, he can swap a tach or a full cluster. Simple fix. Enough of these cars in the junkyard and people parting them.

-- Joe
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