It shouldn't go thru any oil should it? 
BB owners step in here please
Thread Starter
Melting Slicks
Joined: Mar 2005
Posts: 2,187
Likes: 7
From: Chetwynd B.C.
BB owners step in here please
Not sure if this should be here or general. Mods can move if necessary.
BB owners.
What RPM do you normally shift at? If I'm not pushing it I normally shift around 3500 but if pushing it then 5-5500(max).
What RPM do you cruise at on the higway? Because of my 3.70 rear gears I have to cruise at 3000 at 62 mph (speed limit) in my top gear of 4th (so far). Will cruising at 3000-3500 all day on a LONG road trip hurt the BB? I'm thinking it can't be good for it
Again because of the rear end gears this is what I have to do. Just want to get a feel as to how soon I should buy that 5 speed
shmoky
BB owners.
What RPM do you normally shift at? If I'm not pushing it I normally shift around 3500 but if pushing it then 5-5500(max).
What RPM do you cruise at on the higway? Because of my 3.70 rear gears I have to cruise at 3000 at 62 mph (speed limit) in my top gear of 4th (so far). Will cruising at 3000-3500 all day on a LONG road trip hurt the BB? I'm thinking it can't be good for it
Again because of the rear end gears this is what I have to do. Just want to get a feel as to how soon I should buy that 5 speed
shmoky
Drifting
Joined: Jul 2002
Posts: 1,697
Likes: 3
From: Woodinville WA
I have 3.36 in mine and don't like to drive it for more than about an hour at freeway speeds, so I tend to take side roads. It will definitely put more wear on the engine running at 3000 RPM for an hour vs 1500 RPM for an hour.
Burning Brakes
Joined: Mar 2006
Posts: 793
Likes: 1
From: Houston Texas
Original owner changed out the factory 3:70s for 4:56s. I feel sorry for OPEC so will not change the 4:56s 
till oil rebounds. 3900 R's at 60mph with the M21 so I keep the bank account from over-filling 
till oil rebounds. 3900 R's at 60mph with the M21 so I keep the bank account from over-filling
Melting Slicks
Joined: Feb 2004
Posts: 2,039
Likes: 105
From: State of Confusion!!!
2018 C2 of Year Winner
Do yourself a favor and get the 5 speed!!! You have a similar setup to mine, and I just did the swap...WOW what a difference!!!
I run about 2100rpm @ 70mph and it just cruises along. With the lower first gear it launches like it has 4.11's in the rear...best of both worlds!!!
I run about 2100rpm @ 70mph and it just cruises along. With the lower first gear it launches like it has 4.11's in the rear...best of both worlds!!!
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Burning Brakes
Joined: Mar 2006
Posts: 915
Likes: 2
From: Lima, OH -- 69 L71 427/435hp
They sell overdrive kits for muncies as an option also. I have either 4.11 or 4.56 rear end in mine, with the conversion I can run 3.90 roughly as a final drive ratio.
You just change the cluster gears and flip the 3/4th rod lever over, and you're good to go.
May be a bit cheaper than a new trans or rebuilding the rear end.
Here's example, probably cheaper if you look around, I can't remember who I bought mine from off hand, but they were really good, I can get a name/number if you want.
http://www.riversidegear.com/categor...oduct-166.html
You just change the cluster gears and flip the 3/4th rod lever over, and you're good to go.
May be a bit cheaper than a new trans or rebuilding the rear end.
Here's example, probably cheaper if you look around, I can't remember who I bought mine from off hand, but they were really good, I can get a name/number if you want.
http://www.riversidegear.com/categor...oduct-166.html
Thread Starter
Melting Slicks
Joined: Mar 2005
Posts: 2,187
Likes: 7
From: Chetwynd B.C.
They sell overdrive kits for muncies as an option also. I have either 4.11 or 4.56 rear end in mine, with the conversion I can run 3.90 roughly as a final drive ratio.
You just change the cluster gears and flip the 3/4th rod lever over, and you're good to go.
May be a bit cheaper than a new trans or rebuilding the rear end.
Here's example, probably cheaper if you look around, I can't remember who I bought mine from off hand, but they were really good, I can get a name/number if you want.
http://www.riversidegear.com/categor...oduct-166.html
You just change the cluster gears and flip the 3/4th rod lever over, and you're good to go.
May be a bit cheaper than a new trans or rebuilding the rear end.
Here's example, probably cheaper if you look around, I can't remember who I bought mine from off hand, but they were really good, I can get a name/number if you want.
http://www.riversidegear.com/categor...oduct-166.html
THANX for the link. Haven't seen this before. Might be an option. Will have to do some speed/rpm ratio calculations.
shmoky
Last edited by shmoky; Jul 26, 2009 at 12:56 PM.
Burning Brakes
Joined: Mar 2006
Posts: 915
Likes: 2
From: Lima, OH -- 69 L71 427/435hp
http://www.autogear.net/index.htm
These guys were great and really know their stuff. If you give them a call they can tell you what you'll need, what ratio you'll be at, and any other advice to do it.
If I remember right when I did it, the cost of a new trans or having a new rear end setup was quite costly and this was a rather easy solution. Also as I have never tore a Muncie (or a any transmission) apart before, I was able to do it myself, was rather suprised how easy it was.
You may want to ask about a new circle gear and new speedo gear as well, cause it will throw your speedometer off some, but the guy I talked to at autogear.net knew which circle gear and what tooth speedo gear I needed with the change.
Also this is worth a read as well while your in the mindset, helped me weigh my options when I was going through that decision.
http://forums.corvetteforum.com/c3-t...ial-ratio.html
Let us know how it turns out for ya'.
Burning Brakes
Joined: Sep 2008
Posts: 753
Likes: 0
They sell overdrive kits for muncies as an option also. I have either 4.11 or 4.56 rear end in mine, with the conversion I can run 3.90 roughly as a final drive ratio.
You just change the cluster gears and flip the 3/4th rod lever over, and you're good to go.
May be a bit cheaper than a new trans or rebuilding the rear end.
Here's example, probably cheaper if you look around, I can't remember who I bought mine from off hand, but they were really good, I can get a name/number if you want.
http://www.riversidegear.com/categor...oduct-166.html
You just change the cluster gears and flip the 3/4th rod lever over, and you're good to go.
May be a bit cheaper than a new trans or rebuilding the rear end.
Here's example, probably cheaper if you look around, I can't remember who I bought mine from off hand, but they were really good, I can get a name/number if you want.
http://www.riversidegear.com/categor...oduct-166.html
I already saw that autogear overdrive and it was already on my mind.
1ARace. what about the rpm drop between shifts in respect to M21?
do you feel fine with M21 overdrive in fast driving ( with many UP-down) shifts?Or the gears are too far one from the other?
this my main concern in going for M21 overdrive. price is fine in indeed
Burning Brakes
Joined: Mar 2006
Posts: 915
Likes: 2
From: Lima, OH -- 69 L71 427/435hp
I have a 4.11 rear end and I love it. not so much cruising, just fun, but a 5 speed trans should be the way to go. unfortunately too expensive for me.
I already saw that autogear overdrive and it was already on my mind.
1ARace. what about the rpm drop between shifts in respect to M21?
do you feel fine with M21 overdrive in fast driving ( with many UP-down) shifts?Or the gears are too far one from the other?
this my main concern in going for M21 overdrive. price is fine in indeed
I already saw that autogear overdrive and it was already on my mind.
1ARace. what about the rpm drop between shifts in respect to M21?
do you feel fine with M21 overdrive in fast driving ( with many UP-down) shifts?Or the gears are too far one from the other?
this my main concern in going for M21 overdrive. price is fine in indeed
I kinda like it though, because if I want to get on it I can run 1st/2nd out for quick jumps then hit 3rd to settle it down, however, if I want to keep on it I just run 2nd out a little longer before dropping 3rd (to keep the powerband more consistent), and when you drop 4th hang on!!, because there is almost no lag in the power band.
So yeah there is a small lag in the powerband between 2nd and 3rd, but not a big deal in my opinion. Overall i'm very happy with it, and I can at least get it down the highway now.
I have been meaning to make a new video, so I'll try to do it soon so you can hear the differences.
Last edited by 1ARACE; Jul 26, 2009 at 02:00 PM.
Thread Starter
Melting Slicks
Joined: Mar 2005
Posts: 2,187
Likes: 7
From: Chetwynd B.C.
If I have
Tire diameter 27.0 inch
Rear gear 3.73
1st gear ratio 2.20
2nd gear ratio 1.50
3rd gear ratio 1.00
4th gear ratio 0.87
What formula do I use to calculate my speed and rpms?
I have found calculators on the internet but they always only use specific trannys and #’s. I would like to have a formula to plug in my own #’s.
Shmoky
Tire diameter 27.0 inch
Rear gear 3.73
1st gear ratio 2.20
2nd gear ratio 1.50
3rd gear ratio 1.00
4th gear ratio 0.87
What formula do I use to calculate my speed and rpms?
I have found calculators on the internet but they always only use specific trannys and #’s. I would like to have a formula to plug in my own #’s.
Shmoky
Burning Brakes
Joined: Mar 2006
Posts: 915
Likes: 2
From: Lima, OH -- 69 L71 427/435hp
If I have
Tire diameter 27.0 inch
Rear gear 3.73
1st gear ratio 2.20
2nd gear ratio 1.50
3rd gear ratio 1.00
4th gear ratio 0.87
What formula do I use to calculate my speed and rpms?
I have found calculators on the internet but they always only use specific trannys and #’s. I would like to have a formula to plug in my own #’s.
Shmoky
Tire diameter 27.0 inch
Rear gear 3.73
1st gear ratio 2.20
2nd gear ratio 1.50
3rd gear ratio 1.00
4th gear ratio 0.87
What formula do I use to calculate my speed and rpms?
I have found calculators on the internet but they always only use specific trannys and #’s. I would like to have a formula to plug in my own #’s.
Shmoky
http://forums.corvetteforum.com/c3-t...ial-ratio.html
GR x MPH div/by .006 div/by 1/2 Tire Height = RPM
3.73 x 65mph div/by .006/by 13.5 =2993 RPM @ 65mph
Edit: However that is 1.0 gear ratio final drive, with .87 final drive ratio I 'believe' it will put you around 2600rpm@65mph. I'd call autogear.net guys to confirm that though, or someone else here can correct me if i'm wrong.
Last edited by 1ARACE; Jul 26, 2009 at 02:54 PM.
Thread Starter
Melting Slicks
Joined: Mar 2005
Posts: 2,187
Likes: 7
From: Chetwynd B.C.
Thanx 1A. were you just guesstimating the 2600rpm@65mph or did you plug in a different # somewhere to get that? I will call autogear tomorrow if no one else chimes in here.
(2600 rpm is 87% of the 1.0 final drive rpm of 2993)
shmoky
(2600 rpm is 87% of the 1.0 final drive rpm of 2993)
shmoky
Last edited by shmoky; Jul 26, 2009 at 03:05 PM.
Burning Brakes
Joined: Sep 2008
Posts: 753
Likes: 0
1ARACE,
a video would be great. keep me posted when you do it.
the lag between 2nd and 3rd is possibly a problem... I have already troubles in downshifting 4 to 3 now, I suppose it will be impossible with the overdrive M21.
I'll study the thing...
Shmoky
with my engine which redline is 6500 rpm , I shift at 5000-5500 rpm which on the paper looks to be hi-torq point, so I keep a certain headroom from redline and possible miss , I sometimes miss the 3rd...
whith the new L88 engine coming soon, I'll probably have a 7000rpm redline . I'll check the torque and power graphs after dyno and see if I can shift at 6000rpm. But I don't have a rev limiter now, so I have to be careful
a video would be great. keep me posted when you do it.
the lag between 2nd and 3rd is possibly a problem... I have already troubles in downshifting 4 to 3 now, I suppose it will be impossible with the overdrive M21.
I'll study the thing...
Shmoky
with my engine which redline is 6500 rpm , I shift at 5000-5500 rpm which on the paper looks to be hi-torq point, so I keep a certain headroom from redline and possible miss , I sometimes miss the 3rd...
whith the new L88 engine coming soon, I'll probably have a 7000rpm redline . I'll check the torque and power graphs after dyno and see if I can shift at 6000rpm. But I don't have a rev limiter now, so I have to be careful
Burning Brakes
Joined: Mar 2006
Posts: 915
Likes: 2
From: Lima, OH -- 69 L71 427/435hp
But yeah, let me get a video together to compare the differences, then you'll see there's not much to worry about.
Burning Brakes
Joined: Mar 2006
Posts: 915
Likes: 2
From: Lima, OH -- 69 L71 427/435hp
Melting Slicks
Joined: Jun 2009
Posts: 2,343
Likes: 4
From: Anderson SC
And to DIP51 - what's your rear ratio, same as his? >
-W
Last edited by Clams Canino; Jul 26, 2009 at 04:38 PM.