c6+gearvendor or tremec 6 speed?

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73rustang

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Dec 10, 2014
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Location
dora al
My Car
1973 coupe 429, c6, and lots of "weight reduction" via rust lol
how well does a gearvendor work? I was just wondering about it performance wise, how well does it hold up to a big block? does it get better or worse gas milage than a tremec 6 speed? ive tried looking it up but I cant find any kind of information.

 
how well does a gearvendor work? I was just wondering about it performance wise, how well does it hold up to a big block? does it get better or worse gas milage than a tremec 6 speed? ive tried looking it up but I cant find any kind of information.
a gearvendor what?

if you buy the 600 and plan on shifting it quickly i would get new kevlar lined blocker assemblies for 3rd gear.

 
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how well does a gearvendor work? I was just wondering about it performance wise, how well does it hold up to a big block? does it get better or worse gas milage than a tremec 6 speed? ive tried looking it up but I cant find any kind of information.
a gearvendor what?
sorry I wasn't clear I meant a gearvendor over\underdrive I have a c6 behind a 429 and I was just looking for tranny options

 
how well does a gearvendor work? I was just wondering about it performance wise, how well does it hold up to a big block? does it get better or worse gas milage than a tremec 6 speed? ive tried looking it up but I cant find any kind of information.
a gearvendor what?
sorry I wasn't clear I meant a gearvendor over\underdrive I have a c6 behind a 429 and I was just looking for tranny options
i used one once but had to best the tranny tunnel hp aroubd 1" for clearance . . they work fine . . they shift just like a new 6 speed auto which is a few too many times for me.

 
I went with the Gear Vendor behind my C6 and so far I am happy with it. It required no modification to the tunnel area and the kit came with everything needed to get it installed. The only modification was with the drive shaft which needed to be shortened but that was not a big issue to deal with. Installation was simple and I had it mechanically set up in one day. Its rated to about 900hp and with my 3.89 rear when in overdrive it's equivalent to 3.03 rear. I had 3.25 so I would expect to see some better fuel economy however engine upgrades that I did probably makes it a wash. I can say I really notice the launch difference in the car now and I know at freeway speeds the engine will be around 2200 rpms or so.

Will e on this site also has the GV and has some miles on it now and I think he's happy with it. He'll probably chime in soon.

No experience with the Tremec setup so I can't help there. If you have any questions let me know.

thx

 
We've got four cars with T56s in them. All are the Viper version I find them to be fine in street driving, OK for road course and I'm with those who don't care for the way third gear shifts during drag racing. I've used stock, Pro 5.0 and B&M shifters. I hear the MGW shifter is best but haven't tired one. Friends have three vehicles with GV ODs. One is in a high perf application (502 '69 Chevelle with a Muncie). He is very happy with his choice. I've never felt a TKO 600 or T56 that shifts as well as a Super T10, Muncie or Top Loader with a decent Hurst shifter.

 
+1 on sicndhed"s post. I know two guys with the gear vendors overdrive and they are happy with them. I had a MGW in my 07 Mustang. Absolutly terrible. I put the original back in. I've heard they redesigned the shifter. Tremecs overall do not impress me. They need some competition. Chuck

 
No experience with the tremec but I have been running the GV. I have about 1800 miles on it now, the last month or so I have driven the car almost daily.

c6, 3.50 and 225/70R14

I would say it is one of the best upgrades I have ever done. Installation was straight forward. No tunnel modifications but it does seem to hit the shifter housing. I can 'feel' it move the housing when I get on it.

I spend a lot of time on the freeway and was getting about 7mpg, now I get about 9. It is so much quieter at 75mph.

There are two modes. Auto drive and non-autodrive. You select with a switch. There is a second switch (I use the provided foot switch) that turns the OD off and on.

In auto-drive, with the foot switch 'on' the OD will engage at approx 42 mph. This is great for normal driving. It's a little weird if you are 'getting on it' because it will shift at 42 regardless of what gear the transmission is in or how fast you are accelerating. So the transmission might shift into second and then pretty quick after that the GV shifts in as well (second over).

I mostly shift it myself with autodrive off and the foot switch. I rarely attempt to go 'first over'. The RPM's are getting up pretty high and since the GV is driven by an internal pump based on drive shaft speed, it doesn't shift as quick at lower speeds. I have also managed to 'miss' the foot switch on occasion.

What you can do, and I have started playing with this more, is in non-autodrive, you turn on the OD while stopped. It won't actually engage because it is pump driven. But as you accelerate in first it will engage just as you are getting close to your max rpm. Makes me nervous but I am getting more comfortable with it.

In theory you can shift out of OD and up to the next gear at the same time. I am getting better at this but it is still kind of hit/miss. I have learned that the foot switch is slow to respond but if I keep my foot on it and partially pressed it is more predictable. (Think of how you dimmer switch works).

So to get '6 forward' gears on a single acceleration you have to:

start off in first. When you get up in RPM (and speed) you engage the OD (first over).

When you get back up in RPM you have to shift into second at the same time as you turn off the OD. (second under)

Then you engage the OD again when your RPM's are up (second over)

Shift into third while turning off the OD (Third under)

And finally you engage the OD in third (third over).

I rarely try hitting all 6 . It can only be done in manual mode. Keep in mind when you are in 'first over' if you shift off the OD before catching second gear your RPM's will, but for a moment, jump up probably beyond where you want. If on the other hand

you are a little slow to turn the OD off then you go first over to second over then back to second under. No harm done but not a smooth shift.

I have always liked upshifting the gears so I often use the console to go from 1 to 2 to drive. I also DO NOT have a kick down lever.

If I am driving normal and in traffic I tend to turn the OD on/off in third gear at about 45 mph (on) and 20ish (off). I don't shift down (3-2-1) manually.

If you forget to turn off the OD and you have their controller it will turn it off for you.

When I am feeling more spirited I tend to do 1 to 2 and then 2 over. Then I will either just go 3rd over or do the shift into 3rd while turning the OD off.

On the freeway I normally leave it in 3rd over. The torque of the engine allows for accelerating but if I want a little more fun I find myself switching the OD off rather than going into 2nd (over). All that being said, I do have my passing gear back! So at 65mph while in 3rd over you can drop into 2nd over and it's like having the 2.72 rear end again...

Sorry for the long write up but I figured it would help hearing some 'real world' use.

 
Will e gave a very good functional operation description. I have a GV on my 72 Mach 1 Q code and I would say it is one of the best upgrades I have added. I have put about 3300 miles on mine with no issues. It bolted right on with no mods. One of the main points I like is I can put the drive train back to original as I had a new drive shaft made for the GV setup.

 
wow thanks everybody, id been looking at them bc for 1 its going to cost me like 6 grand overall to put a 6 speed and convert my car to a manual (and then my not-quite-wife-yet wont be able to drive it XP) but I needed something that can take a beating from my 429 im building to a scj,but be able to take trips in it (I know that's asking a hell of a lot) if I can get 12mpg with a 373 rear gear and 295,50,15s on the back ill be happy lol right now the car will do 12ish but its just a stock motor out of a Lincoln (or so the previous owner tells me). but thanks for the advice its one more thing for the list lol :D

 
The one thing I would expect the T56 to do better is fuel economy vs the GV behind any automatic even with a lock up converter trans. The GV will help (probably a lot) behind the C6 but if MPG was the biggest concern an OD manual would likely be the winner. If you do the math you need to save a lot of gas to justify spending even $2K in search of better mileage though. If you go from 12 MPG to 16 MPG, it takes over 30,000 miles to get $2K in savings at $3/Gal.

 
wow thanks everybody, id been looking at them bc for 1 its going to cost me like 6 grand overall to put a 6 speed and convert my car to a manual (and then my not-quite-wife-yet wont be able to drive it XP) but I needed something that can take a beating from my 429 im building to a scj,but be able to take trips in it (I know that's asking a hell of a lot) if I can get 12mpg with a 373 rear gear and 295,50,15s on the back ill be happy lol right now the car will do 12ish but its just a stock motor out of a Lincoln (or so the previous owner tells me). but thanks for the advice its one more thing for the list lol :D
you do NOT want a 6 speed manual trans . . it is a complete and total waste . . 5 is ideal.

 
wow thanks everybody, id been looking at them bc for 1 its going to cost me like 6 grand overall to put a 6 speed and convert my car to a manual (and then my not-quite-wife-yet wont be able to drive it XP) but I needed something that can take a beating from my 429 im building to a scj,but be able to take trips in it (I know that's asking a hell of a lot) if I can get 12mpg with a 373 rear gear and 295,50,15s on the back ill be happy lol right now the car will do 12ish but its just a stock motor out of a Lincoln (or so the previous owner tells me). but thanks for the advice its one more thing for the list lol :D
you do NOT want a 6 speed manual trans . . it is a complete and total waste . . 5 is ideal.

whats wrong with a 6 speed? its another 500 bucks on it yeah but its another overdrive wich would help milage right? and you get to say its a 6 speed so there is another plus there lol, its an honest question tho I mean this car will spend a good bit of time on the interstate if that makes any difference?

 
The broad torque range of a big block usually is pretty well matched to five gears. The five speed is lighter, smaller and cheaper. I think the TKO 600 shifts better than my T56s.

 
With a 6 speed manual gear box you're always shifting. My brother had a 6 speed honda accord V6 coupe. Quick car but way too much shifting for me. I'll stick with my 4 speed.
LOL, I wanted a manual too but then thought more about it. It's fun to race around with but a pain to be shifting all the time.

 
Another thing to consider is parasitic loss. A c-6 takes about 75 horsepower just to power the trans in stock form. A manual will use maybe 15 horsepower to drive the trans. That is a significant difference I could feel when I swapped to a t-5 in my car.

Just throwin that out for thought.

 
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