Gear Vendors Overdrive

[BillR1212]

Hi Team,

Tried doing a search on here but didn't see anything come up. Is anyone running the GV Overdrive? I'm currently working with 3.23 gears in a 3 speed 727. I'm needing to upgrade my driveshaft/ u joints etc. so I can take more aggressive launches at the drag strip. Since I need to get a new driveshaft anyways, I was thinking now is the time to install an overdrive so I don't have to do the driveshaft twice. Anyone running one?

I"m interested in how you split shift? I'm confused how this works with a slap stick. Say I want to go 1-2 then 2 to 2OD then 3 and 3 OD. From I'm reading you have to click out of the OD everytime. This seems cumbersome and not real conducive to controlling a prized possession down a track. So I'm guessing I'll just use 1 then 2, then hit 2nd OD then right to 3OD and try to keep the big cubes in the lower RPM range to take advantage of the grunt down there.

If anyone has one, and can confirm that please let me know. I think having Overdrive alone would be great as I'm 3300 to 3400 RPMs on the highway currently.

[GoodysGotaCuda]

Split shifting is possible, but as you mentioned, not very practical.

You would shift , 1, 1OD, 2, 2OD, 3, 3OD


Sent from my iPhone using Tapatalk

[Chryco Psycho]

Mick just finished installing one https://forum.e-bodies.org/engine-transmission-and-rear-end/4/gearvendors-install-completed/5602/
I have installed one also but I did not drive it much as it was a customer car , once I confirmed it was working correctly I let the customer have the car & I never beat on it , but it can be shifted automatically or manually , the car may be faster down the track manually shifting it in & out & splitting the gears keeping the engine in a narrower powerband , in theory you would never use 3OD anyway  unless you change the rear gears as 3 direct should easily get you through the 1/4 mile

[Mickm]

BillR1212,
As Chryco stated, I have just completed a GV install in my "72 Cuda with 340, 3:23 gears in a 727. The difference here is, my total intention is to use it for highway traveling at 75 mph not racing. For my application, I am extremely happy to this point but, that being said, I only have probably 50 miles or so on it.

Also, I have not manually shifted thru all 6 gears  yet but probably will just for fun at some point. From my reading the manual (several times) I remember you do have to turn the GV unit off between each main gear and this does not seem like a good routine for racing, in my humble opinion but....

I would suggest your calling Mike at Gearvendors. His extension is 115 and he will take the time to discuss your needs and answer any questions you may have. I did this with him and I can say his customer service was second to none.

I hope this helps.

Cheers!
Mickm

[1 Wild R/T]

I know four people that have run them, none actually split shifts... 1st,2nd,3rd,O/D Only reason to use 1st OD or 2nd O/D is if it happens to put you right into the sweet spot when cruising at a steady speed....

[Marc70challenger]

Splitting the ratios (especially 2nd-over) is always valuable to the 3-speed car. 1st-over can be very valuable for hooking up with our AutoLaunch circuit on cars up to about 800hp but is a big torque multiplier and so cars with higher hp may break traction depending on their chassis setup. 2nd-over keeps the converter tight and produces torque multiplication right when the aerodynamics are starting to load the car heavily. We've never heard of a car that didn't run quicker going 1st, 2nd, 2nd-over then 3rd.

http://www.gearvendors.com/racing.html  (3 speed drag racing section)

The Autolaunch shifts to 1st over on its own (still true).  Then .... .......EDIT .... You have to manually turn off 1st over when you go into 2nd.  so second is "normal" (GV not engaged ).  I can't find the specifics on Autolaunch on the website but detail info came with their unit.  I found this:  half way down explains Autolaunch. http://www.gearvendors.com/hrdodge3s.html


2nd to 2nd over and to 3rd Is done manually (with "on" "off" button set up ).   2nd to 2nd over is easy. Just hit button.  Disengaging (hitting button "off" ) then shifting to 3rd takes some practice but many do it at the strip.     Guys I know of that use this run low rear end gears (4.0+).

On our car I didn't use their computer module. Mick set his up if I remember his thread correctly

I just needed GV for highway running - so it's on/off switch to the GV solenoid - that's it.    We have 4.56 rear, drag spec 1st and 2nd geared-ratio TH400 and 28" tall tires rear (15" wheels and 275/60/15 ET pro radial MT) ... our starting line ratio is almost spot on .  Don't think Autolaunch do much for us.  We trap right at upper edge of HP at 6900 rpm.  Going to try 2 to 2- up this year though.

With your rear gears I would think the Autolaunch would be where you'd really have some benefit racing with GV  But in all honesty, unless your going to get into dragging it for more than just some fun now and then ... you probably need to revisit your rear gears and maybe trans as well 1st and 2nd ratio.

Of course, for cruising that in itself is worth it.  You could get a little steeper rear and be fine on highway.

But like Mick said, call them. They are great to deal with and can get into ratios and specifics to maximize what you want.  They're great to work with.

[BillR1212]

Thank you everyone for the responses. I appreciate the feedback. It will mainly be for OD on the highway. I usually have to fill up the car twice in one day when I'm cruising around town. Maybe cutting it down to one and a half would be perfect!

Where did you guys mount the button? I did call GV and they are great to talk to. They suggested floor board as I have the slap stick. Did you guys do that too? Any other preferable area's? They also recommended I double check my rear end. It's been a few years and I've always had 3:23 in my head when we did the driveshaft spin test. I may crack the rear Diff and look just to make sure.

I'm a novice at the drag strip. I guess it would be fun just to see if I can crack a high 10. My best is a 11.7 and that is with a dismal 60 foot time of 2.1 seconds  at 117mph. Thats running Nitto Drag radials air'd down. My thinking is with a stronger drive line and u joints I can get some slicks and cut into the low 11s? Then some rear adjustable shocks etc to shave the last few tenths off.

Also for what it's worth. I just installed some Jegs Electric cutouts. My thinking being my car is pretty tame as I have a mild Cam in it and 2.5 inch exhaust. Fully open is too loud, and you can feel the exhaust pulsing the seat. But if you just barely crack it you can get a nice tone that enhances the 2.5 inch exhaust. I've gotten a ton of compliments on how it sounds in the past few days.

Was supposed to get some track time in today, but they did test and tune yesterday. Oh well!

[Marc70challenger]

No prob!

I have the GV switch wired to the Speedwire switch panel now.  That's only because we were running out of time and it was quick and easy.  Intentions were to wire it to a floor switch (like the old high/low beam switch ... that's what comes with GV kit as well).  Might do that this summer if we decide to try using 2-up on the strip.

That's good ET and mph for that 60" time. Definitely have to room to better ET.  What track do you race?  What's their tech like ?  Just asking because if you dip down into ET you want then you're entering into more serious mod rules:

Section 4A, NHRA rulebook

ROll BAR
Roll bar mandatory in all cars (including T-tops) running 11.00 (*7.00) to 11.49 (*7.35), in convertibles running 11.00 (*7.00) to 13.49 (*8.25), and in all dune-buggy-type vehicles running 12.00 (*7.50) seconds and slower. Permitted in all cars. See General Regulations 4:10, 10:6.
ROll cAGE
A roll cage is mandatory in cars running 10.99 (*6.99) or quicker or any car exceeding 135 mph. In full-bodied cars, with unaltered firewall, floor, and body (from firewall rearward, wheel tubs permitted), running between 10.00 (*6.40) and 10.99 (*6.99), roll bar permitted in place of roll cage. In convertibles running 10.99 or quicker or exceeding 135 mph, roll cage mandatory. See General Regulations 4:4, 4:11, 10:6.

There's also drive shaft loop, trans blanket/shield and other considerations  (around pg 72).   http://highschooldragracing.ca/pdfs/NHRA_Rulebook.pdf

Not trying to be downer just a heads up.  You start getting 120 mph +. You want to be safe.

What set up do,you have now?  Motor? Etc. 

[cataclysm80]

I just bought a Gear Vendors, but haven't installed it yet.
I'd think you'd want different gears than 3.23 in the rear.
I'm planning to run 3.91, and with 3rdOD engaged it will drive like 3.05.  That's probably enough gas mileage for me.  I don't think I need to be in the 2.76 range or less.

[BillR1212]

No prob!

I have the GV switch wired to the Speedwire switch panel now.  That's only because we were running out of time and it was quick and easy.  Intentions were to wire it to a floor switch (like the old high/low beam switch ... that's what comes with GV kit as well).  Might do that this summer if we decide to try using 2-up on the strip.

That's good ET and mph for that 60" time. Definitely have to room to better ET.  What track do you race?  What's their tech like ?  Just asking because if you dip down into ET you want then you're entering into more serious mod rules:

Section 4A, NHRA rulebook

ROll BAR
Roll bar mandatory in all cars (including T-tops) running 11.00 (*7.00) to 11.49 (*7.35), in convertibles running 11.00 (*7.00) to 13.49 (*8.25), and in all dune-buggy-type vehicles running 12.00 (*7.50) seconds and slower. Permitted in all cars. See General Regulations 4:10, 10:6.
ROll cAGE
A roll cage is mandatory in cars running 10.99 (*6.99) or quicker or any car exceeding 135 mph. In full-bodied cars, with unaltered firewall, floor, and body (from firewall rearward, wheel tubs permitted), running between 10.00 (*6.40) and 10.99 (*6.99), roll bar permitted in place of roll cage. In convertibles running 10.99 or quicker or exceeding 135 mph, roll cage mandatory. See General Regulations 4:4, 4:11, 10:6.

There's also drive shaft loop, trans blanket/shield and other considerations  (around pg 72).   http://highschooldragracing.ca/pdfs/NHRA_Rulebook.pdf

Not trying to be downer just a heads up.  You start getting 120 mph +. You want to be safe.

What set up do,you have now?  Motor? Etc.

Thanks - I usually get walked in the 60ft, but once I get traction I pass most cars by the time I hit 2nd gear. Seems to run out of steam after the 8th in the higher RPM band. Likely a Cam/Head problem. But I didn't build it for the strip but rather a fun street pounder.

Current set up is a 505 stroker. 10:8:1 compression. CNCed Performer RPM heads, Victor 440 intake, 950 AED carb/ Comp Cam -  23-712-9. I was planning on running fuel injection but that didn't happen. I'd imagine a more aggressive Cam would free up some power and maybe changing out my hydraulic roller set up, but for now it's pretty low maintenance, and runs well. I'm shifting around 5800. I thought I'd get more RPMs out of it with that Intake, but again thinking Cam may be too mild? Not sure, I'm not a pro, but she should live a long life shifting that low, with light internals. (SCAT crank/MAHLE Pistons)... 475 wheel HP at 5200/and 480tq at 4800. 32 -34 degrees of timing I forget.

Firm feel steering box, Tubular upper/lower control arms, QA1 single adjustable up front. Rear is pretty stock outside of some traction bars. Planning on doing double adjustable shocks out back and note sure what else from there for traction.

I go to KDS Motorsports in Kinston NC. I've never been through Tech as it's test and tune. Heck they don't even check for helmet, although I'm going to start wearing one. Once I get a speed that needs all those MODs I'll likely buy a beater and make it my drag car. Not sure I want to put a roll bar in my Cuda. 

[BIGSHCLUNK]

That was always my thought on this too.  Better launch, and better hiway, too much different tho, I'm thinking would put me to far out of my power band. 

[BIGSHCLUNK]

cataclysm80 - That was always my thought on this too.  Better launch, and better hiway, too much different tho, I'm thinking would put me to far out of my power band.

[Mickm]

BillR1212,
I mounted my button in my shifter.


I too have 3:23 gears. You should be able to find a small aluminum tag on the mounting bolts of the chunk, if it hasn't been removed over time.

You will not notice any rpm change until you get over 60mph. But at 75, when you switch on the OD, the rpm's fall like a rock.

Cheers!
Mickm

[BillR1212]

Wow - Mickm - That looks good! I like that position for the OD button. I was originally thinking of just using the high beam switch as others have suggested prior

[Mickm]

BillR1212, You can use the dimmer switch under your brake pedal but this made more sense to me. And now that I have tried it, I love it. It is in the perfect position to turn it on and off without having to have your foot hunt for the switch.
It took a bit of work as I had to drill the hold at an angle into the plastic grip, then machine a .120" slot down the front center of the aluminum shift plate to hide the wire. This could be done with a cut off wheel but you would need to be very careful or make some sort of a jig to hold it so you could get it straight.

Cheers!
Mickm