Anyone had any experience with a Gear Vendors Overdrive unit? I've read good things in magazines but wondered if anyone had any first hand experience?
JW installed one in a GS 455 for a customer. Use the search key as I think it was discussed and there may be some pics.
I am running one in my camaro and like it alot. I am sure I will like it alot better when I pull out the 3500 stall and do the switch pitch!
I have one istalled on my SP 400. It works great. Lowered my RPM on the highway roughly 600 RPM. Seems very sturdy, you know when it shifts. GV overstates it's usefulness on the dragstrip though. My experience shows me that the electronics are really too slow to shift it with any precision at the track. There is at least a second or so from the time you activate the switch to the time it actually shifts. The only thing I haven't tried yet is leaving the trans in 2nd gear on a pass, and activating the GV so that I go through the traps in 2nd over. With my 3.42's, that would be like 3.90's All told, it costs me about 3200 including the labor and driveshaft.
I found mine used online. Got the TH400 and GV for $1200. Ended up selling the extra 400 for 250. So have about $950 into it. Did have to shorten the driveshaft though.
Thats a real good deal for that price, just make sure you change the fliud every 5000 miles, i plan to use synthetic in mine.
The gear vendors is really a tight fit, and needs a few mods in a G body anyway. I should have made a new crossmember but, was too late after i realized how much trimming it needed!
this is a cool add in unit for your original 3 speeds, but wouldnt it be more cost effective to just buy and swap in a 200r4?
Not really Mike. It costs me about 3200.00 including installation and driveshaft. That is very close to what it will cost for the best 200R4, new converter and other essentials. Make no mistake about it, you have to beef the 200 up substantially if you want it to survive behind a healthy 455 that will see even minimal track duty. Around here, anyone can build a stout 400 for 600.00 or so, and the gear vendors will handle 1200 HP. It is warranteed at the track. It is made to be shifted at ANY throttle opening, at ANY speed. They flat out tell you in the instruction manual to play around with it and do what you will, you can't hurt it. Then there is the gear splitting feature, which is a challenge to use, but versatile. If I didn't have my switch pitch (a feature I enjoy immensely), I might have gone the 2004R route. www.gearvendors.com
cool so it essentialy makes it into a 6 speed, 1, 1 over 2 2 over 3 and od. sweet i thought it was simply an overdrive unit..and simply overlooked it due to a few companies selling built transmissions for under 3k good to know if my th350 ever craps out on me i'll be going this route!
Yes, that is a cool feature. However, it is very difficult to use at the track like that. The problem is the electronics are a little slow. The shift takes at least a second or so from the time you hit the switch until the time the shift happens. That's not fast enough when you're going down the track at WOT. Remember, you have to activate and inactivate the GV as you go down the track and the 400 shifts. The GV engages at approximately 40 MPH in any gear. The 1-1over shift will occur automatically if the GV is turned on. But when the 400 shifts to 2nd, you must inactivate the GV to be in 2nd, and then activate it again to be in 2nd over. Then you have to inactivate it again on the 400's shift to 3rd to get 3rd and not be in 3rdover. That's alot of shifting in 12 seconds or less, and with it being so slow, it might not be feasible. Someone told me GV is working on faster electronics but I haven't been able to confirm this. One thing I haven't yet tried is leaving the 400 in 2nd gear, and activating the GV at the proper time, and going through the traps in 2ndover. With my 3.42 axle, that would be like going through the traps with 3.90 gears in 3rd.
Difficult to say. I never had it in my hands. Based on it's size, I'd expect it to weigh 40 lbs or so.
Only reason I ask is because I definitely need some type of overdrive. Only question is which way to go? I definitely don't need to add any more weight to my '73. That is the only reason I am leaning towards the 200r4 route. Steve
Well, with the GV, you unbolt the extension housing and bolt on the GV and adapter. You have less driveshaft because it has to be shortened. So you lose and gain weight. What's the net change?, don't know. The GV is for all practical purposes, indestructable at our power levels. If the 400 needs a rebuild, what will that cost. If the 200R4 needs a rebuild, how much will that be? Does that make it any easier?
The t400 unit weighs 46 lbs about with no sump model, like i have. Don't forget the overdrive ratio is .78 compared to .67 of the 2004r which is a huge difference. A 3.73 gear becomes 2.50 on a 2004r and 2.90 on a GV 400.
Yes, but that .67 overdrive takes a lockup converter to get the most out of it. One of the reasons GV went with a .78 is so that you could use a moderate stall converter with it. That and .78 splits the gears more effectively. With a cammed motor, and jetted carb, you can have too much of an overdrive. Slow the motor down too much and it becomes just as inefficient. Mileage isn't as good as it might be.
