[NZ440R/T]

I would usually post this in Transmissions but it's also an urgent issue....


Dave, I am looking into ordering a Gear Vendors overdrive/underive unit for my Challenger.
I took the dimensions around to my resto team and got an email (printed) to take too.

Now, question: On the email direct from GV they said there unit adds 14 inches to the back of the Torqueflite-727 in a Challenger.
Is this true? I really need some photos of the set up, do you have some?

Because it looks like we may need to do some serious mods, well, semi serious because it is that long....but the thing is we don't know if we have the exact measurements or if we are taking in the information correctly.

My resto team asked if these GV units have been coupled to any Challengers....I said yes yours, so we know it can fit.
I have an X-Pipe, but that isn't our worry....does the unit sit low??


Sorry about all the questions but as you know these aren't cheap so shipping one out to New Zealand to find we have to make a mess of the Challenger would really suck.


Photos would be good or measurements from diff to GV unit etc....
Also, my resto team asked if they could email you if they need to know something about the install.
They have never heard of this unit so any help is much appreciated.



Thanks Dave,
Carl
NZ440R/T

[NZ440R/T]

Dave, I have searched the forum and found out how the unit looks bolted to the 727.
I found the photo below.


All I basically need now is how you installed it. lol
Could you possibly post how you did it from start to finish, and/or what mods where needed for the install.

I know we could probably get it in, but how low does that thing sit?


Cheers,
Carl

[NZ440R/T]

Sorry Dave.....I seem to be find more info as I search.
I printed off your topic (the 3 part install)...excellent, exactly what I needed.

How high is it from the ground?
Because from one of your photos it looks like it is quite snug with plenty of room, even quite a bit higher than your exhaust.


A couple of questions about how it drives:

- On the video below, the 1st to 1st-O sounds bloody mean...but then when he shifts to 2nd it dips/lags then clicks in...then 2nd to 2nd-O sounds mean...and so on. I was expecting a smooth shifting system, like the 1st to 1st-O all the way through....

(The driving part is at about 6-7 minutes in but worth it)

Video - http://www.gearvendors.com/videoclips/h ... adband.wmv



Why is this?? Is he not doing it properly?
I asked one guy with it installed and he said his doesn't do it, he said it takes a little bit of time getting the system (and you) to make it smooth transition...is that correct? GV help line said the unit takes between 0.2-0.4 seconds to engage so you have to hit the OD button a few rpms before you actually what to shift.

How smooth are your shifts? Do you have a video of it going through the gears? I have seen your other (3 or 4 videos) but you can't quite get a good sneaky listen in.

So far I am aware that the shift goes like this:

- 1st > (OD on) 1st-O - (OD Off) shift to 2nd.
- 2nd > (OD on) 2nd-O - (OD off) shift to 3rd.
- OD on for cruising......(6th gear)

That correct?


Thanks mate sorry about the questions but I am excited and just wanting to know what I'm in for AND so I can start drooling now. lol

[Christer]

:oops:

I guess you are excused Carl, thanks to the fact that you joined the MB after Dave was ready with his installation...

Cheers
Chris

[NZ440R/T]

I'll say, I'm glad I'm not doing it first.

[dave-r]

So what was the question?

Just kidding.

You posted all those though the night here so I wasn't around to reply sooner.

The unit fits snug under the car once the tunnel has the dimple in and the tail of the trans dropped a half inch or so. You can't see it unless you get your head under the sill to look for it.

Make sure you also read the seperate threads on the problems I had after. There is a link from the last installation thread.

Other people don't seem to have had a problem but I would check the output shaft endplay anyway just to be sure you don't get the problem I had.

Also check the angle of the dangle on the axle pinion once it is in place.

The fancy shifts take some practice and to be honest I wouldn't bother. Too easy to mess up and accidently over-rev the engine.

I just leave my car in drive and the GV unit in manual mode. In auto mode it does not switch on until over 50 mph. But in manual mode I can switch it on at any speed over 28mph and switch it off under braking to get a little engine braking when I am going too fast. Which is most of the time.

Despite the problems I had I can honestly say it is one of the best things I have ever done to the car. Being able to instantly switch from a cruise 3.30:1 axle ratio to a race 4.30:1 makes driving a totally exciting experience. It is like manually shifting up and down a gear without taking your hands off the wheel.

On the strip I was shifting 1-2 then 2-over, then 3, and then 3-over.

The 1-2 shift with low axle gears and over 500hp is just a very few seconds anyway. You would have to be bloody fast to do that fancy shift in that time and trying to keep the car straight at the same time.

In future I will just be racing with the normal shifts and only switching the overdrive on if I run out of rpms at the top end of the strip.

In this video clip you can hear me making some of those fancy shifts but due to lack of traction I am shifting well below the normal shift point and I am not practiced at shifting and switching the OD off quickly so there is some delay.

http://www.aros-max.co.uk/holleystuff/v ... action.wmv

[NZ440R/T]

Awesome...thanks Dave.
Sounds great. I was told by the GV people that don't EVER shift into the next permanent gear with OD off.....They said always shift into the next gear then turn it off our else you could see your engine behind you. lol

I guess it'll just take some getting use to. I printed off the subjects and this thread (your post) and will take it around to my resto team.

Hopefully with 4:10's my car will be able to grip a "little" better and also give me that spilt second longer between gears to change and keep it straight.


Thanks Dave,
Carl

[NZ440R/T]

Dave, forgot to ask......


With the car in [D] (drive) and GV unit in Manual mode does it do the 6 crisp shifts for you???

[dave-r]

It never does the 6 shifts for you.

I guess you could in theory switch the GV on and off as the trans switches up automatically but you would have problems doing that in practice.

GV themselves tell you there is no advantage to switching the overdrive on between 1st and 2nd.

[NZ440R/T]

Found out today my car has 2:76 gears!!!!?!?!?!
I am upgrading to 3:55's instead of the planned 4:10's.

I will get the same cruising speed I am now (65mph @ 2,000rpm, or under) and a much better take off than I am getting now, BIG difference.


About the 1st-2nd shift, may not help but shlt, it sounds bloody awesome!!! Pro-stock gear changes.....there are some guys and articles about going through the gears manually, how it's a blast and easy to do with practise...banging through 6 gears like a pro stock driver etc.


You know when you change into the existing gear (out shifting) have you timed it so there isn't any OD off lag for that split second?
Like shift from 2nd over to third and just as third hits bang the OD off so it's smooth as silk...or is it too hard to do?


Thanks Dave, I'm learning a lot.

[dave-r]

Stick the 4.10s in. With the overdrive on it will still have around 3:1 final drive which is plenty for high speed cruising. You really don't want to be cruising under 2500rpm with a stock converter because it may be slipping slightly which causes the trans to get hot and mileage suffers. Also if you are below the rpm where you are making peak torque you are not getting best mileage that way either.

I really haven't practised the shifts very much. My car is so damn fast I'm up to 140mph before I know it and there is just too much traffic around no matter where you go in this country.

Plus I don't see the point? I like to hear the engine pick up from 4k or 4.5k rpm to 6000+ rpm. With these fancy shifts the rpms only drop to 5 or 5.5K so each shift is very short indeed.

I prefer to hear the revs climb in each gear so I just use the GV as a 4th gear.

[72 Challenger (Hans)]

Dave, you noticed you were driving on the wrong side of the road...??

and then they say dutch guys are crazy...

[dave-r]

About time we had some video of your car I think Hans?

[NZ440R/T]

Thanks for the tips and advice Dave......I'll be sticking with 3:55s though as I don't want to get the GV unit and be doing higher rpms than I already am....I won't be gaining anything. I may get some "little" goodies for the trans, it is completely stock at the moment (shifts great still) but with the GV unit shifting pretty hard it may be a anti-climax to shift into the existing gears and find it not as crisp/hard as the GV unit's shifts.

What do you use? I was thinking of a Trans-Go TF2 kit, TF 1 kit sounds great, but maybe a "little" soft in the shifts.....I don't mind harder shifts as when in manual mode the shifts aren't going to be cruisie. Plus, I've heard you have to nail it or be climbing the rpms to get the hard shifts...around town driving is not as harsh.



Cheers,
Carl

[NZ440R/T]

I/we/Info help have decided that we are going to go with 3:91 gears.
3:55's or 4:10s have been hounding my head for days on end (even in my sleep) then I decided to get 3:91's....gotta love it! lol

3:55's weren't enough, 4:10's were too much, 3:73's were close but 3:91's are spot on.
I still get an OD cruising gear of 3:05 good for 65mph @ 2,380rpm.


Thanks for your help.