Gear change with w2 408

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cpearce

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Well, as we all know life often has priorities that come before our cars. Mine this year has been landscaping our yard, and children's sports. (And steady rains for almost 2 months)

That said, I finally changed the rear gears in my w2 408 Dart and have had enough time between rain storms to get it out and critique.

As some may recall I have a 65 A833 commando box in my car with the 3.09 first gear ratio. Initially I tried the car with 3.55 gears, although a great deal of fun in town, not so much on the highway. Where I live, in small town Alberta, anywhere I go are highways with 110 km/h speed limits.(68.5MPH) so this is an important aspect to consider. First gear with the 3.55's was extremely short with nothing but rubber.

Next, I installed a 2.94 center later last summer. This was in advance of a car show about 400 miles away. While these were a blast on the highway, it wasnt optimal in town or on secondary highways. Second gear was almost too fast in town, first not ideal at lower speeds. Starting out on inclines or up curbs required feathering clutch more than I'd like. These were just not enough gear for this particular engine combo, it wasnt very happy anywhere but on the highway. (Not huge surprise, but I had them so I tried them)

Last week I installed my 3.23 chunk, this seems to be the ticket for multi use enjoyment. Around town, roll out is very easy, as are inclines into garage or parking lots. Once warm, car pulls along in 1st with little surge or bucking, likely tuning will eliminate. Second gear is perfect speed for in town use, and highway speeds are perfect at around 2700rpm. First, and a lot of second, it will annihilate the tires with ease. I think these are the perfect gear for my application.

For those of us without OD transmissions, gearing our cars is always going to be a compromise. We live in a small town, simply cruising town gets boring very quickly, so we like to take the car on road trips where we are at 60-70 mph for extended periods of time. Heck, the closest track is 2 full hrs away, still havent made it there with the Dart.

Nice thing the 8 3/4 allows pretty quick and easy gear swaps, can change out depending on usage requirements. Anyways, thought I'd share my results with the group, I too am a fan of the 3.23 gears with a large torque engine. Especially with the 3.09 first gear transmission.

Ps, tires are 235 70r15, listed at 27.9".
 
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Out again tonight for a drive, I'm loving this gear change. I think these will stay in for a while.
 
What you could do....

With the 904 torqueflite I’m in the middle of building. It’s not even done yet and I just took a quick crash course in the 904 the past 3 weeks.

You can easily......put 2.74 first gear and 1.50 second gear 1:1 final gear

This gear set replaces the 2.45 first gear and the second gear as well

The third gear is still 1:1

What this does is give you good take off and keeps your highway gears.

Your chnging the 2 gears in the transmission instead of in the differential.

But your only changing 2 of them so you can run that 2.94 and have that for the highway

But on take off....it’s a 3.60

You get the take off and don’t lose the good part of what the 2.94 or whatever you run provides.

So this gear set is easier to put in than it is in the 8 1/4 but the 8 3/4 would be easier.

It’s not hard to drop in new gears in the transmission., way easier than I would have thought.

This is the route I went. While I was in the transmission I’m upgrading it. Never had one apart before but it’s gonna make a huge difference.

Now.....if you find a 999 transmission with a lock up clutch.
You already get these gears with it. As well as an added clutch disc and a lot of times a lock up clutch.

When you really get into all this......it’s a win win situation and can be had for about $60 by changing the first planet set and sun gears.
 
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This is what you need. Remove the pump and the rest falls out. Put this back in.....put the pump back in.

Adjust the bands and done.

I did see you have the 833.....but if you were to venture into automatic land....that’s a good choice also
 
I just swapped in a set of 2.76 for a road trip next week. This in the Cuda. The W2 Dart is still a ways out.
Is your leak gone ?
 
2.94 should be perfect for a 408, but maybe your cam and 28" tires are not a good match
I like 3.23's in a well tuned stock 340 with stock size tires and converter.Cruises on the highway at lo rpm and blows the tires out easily at lo speeds. Going to try 2.94's...I tried and did not like 3.9's and 3.5's
 
2.94 should be perfect for a 408, but maybe your cam and 28" tires are not a good match
I like 3.23's in a well tuned stock 340 with stock size tires and converter.Cruises nicely at lo rpm and blows the tires out easily at lo speeds. Going to try 2.94's...I tried and did not like 3.9's and 3.5's
Gearing with the 4 speed has less tolerance to under gearing than with automatic, since there is no convertor to multiply the torque and absorb ignition pulses at low rpm. Another factor in my case is the the lightweight flywheel, if I recall correctly mine is 16lbs, rather than the normal around 30lb unit. Many people seem to like the 2.94 gear coupled with an automatic, for my car the 3.23 just feel right. The engine is "in the zone" on the road at 2700-3200 rpm.
 
I finally figured out to gear my A833 combo to redline at 60mph in second gear; redline being peak power plus ~300 on my long slow flat peak.
With my GVod used as a splitter, and the 3.09 Commando, this is 3.23s, as first-over is 2.41, and 60=5800. (3.55s gets me ~6400)
Thing is, the car goes 93 in the Eighth, requiring about a 5.19 ratio. I get that with 3.55s in second over(5.32). That's one pull on the stick and two electric shifts, ending at 93=6150.(or 5600 with 3.23s.)
I went with 3.55s cuz the GVod gets me 65=2240.
And the rest is what it is.
I like the heavy flywheel with my lil 367, cuz that makes it a dump-it-and-go deal around town. Just blip the throttle and feed the clutch out, letting the flywheel inertia make a nice smooth take-off.
One thing I discovered real early was the engine jumpiness off idle with hi-way gears. My 230* cam does not like an idle speed below about 700 with "normal" for automatics timing. At 177psi cranking cylinder pressure, the power pulses are just too strong. So, 700 with 3.23s and a 2.66 low makes the minimum speed to be 6.6 mph, and parading was out. I swapped in 3.55s and a 3.09 low, and retarded the timing (with a dash-mounted, dial-back, timing delay box), and got her to 4mph @550rpm@5* advance; on a 500 rpm minimum in gear and rolling,idle-speed. And the heavy flywheel helps smooth the power pulses.Now, parades were back on the table.

As you have discovered also; for a streeter, second gear is where it's at, and the rest is what it is.
and driving too slow makes a jumpy car that the only cure for, is to toe-the-clutch. And you can't really get away with that for a 20/30 minute parade.

But hey, yur gonna need some more serious rubber real soon,lol.
and maybe slapper bars at the least. Yeah I really said slapper bars,lol.
 
Well, I had a good opportunity last night to really take the car for a run, put on about 80 miles. I must say, I'm very very pleased with the setup. Pulling onto the highway last night I was able to really lean on it, 1st gear was just smoke, all of second gear the tires were fighting traction with the telltale howl, and a solid chirp into third. Pulled 6300rpm in 1st, 6200rpm in 2nd, then eased off midway through third. I have achieved what I wanted with this car, a very hot yet driveable street car. 3rd gear rubber with 3.23 gears works for me.

Might also have something to do with my brand new Thumper carb. That will be a fresh post.
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