Gear Change

[vms4evr]

Well I got sick of listening to the gears whine. They got terribly noisey and something else must be wrong in there. So I bit the bullet and ordered a completely rebuilt unit from Ikerds. This unit comes with the Strange (US Gear) 3.54 set. At least this time the whole unit is built by someone who does it for a living.

Completely rebuilt posi, new gears, new bearings and redone yokes. So the unit will bolt right up to the half-shafts and drive shaft with no settings required by the installer. It came with the lube, additive, rtv sealer and detailed break-in instructions.

The car is in the shop now and I'll have it back by Saturday. Maybe earlier if we don't get totally sc$#@ed by Isabel. I'll post an update after I get it back and start on the break-in.

I already know what to expect as far as performance that's why I'm sticking with the 3.54 gears.

Graham

 

[vettn94]

That's what I did, bought the complete pumpkin outright. Paid around $1200.
I also picked up an extra batwing for $100 so I still have the stock rear in the garage with the cover still on it.
good luck with the new rear end & surviving the storm.

 

[Corvette-Pilot]

invinceable..... yes I changed out the torque converter to a 2500 stall. The trans shop I had the work done said they didn't recommend going to any higher than a 2500.

Dave

So what is it that the torque converter does to help performance ?
What is stock in the car (94 auto) ?

Buying a rebuilt pumpkin section, how much of a hassle is it to swap it out?

 

[lt1vert]

So what is it that the torque converter does to help performance ?

To keep the answer simple without getting into all the highly technical stuff...

A higher stall torque converter basically let's your car rev higher before locking up. Instead of locking up at 1500rpms, (not much horsepower there) the converter will rev all the way up to say 2500 and then lock up.

say you drop the clutch on a manual tranny at 1500rpms vs. dumping it at 2500 rpms. the lower rpms will take off slowly and the higher rpm dump will spin the tires.

I know it's an overly simplistic explanation but it's just to get the idea.

 

[Corvette-Pilot]

That makes sence !
But how does this affect driving around town in the low RMP range??
It wont be locked up so does it slip and thus waist energy??

 

[Hotred94]

A lot of people talk about doing 3.54, 3.73, and even 3.07 gears. Has anybody tried the harder to find 3.30 (I think that is the right ratio number)? I think this may be a better ratio for me than the 3.54 gears since I do a lot of highway miles. Any comments on this ratio?

 

[lt1vert]

That makes sence !
But how does this affect driving around town in the low RMP range??
It wont be locked up so does it slip and thus waist energy??

Sorry I forgot to go into that detail.
under light/normal acceleration, the torque converter does lock and shift at the designated speeds the computer sets.
Once you go full throttle, the converter will unlock and rev to 2500 (depends on tc) instead of accelerating from 1500.
If you have gears, they will normally be running in the 2200 to 2500 rpm range under normal acceleration. and that's why converters work so well with gears. It puts you right in the gears powerband.

It takes a little re-learning how to drive with the new tc with that extra slipping but once you figure it out, lot's of fun are to be had.

btw...you'll go through rear tires much faster. With 315's in the rear, it ain't cheap

3.54 gears since I do a lot of highway miles

The 3:54's will put you in the 2400rpm range at 75 in OD. The 3:73's are at 2600 and with muffler elim's it is very loud around town and on the highway.
whatever ratio you decide, make sure you have a programmer to set the ecm with. I fried my tranny after my gear install cause I waited to program it(it's beefed up now) The tc won't lock at all without the programming.

 

[WhalePirot]

wish I had the 3.36

I looked all over, a few years ago, to find something other than the stock 3.07s, which first went in my warmed up L83, then behind my 406cid. The 3.73's just too much, for my driving. I love acceleration but the Crossfire just had no revving capability and all I get, now, in first is wheelspin on these 315x17s.

While pull is way cool, I also like low revs on the highway. The +3 Nash helps, but another O/D in the line would be perfect; or a lower ratio.

Hotred, which rear gears do you have now and how high do you like to rev your engine B4 shifting?

BTW, going to 3.73 from 3.07 meant opening the talishaft housing to change the gear on the output shaft. Lesser changes would have allowed a simple, exterior gear change. OR using the external electronic pulsing box, mentioned above.

 

[Hotred94]

I currently have the stock 2.59 gears with 315/17 tires. The stock trans shifts at lower speeds than I would like. I would probably go another 500 rpm before shifting myself.

I have the 4L60E transmission, electronic being the key word here. Do I still have to change the two gears in the transmission tailstock or will a hypertech programmer be all I need? I keep hearing yes and no to that question.