S10 converter

[eventhorizon66]

I was considering swapping in an S10 converter.  Want to squeeze a little more out of my stock 350 off the line and I think the stock 1300-1500 stall converter is holding it back some.  I understand that the S-10 is rated for 2050 stall.  Is this rating established with a 4.3L, meaning my engine might ring out about 2200 stall?  Is this still a popular upgrade for the 700R4?  What part number should I look for?

Also another related question: After lifting completely off the throttle, while cruising on the highway, my torque converter unlocks briefly after getting back on the throttle.  I realize this is normal and desireable, but my complaint is that it locks back up too soon, unless I immediately give it enough throttle to downshift.  I would like it to wait a little longer, so I can more easily get around the jerk that cuts infront of me (going 5 under, of course) without downshifting into third.  Will a higher stall S-10 converter affect this at all?

[DnStClr]

I think the most impt factor in choosing a torque converter is supposed to be the cam shaft. Whatever peak torque rpm the cam shaft allows the engine to make determines the stall of the torque converter you should use.  Also, a performance torque converter will be quicker off the line than a stock converter. Your heavier truck will also make that S10 converter have a higher stall speed, so 2200 rpm might be pretty close.
It makes sense to me that the higher stall converter would allow your truck to develope more rpm before unlocking. I'm not a mechanic tho.

[Blue 82]

The Corvette Converter might be a better choice
the stall speed is about the same 2000/2200
yet has stronger internals

[HAULIN IT]

Even, Yes, The stall rating is for that engine in the weight of the vehicle (give or take for ex-cab,Blazer, ect.)it is originally installed in. Yes, It will likely stall slightly higher due to having more torque than the 4.3 & more weight (?, not sure, the 4x4 S's aren't that light) but even right around 2000 RPM should be good. I've been using a S-10 converter for a year & a half or so. I haven't had any durability problems yet, lots a torque-big Olds & ET street radials with 20+ dragstrip passes. It drives on the street nice also. Mine's a used GM one off the core shelf in my friend's tranny shop. I will most likely replace it with a higher stall, high-end multi-disc unit before long though. Lorne

[eventhorizon66]

The Corvette Converter might be a better choice
the stall speed is about the same 2000/2200
yet has stronger internals

I've read that the corvette and S10 converters are 100% identical in every way.  The difference is that the Corvette converters are only available rebuilt, whereas a new S10 unit can be had for the same price.  I might be wrong, though.

[Blue 82]

if you are getting a rebuilt converter
then yes, they are the same
replacements usually come in three variations

low 1200/1400
med 1400/1800
high stall 1800/2200

however
go to the GM parts counter
and you will see a different story
some s10 high stalls have damper springs that reduce shudder
some vette applications come with carbon impregnated clutches

here's a link to some good stuff
http://www.goissca.org/~indipalass/ARCHIVE/TechCorner/ARTICLES/Torque%20Converter%20Upgrade.htm

[eventhorizon66]

Thanks a ton for that link Blue 82.  It was a good read.

[Blue 82]

If you have the vacuum switch on the firewall that unlocks the converter
the diaphram may have hardened (over time) and may not be as sensitive to vacuum changes as a new one causing a (longer) delay to unlock

A mity vac and and ohm meter will help you determine the "quickness" of the switch delay

Take your mity vac to your parts store with your ohm meter to compare your findings to a "new" vacuum switch

I piggybacked a toggle switch and mounted  on the column shifter to unlock the converter when I had the 700r4 in my truck, by using a double throw switch I could lock the converter in 3rd or 4th when towing, eliminating the annoying unlock/lock of going over overpasses and passing slow people. By puting the switch in the center position (off) the converter function would function normally

[eventhorizon66]

My switch is new.  I really don't ever tow, so manual lock/unlock isn't needed.