Author Topic: stock converter stall speed  (Read 27213 times)

Offline micahadams

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Re: stock converter stall speed
« Reply #15 on: October 12, 2009, 10:09:40 PM »
I typed that wrong. I have 4.11, but with the high stall it feels like having 5.13
Im the same as you Donut, 3k @ 65mph and I think thats too high for a big block.

A stall converter is just another name for a torque converter.

Offline Donut

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Re: stock converter stall speed
« Reply #16 on: October 13, 2009, 09:09:20 AM »
IMO, if you don't like the rpm range, you should look at lowering it.  Taller tires, lower numerical gear, OD trans, or a combination.
I don't believe the converter will affect your final drive.

I did have the fun of driving an old furd SD with a real steep gear.  Above 55 all it would do is make noise.  At low speeds it would pull just about anything as long as you could keep traction.  (460, auto with OD)
'73 Chevy K-20 ***SOLD***
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My plow was half price if i took the truck with it.

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Offline screamin86

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Re: stock converter stall speed
« Reply #17 on: October 13, 2009, 03:15:05 PM »
The only time a converter will effect rpm at certian speed is if you have a very large converter and the stall speed is higher than your cruise rpm. Like having a 3500 stall and your cruise rpm would normaly be at 3k but the converter will not lock in untill you reach 3500.
86 k10 lwb 4x4:350 .040 214/224 444/466 112lsa performer rpm 1406 lt's summit racing th350 2800stall
03 yukon xl:tint debadge full boltons
86 ta:lm7 hot cam boltons

Offline micahadams

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Re: stock converter stall speed
« Reply #18 on: October 13, 2009, 11:31:29 PM »
Because this converter does lock up it does change your final drive ratio. When I say lock up I mean like a locking converter style. With out a lock up converter, your non locking converter will always be slipping. The more load you put on it the more it will slip.


Offline Donut

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Re: stock converter stall speed
« Reply #19 on: October 14, 2009, 07:05:10 AM »
http://en.wikipedia.org/wiki/Torque_converter

If it in fact does change the final drive ratio (noticeably)  Couldn't the OEMs get rid of that pesky OD?

My redneck understanding of a torque converter is that it's nothing more than a hydraulic "clutch", lock-up converters quit slipping and helped give you 1-1 on the final drive.  Lock up and stall converters are 2 different animals (IMO)  I briefly looked into a different converter for my truck, a lock-up wouldn't help me off idle, which is where I plow, a high stall would be slipping at that low of an rpm.  The stock converter fit me OK, probably not the best, but a fair compromise across the board.
I maybe all wrong. If someone could correct me please do, it may make a good blurb for the tech-pages.
'73 Chevy K-20 ***SOLD***
350/tbh350/np205
My plow was half price if i took the truck with it.

'86 C-30 dually, 454/tbh400

Offline VileZambonie

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Re: stock converter stall speed
« Reply #20 on: October 14, 2009, 08:34:09 PM »
A lock up converter has nothing to do with final drive ratio. The only purpose of a locking torque converter is better fuel economy during the coupling stage.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline micahadams

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Re: stock converter stall speed
« Reply #21 on: October 14, 2009, 10:27:53 PM »
Quote
lock-up converters quit slipping and helped give you 1-1 on the final drive.

Right.

It doesnt effect your final drive "ratio" but it does effect drive rpm. Thats what I am interested in. All torque converters slip, the more stall rpm, the more they slip. If you have a lock up style then its 1:1 once it locks up.

My point is take 2 vehicle all other things being equal. 1 has a high stall converter, and the other is low. Cruising rpm will be different.

Anyway, I have a approx 1500 rpm converter coming from Hughes this weekend. I am going to put it in and report my findings. Any predictions?

Offline TexasRed

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Re: stock converter stall speed
« Reply #22 on: October 14, 2009, 10:29:54 PM »
I predict it'll take longer and you'll drink more beer than previously budgeted.

Offline malibu795

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Re: stock converter stall speed
« Reply #23 on: October 15, 2009, 10:34:11 AM »
im running a 2400 stall in my 75..
4.10/285/75/16 (33") 70 is ~3000

looking at going to 35" tires
adam wildman
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Offline screamin86

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Re: stock converter stall speed
« Reply #24 on: October 15, 2009, 05:21:19 PM »
My 86 has a 2800 stall. With 3.42s and 31s
86 k10 lwb 4x4:350 .040 214/224 444/466 112lsa performer rpm 1406 lt's summit racing th350 2800stall
03 yukon xl:tint debadge full boltons
86 ta:lm7 hot cam boltons

Offline Donut

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Re: stock converter stall speed
« Reply #25 on: October 15, 2009, 08:53:33 PM »
...Anyway, I have a approx 1500 rpm converter coming from Hughes this weekend. I am going to put it in and report my findings. Any predictions?
I predict (everything else being good) that you could slow down 5 mph and get the same results cheaper.
Isn't a 1500 rpm converter essentially a stock replacement?  I believe Captkaos posted that stock was 15-1800 stall.

I am curious to see your results.  I actually hope my prediction is wrong, and you get what your looking for.
« Last Edit: October 16, 2009, 05:55:59 AM by Donut »
'73 Chevy K-20 ***SOLD***
350/tbh350/np205
My plow was half price if i took the truck with it.

'86 C-30 dually, 454/tbh400

Offline micahadams

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Re: stock converter stall speed
« Reply #26 on: October 15, 2009, 09:48:47 PM »
UPS says it will be here tomorrow around 4pm. I am curious too.

700 rpm reduction at stall probably is only a couple hundred rpm reduction at cruise throttle position(because of lower hp input into the converter) Thats my prediction.

Screamin 86, do you remember your 65-70 rpm?

I would be curious to drive the same truck with 2100 rpm stall and something real low, like 1100. Keep in mind this isnt my daily hotrod, its manly a hauler.

Offline VileZambonie

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Re: stock converter stall speed
« Reply #27 on: October 16, 2009, 04:40:58 AM »
Your converter should only stall on a launch or climbing a grade, passing uphill etc not at cruise. Cruise is trhe coupling phase of the converter. A lower stall speed may help you with around town fuel economy but if you are looking to reduce cruise rpm don't expect any miracles.
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                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

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Offline SUX2BU99

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Re: stock converter stall speed
« Reply #28 on: October 16, 2009, 10:15:45 AM »
^ Right, doesn't a higher-stall converter still behave like a low-stall converter at lower RPMs and/or lighter throttle input? Meaning, if you have a 2500 stall converter and putter around town at say 1800 RPM, that doesn't mean that your converter is slipping by 700 RPM at all times. If you stomp on it though, it should flash to about 2500 and go, right? Camshaft profile, tire height and gear ratios can affect how your converter behaves as I understand it.
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline screamin86

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Re: stock converter stall speed
« Reply #29 on: October 17, 2009, 04:11:39 AM »
Tires gears tq your engine makes ect all will play a factor. I have a 9.5in 3500 stall in my 82 ta and its not too loose to me but you can feel it slip until you are cruising at an rpm above 3500 then it will completelty lockin. I had the 2800 in the car b4 thats now in my truck and it would flash to 2200 and footbrake to 1900 and i barely felt any slip with 3.42 gears then 3.73s with 26in tall tire. The 2800 i have is a 12in converter. I havent been able to drive my truck yet with the 2800 verter since the weather has been bad and ive had a cold and havent been able to finish putting everything back together. My only reason for putting in that converter is to insure good idle in gear and well i had it already so why not ;)
86 k10 lwb 4x4:350 .040 214/224 444/466 112lsa performer rpm 1406 lt's summit racing th350 2800stall
03 yukon xl:tint debadge full boltons
86 ta:lm7 hot cam boltons