Someone school me on converter/pump relationship please!

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clinteg

clinteg

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Currently I have a Hughes 10" 24-30 pro street converter (3000 stall). I'm wanting to go somewhere between a 3500-4000 stall. Before, when I put the trans in gear, the RPM really dropped and I was always putting the trans in neutral just because I didn't like it idling very low. Due to the fact that I'm going with a larger cam than before (~ .650" lift) and want to eliminate this issue, I'm shooting for very little to no drop in idle RPM and also have higher rpm launches.

So I call up Hughes and they said that by the time they change the stall on mine, I'll be close to what a new one would cost. They recommended their 24-40 10" converter that has a 4000 stall. That seems pretty high to me for some street use, but that's besides the point I'm getting to. What got me was he said "You'll new a new pump side". I didn't want to look the fool of course because I had no idea what he meant so just said "ok". I can only assume he meant that I needed to change the trans pump out, but why?
 
I think he said "pump site" not "pump side". Which now makes more sense after talking with some people.
 
Call back and clarify.

You'll be a bigger fool putting it together and tearing something up.

Maybe a new converter bushing in your pump?
 
Long shot but might take the thicker pump gear tangs which means the pump would have to come out. I'd also call back before ordering.
 
I'm guessing he's saying you will need a completely new impeller side of the torque converter. In a way, the impeller can be thought of as the "pump" of the torque converter.
 
74DartSwinger said:
I'm guessing he's saying you will need a completely new impeller side of the torque converter. In a way, the impeller can be thought of as the "pump" of the torque converter.
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I agree. It sounds like the modifications needed to make the converter a 4k stall included modifying the impeller side (pump side) of the converter.
 
74DartSwinger said:
I'm guessing he's saying you will need a completely new impeller side of the torque converter. In a way, the impeller can be thought of as the "pump" of the torque converter.
Click to expand...

I talked to a different place and that's exactly what they said. It has to do with changing the stall on my existing converter. So who here runs 3500-4000 stalls on the street?
 
I have. It's not that fun after the first day or two. That being said - what's the rest of your combo, and what are the tuning specs?
 
Motor is/will be a 417, 11:1, W2's, Victor W2 intake, Holley 950, TTi 1-7/8 headers, 727 with forward manual valve body, triangulated 4 link, 3:73 gears for now, and the 3000 stall converter. Cam is a roller with .645 lift and somewhere around .270 duration @.050 and 106 LSA.
 
Nice combination.
Cracked back posted: Call back and clarify.

You'll be a bigger fool putting it together and tearing something up.

Maybe a new converter bushing in your pump?
Not the fool part,obviously. Good aftermarket converter input snouts,are usually a less sloppy fit,that stockie stuff. Make sure it fits nicely. The bushing from one place,the converter from another. It sounds silly,I had to pull a transmission apart to fix it.Sorry ,about the post length.
 
270 at .050 is a pretty radical cam for a street 417. You might consider a 9.5 inch or smaller converter instead of a 10 inch. If you are not willing to run much stall, you might want to back down a size or two on cam.
 
Didn't mean to make it sound like this is just a street car. I was meaning that it will see the streets here and there. I talked to a guy over at Continental and he suggested going with a 9" converter for my combo. After talking with my engine guy, he is suggesting a good converter should be on the horizon. One scenario he had years back, I guess he was running a car 11.70's with a cheap converter. He decided to upgrade to a high dollar unit and changed nothing else about the car and ran 11.2's after the converter change alone. He says a converter is one of those things that you really do get what you pay for. So I'm out with Hughes for now. We're going to hunt down a good converter for this car.
 
continental is a good converter company,wheels up 73 runs one that car is deadly consistant.....
 
bad440 said:
continental is a good converter company,wheels up 73 runs one that car is deadly consistant.....
Click to expand...

Is that the white car that pulls moster wheelies off the line with the female behind the wheel?
 
So does anyone know that magic stall speed that will keep from bogging the motor down when put in gear? Or is that mainly going to depend on brand and size of the converter?
 
As far as worring about the stall speed my dynamic was a 3900 stall. It was unoticable as is my current art Carr 3500.

Here is something i'd liek to share that dynamic told me. They said they could make me a 9" or 10" convertor that would stall at 3800-4000 range. (where my engine made peak torque). hoever they recomended "a tight 9"" which would be more efficient than a 10" that stalled at the same RPM. In their opinion that woudl be better for street driving.
 
forphorty said:
270 at .050 is a pretty radical cam for a street 417. You might consider a 9.5 inch or smaller converter instead of a 10 inch. If you are not willing to run much stall, you might want to back down a size or two on cam.
Click to expand...

That's what I was thinking especially with a .645 lift.
 
I have used a 10" 4000 stall on the street. It is not fun. I had 3.55 and 255/60-14 tires. I t was an expensive converter too. Anyway, dont go buy more stall because it wont idle as you like it. A converter will act differently for many reasons. Cam is one of them. I changed cam in my and it would start to pull on idle even though I had that 4000 stall converter. Before the swap it did not do that on the exact same rpm. So it depends a lot on the setup.

Anyway, I will never go for something with that much stall for a car that sees the street atleast 30% of the driven time. I have a 3000 now and it's just so much better, and it idles just fine even though I have a huge solid cam (282 magnum comp cams) in that little 273.
 
"Bogging the engine down" is not a function of the covnertor. It's the function of the tuneup. Generally the timing is not as far advanced as it needs to be, and/or the carb is lean at idle (whicch may require air bleed changes). For what you have - you shouldnt have a 10". That should be an 8" IMO. It will feel loose on the street but who really cares. If you wanted a cruiser you need to rethink the combo. that's a really nice strip/streeet combo and needs to be assembled as such. At least all in my opinion.
personally - I'd call Lenny at Ultimate Convertor Concepts.
 
moper said:
"Bogging the engine down" is not a function of the covnertor. It's the function of the tuneup. Generally the timing is not as far advanced as it needs to be, and/or the carb is lean at idle (whicch may require air bleed changes). For what you have - you shouldnt have a 10". That should be an 8" IMO. It will feel loose on the street but who really cares. If you wanted a cruiser you need to rethink the combo. that's a really nice strip/streeet combo and needs to be assembled as such. At least all in my opinion.
personally - I'd call Lenny at Ultimate Convertor Concepts.
Click to expand...

Well I agree, but maybe I didn't say that right. I just didn't like the car slamming into gear and I didn't like it changing from 1100-1200 at idle down to 700-800. It never died, ran good, I just didn't like the slow idle in gear. I feel the carb was set up good at idle. It would always idle well and start quickly. But maybe I'm wrong on that. It's just that I would always want to kick it up in neutral at lights. It's pretty hard on an engine setup like that to idle at low rpm. The other thing is that the higher stall "should" help with launches at the track over the one I have. Chris at Continental seemed to think that a 9" with something 3500 or above would be what I need. Previous owner had a 3800 in another car and he claimed it was perfect because the motor idle rpm didn't change in gear from neutral. He believes that's what this car needs. But I'm still green behind the ears and learning so I'm trying to take it all in. Ultimately, I have to put a lot of trust in my engine builder. He held the stock eliminator record for several years until somewhat recently so that should to say something about the guy and his knowledge of getting the right setup. I tell him what I want to do with the car, and he tells me what to do, this is what cam you're going to get, this is the CR you'll need, etc etc. Some things I just like to leave in the hands of someone much more experienced in the subject.
 
I understand. I wouldn;t want a solid roller idling at 800 either. But as I said - I don;t think that should be happening with any performance type of convertor. If it was tuned on the engine dyno that would explain the drop in rpm once it's in the car because there was no load on it. I'd be expecting a drop of a few hundred rpm if that. In any event - any race convertor will be an upgrade for the one you have...lol.
 
Here's a vid kind of showing the change in idle rpm on that coverter

[ame="http://www.youtube.com/watch?v=N4LWwP4tkfo"]Dart rolling out - YouTube[/ame]
 
I have a 9.5" 4000 stall its fine on the street. its a Dynamic converter.
I bought it from A&A best part was he said if it was to loose or tight I could call up and exchange it ( as long as I did it right away ). that was a Long time ago. not sure if they still do that. they would be the first place I called if needed a converter.
 
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