Moparts
Lazy performance with High stall converters...
Posted By: Kern Dog
Lazy performance with High stall converters... - 06/07/12 04:13 AM
I'm starting to wonder why we decide to go with these High stall converters. I dont drag race at the track. I do some spirited driving on the street and I DO intend to run the car on a few road race courses just for fun.
Here is the combo: 440 based 493. 10.8 squeeze, MP '509 cam, 2" TTI headers, Edelbrock heads, 850 carb. 727 with 9 3/4" converter, Gear Vendors overdrive. 3.91 gears. The car will move off of idle, but it slips more than I like. If I lean on the throttle, the rpms go up but the car doesn't respond in direct proportion. In short, it slips too much before the stall rating. It feels like I'm leaving from a standing start in a manual trans car. The engine idles nice at 900 rpms.
My 2007 Ram truck pulls nicely right from idle. The fairly stock 360/904 in my bro-in-laws 72 Duster also responds quickly right off of idle. I know... stock cams are designed for that. I just wonder if a stock converter might work for me. I am not as experienced as others in terms of torque converter science. My engine makes great torque and HP even at low rpms, so do I really need such a high stall unit?
Freeway driving feels lazy too. If I'm rolling along at 65 mph and try to floor it, there is a noticeable lag before the car really responds. At 65, the car is going too fast to downshift to 2nd automatically, and for some reason, the GV will not unlock from OD until it slows below 45 mph. Yeah, I know... 65-70 is the speed limit and I shouldn't exceed it....Still, with the car rolling along in OD with a final drive of about 3.05, it feels sloppy. It feels loose from the standing start and sloppy at cruise speeds. I talked to the builder of the converter. He said that he could cut it open and change a few parts to lower the stall, but the question is... how much? 200 rpms isn't going to do it. I'd like the stall to be somewhere around 2000.
Would it make more sense to look for a 11" converter? As is, the car will boil the tires if I just stab it from the start. I can fry the tires halfway through 2nd gear. I have no complaint about the performance at full throttle. My issue is part throttle starts and any other situation where the car is running "under the stall" rating.
Thanks, Greg
Posted By: DaytonaTurbo
Re: Lazy performance with High stall converters... - 06/07/12 04:20 AM
Who made your converter? A good quality one will minimize the issues you're experiencing. Also, the overdrive will place your engine and converter lower in the rpm range, where your high stall converter is naturally going to be less efficient.
The 509 is known to be a lazy, old school cam. Not helping your combo either.
Posted By: DARTH V8Я
Re: Lazy performance with High stall converters... - 06/07/12 04:29 AM
Yep.. The 509 is a very lazy camshaft.
Posted By: Kern Dog
Re: Lazy performance with High stall converters... - 06/07/12 04:59 AM
I should have mentioned that before I installed this converter, I had a 11" TCI converter in the car. The car felt great but a Dyno operator suggested a looser converter for better dragstrip performance. I went with a local company in Sacramento, D and P converters.
I had a Comp Cams XE 285 flat tappet in the car with this converter. The car felt about the same.
My question though is maybe a little hard to answer: With an engine nearly 500 cubic inches with over 500 ft/lbs or torque, how low of a stall can I go and not end up with an engine that bogs out of the hole?
Maybe I should have stayed with that 11" TCI converter. Oh... I'm not married to the '509 cam. I may switch back to a Comp since they now offer a better hardening process.
Posted By: 70Duster440
Re: Lazy performance with High stall converters... - 06/07/12 06:28 AM
I've got a PTC converter behind my 440 (.474" cam) with a stall rating of about 2800 rpm. Feels a little mushy for my tastes too under the driving conditions you describe. I'm going back to a stock 12" soon. It should stall at around 2200 (according to Pat Blais).
Posted By: speedy515
Re: Lazy performance with High stall converters... - 06/07/12 06:32 AM
I'm no expert, but experienced something similar: The car felt like a manual transmission with the clutch pushed in part way until the stall speed was reached. Anything below that and my throttle felt "spongy". In cases where I spent some time below the stall and then mashed the throttle, the engine would rev and then it would feel like I "Popped the clutch" when the torque converter decided to catch.
I went to several tranny shops who suggested swapping to a lower stall converter.
A random person at a car show explained to me that the converter was "draining" faster than the pump was filling it when below stall. The "Laziness" was a result of the torque converter filling first and then doing what its intended to do. I took my car to a knowledgeable shop and mentioned this. They installed some sort of "Block-off plate" in the valve body. (This is what I was told).
Now the car acts like it was supposed to: No more hesitation, No more spongy throttle.
My
Posted By: Hemi ragtop
Re: Lazy performance with High stall converters... - 06/07/12 11:11 AM
Very interesting post. I have only put about 300 miles on my car since finishing it and I am wondering if a stock converter would'nt be more fun to drive. I have a 540 ci hemi with 10.8 compression, 248/254 @ .050 roller cam, 3.54 Dana and 3500 stall converter. I used the converter after much discussion with one of the top trans builders for the 727. Part throttle is just "mushy". Full throttle is not even possible on street tires so what is the point of all of that stall? I will wait until I get a chance to run it at the track on slicks to decide to go to all the trouble to change it. No doubt the et will be better with the converter I have, but I drive much more on the street.
Posted By: jake4cars
Re: Lazy performance with High stall converters... - 06/07/12 11:19 AM
Quote:
Very interesting post. I have only put about 300 miles on my car since finishing it and I am wondering if a stock converter would'nt be more fun to drive. I have a 540 ci hemi with 10.8 compression, 248/254 @ .050 roller cam, 3.54 Dana and 3500 stall converter. I used the converter after much discussion with one of the top trans builders for the 727. Part throttle is just "mushy". Full throttle is not even possible on street tires so what is the point of all of that stall? I will wait until I get a chance to run it at the track on slicks to decide to go to all the trouble to change it. No doubt the et will be better with the converter I have, but I drive much more on the street.
Love this car 
Joey
Posted By: Hemi ragtop
Re: Lazy performance with High stall converters... - 06/07/12 11:29 AM
Thanks Joey, I do too! LOL
Lynn
Posted By: mikemee1331
Re: Lazy performance with High stall converters... - 06/07/12 12:40 PM
if you want a snappy response driving around town, an 11' would work well for you if you don't have to idle too high because of your cam. also keep in mind with an 11' running a 1/4 mile you will be hard pressed to get the car into its power band. that's the problem i have with my 440-6 RR. i tried a 3500 converter and on the street it was a big slop box. i went to an 11' and while it is snappy on the line it seems in the 1/4 mile i'm leaving alot behind as the race is over before before i'm actually making full power. also due to my cam, i have a world of trouble getting a decent idle sitting at a light because the converter is locked on. i just got a PTC 2800 that was built for my car factoring in engine size, 6-pac, gear ratio and ridiculously wide Mickey Thompson tires. it will be a bit before i get everything back together again but should be in the next month or so. i'll let you know
Posted By: Streetwize
Re: Lazy performance with High stall converters... - 06/07/12 05:58 PM
The best verts to me
are fairly tight feeling stall (I call that "responsive" to throttle input) but can flash right into the meatiest point of the torque curve in high gear. I have always hated a part throttle 'slipping clutch' feel in a daily driver, won't ever have one that way. That's why I drove sticks all the time before converter science technology caught up.
what's the part of all that juicy stroker "dyno" torque if you can't feel it until 4500-5000 RPM? That's why I don't chase top end HP with the cam, build the short block for torque and let the head flow put the HP where you want it. On the street you really want more of a road-race wide powerband, not a Drag Motor type torque curve....unless it's a really light car that can't hook what you have. The smaller diameter verts are more efficient and obviously less rotating inertia at high RPM. you've got to find the right balance for your combo but for strokers you're almost always better with a custom built unit.
Posted By: Graham
Re: Lazy performance with High stall converters... - 06/07/12 06:05 PM
What stall is this converter rated at?
From what you've written, it appears that for street use, far too much stall speed.
Properly applied, a higher stall converter is great, improperly applied, the worst performance investment you can do.
Graham
Posted By: PHJ426
Re: Lazy performance with High stall converters... - 06/07/12 06:39 PM
We just took the 72 Runner for one stop on the power tour. Its powered by Bobby's (Wize's) old 508 stroker, six pack intake, HP manifolds, 9 1/2" UCC converter......currently there are 2.94 suregrip center in the 8 3/4 and a 255/50R16 tire.
Off the line the car honks and screams. The converter in this car does not slip at highway speeds (atleast to the point that I notice it) I will be checking slippage later today when I get out of work to calculate a true % of slip.
This converter currently feels to me that its tight when Im cruising or loafing around. Apply light to moderate throttle at any speed in any gear and it accelerates, (I dont feel rpm slippage and then the car going) and when I mash it it will flash and go.
Kinda like the way Bobby described how he wants the converter to work.
The cam in the car is from Scott Brown and I had him spec out the UCC converter as well. If you call him tell him I said Hey!
Posted By: Kern Dog
Re: Lazy performance with High stall converters... - 06/07/12 07:17 PM
Quote:
What stall is this converter rated at?
From what you've written, it appears that for street use, far too much stall speed.
Properly applied, a higher stall converter is great, improperly applied, the worst performance investment you can do.
Graham
Going back to 2005, I took my car to a shop that had a chassis dyno. The operator said that with my combination, the 11" converter was loaded against the motor at too low an rpm. I had the '509 cam advanced 4 degrees then and the car idled at about 1000 rpms. Since then I went with the 9 3/4" converter estimated to stall at 3000. I returned the cam to a staight up position which degreed at 1.5 degrees retarded. I've also added slightly larger headers and went from a 4.10 gear to a 3.91 with a GV overdrive. The motor now idles fairly smoothe down to 750 rpms. Raising the idle to help crutch the stall results in run-on dieseling on shutoff. Maybe these factors have all conspired to make the car feel lazy. No matter what, I want the car to feel tighter. The slip makes the car feel like a race car in bumper to bumper traffic: totally wrong for the circumstances.
Posted By: JohnRR
Re: Lazy performance with High stall converters... - 06/07/12 07:59 PM
Why did you not install the cam as it was before ? First thing I would do is put it back advanced, it will cost you a gasket or 3 and time .
Posted By: mikemee1331
Re: Lazy performance with High stall converters... - 06/07/12 08:35 PM
as stated, you have to decide what your looking for when selecting a converter. i heard alot of good things about this PTC unit i bought, and although they were clearly more Chebbie directed i was impressed with the guy that took my order. he asked the right questions, followed up with a call when he needed more info and the fact it took 2 weeks from time of order to when i got leads me to believe it was custom built for my car and driving. hopefully that isn't just 'smoke and mirrors'!
Posted By: RSNOMO
Re: Lazy performance with High stall converters... - 06/07/12 08:51 PM
I've got a similar set-up in a B-body...
484;shift-kitted Torqueflite;street-hemi converter;3:91's...
Am experiencing nothing like what you're describing...
What did you have, trans-wise, in front of the 4:10's???
Posted By: DaytonaTurbo
Re: Lazy performance with High stall converters... - 06/07/12 10:10 PM
Watch out with dropping your converter too low. Too low of stall is going to give you one hell of an rpm drop from neutral to drive if you have too big of a cam.
Quote:
I've got a similar set-up in a B-body...
484;shift-kitted Torqueflite;street-hemi converter;3:91's...
Am experiencing nothing like what you're describing...
What did you have, trans-wise, in front of the 4:10's???
Your "street-hemi" converter is likely nowhere near as much stall as his.
Posted By: mikemee1331
Re: Lazy performance with High stall converters... - 06/07/12 10:15 PM
Quote:
Watch out with dropping your converter too low. Too low of stall is going to give you one hell of an rpm drop from neutral to drive if you have too big of a cam.
Quote:
I've got a similar set-up in a B-body...
484;shift-kitted Torqueflite;street-hemi converter;3:91's...
Am experiencing nothing like what you're describing...
What did you have, trans-wise, in front of the 4:10's???
Your "street-hemi" converter is likely nowhere near as much stall as his.
exactly! right now i have to idle in park at almost 1000rpm, drop into drive and it's like 650-700 and so 'loopy' it still feels like it wants to stall out.
Posted By: RSNOMO
Re: Lazy performance with High stall converters... - 06/07/12 10:31 PM
He says 3-grand...
Mine's 2800...
Moot point...
Posted By: Mr.Yuck
Re: Lazy performance with High stall converters... - 06/08/12 01:42 AM
?? I have a turbo action 3800 and it's anything but lazy. For your combo I'd think a 3400-3800 would work well. Maybe your convert is spent...what else is going on? that cam should run good if you realy have almost 11:1. with even a 3000 it should blow the tires up. What's your tune? maybe you need to get a good light on it and a vaccumm gauge. more to it than a high stall
Posted By: Mr.Yuck
Re: Lazy performance with High stall converters... - 06/08/12 01:46 AM
Quote:
Very interesting post. I have only put about 300 miles on my car since finishing it and I am wondering if a stock converter would'nt be more fun to drive. I have a 540 ci hemi with 10.8 compression, 248/254 @ .050 roller cam, 3.54 Dana and 3500 stall converter. I used the converter after much discussion with one of the top trans builders for the 727. Part throttle is just "mushy". Full throttle is not even possible on street tires so what is the point of all of that stall? I will wait until I get a chance to run it at the track on slicks to decide to go to all the trouble to change it. No doubt the et will be better with the converter I have, but I drive much more on the street.
Dude you built a 540 cubic inch hemi what did you expect?
Posted By: PHJ426
Re: Lazy performance with High stall converters... - 06/08/12 03:22 AM
Just calculated converter slippage for the 9.5" UCC in my car.
I used a GPS speedometer app on my phone for speed.
The Autometer tach is run off the tach output on the MSD box for rpm.
I did not measure roll out on the tire. I just calculated circumference. There could be some error introduced in the calculation here.
I used this online calculator to do the math:
http://www.wallaceracing.com/converter-slip.phpAt lower speeds in third gear slippage is greater.
All these are in third gear:
MPH Slip
36 8.7%
50 4.9%
58 2%
What is your slippage currently? It is pretty fast to grab a couple of mph / rpm readings and plug them into the calculator and make sure your chasing the problem from the correct position.
Posted By: Kern Dog
Re: Lazy performance with High stall converters... - 06/08/12 04:29 AM
Quote:
Why did you not install the cam as it was before ? First thing I would do is put it back advanced, it will cost you a gasket or 3 and time .
It was more detonation prone when it was advanced.
The earlier intake closing gave me a 230 psi cranking compression! With the current "straight up" setup, (Actually 1.5 degrees retarded) the cranking #s are around 190.
Help me out here, am I to understand that dropping down to 2000-2200 stall would make the performance suffer even with an engine this big? If so, maybe I should look to swap in a cam that better suits my driving style. I get the overall theory: Too tight of a converter on a high strung mill is comparable to engaging the clutch of a manual trans right off of idle. I wish that I had a car lift. I'd just test a few converters just to know firsthand.
Posted By: 383man
Re: Lazy performance with High stall converters... - 06/08/12 07:32 AM
I run the Luppo Dynamic 9.5 street/strip converter and it works great behind my 493. It will flash about 4200 at the track but does not slip driving at all as it takes off normal with no slipping even when driving slow and I have a good size cam of 264 & 270 at .050 with around .630 lift. With the .509 you dont want to go to low on the stall or it might be a pig down low. I know alot of guys running high stall converters on the street that seem to work good for them. But as for me my 9.5 Dynamic works perfect for me. Drives like a normal car and has a decent 60 ft for a stock suspension leaf spring car. They are SS springs. Maybe you might want to call a good converter company like Dynamic , PTC , Turbo Action , ATI , Coan or any good know converter company. You get what you pay for in converters and the wrong one can really make a car run bad. Good luck , Ron
Posted By: Kern Dog
Re: Lazy performance with High stall converters... - 06/08/12 09:45 AM
Thanks to all who have posted with advice. Regarding these name brand companies, what kind of money am I looking at here? I paid $450 or $500 for the one in there now. It is hard to believe that a converter can have high stall and still be responsive at part throttle.
THAT would be nice.
Posted By: dustergirl340
Re: Lazy performance with High stall converters... - 06/08/12 12:20 PM
Quote:
You get what you pay for in converters and the wrong one can really make a car run bad. Good luck , Ron
you nailed it there. I love my PTC and it matches my Duster's combo perfectly. Drives perfectly on the street and comes alive at the track. Lowered cruising RPM by a couple hundred too.
Posted By: Mr.Yuck
Re: Lazy performance with High stall converters... - 06/08/12 12:58 PM
Quote:
Quote:
Why did you not install the cam as it was before ? First thing I would do is put it back advanced, it will cost you a gasket or 3 and time .
It was more detonation prone when it was advanced.
The earlier intake closing gave me a 230 psi cranking compression! With the current "straight up" setup, (Actually 1.5 degrees retarded) the cranking #s are around 190.
Help me out here, am I to understand that dropping down to 2000-2200 stall would make the performance suffer even with an engine this big? If so, maybe I should look to swap in a cam that better suits my driving style. I get the overall theory: Too tight of a converter on a high strung mill is comparable to engaging the clutch of a manual trans right off of idle. I wish that I had a car lift. I'd just test a few converters just to know firsthand.
the 509 is not designed for the street. It is a bracket racing cam. It likes to work from about 3500-6500+. There are much better cam designs if you are going to be driving around a lot. What is lazy anyway? If you dead stomp the car it should either explode the tires or take off....any "high" stall converter is going to be a tad "loose" under normal driving conditions.
Posted By: JohnRR
Re: Lazy performance with High stall converters... - 06/08/12 01:29 PM
Quote:
Quote:
Quote:
Why did you not install the cam as it was before ? First thing I would do is put it back advanced, it will cost you a gasket or 3 and time .
It was more detonation prone when it was advanced.
The earlier intake closing gave me a 230 psi cranking compression! With the current "straight up" setup, (Actually 1.5 degrees retarded) the cranking #s are around 190.
Help me out here, am I to understand that dropping down to 2000-2200 stall would make the performance suffer even with an engine this big? If so, maybe I should look to swap in a cam that better suits my driving style. I get the overall theory: Too tight of a converter on a high strung mill is comparable to engaging the clutch of a manual trans right off of idle. I wish that I had a car lift. I'd just test a few converters just to know firsthand.
the 509 is not designed for the street. It is a bracket racing cam. It likes to work from about 3500-6500+. There are much better cam designs if you are going to be driving around a lot. What is lazy anyway? If you dead stomp the car it should either explode the tires or take off....any "high" stall converter is going to be a tad "loose" under normal driving conditions.
Remember he has the cam in a 500" engine , the extra cubes should move that rpm range down.
Wordmiester, just because you 500 for the convertor doesn't mean it's any good. Torque convertor science is voodoo. In the hotrod diesel pickup market a number of companies were taking stock convertors and cutting them open , machining the cast alum down smaller to lower the stall ($35 operation) put a fresh clutch lining in them and selling them for $1000.
Posted By: PHJ426
Re: Lazy performance with High stall converters... - 06/08/12 02:09 PM
Give Scott at Competition components a call. Tell him what you have and then tell him what you want to do with the car.
Cam and converter technology hs changed alot since my mother use to buy me plaid pants when I was a kid in the Seventies.......
Scott Brown email is
scotty.brown@ymail.comHis business is Competition Components.
www.buyracingparts.comTell him Paul from Chicago sent you.
Posted By: DARTH V8Я
Re: Lazy performance with High stall converters... - 06/08/12 03:03 PM
Yah I'd say. I bought a Debs (iirc) converter that flashed something fierce, but felt way to slippy for me.. and I mean alot slippy. Replaced it with a B&M holeshot and right off the hop went 6/10ths faster, and much less slippy, but still a tad slippy.
Opened the Debs converter and found every other fin cut off
The price was about the same for both. Next time I'll just find a stock Vega converter, change the hub, weld the ring gear on all for about a $150 and see how that flys
Posted By: Streetwize
Re: Lazy performance with High stall converters... - 06/08/12 03:48 PM
Hey Paul,
Where's that smoky video?
That motor was/is a real thumper, probably Didn't even notice you swapped gears from 4.30 to 2.94's
I'll bet you could hook a 32 foot travel trailer behind it and not bog it down. Loved that old 508!
Posted By: PHJ426
Re: Lazy performance with High stall converters... - 06/08/12 04:08 PM
Hey Bobby,
Ill have to get a video of my boiling the hides with the 2:94 now. I really wanted to get the car to the track to document what it did with the old 4:30 and Drag Radials vs the 2:94 and new XHD leafs.
But the few times I could have made it out the weather was not cooperating and the track was rained out a few weekends earlier this year.
Before with the 4:30 gear I was shifting in a second or two off the line the 508 was at 6000 plus........Now it takes a few seconds to get to 6000 in first but it makes the car much more street-able and I like driving faster than 45mph...
And what it does for the car on the highway, impressive!
The 508 is a torque monster it moves this 4000 pounder around well, with a nice fat area under the curve gotta love Integrals!!!! Speaking of that its back to night class next week, Circuits II and lab for an 8 week stint.
Here is the new look.
Posted By: Triple Threat
Re: Lazy performance with High stall converters... - 06/08/12 04:49 PM
Nothing "squishy" about a GOOD converter. Efficiency is key, most cheap converters aren't that efficient, a tight lower stall converter is more likely to be efficient. Just the nature of the beast.
My 8" will flash to 4700, and will drive itself around at idle all day.
Posted By: mikemee1331
Re: Lazy performance with High stall converters... - 06/09/12 12:27 AM
my PTC was around 450 plus the ride. bought it on the advice of dustergirl (up above) and will of course hold her responsible if i don't like it!
Posted By: dustergirl340
Re: Lazy performance with High stall converters... - 06/09/12 12:32 AM
Quote:
my PTC was around 450 plus the ride. bought it on the advice of dustergirl (up above) and will of course hold her responsible if i don't like it!
UH OH! Man, if you don't like it I'd be surprised. We have two PTC's and they've worked flawlessly. Mine has been in my car for 7 years now.
Posted By: Dan Halen
Re: Lazy performance with High stall converters... - 06/09/12 12:52 AM
I have the Lupo(Dynamic) 9.5", excellent converter for street/strip.