torque converter

[Rootie524]

when i went to get my car dyno tuned the guy tuning it said that my torque converter is robbing me some serious power. problem is i have a 3100 engine and we are both pretty sure they dont make "performance" converters for my engine.

if anyone out there has any idea of a good aftermarket converter or some way to fix this limitation please let me know!

i know this is for the 3800 but will it work anyway? im clueless. https://www.zzperformance.com/grand_...=133&catid=105

[86FieroSEv6]

You can have a converter shop make one up or modify yours. Here locally we have Suncoast Converters, http://www.suncoastconverters.com/ , you should give them a ring and see if they can fix you up within your budget. There is also BTE Performance, http://www.bteracing.com/ , they did the converter for my buddies Camaro . . . http://www.youtube.com/watch?v=yALmUynDm2k , and this beast lives on the street in stop and go summertime traffic with no problems.

[Rootie524]

sweet thanks for the links im going to see if they can help me out. and i reallllllllllly want that camaro! lol

[Superdave]

I just had Revmax custom build a 3500 stall converter for my project, it was $274 shipped. Give them a call at 877-780-4334 to see if they can put one together for your trans. I told them how much power my engine was making, the stall speed i wanted and what trans i was using, they took care of the rest.

I haven't used it yet of course but i will soon enough.

[3400-95-Modified]

PDQ and Yank will also make converters to order. I have a PDQ one for a 4t60e that I'll be trying once again this year... I've tried it before but I never gave it a chance and I went back to my cheap 2095 stall one... But hopefully this works better... its a 3190 stall or something like that.

[Rootie524]

How do I know what stall speed I should have?

[3400-95-Modified]

Call up the torque converter company, they know more than we do. Tell them what your running, cam, compression, displacement, estimated HP, and gearing in the trans, along with gear ratios of gears, and any reduction or multiplication on the drive driven gears, and your intended use... And after ALL of that they should be able to suggest a good stall speed for you.

What transmission is this for? 3t40? 4t60? 4t60e? 4t65e? or a RWD application?

Nevermind, its a 4t45e if its the malibu

[86FieroSEv6]

Just as said. Be sure to take your time, do your homework and think very carefully about what you will ultimately be using the car for. Street fighting? Drag strip? Daily driver? I can't count the number of times a poor converter choice put an otherwise good machine at the back of the pack, or back on the trailer . . .

[Rootie524]

yeah true. i guess i never really thought about how important the torque converter really is. serious thought will need to be put into this.

[Rootie524]

went back to the dyno today and didnt get much more out of the car. he said my torque converter is really limiting me. he said they never usually put cams in a car unless they put in a new torque converter as well. so now i know. im looking around at some of the places you guys gave me to find someone that can do it. but he said it will make allllll the difference getting a new converter.

so im not a converter specialist and dont really understand what they do thats so important. sure i understand alittle from their name but can someone explain to me what it does and what the different stall speeds do and all that. trying to learn a few things. lol

also..do only automatic trannys have a converter?

[bszopi]

http://auto.howstuffworks.com/auto-parts/towing/towing-capacity/information/torque-converter.htm

[pocket-rocket]

also..do only automatic trannys have a converter?

All automatic automotive transmissions have torque converters. A "stall converter" is usually what an aftermarket torque converter is refered to as (one that doesn't operate at stock stall speed).

[86FieroSEv6]

"do only automatic trannys have a converter? " . . . Well, yes and no. First a bit of basic information. A "Torque Converter" is basically a fluid coupling between a power input and it's associated power output. In our case, between an internal combustion engine and a mechanical gear reduction device a.k.a. transmission. A manual transmission uses a lever or hydraulically actuated friction disk type coupling. For a time, Volkswagens used a fluid coupling/torque converter with their manual transmission known as an auto-clutch. One simply eased up on the throttle to reduce engine load and effected a shift to another gear. I am sure there are many guys here whom have had to shift their cars without the benefit of the clutch releasing when their clutch cable has broken or their clutch hydraulics gone out. Quite simply, there has to be a way to "decouple" the engine from the transmission in order to change gear ratios and to idle when stopped. In an automatic transmission environment, the engine is never truly "decoupled" and must therefore incorporate a given amount of slip to satisfy the "decoupled" state. If you've ever had a vehicle pass by you slowly, you hardly feel a thing. If that vehicle passes by you a high rate of speed you can feel the "push" of air being compressed between you and the other vehicle. For our purposes, you are the stator in the converter and the other vehicle is the impeller. Within a torque converter are fixed fins or vanes and a turbine or opposing set of fins/vanes that rotate in close proximity to the fixed vanes. At lower RPM's the fluid can flow between the fins/vanes quite readily and no movement is imparted to the fixed fins by the rotating fins. The amount of "slip" allowed is determined by the size, number and spacing of the fins as well as the viscosity of the fluid being used. As the impeller is spun faster, a "push" develops against the stator because the fluid starts to "compress" in the restrictive paths of the fins/vanes. This then imparts energy to the transmission. The "stall speed" is the theoretical point of hydraulic "lock" between the impeller and the stator when the output speed matches the input speed. To prevent tire spin you have to apply the torque load to them in a linear fashion that does not exceed their "grip". In very high powered cars grip is sacrificed as well in order to prevent engine and driveline damage from torque shock. How many times have you heard a disappointed driver say he "shook 'em down" or it "hopped like a drunk rabbit". When you build an engine for high power, it often involves a change of camshaft that will compromise manifold vacuum at low RPM's such as idle. If you have a manual clutch, problem solved, you just step on the clutch pedal. For an automatic with it's associated fluid coupling, you will need to use a torque converter with a higher stall speed. If not, you would end up with the throttle adjusted too far open in an effort to maintain an idle that you will be tipping in fuel from the venturi's and wasting accelerator pump movement thereby robbing your car of power because your carb. is half used up before the light goes green (or the other dudes most excellent looking girlfriend starts the race with a panty wave). On fuel injection, forcing a butt load of air by the throttle to get an idle causes lag inducing turbulence in the intake and a sucko idle especially in gear. Use a tighter converter for low end punch at the risk of burning rubber instead of asphalt. A looser converter (higher stall) will transfer maximum load at a higher RPM and the trick is to hit the sweet spot. That sweet spot is going to be, usually, as the engine approaches about 60-80% of it's torque potential. After that, it's up to Mr. chassis to transfer that power to the tires and hopefully a big ass smile on the brave test pilot. Hopefully somewhere in this meandering narrative I have provided a useful piece of imagery capable of honing your thoughts on the choice of torque converter you will make. It can literally, make or break your ride and your wallet. Good luck and don't forget to post up your win slips.



Yeah, it was a bit corny but I just couldn't stop typing . . . . . ya know?

[pocket-rocket]

You forgot when the throw out bearing goes out as one of the driving without a clutch scenarios.

[bszopi]

or the other dudes most excellent looking girlfriend starts the race with a panty wave

Great quote...