Torque Converters.. What are you using?? Why??

[Steve P.]

I've just been talking with the folks at ATI converters.. I am either an idiot or they are SOOOOO technical that they left me clueless..

Here are the questions I asked them and why I did..

1) Is there a difference between a SMALL block converter and a BIG block converter other than bolt holes on engine side?
Reason I asked is that my cousin Mike,(VegasMike), has one of their converters and it seams to be very tight early. He called them and asked what the problem could be. They answered him ,(YOU HAVE A SMALL BLOCK CONVERTER).. They say it is a street converter that stats locking around 1000rpm.. HUHHH?   Summit advertises it as a 3000 to 3500 stall.. Part # is ATI-729330.

2) So why do they call it a 3000 - 3500 stall??   Answer: There's a difference between small block and big block..  Again, HUhhhhhhhhhh!!

  I am pissed.. I figure that if I am spending money on a product they should be able to answer with some sense of intelegance....  

So now I am looking into a TPC converter and wonder if anyone here is using one of them and how they like it..

[firefighter3931]

Steve,

Converters are rated for a range of stall and the range will depend on the torque input to the converter. So a converter that stalls 3500 rpm behind a 520 ftlb 440ci might only stall 2800 behind a 450 ftlb 360ci. Converters come in various configurations ranging from loose to tight. Turbo Action rates theirs based on the size of the engine....loose for smallblock and tight recommended for bigblocks etc...

Generally speaking a small converter that is tight will be more efficient than a big converter that is loose. PTC, Dynamic and Turbo Action all make excellent street/strip converters. The turbo action tight 10in is a very nice converter for a healthy street 440. The dynamic 9.5in also works well in this application and will stall ~4500 yet feel like a stocker during normal driving conditions. With a higher stall, the idea is to gear the car a little deeper to facilitate lookup sooner.

ATI is a good quality unit....it should stall higher than 1000rpm. It's advertised at 3000-3500 so there is something wrong with it. To check stall speed: roll the car along at 10mph in 3rd gear and hammer the throttle....looking at the tach. The point at which the car launches is the stall speed for that specific combo.  

Smallblock and bigblock converters are interchangable, even the flexplates. A smallblock flexplate will bolt onto a 440 crank. The one exception is the hemi 8 bolt crank which has 2 extra bolts on the crank register and those bolts are larger.

Ron

[8WHEELER]

My one 440 has 12.5 to 1 comp and 484 284 mopar cam and ported heads etc, I put a 340 stall
converter in it 25yrs ago and its still all in the car today. I bought it from Chrysler from the
the performace expert at the time, he though I would get about a 2600 rpm lock up with it.

Dan

[Runner]

im running a turbo action 10 imch converter why?  becasue i called several places and i liked paul forte the best.  he wasnt overly friendy like the rest of the guys,  he didnt tell me that my car was giong to gain X amount of et, but he was straight forward and even told me my car might slow down if i couldnt hook it up. i like that!  he did take the time to explain to me exactly what i could expect from each converter.  he also hit my converter stall speed with in 50 rpm and thats amazing. 

[Steve P.]

Hi all. I'm being had by the flu right now and may not be making good sense. I understand the workings of a converter. I have just never heard of anyone describing a MOPAR converter as small block or big block.. This makes no sense to me.. With the ATI converter you have to install a special bushing into the trans. for THEIR converter. No other special anything..  No problem, but rather than admit that their more than likely is a problem with the converter, he is trying to baffle me with the BS. I consider this strike 2 and 3...

I went to PTC's site today and they START with a questionnaire that you must fill out before they will recommend any converter.. I like that...  I mean, I don't post questions on here so that people that know and understand LESS than I do will answer my questions!! I even asked them why they advertize that spacific conv. as 3000 to 3500 stall?? He again tried to answer with big or small block.. No question of HP or gears... Why should I spend money with a company that can't be up front and truthful?? When someone answers my question with (I have to answer another phone),,,,,,   NOPE!!!!!!! 

Ron has a very good explanation here and I think his words should be archived.. Sometimes I feel like an idiot as I just can't write what I think.. I don't mean to sound short or intolerant. I just want to get straight answers from these companies.. Is that too much to ask??

[Ghoste]

No it isn't at all Steve and they should have taken the time to explain what they meant.  ATI are a quality mfg, BUT, converters are an area where you definitely can get what you pay for.  Buying a "one size fits all" converter from Summit will save money.  But if you want to make the most of it, you really need to buy a custom built unit from one of the places like Cope, Dynamic, SMR and so on.
I'm sure I'm not telling you anything you don't already know.

[Steve P.]

Ghoste, I 100% agree with you.. I didn't buy this converter, but it was highly recommended by Mike's buddy that has used ATI for years.. I obviously don't know everything there is to know about converters, ( or anything else for that matter). BUT from what I have allways been told is pretty simple. If it says 3000 to 3500 and you are making 522HP, you should be on the higher end of the 3000 to 3500....   Small block, big block, the converter only knows RPM, HP and torque.. I have called a few other converter builders and asked them if there is a difference in BB, RB and small block. They kind of laughed... When I told them why I asked they made rather bad references..

After the new motor is all done on the dyno we will be ordering from PTC.. THEY seem to know what they are talking about....