Is there a difference in torque conv. for F/I and N/A????

Just what the title says???? as most of you all know, i went from n/a to a boosted set up and now i think i have a torque convertor that is not playing nice......

Do not want to go into all the details, but the consesus was the tc was not working correctly during recent tuning. just wondering if there is a difference in the trq conv from f/i to n/a....and if so, what is the difference???

anyone have suggestions for a good 2800 stall torque conv. for a blower car???

 

No. n/a or f/i won't make a difference.

 

No Power.

 

and you're going to have to come up with some details... I don't think you're making enough power that you'd run over the stock TC.

I'm guessing it's lockup in third gear? Did anyone mention "lockup" when talking about the problem?

 

Sun Coast (I think that is the name) out of Florida is what I have had for three years. Mine is a 2800 stall.

And yea, no difference.

 

dave - i do not have a stock conv. 2800 stall is in it. car was being cmr tuned by johan at diablosport, so i am not worried about my tuner. the part throttle tuning is fine, it is the wot that is in question. car made 440 to the wheels........ well below what is to be expected with my set up. johan immediately commented that the car did not feel right and seemed to "bog" early in the run. his comments echoed my own recent experiences with normal driving of the car. low rpm (1200 - 1500) the car seems to lock up too soon and bogs down then quickly flashes up and goes. under wot driving from avg. speeds, the car behaves in the same fashion..... initial bog (if the car does not kick down a gear) and then takes off. this was evident before and after blower install. just became that much more apparent while being on a dyno. my question in regards to a difference is based upon the response i recieved from the supplier of the convertor, in that i went fro n/a to f/i. again, i am not an expert in the field of transmissions or convertors, but i had not heard of this in the lx world.

 

Ok. I don't know what I'm talking about (but I'll talk about it anyway haha) but that sounds like a clutch lockup problem and not the TC part. And I think the TCM controls that. From what you describe it sounds like the clutch is grabbing/dragging/locking up at low rpm, then it releases and the engine winds up to the stall like normal? I didn't think you'd be able to drive around normal at 1200 with a 2800 TC?

and if you're just cruising steady at about 30mph what rpm are you turning?

 

If I am in 5th gear, I believe I am around 2K rpm? Will have to verify tomorrow.

 

yea, something like that. So if you have your foot completely out of it and then gave it some gas it should spin up like it's in neutral to 2200-2500 or something before you get any significant torque transfer right?

So if Chris is bogging at 1500 then it's the motor falling over when the throttle opens (tune problem) or it would have to be the clutch right? It's not like there're any valves in the TC that open or close and could stick. (I don't know that I've ever heard of a clutch locking up or dragging when it shouldn't).

 

Chris, I just ordered my TQ from Steve at RDP and made sure I told him the specs for the 426 and Techco blower. I referenced your name and told him that I wanted the car to behave similar to what you decribed in your thread soon after your converter install. I asked him if that fact you were F/I now made any difference and he indicated no it didnt. So I told him to build me one like yours. Have you talked to Steve about it?

 

Chris, my car has that bog at 1400 RPMs with the stock converter. I always thought it was my cam, but now I'm thinking maybe not. I know Mike improved that spot with part-throttle tuning, but its always bugged me too. When I put the forged bottom end in, I'm planning on advancing the cam hopefully that will help.

 

Chris, take a log of this phenomena. Send it to me and I can take a screenshot of it and post it for you.
Pedal Position % (and/or engine load)
Actual Spark Cyl_1
IAT
ST KnR
RPM
Vehicle Speed
Current Gear

Should be able to see the bog from the rate the RPM rises after you mash the gas.

Softpedal it and just cruise about 20 to 30 for a few seconds in full automatic.
Softpedal it and go from 1st into 2nd.
Softpedal it and go from 2nd into 3rd (bit more softpedal than above)
Then reproduce the bog.

At least we'd know exactly what you're talking about (and you could learn how to log :happy

 

pm sent......

 

What converter are you running? Was it installed prior to the blower? Who installed it? There should be no difference between F/I and N/A for a Converter. We have had alot of success with the ProTorque Stall. Everyone seems to be happy that is running them...N/A cars as well as F/I. Landshark is running one on his heads Cam Vortech 5.7 and putting out 525 RWHP, he said it was a night and day difference when it was installed.

Something is definitely up though, no way you should be at 440!

 

rdp 2800 stall convertor, was installed by my dealer well before the blower, and yes kris, the car should be weeeeellllll above where it came in at..... especially considering all of the tuning data johan was looking at..... like he said right after the first pull, "something just does not feel right....." i also did not think there was a difference, hence the reason for this thread, but i was informed that my blower install is why things are acting up??????

 

the difference in torque conveter for na/and f/i is some of the parts are made with different materials to handle the higher out put of the engine but they would perform the same way

 

sigh... no logs yet... :cry: Time for more wild speculation :clap:

Forget the first couple of experiments.

Stop, and from a dead idle, gradually do a little break stand. Not too hard, don't have to break the tires loose or anything.

Then from a dead idle again, release the break and then immediately give it about 1/2 throttle. I think that would show where the TC starts to take hold.

Next try to reproduce the bog situation.

Just doesn't make sense that your torque converter is causing a bog at that low of an rpm. For the TC to cause it to bog it would have to be transfering enough torque to put a good load on the engine at that rpm. I'd expect it to be transfering a bit of torque and doing a lot of free wheeling at 1400 rpm? Is it possible it's locking up prematurely in 4th gear? Did you have any secret TCM programming done?

 

no secret programming!! one of the comments i have gotten back from others is that it MAY be locking up too soon........ again, no matter what angle i am looking at it, or having the "experts" give me their feedback, it seems to point to the convertor. redfoxx did mention clogged cats on lxf, but my car had zero knock, does not run hot, nor do i hear any of the tell tale pinging in the exhaust when i shut it off (thanks hemi~c for this tid-bit)....... anyway, i will try and do some logging this afternoon before the rains come in....... after all dave, my precious is all clean in the garage and i do not want to get it dirty!!! dahahahahahaha

 

You mean like in post #4? and if you don't dilly, dally the picture right now is "scattered clouds"... just because the space shuttle didn't come down there doesn't mean it's raining outside.

 

rotglmao!!!!