Hey guys I moved this topic onto a new thread as to not disturb the cylinder head shoot out. So as I read, unless I misread, the stock converter DOES NOT engage under WOT until 3rd gear? How does this effect RWHP #s and acceleration on the road?? Besides the obvious, andis there any way to fix it?
The converter is not supposed to lock at all under wot in third gear, but when you are on a dyno, you want to wait till you hear the converter lock and then start the pull with it locked. In some cases, I can see converters trying to lock during wot which is going to cause converter clutches to blow out. I cant wait for Diablo to release converter lockup control.
Can we get a mod to move the previous posts on this subject to this thread? I'm interested but I'm lost.
So if it is not locked up fully on the dyno is that gonna effect your #s?? Seems to me it would be and may well account for some of the low #s people get if they didn't know this!!
I don't get this. You said the converter is not supposed to lock at all WOT in 3rd gear, yet you wait until you hear the converter lock then go WOT and run the pull.
When you go WOT from a dead stop, the converter does not lock-up. When you are on a dyno, you want to slowly get up to speed so that the converter does lock up, once it locks up, then you go WOT and hope that it doesnt unlock. You want it locked for more accurate results, if it is unlocked, your numbers will be lower because of the slipping that is taking place.
I think that is why some guys see better dyno numbers than others. Even with some extensive mods, some of these cars don't dyno for s#$t and it is probably from the convertor issue. Seems to be hit and miss....I know my car won't dyno for crap, but like my sig states; "it runs alright for a wagon....."
wow...... might explain some of my dyno issues as of late........ can you actually hear an audible sound when the converter locks.....and anything when it may subsequently unlock????
Yea that is exactly why I persued this line of questioning. That I am sure is the reason ALOT of people with big mods are not dynoing well, the more power you have the more reason for slippage. Especially Torque.
Stands to reason that alot of guys don't post their dyno numbers even after having extensive mods done. We would love to see the "big" numbers after modding to let you know the money is well spent but it isn't always reflected with these cars. Just use the old adage "A dyno is for tuning." People ask me my dyno numbers and my answer is "I honestly don't know." I also don't tell people all the mods I have either but that is besides the point....
One time I went to the dyno and it is a father and son shop and the son was out so he had me drive the car during the pulls. He had me go in autostick to 3rd gear run it up a touch and let up on the throttle and doing that you could feel the converter lock up and then he had me go to WOT
Here is basically most of it Quote: Originally Posted by HoP Racing If I remember right increasing line pressure is done via the epc "electronic pressure control" solenoid. I don't think an increase in line pressure will effect the lock up function of the converter. The lock up is in the converter itself. Resembles the clutches in the clutch packs or drums in the transmission itself but just larger. I could be wrong, if someone knows a lot about converters please chime in because this is annoying. For probably 8 months I had the converter trying to lock up at the track in 3rd gear @ about 90 + mph. You could even see the dip in rpm during data logs. I called Precision Industries finally and asked about it and they told me the converter should not lock up at wide open throttle and if it was trying to lock up it was something in the computer that was causing it. So I decdided to get another Mopar Performance TCM and after 8 months of having problems it immediatley dissapeared, here are 2 data logs from 1/4 mile runs about a week or 2 apart in the first one you can see the dip in rpm which was always there when the converter was either trying or locking up. Then in the second data log with the Mopar Performance TCM it was completely gone. I have a Precision 3200 stall. Being that the TCM cured the problem the answer must lie in the TCM and programming it Andy diagnosed this problem early on when we couldn't figure out what was happening up in third gear when we were all looking at it as KR and other things Quote: Originally Posted by JMatt Interal - that's some seriously valuable info!!! Thanks. I called Precision Industries today and talked to Jack and he told me that under normal driving conditions the converter will lock up right after going into 3rd gear but at WOT the converter should not lock up and if it is something in the computer is telling it to ( sending a electric signal to the solenoid ) to lock it up. Maybe because these are high stall and running on the the stock TCM program it is sending this signal out at the wrong time in some cases, where the Mopar Performance TCM is programmed for a higher stall converter the signal goes out when it should.
Ahhh, ok. thanks. I got some of that. Don't want to stray from the converter but how about just a one liner on why your spk adv looks so solid when mine jumps all over the place? (promise I won't followup on the spk)
it wil jump around if there is knock sensor activity. his dyno has zero knock voltage and looks like advance is dialed in right.
Has anyone considered an external mod to the solonoid to command a lock-up? The idea being that this control function, which I am thinking has no feedback to the ECM/TCM, may be accessable by way of the external transmission wire harness...
HHHmmm this is very interesting. Now if you have a predator do you need to get the TCM module from GSM or MPC or does the diablo do the same thing for you?
