The restalled stock unit that Lexteme sells & the PI unit both have there places.

The Lexteme setup is nice for people on a budget.

The billit unit from PI is a really nice converter. They're more a hard core/race converter. You can get stall speeds on the PI unit that just wouldn't be possible with the lextreme unit. Say you have a fully built turbo car that doesn't see max torque until 4500 rpm, the PI unit can be made to stall up to 6,000 rpm. Since it's lighter smaller design it should have the effect of putting on a light weight fly wheel (but for a/t cars). It will take much more punishment than the lextreme unit. If it is like other PI units, it may also be a little noisy.

 

I have a really quick question

I have installed the Lextreme TC on my car - I noticed that when I go from a complete stop, flooring my gas pedal, the tachometer needle still stops at 2100 - 2200 RPM for a second then start going up

Doesn't that mean that stall speed is still around 2200 RPM ? or a little less?

help please!

 

Anyone? I am starting to think I either have a non-modified TC or the guys who installed for me just put in a random refurbished one

Feedback please

 

It doesn't sound like Lextreme's TC. You can jack up the car, you'll see a little opening where the engine's flywheel is. You must position right underneath and in front of the crossmember and look back up. The opening is right between the engine and the tranny. Open two 12mm screws that hold the plate of that opening. Try to shed some light into that opening with a very strong flash light. If you see the TC (hopefully you can see it) with either white, purple, or blue color, then that's Lextreme's TC. Check with Lextreme for the correct color. If it's just black metal, then that's something else.

I'm using the Lextreme TC with 2800 stall speed and in my opinion, it's really good. If I launch from dead stop, it won't shift to the 2nd gear until around 40mph. According to other discussions with other people who uses the PI TC, it's about the same, so I think this is usual for a modified high stall speed TC. It's my bad that I never paid attention to the Tach. But I believe it passes 3000 RPM easily at 40 mph.

It's more jerky than the stock one of course because it shifts at a higher RPM than stock. Therefore, the hp is transferred to the wheels quicker without the hic cup between the shifting. The peak hp stays the same because that's the max hp of the engine output. I don't feel that I lose any hp at the high end.

 

 

Thanks Steve! I will go ahead a check - I think mine was light blue and it doesn't shift until 40mph, but I thought the car should start moving full force when the tach. hits 2800 RPM, is that the case? or maybe I just understood the concept of stall speed wrong?

Thanks again

 

If this claim said that a 2800 PI torque converter added 40-50tq, then may in fact be a valid claim if one was considering the torque available at lockup. Perhaps the difference in torque between the stock 1900 rpm limit and the upgraded 2800rpm limit would be on the magnitude of 40-50tq. It is hard to say without a dyno sheet to verify exactly. Although, I am assuming that is what the implied-but-not-expressed situational nature of this claim was implying.

Of course, the advantage to the PI torque converter is greater than just the stall speed. The smaller diameter and lighter weight decrease rotational mass and thus lower the rotational inertia of the vehicle, allowing for more responsive acceleration with the same engine output. Going to an ultralight wheel and tire combination would have a similar effect.

The phrase "moving full force" is a bit difficult to interpret exactly.

The torque converter is a fluid coupling of two discs that spin in accordance at rpm levels at or above the stall speed and in opposition at rpm levels below the stall speed. They spin in opposition to allow the motor to spin freely without engaging the drivetrain, preventing stall out at a stop. The spin in accordance to fully transfer power from the engine through the transmission and ultimately to the wheels when that power is needed.

If "moving full force" implies that the engine and transmission are spinning in harmony because the torque converter is "locked up," then you are correct in your grasp of the torque converter.

The issue with your shift point being high could be a result of confusion at the electronic level between the sensors that are relaying information and the computers that are processing that information.

There is a thread on this forum, started by O. L. T. if I recall correctly, that offers a suggested method to raise or lower the shift point by rotating a sensor that gives input to one of the computing units that governs the transmission. You might try to dig that up as a way to combat the problem in the meantime, until you find the desire to seek a more permanent solution.

 

I took a video of my tachometer with the new stall TC (2700 2800 RPM)

http://www.youtube.com/watch?v=Qr6yQk5_YZE

Don't mind the CEL it is because my AFM is disconnected - Let me know if you think the TC is working as it should be - Thanks again guys!

 

Steve this is exactly what I meant by "full force" - Just like when you release a clutch all the way up in a manual trans. car

So as you notice in my vid, the auto "clutch" is released at 2000 almost - You can actually hear the wheels skweek - I am starting to really think it is only a refurbished stock TC

 

and here's another video of me having left foot on brake, and right one on gas pedal - note how the engine revs around 2100 RPM

http://www.youtube.com/watch?v=IovXTAcYWaw

opinion ?

 

Did you guys get a chance to look at the vids?