Once again I ask, what clutchpacks and what part of the planetaries inside do you propose to modify. Do you know how the powerflow works on a 4L60??

 

https://sites.google.com/site/peteszr1garage/

http://www.digitalcorvettes.com/foru.../topics/143767

 

I do not know how it is done, and I do not know if it can be done. If you or anyone else knows that it cannot be done please explain why. I am all ears because I have no interest in driving way down a deadend street to nowhere. Unless I am told that it cannot be done and why, I will probably buy a 4L60E manual and see if I can determine how it could or could not be done. I am not a transmission mechanic and I do not play one in real life. I am totally ignorant about the fluid flow and actual physical gears in a 4-Speed trans. For me an auto trans has been just a mysterious black box electronically controlled. However, I have worked on some very complicated electrically/electronically actuated hydraulically operated equipment. PCS has done it with a 4L80E by modifying the valvebody. Before PCS did it, conventional wisdom was that it could not be done - and I accepted that. I do not know how PCS did it without adding a physical gear!?

I understand in a 4L60/65/70/80... there are 4 solenoids for 4 gears and there is no way to get another gear without adding another solenoid or gear!? Another controller is needed (PCS) because the C4 PCM is not programmed to control 3 solenoids. PCS did it on a 4L80E with a modified new valve body and a PCS controller to get a 5-Speed (actually a 6-Speed, but 4th gear had such a small ratio that they dropped it) and all this with a new gearset if you want a 6-Speed. If it can be done with a 4L80E, it seems that it may be possible with a 4L60E. If the math is done on the PCS mod, we find that the new 2nd gear = 1st gear x OD and the new 4th gear = 2nd gear x OD. How did they do that!?

If the 4L60E valvebody can be modified to give 5-Speeds (actually 6, but again 4th gear has a small ratio) it would be a lot less expensive and difficult than switching to a 4L80E. I am willing to call PCS again and ask more questions once I better understand what questions to ask.

 

Here is the scoop. A 4l80e is for all intents and purposes, a Turbo 400 with a separate planetary gearset added to the front. The overdrive gearset works completely independant from the other gearsets. Therefore, it is relatively easy to split 1 and 2 gear to create two more "in between" gears. A 4l60e is an entirely different animal. It has two gearsets and depending on what gear you are in, both gearsets are used in different ways to accomplish the job. It does not have an independant gearset for OD. Splitting the gears would be impossible because you would be asking the gearsets to do two different things at the same time.

 

Thanks! I believe that settles and explains everything to my satisfaction. I do appreciate that. I thought/hoped that the 4L80E was just bigger stronger version of the 4L60E series. This is probably why PCS is not pursuing the 4L60E. It simply cannot be done. According to your explaination, it must have been fairly easy for them to come up with the 6L80E?!

Thanks again, seriously! As I said, I am ignorant about auto trans. It is going to be a few years but I guess I will be looking for a rebuildable 4L80E. Not in the market just now. I had a 98 Chevy diesel truck with the 4L80E, had a shift kit put in and with about 160K+ miles, it was shifting and operating very well. They are tough.

From your description above, I believe the OD in my 2002 Dodge CTD auto (47re IIRC) operates like a 4L80E. Gears 1,2, and 3 shift according to torque demand, not electronically. However, the OD gear is controlled electronically.

Any way, thanks again for the clarification.

 

If you want to learn a bit about the workings of an auto, I would first suggest doing some research on the net about planetary gears. Learn the relationship between the three components(four if you want to count the carrier and planets as separate). After you grasp that, the rest is a piece of cake. Automatics merely stop or start different planetary components via clutches or brakes. While the theory is the same for all autos, they are like fingerprints - similiar but never two the same. The 6l80E has a yet again different geartrain based on the LePellier. The 6l80E has no direct(1:1) gearset.

 

That is interesting! Esp. the 6L80 havin no 1:1 gearset. To me engines are all the same, minor differences (to me), but all basically the same - rotation, compression, fire, fuel/air at the right ratio and it will run. I would have thought that transmissions would have been the same, but the more I learn the less I feel like I know. As soon as I hear sun and planetary, my head starts to spin.

A question, a little off topic but related to the 4L60E. I just read from Robert Rauscher (2001) that the 4L60E does NOT route fluid to the cooler unless the TCC is locked!? Really?!

 

I am not able to comment on that as I don't know. It is possible if the TC does not lock up until it is up to temp also.

 

I called Transmission Center today and they said the C4 Adapter Kit is no longer available same as is advertised at PATC. He said it would take about 200 orders for them to make a production run. Can we mount this nationwide? So... if anyone wants to put one of these trans into their C4 they will have to make their own mods. Sorry!?

Since it is clear that the 4L60E cannot be modified for 5/6-Speed, I may do it in a couple years down the road. It seems it can be done without extensive mods. As I have read, no mods are needed to the tunnel. Mechanical mods: replace spline on front of driveshaft, shorten driveshaft, and shorten & modify C-beam. Did I miss something mechanically?

I plan to be up around 400hp and torque in about 2+ years and will need more trans than the 4L60E, and besides, 6-Speeds is just way too cool!

 

Try this place.

http://www.shiftworks.com/tailhousing-corvette.htm

 

I have read that on almost all cars the TCC will not lockup until the engine (or trans) is up to a certain temp. Just like closed-loop on the engine controls. But with the trans not pumping fluid to the cooler unless locked up, seems it would have a tendency to heat up esp. when stopped. Until I changed the shift points on my 4L60E the TCC would not lock until 48mph in 4th - and it should not. But in a 45mph zone you are in 4th gear! I changed my shift points to not shift into 4th until 55mph. So, now at 45mph I am in 3rd gear and the TCC locks at 42mph in 3rd.

 

[QUOTE=DrDyno;1588970864]THIS!

By "wake up" your car, I should think you mean its acceleration. The best place to start is at the rear end. A stock rear end for a C4 A4 will have 2.59:1 gears. The "Performance Ratio" for an A4 Corvette is 3.07:1. That's a 16% mechanical advantage for acceleration.

If you were to go from 2.59:1 to 3.36:1, you'll get a 23% mechanical advantage over a stock rear end and that's something you will feel, IMMEDIATELY! You can probably get that done for well under a grand and, if you still think your car's a little sleepy, THEN you can start fooling with engine mods. :
\
Just wondering, I have 2.59 in my 96 lt1 and am scheduled to have 3.07 gears installed in march,, I keep thinking about going to a 3.36 instead just wondering if it would be to much for those long freeway trips I plan to do, but the extra punch sounds fun though..

 

I just ordered one from this guy... With his adapter you can use the stock manual c-beam og the stock manual driveshaft. He still had one available when I asked, don't know if he has more...

petezr1@gmail.com

https://sites.google.com/site/peteszr1garage/

http://www.digitalcorvettes.com/foru.../topics/143767

 

[QUOTE=bob arrowsmith;1589046886]Go here:
http://www.f-body.org/gears/
Put in your tire size (285/40ZR17), axle ratio, 6000rpm, gears, and click "calculate". You can then see what rpm you will be turning in each gear. At 75mph with 4L60E and 3.36 you will be at about 2300rpm.

 

Wow! That's great. If I new what year trans I was going to end up with, I would order one today!