Transmission / Engine Modifications

[Strick-9]

I'm always thinking of new ways to modify my truck and since I'm near the limit or available power from my 'little' P7100, I have to find other ways to entertain myself.



One common problem a lot of us automatic owners face is nonlinear power delivery from our engines. My governor spring kit caused a huge power surge just off idle and my truck put out most all of its power by 1/2 throttle. I've spent days upon days, experimenting with the governor springs to get my pump's power delivery more linear. I want 1/4 full power at 1/4 throttle and 3/4 full power at 3/4 throttle and so on. The line pressure (that prevents clutch slippage) in our automatics is proportional to throttle angle, so in a perfect world, shouldn't our power delivery also be?



Any time I removed the off idle surge of power in my 160 hp pump, my miss and stumble associated with the 370 injectors came back.



I've given up on solving the problem through engine modifications, so now I will try to help the problem by TV lever modifications. I would like to fabricate another TV lever to replace the stock lever. With a shorter TV lever length, the increase in line pressure would be greater per throttle angle than our current system.



If I'm getting 80% power at 1/2 throttle than maybe I should try to get 80% of my line pressure increase at 1/2 throttle.



The obvious problem with this is that I would further limit my current total throttle travel. I would like to setup a stiff tension spring in line with my TV cable that would allow my throttle angle to travel past the limit of the transmission.



I also need an adjustable stop for the TV lever to attain proper WOT shift points.



It seems this would allow much more adjustability than the current crude TV lever adjustment.



Has anyone experimented with different TV levers? Bill? Anyone?



Thanks for listening. Sometimes, I think I have too much time on my hands.



-Chris

 

[Cummins Corvette]

I think that the cam plate has more to do with this than the governor- I could be wrong though. Piers is working on a plate to do just what you discribed for that exact reason. Now I have some questions for you if you don't mind. Does the hx-40 you're running work reasonably well with the 91% tc that you have? Do you have the afc adjusted for tuns of smoke? At what rpm does boost finally arive? And finally, what altitude do you live at? If you have time to answer these I would greatly appreciate your input. Thanks much Chris. (I think that I can remember your name as mine is the same )

 

[Strick-9]

CAnderson,



I know Pier's is working on his "linear" camplate, but that is in conjunction with his governor spring seats. He used to sell a set of seats that held the inner spring up REAL high. That caused a lot of the off idle power surge. Too much preload down low in the RPM range. His current seats no longer have this raised area for the inner spring, but that configuration makes my truck stumble.



I answered your questions in the "dueling dodges" post.



This should be the correct link.



-Chris

 

[Bill Kondolay]

Chris,



I see you are trying find ways to entertain yourself again,



You can accomplish some of this by cranking up your line pressure and backing off your top end line pressure.



We did play for a short time with the tv levers, found that it caused delayed upshift under light throttle.



I drove Piers's truck with his new camplate in it, it is going to be a sweet setup once he gets it dialed in.



It had low power at the bottom end and came on like gang busters at the top end.



With Noels truck we ended up going to a manual shift vb, it might be the answer for some people but you would have to calibrate the transmission to accept the manual shift vb.



Looser clearances on the 3rd gear clutch pac , stronger 2nd gear band release spring ,



At the seminar i am giving in Texas, we will be going over stuff like that and Piers is giving a seminar right before me so he you should be able to pick his brain also.



The owner , Chuck of



A1 transmissions in Kerville Texas

2620 Junction Hwy, #C

Kerville Texas

830-367-2200



has generously donated his facility for me to use to demonstrate how we update the transmission, and why we do what we do , also tweaking tips and what to look out for with your transmission ect,



This is to be held on Saturday September 29 , maybe we will see you there. This is a free seminar, as always



I am looking forward to putting faces to names.

 

[Strick-9]

Thank you for replying Bill. I know you are pressed for time most everyday.



I'm definately going to have to talk to Pier's about his camplate. I could be completely wrong, but I thought the camplate dictates power versus RPM. His camplate sounds like a great idea for manual transmissions. Limit that clutch shredding torque at 16-1900 RPM and then turn the power loose on the top end.



I'm sitting here trying to formulate my thoughts, and the more I think about this, the better it sounds.



My first thought was camplates dictate power versus RPM not power versus throttle angle like I'm concerned with. But then I realized, with an automatic you can only achieve high RPM with Large amounts of throttle or else the transmission will upshift.



There is most likely a situation with Pier's plate that at high RPM you can still generate a lot of power with light throttle, but I couldn't operate in that region, unless I was manually shifting.



This is the first time I've seen a NEED for a fuel curve with an automatic.



Thanks.

-Chris

 

[Cummins Corvette]

Thanks Chris, I forgot I already asked you that. You should be at a higher hp level than I am at, so I definetly won't be throwing money that way. Mabey one of Piers's turbos is the ticket.

 

[DMorrison]

the adjustment on the tv cable does not stay the best way to adjust to get full throttle is to bend the mounting bracket at the transmission.

 

[Strick-9]

DMorrison,



What do you mean the adjustment on the TV cable doesn't stay? Does yours slip?



I understand that you could bend the bracket at the transmission forward to allow more throttle travel, but you would be giving up line pressure at low throttle to get it. It has the same effect as loosening the TV cable at the adjuster.



-Chris

 

[DMorrison]

mine never would hold adjustment it would reset back to original position so we bent bracket to achieve full throttle and it works great

 

[Swamp Donkey]

Strick-9,



I have the same problem. Way to much power at low throttle positions. I never have to go over 1/4 throttle for anything and this does concerne me because I am making alot of power with very little pedal movement and transmission line pressures are directly connected to throttle position if I am not mistaken. At 50-60 mph the throttle is so light I actually sometimes get a bit of shudder because of the low line pressures. I even have my tc come unlocked because there is NO throttle being applied on the flat when I am unloaded. Hope the DTT stuff fixes some of that. If you ever find anything out let me know ok! Thanks.