4l80e manual transmission

[Roadrage David]

You guys heard of the 4 speed overdrive manual 4l80e transmission without the computer. witch only operates bij manual up and douwn shifting!! no clutch kopling just 2 paddles. brake and gas. range from 1000 upto 1200 hp..... sounds intresting

[rocketman]

I put one in my old pro street car before I sold it. It was horse of tranny, but you have to shift it like a regular manual tranny. I had it behind a 710 bbc

[hardline_42]

The 4L80 can be run with a manual valve body to avoid having to buy a separate electronic controller. However, to run the paddle shifters that you're talking about, you WILL need the computer. Otherwise, it shifts like a TH400 with a manual VB. It has a vacuum modulator that controls line pressure instead of a kickdown or TV cable.

[Roadrage David]

I put one in my old pro street car before I sold it. It was horse of tranny, but you have to shift it like a regular manual tranny. I had it behind a 710 bbc

Rocket man forgive my ignorence , but im not sure if you liked it ore not.......

[Steve Chryssos]

Works fine, but it's kinda like choosing a typewriter over a PC.

[rocketman]

Rocket man forgive my ignorence , but im not sure if you liked it ore not.......

Yes I did

[Roadrage David]

Works fine, but it's kinda like choosing a typewriter over a PC.

why is that!!!

[Steve Chryssos]

...Cause both can be used to type letters, but the personal computer does so much more.

The manual valve body transmission is full manual only and shifts are non-adjustable (usually harsh) across the board. The computerized version, on the other hand, offers manual and auto at the push of a switch. All of the aftermarket controllers offer this feature. Also the computerized version provides extensive converter lock-up control and fully configurable line pressure and shift timing. Also accidental downshift prevention and much more. Setup and programming is extremely simple.

[Roadrage David]

Ok steve i understand , but wouldend the manual set up be more racey! with firm shifts and deseleration on the backshifts..like a normal manual transmission. prevention of backshift is sutch a limitation when going around the cource ore am i wrong. just asking because in the near future i need to make a disision witch direction im going with my 69GTO............

[Steve Chryssos]

That depends on specific conditions of load (throttle angle), selected gear, vehicle speed and available traction. Let's start with the easiest condition: WOT/acceleration/full traction. At 100% throttle angle during acceleration upshifts, the manual valve body is king if full traction is available. Therefore, manual valve body transmissions are popular for drag racing--preferably on slicks at a track with good prep.

It's a common mistake for enthusiasts to focus on WOT upshifts when discussing transmission choices. When traction is available, WOT upshifts are the easiest set of parameters to define and achieve. Max pressure/minimum shift time.

As load and/or traction decrease and under varying combinations of positive and negative acceleration, pressure and shift time must also vary. Much like comparing a carburetor to digital fuel injection, a computerized transmission is just better at handling a wider range of variations. It's just a shame to throw away that capability.

Regarding engine braking, the electronic manumatic was at a distinct disadvantage four years ago. The GM electronic overdrive was designed specifically to maximize fuel economy in the face of toughening regulations. And engine braking robs fuel economy. By design, the GM 4L's freewheel on deceleration. We've worked around that issue by providing a heavy duty lock up clutch converter that provides "enough" engine braking. More engine braking is available through the use of modified valve bodies from Bowler that engage the coast clutches under a wider range of circumstances. By comparison, that manual valve body transmission can yield excessive engine braking at the wrong time. And the transmission will slowly eat itself alive.

Ultimately, if you're building a pro streeter and want overdrive, a manual valve body 4L is a viable option. If you are building a pro-touring car, where technology and versatility are desired, I recommend against it.

[Roadrage David]

mmmmmm point taken, tank you...........

[Steve Chryssos]

Sure. It's a common question. The thought of replacing a highly accurate throttle position sensor with an archaic vacuum modulator drives me nuts. Some dislike the computer, some dislike the expense. Others simply expect better results. But after an install, it becomes readily apparent that the computers are incredibly easy to tune and represent a true value--at least compared to the cost of fuel injection. For example, Compushift has a dyno simulator feature and a lateral accelerometer. The on-board display option is pretty cheap when you think about it. But like I said, you won't know til you are done with an install.

[neki67]

After an install, it becomes readily apparent that the computers are incredibly easy to tune and represent a true value--at least compared to the cost of fuel injection. For example, Compushift has a dyno simulator feature and a lateral accelerometer. The on-board display option is pretty cheap when you think about it. But like I said, you won't know til you are done with an install.

Idd, makkelijk te installeren (de controller en de TPS), de bak is makkelijk te tunen en een absolute aanwinst. 4L bak schakelt super snel maar zonder schok zoals bij een oud type bak met shift kit. Het ontbreken van afremmen op de motor is tot nu toe het enige nadeel dat ik ben tegengekomen maar daar wordt aan gewerkt.

Sorry for doing the above in Dutch . . . I could provide you with a translation BUT in the true Dutch spirit, I would have to charge you!

[Steve Chryssos]

Rene'
Have you tuned your lock up parameters, yet?

[neki67]

I've been playing a bit with it Steve but due to personal circumstances I couldn't/didn't want to find the time to dig into it to deep. My father is quite sick at the moment and that's demanding a lot of my time, as you will probably understand.

René

[Steve Chryssos]

I'm sorry to hear that Rene'. I know it well. Best wishes to you and your family.
/Steve