Auto or Manual? which is faster

[94turboidi]

Yeah I quit caring about speed along time ago with my truck. I really only care about reliability anymore. But I think most people are just honestly answering the original question of which shifts faster an auto or a manual. I don't think any of us could shift as fast as auto that is in good condition even if we didn't use a clutch and slammed from one gear to the next, not that anything would last very long like that.

 

[Brianedwardss]

Update...

I have yet to race any of my IDI's ever, I didn't buy IDI's for speed, trust me on that one. But this thread and my recent purchase got to me today.

At a stop light where the road goes from two lanes to one soon after, a fella I know in an '01 cummins 6-speed with a chip, exhaust, cold air, etc pulls up on my right. I'm in the '87. Yep he wants to race and knows he's gonna just kick my tail. I usually just look away and let folks bomb on thru the green. I really could care less about racing my truck.

Well..... I rev'd as high as it would go without pushing through the brakes, and when it turned green.. FLOOR! It was a tie off the line, but everytime he shifted, he fell back about three feet. He shifted twice before we reached the merge, his bumper just ahead of my rear tire, Winner! Holy smokes, only with an automatic would an IDI beat a cummins, and it did. I tried calling him later and he didn't answer.....

So.. Automatic diesel wins the race. That '01 Cummins easily has twice the power of mine, but he had to shift

If I was in the crewcab tho, my grandma with a pegleg could've beat me thru the light.

 

[Compu Doc]

Hear is an actual scenario. A guy I used to work with was at a rest stop on the turnpike. Hos work truck (Company truck) had an automatic 6 speed Allison. The truck I was driving was identical except the truck I was driving had a 7 speed stick. We both left the rest stop at the same time and he got to the place we worked at 10 minutes ahead of me.

Usually I drove an automatic for the job but that day my regular truck I drove for work was in the shop. Usually when we both leave the rest stop we are just seconds from each other going back to the shop.

The job I have now I used to drive a Ford L8000 with a six speed manual and that was until the heater core decided to let go and fill the truck with steam coming out of the vents. That truck could not move out of it's own way with a load of 3000 gallons of diesel. The truck I have been driving lately and hope to drive for the foreseeable future for work is a 2002 International with the DT466 and a six speed Allison automatic. That truck will move fully loaded with 3100 gallons of diesel like it is empty.

 

[kas83]

Update...

I have yet to race any of my IDI's ever, I didn't buy IDI's for speed, trust me on that one. But this thread and my recent purchase got to me today.

At a stop light where the road goes from two lanes to one soon after, a fella I know in an '01 cummins 6-speed with a chip, exhaust, cold air, etc pulls up on my right. I'm in the '87. Yep he wants to race and knows he's gonna just kick my tail. I usually just look away and let folks bomb on thru the green. I really could care less about racing my truck.

Well..... I rev'd as high as it would go without pushing through the brakes, and when it turned green.. FLOOR! It was a tie off the line, but everytime he shifted, he fell back about three feet. He shifted twice before we reached the merge, his bumper just ahead of my rear tire, Winner! Holy smokes, only with an automatic would an IDI beat a cummins, and it did. I tried calling him later and he didn't answer.....

So.. Automatic diesel wins the race. That '01 Cummins easily has twice the power of mine, but he had to shift

If I was in the crewcab tho, my grandma with a pegleg could've beat me thru the light.

My experiences when running both my Cummins were just like you describe. And I don't claim to be the fastest or best when it comes to shifting, but I can row with the best of em, and bang thru the gears pretty damn good.

Reason for not seeing 'racing' manuals for a diesel is simply because they make too much torque for lighter components and housings to handle.

Nate, get that damn truck fixed and bring it up here so we can make a video of losing boost during a shift, no matter how you do it. That non-gated Banks really shows how much you lose with a manual. Boost is a product of heat/velocity spinning the turbo, caused by load and fueling plus rpm. Drop one of them, you're gonna lose boost. Example, lift off the throttle to float the gears or clutch it, load is taken off the engine, generating less heat, causing boost to drop, simple turbocharger theory.

And let me reiterate, original conversation regarding this involved more powerful diesels, in which some use for racing. Nate, 93fordturbo, likes to burn rubber and haul ass, wish he would've put that into his original post.

And when it comes to IDI's, they're pretty darn close either way, slow all the time. Get more power, and the differences become very apparent.