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How come????????

2K views 22 replies 10 participants last post by  MOOSE 04 
#1 ·
How come our venerable 5.9l Cummins/Dodge isn't as fast as though 8 cylinder (6.0l or even 7.3l) international/Ford?

My friend has a 06 6.0l with a 5" exhaust, and a SCT w/custom tune and that truck is a rocket. I have a 4" exhaust, Stage III injectors, Quadzilla, and brand new HTT turbo, and a rebuilt tranny, and the truck is fast, but not Ford fast.

I love my truck, and would never give it up, but it is a little disheartening with a little tune, that 6.0l is barking 2nd gear, and screaming down the highway. Even his old 99 7.3l was fast.

I don't want to start a Ford/Dodge debate, but would like some real answers. And if anybody denies my claims, go drive a ford with a nice tune, and then get into your dodge, and get back to me.

Also how are the new 6.7l cummins doing in this race?
 
#2 ·
my best guess would be rotating mass inline motors are not really designed to spin like a v-8 design yea a power stroke has more pistons and rods and so on but they are smaller and easier to spin or maybe you just need a lead insole for your right foot
 
G
#3 ·
Are you sure it is a little tune? What gears does he have vs. what you have? Is he running huge tires like you are? There are a lot of variables that can go into that equation. My trucks is not fast off the line, but once rolling I can keep up or pull away with anyone.
 
#4 ·
by little tune, I mean; plug in his SCT tuner, select the tune, let it download, and off he goes. Thats what I mean. It is definitely not a "little" tune, I should have said "with a little tuning". Tires are definitely smaller, stock size for a 4x4 of that year, gearing not sure,

I agree, off the line my truck is slow, but when I need to pass some one on the highway, there is no problem doing it.

And I also agree that there are alot of variables that go into it, like year, 4x4 vs 2x4, gearing, cab size, etc... but generally speaking these v-8's are just quicker, why?
 
G
#5 ·
I don't find the V-8's generally quicker. To me it's on a truck to truck basis.

One thing you have to remember these newer Ford and Chevy V-8's have a fair amount more stock HP than your 99' Cummins, so you have to play catch up to them before they ever add anymore power. Although a V-8 will build rpm quicker and their powerband is higher in the rpm range than our Cummins.

A V motor is built for rpm generally and a inline motor is known for torque.
 
#8 ·
you know i raced my buddies ford the other day and i had no problem beating him i mean he got maybe 10 ft infront of me then once i hit third gear i was gone and my buddy has alot of stuff done with his truck like injectors, programer, exhaust, intake, ATS diesel tranny and tork converter.
 
#9 ·
all is so true. Maybe I am just trying to justify to myself that I need to go faster and have more power.
 
#13 ·
Get yourself some real injectors in there and you will notice a night and day difference. The difference between Nozzle tips and a Good complete injector is really bigger than most people think. Temps should come down, and with a mach 4 or mach 5 injector you'll cook your buddy's ford. Mach 5's will still get really warm in your truck, if you're gonna use it for towning I'd stick with a mach 3 or 4.
Sean
 
#14 ·
Why whats wrong with my DDP's, I love them. And alot of other people stand by them. The mach's from what I hear are great, but the price tag is a killer for just injectors.
I think I am going to install a torque converter lock up switch to transfer all of my power. Any good ones out there, or any homegrown plans to build one.

I am also thinking of stacking a smarty for timing. I think that would help.
 
#15 ·
A lock up switch is pretty easy to install/build yourself. TST has instructions on their website which you should probably double check, but Thats just cause I may be forgetting the exactly which wire.

IRRC its number B11 in the middle bundle on the ECM. In that bundle, there are 3 rows of wires, its in the bottom row of wires, and its orange with a black tracer. Tap this wire (do not cut) and run it to a switch mounted where you like in the cab. Then from the other pole on the switch, run a wire to a ground, somewhere on the firewall should work well. You can also run your newly tapped wire to a relay under the hood and put the relay on a switch, just another alternative.

Then just by pass the TC lock up relay and you're good to go. Remember, it won't lock until you reach 18mph. However, If you leave it locked and come to a stop, it won't downshift and unlock and you'll stall the truck.
Hope this helps.
Sean

On Edit: Double checked the TST site, and this all looks correct. I'll send you a link and you can down load their instructions that come with a nice little diagram. Its really cheap to do this mod yourself. Just a couple bucks for a switch and some wire and a tap.
http://www.tstproducts.com/index.asp?PageAction=Custom&ID=4
 
#17 ·
We're not exactly talkin about stock diesels here, and this is also old versus new. The new trucks come from the factory with quite a bit more HP and the newer injection systems responde much better to electronic upgrades. Thats why you can get a new dodge or chevy into the 13's with only tuning and a conveter and VB.
Sean
 
#18 ·
I found the TS site with the TC lock up, thanks, that will be the first thing I do when I go home. And you are right about the new trucks, technology is a great thing.
 
#21 ·
they're is NOOO comparison to pulling a Dura-dick or Dura-maxipad or even a Dura-crap...hahaha with a Cummins!!! but he's talking heads up stock to stock race, and they're just tooo quick!!! and they can get so much more outta the stock turbo! around here if you dont pull stock turbo, you have to pull w/ the Super Stock Guys whos trucks go driveway/trailer (usually pulled by a bad diesel)/track to hook/trailer/home! thats how it around at fairs where im from! and thats GAAAAAYYYY!!!

Nathaniel
 
#23 ·
back to the original topic of this thread, a d-max or a PSD are not really faster but they come off the line harder, than our cummins because they can spool up at a higher rpm. i can get beat off the line by any d-max but after 20 i run them down and then eat there @$$.
 
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