My 69 C20 beating a Cummings Diesel with 40 pounds boost. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Devil Pup · 06-06-2009, 02:08 AM

[IMG]http://i471.photobucket.com/albums/rr80/pr0v0...

What do you all think

67shortie · 06-06-2009, 04:29 AM

Awesome, what did you end up running?

Devil Pup · 06-06-2009, 04:47 AM

Quote:

Originally Posted by 67shortie

Awesome, what did you end up running?

17.33. not too fast i know but a heavy truck

Shaky · 06-06-2009, 05:36 AM

So what's in your C20? Must be good to get the pressurized diesel off the line...

big_al_71 · 06-06-2009, 08:16 AM

That looked cool, but I hardly doubt that your truck running a 17.33 will beat a 40psi turbo truck I definetly do not agree that other truck was boosting anywhere near 40 psi maybe 4-6 pounds if not the driver cant drive for crap. Here are some examples of truck with 40 psi.

YouTube - Fast diesel trucks at the drag strip!...

YouTube - diesel drags countyline miami

**bigsnookmaster** · 06-06-2009, 10:41 AM

I agree with Big Al.

glock35ipsc · 06-06-2009, 10:53 AM

Quote:

Originally Posted by bigsnookmaster

I agree with Big Al.

Me too!

Devil Pup · 06-06-2009, 12:14 PM

He did say at the end of the race that his clutch was slipping, but eh. . who am i to complain i was happy to take a win

72freak · 06-06-2009, 01:45 PM

Quote:

Originally Posted by bigsnookmaster

I agree with Big Al.

yep........no way no how......but take the win anyway you can get it!!!!!!!!!

Pont406 · 06-06-2009, 04:47 PM

Devil Pup,
whice race track is that?

Devil Pup · 06-06-2009, 06:09 PM

Quote:

Originally Posted by Pont406

Devil Pup,
whice race track is that?

Sirace out in Tucson, Az

**Classic Heartbeat** · 06-06-2009, 08:05 PM

A win is a win. Congradulations!! Seeing how there are same diesel drag races on this thread, this is one of my favorites!!

YouTube - Duramax Diesel Drag Racing a Mustang

WES

Tx Firefighter · 06-06-2009, 09:33 PM

Quote:

Originally Posted by big_al_71

..... I definetly do not agree that other truck was boosting anywhere near 40 psi maybe 4-6 pounds .....

You realize that a bone stock Cummins runs 20 pounds of boost right ? A fuel box and a boost fooler will get you in the mid 30's easily. It's completely feasible that the guy was hitting 40 pounds.

I speak from personal experience having a string of hot rod diesel trucks in my life. I pulled trailers everyday with my trucks running these kinds of boost numbers. Remember, black smoke like seen in those videos is overfueling. It doesn't necessarily have any real connection with boost numbers.

kamikazekyle05 · 06-07-2009, 12:14 AM

Quote:

Originally Posted by Tx Firefighter

You realize that a bone stock Cummins runs 20 pounds of boost right ? A fuel box and a boost fooler will get you in the mid 30's easily. It's completely feasible that the guy was hitting 40 pounds.

I speak from personal experience having a string of hot rod diesel trucks in my life. I pulled trailers everyday with my trucks running these kinds of boost numbers. Remember, black smoke like seen in those videos is overfueling. It doesn't necessarily have any real connection with boost numbers.

Looked like a first gen. cummins, he probably just had the fuel screw turned all the way in, but i pretty sure the stock turbo on the old 12 valves werent capable of that psi even with an adjustable boost elbow. 20psi is very common though. I maybe wrong, anyways good run man!

Tx Firefighter · 06-07-2009, 07:44 AM

Ya know, in that vein, a lot of fellas really turn the fuel up on these things and put the turbo way out of it's efficiency range. For instance, the HX35 on my Cummins truck really became inefficient around 35 pounds of boost. It would make more, but it also made lots of heat. It sounds impressive to turn a turbo into the stratosphere, but it's a bad idea. A turbo upgrade is in order at that point, but very costly.

We also get a lot of guys around here that add massive fuel through boxes, grinding the plate, or adjusting the fuel screw (depending on pump type), but never buy a pyrometer to keep track of EGT. Those guys learn an expensive lesson pretty quick. And, when dealing with Cummins engines, lessons are expensive indeed.

The fellow above stated that the Cummins guy said his clutch was slipping. That is very common when you really step on one of these things with adding torque. A good Southbend upgrade clutch will run between 1000 and 1500 just for parts alone. That's why so many diesel guys are running around with slipping clutches. They don't want to pay to play and do it right.

big_al_71 · 06-07-2009, 01:41 PM

That truck could had been boosting 100 pounds but still got smoked by a 17.33?

We have so SERIOUS diesel power machines downhere running mid 10's and driven daily and my point was that the other truck was a pig.

69halfton · 06-07-2009, 02:41 PM

so does that mean when you see a diesel truck smoking like that..its really running way overfueled?

and that even when you turn the boost up etc, the truck should still run clean?

i know a little smoke from like 1000 through 1800 rpm is normal..but beyond that if it is smoking it is improperly tuned?

kamikazekyle05 · 06-07-2009, 02:53 PM

No not necessarily. Smoke right off the line is unburnt fuel(very common) but once you get the turbo lit is should clean it up. So if the truck keeps smoking then yes its overfueled. Of course this varies from truck to truck, the diesel drag trucks throw everything they can at them, but your common street truck it shouldnt

Tx Firefighter · 06-07-2009, 07:52 PM

Exactly.

When you whack it at low rpm, it will blow black smoke. As you watch the boost gauge climb and hear the turbo build, the smoke should clear up almost completely. At full boost, if it still is smoking, you are dumping way too much fuel into the system. Too much fuel under full boost will dramatically increase EGT.

caja_larga · 06-07-2009, 09:42 PM

Quote:

Originally Posted by Devil Pup

Sirace out in Tucson, Az

I was looking at the track a said to myself that it looked like SIR.

Devil Pup · 06-07-2009, 11:31 PM

Quote:

Originally Posted by caja_larga

I was looking at the track a said to myself that it looked like SIR.

lol ya its SIR

06-06-2009, 04:29 AM	#2
67shortie Green club Join Date: May 2002 Location: Central CA Posts: 1,059	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. Awesome, what did you end up running? __________________ 71 short/fleet ECE 4/6 drop, LQ4/700r4/3.42 gears 70 SS396 Chevelle 427/200-4R/3.73posi 61 Lincoln Continental, black on black Son you are going to drive me to drinkin if you don't stop drivin that hot rod lincoln

06-06-2009, 05:36 AM	#4
Shaky Six in a row makes it go... Join Date: Mar 2009 Location: Vacationland: Maine Posts: 1,346	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. So what's in your C20? Must be good to get the pressurized diesel off the line... __________________ 67 C20 long step resto: http://67-72chevytrucks.com/vboard/s...d.php?t=342086 66 C10 long step build: http://67-72chevytrucks.com/vboard/s...=1#post3814790 CT to Alaska in a 67 C10: http://67-72chevytrucks.com/vboard/s...d.php?t=399224 “The height of sophistication is simplicity." - Clare Boothe Luce

06-06-2009, 10:41 AM	#6
bigsnookmaster Senior Member Join Date: Jan 2008 Location: St.Petersburg,Fl Posts: 1,270	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. I agree with Big Al. __________________ greg http://community.webshots.com/user/68406Stepside

06-06-2009, 12:14 PM	#8
Devil Pup Registered User Join Date: Dec 2007 Location: Riverside, Ca Posts: 407	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. He did say at the end of the race that his clutch was slipping, but eh. . who am i to complain i was happy to take a win __________________ Lifted 2wd 1969 C20/ 5.3LS/4L60E :http://67-72chevytrucks.com/vboard/s...d.php?t=728388

06-06-2009, 04:47 PM	#10
Pont406 Registered User Join Date: Aug 2007 Location: West Hills, California Posts: 679	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. Devil Pup, whice race track is that?

06-07-2009, 07:44 AM	#15
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. Ya know, in that vein, a lot of fellas really turn the fuel up on these things and put the turbo way out of it's efficiency range. For instance, the HX35 on my Cummins truck really became inefficient around 35 pounds of boost. It would make more, but it also made lots of heat. It sounds impressive to turn a turbo into the stratosphere, but it's a bad idea. A turbo upgrade is in order at that point, but very costly. We also get a lot of guys around here that add massive fuel through boxes, grinding the plate, or adjusting the fuel screw (depending on pump type), but never buy a pyrometer to keep track of EGT. Those guys learn an expensive lesson pretty quick. And, when dealing with Cummins engines, lessons are expensive indeed. The fellow above stated that the Cummins guy said his clutch was slipping. That is very common when you really step on one of these things with adding torque. A good Southbend upgrade clutch will run between 1000 and 1500 just for parts alone. That's why so many diesel guys are running around with slipping clutches. They don't want to pay to play and do it right. __________________ I'm on the Instagram- @Gearhead_Kevin

06-07-2009, 01:41 PM	#16
big_al_71 Registered User Join Date: Jun 2008 Location: South Florida Posts: 11,375	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. That truck could had been boosting 100 pounds but still got smoked by a 17.33? We have so SERIOUS diesel power machines downhere running mid 10's and driven daily and my point was that the other truck was a pig. __________________ Get your facts first, and then you can distort them as much as you please!!!!!. Sylvester's build thread >>>http://67-72chevytrucks.com/vboard/s...ht=big+rebuild

06-07-2009, 02:41 PM	#17
69halfton Registered User Join Date: Apr 2007 Location: King City, Ontario, Canada Posts: 974	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. so does that mean when you see a diesel truck smoking like that..its really running way overfueled? and that even when you turn the boost up etc, the truck should still run clean? i know a little smoke from like 1000 through 1800 rpm is normal..but beyond that if it is smoking it is improperly tuned? __________________ - Jason If you can turn, Youre not going fast enough. Favorite caption: first car to 200 mph in the 1/4 mile, no parachute, drum brakes all the way around.. ..back when men were men.

06-07-2009, 02:53 PM	#18
kamikazekyle05 Registered User Join Date: Nov 2007 Location: Vernon, Texas Posts: 331	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. No not necessarily. Smoke right off the line is unburnt fuel(very common) but once you get the turbo lit is should clean it up. So if the truck keeps smoking then yes its overfueled. Of course this varies from truck to truck, the diesel drag trucks throw everything they can at them, but your common street truck it shouldnt

06-07-2009, 07:52 PM	#19
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: My 69 C20 beating a Cummings Diesel with 40 pounds boost. Exactly. When you whack it at low rpm, it will blow black smoke. As you watch the boost gauge climb and hear the turbo build, the smoke should clear up almost completely. At full boost, if it still is smoking, you are dumping way too much fuel into the system. Too much fuel under full boost will dramatically increase EGT. __________________ I'm on the Instagram- @Gearhead_Kevin



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