I successfully ran a VP-44 equipped '98.5 sled pulling and in dyno events but lost confidence when the VP-44 failed without notice. I had a new VP still in the box but also had a 913 pump, 12V gear, cover, etc and figured I could convert to the P7100 for about what my new VP pump would net me. I knew that I was going backwards in technology, that I had beaten my share of 12V trucks but the extra rpm and reliablity (joke) of the P7100 lured me to do the conversion. Bad idea......... I've ran the 913 stock, modified, a 370 marine P7100 several trys with a 13mm race P7100 and a host of injectors, timing, head work etc. My truck that used to be fun to drive and competitive is now a smoking belching deadheaded monster that has to deal with running with fixed timing, horrible fuel economy......archaic at best. My drive train has taken more beating on the street with the conversion then it did sled pulling with the VP44, but yes I've had drivability issues with the race pump. I didn't mentioned that if you let your P7100 rev to make power your valves are close to float if something in the drivetrain breaks or from lack of attention the valves will smack you pistons. Of course they mark the pistons nicely so that you can flycut them for cleareance. The P7100 is more reliable then a VP-44 especially if you leave them near stock and they drive decent with under 400hp. Higher output pumps have to deal with drive stress on the taper fit gear (if it slips your truck is dead just like a VP44) and stress on the camshaft if you turn the rpms needed with a very inefficient fueling system. I dynoed this month at 527 hp with a B-1. Shy of where the VP44 was, torque down, power curve worse then the VP no low end power. If a P7100 for $500 sounds like a bargain, Ask a pump shop what they charge to recalibrate a P7100 for performance.....................and again and again.

Good electronics enhance the life of a VP 44. The extreme settings of a competition box will not make additional horsepower if you have big injectors so turn the box down. One brand bucks so bad that I'm amazed the engine stays together. Blue Chip electronics run great on '98-2001 trucks, no experience on newer ones. A used 12V engine for $3500 makes some sense if you want to get rid of the VP. Sell your old engine and electronics and you'll have money to spend on head porting and the etc. need to get a 12V up to where the 24V engine was. JMHO but the common rail appeals to me. No one that I'm aware of is real happy with a 24V P7100 conversion unless they have twin turbos or limit the P7100 conversion to low horsepower and rpm. HTH's as is it's my humble history.
Larry

 

Larry:

GREAT EVALUATION buddy!!

Travis, Larry is giving you the honest-to-gosh truth or,
"the other side of the story" to the VP-44 to P7100
conversion!! We (including myself) all watched his
truck compete at the various seld pulling events with
the VP-44 and then later with the P-7100 pump. As Larry
said, he did VERY WELL with that truck with the VP-44!!
I know because I was at a few of those events!!

Larry, I hate to see how badly you have struggled the
past year or so and hope to see you back out there
this year with much better luck!!!

---------
John_P

 

i just can't see where it would be that hard to dial in, i would time the pump about stock,12.5 or so to start with. what else is there to figure out? i mean the motor is stupid, if it gets the fuel when it wants it, what does it care what pump is doing it?

 

With all due respect, just because you can't see it doesn't mean it's not there.....

 

hey i have been lucky at makin stuff work,and i don't think travis will give up on it. and my money says he will get it going pretty quick. he has been talkin to a few people that have done it.

hey they put a 5.9 cummins in a jeep and everyone said that wouldn't work. but on 2.5 ton rockwells and 49" iros it does ok. heck it was the crowd favorite.

 

I think you missed the point: Low HP application(around 400) it worked fine on his truck, but trying to match the performance of the a VP-44 is another story. When I say performance, I mean power, and drivabilty. The VP-44 will perform well manered or wild at the push or a button. The P-7100 will perform tame at lower power levels, or spend most of the day changing to a modified Race pump and perform like the VP on wild. Then the P-7100 bucks, shudders, and blows unacceptable amounts of smoke. Trailer towing is out, daily driver is out, mileage is almost as good as a big gasser, and engine reliabilty is hindered because of fuel washing and high RPM issues.
It looks easy enough, but ....

 

#1 I cant find a good VP, they dont make new ones anymore #2 Bucks and shudders??!! Come ride in my truck, you best wear your seat belt! I've never ridden in a 12 that did that. #3 RPM'S??? Jeff Prince has a 7100 that reves 5500, i've been told that a non-mechanically modified VP only revs 4300 max #4 Mileage?? Does anyone here know of a 24 (VP 44) that beats a 12 in mileage... I don't know of one. I had a 12 with 400RWHP that got 21 and now have a 24 with a little less hp and only get 16/17 max. And finally..... RELIABILITY ?! Are you kidding ? there is nothing reliable about a VP, except that it will blow up, RELIABILITY....... thats my biggest problem with a junky VP powered truck. Reliability, high hp, and a VP 44, these 3 things don't go together ( I never had this bs with my 12, i know I shouldn't have sold it ). BTW I'm only looking for 400 to 450 RWHP ........reliably.

 

I can pull 25 on the highway with my VP running 75. 16 in the city. I've had all sorts of fuel pump troubles and my VP is still working (knock on wood. I have really bad luck). I had an Edge Comp with the wire pierced hooked up to it for 10K miles with a FP pushing 0psi on it. I've now got 53K on it. I love my VP pump.

 

I hope you have good luck with your conversion. I would not change, but what do I know, I have 227,000 miles on my 500HP truck that gets 23highway/18city figgured by hand. I am still on my original VP its never been off.

 

A request for you gentlemen that are highly motivated to try this conversion - great, good, indifferent, bad, or down right ugly, please keep us posted on your progress and results.

I think that it would be usefull for all of us to hear about how everything goes and the problems, or even lack thereof, that you encounter with your efforts.

Thanks and good luck!

Matt

 

Travis:

I agree with what you have said concerning the P7100
vs the VP-44 pumps! I own both a 96' 12 valve and an
02' 24 valve. Like you, my mileage has NEVER been as
good with the 24 valve as it was with the 96' 12 valve
not even when it was bone stock!!! As far as "driveability",
I have also never experienced the "bucking" or "shuddering"
that "CarcajouCummins" mentions! My 96' dynoed at 508
H.P./1311 torque so I would say I am "above" the "lower"
power levels!! I know the 12 valve will tow a heavy load
(11,000lbs +) better than the 02' 24 valve as I have done
that on I-77 (North) going up 6% grades with the same
load on both trucks! With that load, my 24 valve can get
pretty "hot" EGT wise if I am not careful. Where the 24
valve will run 1150-1250 the 12 valve hardly EVER gets
above 1100 on a good hot day and it seems to have
more "reserve" power or torque than the 02'! The 12
valve engines will also take higher RPM. I have the 4K
springs in mine and I can take it all the way 4,000 RPM
with no problems!! As Travis said, Jeff Prince's race
truck will go to over 5,000 RPM and there are MANY of
the sled pullers who at or above that!! Now,.......I
will have to agree with "CarcajouCummins" that the
12 valve P7100 smokes worse than the VP-44!!!

Bosch now has "certified" dealers across the U.S. to
"remove and repair" the VP-44 pumps. Scheid Diesel is
one of the shops that is an authorized repair facility for
these pumps!! They have a Bosch Test Stand similar
to the ones for the P7100 that "flows" and tests the
pumps that are brought to them for repair or problems.

Anyway,.......good discussion fellas!!

-----------
John_P

 

Very informative. I was considering this swap later down the road, but now I'm not to sure. Let us know how it turns out.

 

Quote:

Not to mention all the tuning the conversion involves....

Quote:

You can bolt the parts on for cheaper but making it all work in harmony is the key. Trust me there is a lot more to it than just removing the vp-44 and bolting on a p-pump and that doesn't even cover the tuning issue once its all together.

Quote:

There is no substitute for experience...

Quote:

Another member did his own (conversion) and is not happy with the results.

Quote:

figured I could convert to the P7100 for about what my new VP pump would net me. ................. My truck that used to be fun to drive and competitive is now a smoking belching deadheaded monster that has to deal with running with fixed timing, horrible fuel economy

Quote:

I dynoed this month at 527 hp with a B-1. Shy of where the VP44 was, torque down, power curve worse then the VP no low end power

Quote:

I would not change

-------------------------------------

---------------

Experiance speaks volumes....


What you need is a good VP44. You either are getting some from a bad batch, or your Box is killing them. I know several failures of VP44's that have been a direct cause of Heavy Fueling "boxes", and the failures were not always when using the power.


Merrick

 

come awn merrick, everyone would like to have p7100 on there 24v trucks. it is a better preformance pump, and a more reliable pump. i have not heard any problems from anyone that has done the conversion themself. travis will be doing the conversion here shortly. and i will make sure he puts out any trouble he runs into. and i don't mean saying it is hard to tune in. i mean real problems that come up. and what it takes to get it going. it will be a lot of good info for people looking to do the swap.
and i have a neighbor that puts more miles on dodges than any one i know. his trucks are stock auto 4x4s. he has replace 6 pumps on 3 different trucks since 1999. mine is still on the original pump at 232k and 400 or so hp. face it there is no souch thing as a reliable vp44, when you compare it to a p7100.

 

Gunracer1,

Go back and read Roger rodbolt's post.......