Competition P7100 is a slug, do I need my VP44 back?

[Pit Bull]

Re: Hey Doug good to hear from you.

Originally posted by Huff N Puff

Just a thought,about the 7100 might dyno well,or work well with nitros or have lots of power in a narrow band,but I dont think it will have the range of power the VP44 has. because the VP44 has better timing control than the 7100 could ever have. In a diesel timing is critical.

Merv

That seems logical. Like trading (power) VP44 for (reliability) P7100 ? Very interesting thread If I win the lottery I'm going to try some of this stuff

 

[Jetpilot]

Merv,



It will be interesting to see what we can get my truck to do. I do expect higher dyno HP #'s and really hope to see faster times at the track than with the VP44. The timing issue will come into play but remember that now p7100 guys can set timing to what works best for their trucks not just what a vendor has decided.



Each truck is different (vp44 and p7100) and each needs to have the mods work in unison..... That being said I think a p7100 24v will require a LOT more dyno and track time to get the setup working best as possible. I really don't expect to realize the entire gains from my mods without about a season of tuning and track time. But, when all is done I feel the benefits will shine.



Doug

 

[HVAC]

Injectors?

Roger Rodbolt, what have you done regarding injectors? Still got the biguns in there. The "P" pump won't create the pressure the VP44 will as I understand it. ISB injectors need 4500 psi to pop off. 12v injectors run lower pop pressures. What's been done to compensate for this???

 

[Rob Thomas]

Originally posted by Roger rodbolt

Rob,

You should visualize me on the sidelines at Muncie, cheering you on... ... ... ... ... ... ... ... ... ... I may be interested in a pit crew position.

Don't give up on me just yet, if worse comes to worse I save every part to convert back and haven't cut my head as of yet. I may be the only truck to convert, then revert

Larry

Oh, don't get me wrong Larry, I'm not counting you out, I couldn't be so lucky, LOL. My comments were/are an attempt at humor only, I'm sure your somewhat frustrated with the new mods, and being under the gun for Muncie, just cheering you up! There will be a spot on the pit crew just in case.



Later, Rob

 

[Roger rodbolt]

Thanks to all for your insight and questions. I agree with the timing and computer controll aspects and comments.



Nowell,

I started with DD1's and the truck ran very smooth and driveability was excellant. Power was less then then the same injectors with a VP44 and timing box only. I then changed to the big guns, BD8+~ and both torque and hp went way up. Pulls very strong on top end, but not to the level of the VP44. Throttle became sensitive and somewhat "jerky" on a second gear uphill start, normal street driving.

Larry

 

[KLockliear]

You need a real pump on there.

 

[TxDieselKid]

Originally posted by Roger rodbolt

Pulls very strong on top end, but not to the level of the VP44. Throttle became sensitive and somewhat "jerky" on a second gear uphill start, normal street driving.



Larry

Larry,



Are you saying it pulls harder through the RPM band, EXCEPT on the top end? Or does it pull harder through the RPM band with the VP44, and just more noticable on the top end?



You were hitting full fuel at 4000k with a VP44?

 

[Roger rodbolt]

Originally posted by TxDieselKid

Larry,



Are you saying it pulls harder through the RPM band, EXCEPT on the top end? Or does it pull harder through the RPM band with the VP44, and just more noticable on the top end?



You were hitting full fuel at 4000k with a VP44?

TDK,

I don't want you to make too much of this as with any mod's, perfection is hard to attain. You full well know that no one is fueling a VP44 equipped CTD to 4000rpm and no one includes me. Let me explain my '98. 5 coversion to a P pump by comparing it to my '94 12V mildly bombed CTD and my

Mazda RX 7 rotary engine. With the P pump conversion the powerband moved toward the RX 7 instead of the 12V. I even moved the AFC housing totally out of the way for max fueling and in between. While I get decent power it doesn't compare with the VP44 from 1000 to 2500. The P7100 pulls fairly hard from 2500 to 4000rpm but the VP44 (well tuned) made more power at 3000rpm then the P7100 does at 3000rpm or 4000rpm or anywhere in between. Does that help? Larry

 

[TxDieselKid]

Originally posted by Roger rodbolt

TDK,

I don't want you to make too much of this as with any mod's, perfection is hard to attain. You full well know that no one is fueling a VP44 equipped CTD to 4000rpm and no one includes me. Let me explain my '98. 5 coversion to a P pump by comparing it to my '94 12V mildly bombed CTD and my

Mazda RX 7 rotary engine. With the P pump conversion the powerband moved toward the RX 7 instead of the 12V. I even moved the AFC housing totally out of the way for max fueling and in between. While I get decent power it doesn't compare with the VP44 from 1000 to 2500. The P7100 pulls fairly hard from 2500 to 4000rpm but the VP44 (well tuned) made more power at 3000rpm then the P7100 does at 3000rpm or 4000rpm or anywhere in between. Does that help? Larry

Roger rodbolt,

Just trying to help. Not trying to make a big deal out of anything.



Andrew

 

[KLockliear]

You still need more pump.

 

[Roger rodbolt]

Originally posted by KLockliear

You still need more pump.

Kevin,

I hear you and think that you are correct but I suppose I want to stay in denial. Several folks said that the mighty '913 pump tweeked a little, would fuel twice what the puny VP44 would. Now I'm hearing that the tweeked '913 will MAYBE outfuel a enhanced VP44 but the parasitic drag of the Ppump combined with loss of timing flexibilty means that I will need to go to a race pump with 13mm plungers and barrels. Horsepower drag of the 13mm pump increases again, so then add more fuel--then need an extra turbo if I going to compete in the real world for sled pulling and trailer towing.



Oh well, I'll PM you and see what mystery P-Power pump that I need . Larry

 

[KLockliear]

I'll check my PM's in the AM. Anyway, I'm pretty sure I talked to you on the phone before you started this task... and I would have said "if you're gonna do it, you gotta do it all the way. " We found out early on that you needed a complete package, not just parts. There's a lot more to the swap than most people think. 800hp to the ground was a decent amount with the time Lawrence put into that project. More could have been had.



Anyway, the only real reason to do this swap is POWER - not reliability. Sure, the reliability is nice, but the cost factor far outweighs added reliability... a properly setup P pump outright will run you over $3k, so there's 2 VP44's right there. Throw in a cam, a ported head, big turbo, nitrous kit, injectors, custom fabrication and time, that adds up to about 5 more.



We never tried running Lawrences' truck with a pump that put out less than 1050cc/1000stroke, so that's a healthy pump to start with. That's a little more than our Stage 4, but not up their with the Stage 5 unit we offer now. Injectors - also custom for the application - not off the shelf 24v units. Fuel lines - also not off the shelf units... there's a lot to one of these packages, at least if that POWER is the goal.



It's hard to try to guess at your problem(s) over the internet, but it may be more than just the pump... but that's where I'd look for a start in the right direction.

 

[R.E. Miller]

Just to back up Keith...

I work on these engines everyday in the stock form most of the time. If you cannot get a solid 25psi to the pump you will not have any consistancy in power, smoke, and timing. The lower internal pressure of the pump will essentially retard the timing, not good.

Good luck with your project, it will be worth it when you get it done



Russell

 

[Chrisw]

larry how about an up date on the P-pump



Or is it for sale. I have a vp 44 I can trade if you need a or want a vp pump back

 

[Roger rodbolt]

Chris,

I'm still tuning the conversion, I now have as much fuel pressure as I want but still not the power that I had with the VP. I'm going to a sled pull the afternoon and hope they let me pull exhibtion so I can see if my torque curve is really as bad as I think. I haven't given up and do have a larger P7100 in shipment... ... ... ..... I have a new VP44 as well as a used one and have refused to cut my head in order to undo my conversion if necessary. Time will tell but I may be a spectator at Muncie.

Larry

 

[J.R. Adkins]

Originally posted by Roger rodbolt

Chris,

I'm still tuning the conversion, I now have as much fuel pressure as I want but still not the power that I had with the VP. I'm going to a sled pull the afternoon and hope they let me pull exhibtion so I can see if my torque curve is really as bad as I think. I haven't given up and do have a larger P7100 in shipment... ... ... ..... I have a new VP44 as well as a used one and have refused to cut my head in order to undo my conversion if necessary. Time will tell but I may be a spectator at Muncie.

Larry

Larry,



Gime me a call I might be able to help.



J. R.

 

[Roger rodbolt]

Thanks J. R. , I'll give you a call. Hoping that an "enhanced" P7100 will deliver for me.



I drove a hour and a half southwest of here for a couple exhibition pulls tonight. My favorite sled was there with a operator that has been helpful to me in the past with consistancy, tuning data and advice. It was my first time there and the track was one of the worst that I've ever pulled on... ... ... ... . but it verified what I've been saying. Horsepower and torque are way down from the VP44. I tried different gears to test my new found rpm, with no avail. 199ft and 216ft pulls placed me in the middle of the 6200lb gassers. The open class gassers were challenging me to enter their class after seeing me pull. I've made respectable pulls against the alcohol burners, two wheel drives etc. in the past and the word got around that a street driven 359cid six cylinder had taken prize money from the big boys. It was embarrassing to say no, that I couldn't even make a decent effort. Larry

 

[BigYellowIron]

Larry

I have tried to call you several times but have had no luck getting you.



You might have to PM me with your numbers and when you are home. I have moved so all of my contact info is different.



Later



Adam

 

[Chrisw]

Originally posted by Roger rodbolt

I drove a hour and a half southwest of here for a couple exhibition pulls tonight.

that should have put you close to my house. I would have went to back you up it needed. sorry to hear about your proublems

 

[01_HO]

How about We bring up a crew again and put the electronics on that monster of yours or you can come down and help put the head,cam,fuel system,driveshaft loops and NOS on my truck and then we could put the VP on yours and D. S. Loops on yours as well

Hows that sound