Engine/Transmission (1998.5 - 2002) How big can you go on injectors with a 2001 HO VP44?

[GOT-Torque]

Whats the limit? When does it run out of fuel and need upgraded?



My question is do I upgrade my Mach 4's next or replace my perfectly good injection pump with a hot rod version?



Any experience with this? Thanks!



Truck is finally back together after almost four months and I need more fuel!

 

[Tiger Rag]

I ran my Mach 6's (220hp) with stock HO VP-44 and got about 75 more hp on the dyno over the 155hp BD injectors I had previously. Many say you can't get power over 150 hp injectors but my measurements show differently. I've got a HRVP now and it does flow more fuel than the std HO, but the std HO isn't as bad a some make it out to be.



Good luck,

 

[RGutierrez]

How big?

I was running the H. O. injection pump with Jammer IIIs then I switched to Mach 5s. It ran a little bit better but not as good as I expected. Last week I installed a Hot Rod VP44 and the truck woke up. The throttle response is excellent and very crisp. I was at 500 hp corrected with the Jammer IIIs. I'll dyno later this week when the snow melts a bit more. The new pump made a big difference. I just wasn't getting enough fuel.

 

[johncameron]

I ran my Mach 6's (220hp) with stock HO VP-44 and got about 75 more hp on the dyno over the 155hp BD injectors I had previously. Many say you can't get power over 150 hp injectors but my measurements show differently. I've got a HRVP now and it does flow more fuel than the std HO, but the std HO isn't as bad a some make it out to be. Good luck,

My guess is because the Mach 6's would be way more effiecient with the same ammout of fuel than the BD injectors. I read once that the biggest injectors you "should" run are 4. 5's on a HO pump.



JC

 

[GOT-Torque]

What sort of gains can you expect going to a hotrod pump? 50 hp? 100 hp?

 

[Tiger Rag]

My guess is because the Mach 6's would be way more effiecient with the same ammout of fuel than the BD injectors. I read once that the biggest injectors you "should" run are 4. 5's on a HO pump.



JC

That may be part of it, but the BD injectors are pretty solid..... and yes I've read that too... . (as a matter of fact Don M told me the same, but said I could go with the 6's with no issues since I ran twins and would be ready for future mods. ) I thought the BD's were very good injectors. That said, I don't think anyone makes better injectors that Don does. They guy I sold the BD injectors to loves them. He made right at 500 hp with them. I did about 450 or so with them. He has a TST comp where I had regular TST.

 

[Tiger Rag]

What sort of gains can you expect going to a hotrod pump? 50 hp? 100 hp?

Some who have tested say it can be nearly no gain, it just depends. On mine I dyno'ed about 10 hp more with Smarty, M6's, HRVP, and No TST than I did with same set up on stk HO VP and TST. The claim is between 50-100 hp. I havn't had a chance to dyno with my TST in the mix.

 

[RGutierrez]

I agree with Johncameron's statement about running out of fuel at about Mach 4. 5s and about the efficiency of Don's compared to most others. I have an appointment to dyno tomorrow afternoon and I'll post the results between the H. O. pump and Jammer IIIs compared to the HRVP and Mach 5. 5s.

 

[Tiger Rag]

Some who have tested say it can be nearly no gain, it just depends. On mine I dyno'ed about 10 hp more with Smarty, M6's, HRVP, and No TST than I did with same set up on stk HO VP and TST. The claim is between 50-100 hp. I havn't had a chance to dyno with my TST in the mix.

I should have completed the thought that I don't doubt that I'm at or above 600 hp so the HRVP does what it is supposed to. It definitely flows more fuel, I just need to measure it on the dyno.



HO VP44 is good to about 500 hp. If your goals exceed that, you'll need to go the HRVP route or SO VP44. There are some that run the SO pump in the HO but I haven't researched it enough to be versed on the subject.

 

[RGutierrez]

I dynoed last night. The last dyno I did was with Jammer IIIs and the H. O. VP44 and I got 496 hp and 1,017 lbs torque. I changed the injectors to Mach 5. 5s without a noticable seat of the pants meter increase so I didn't dyno. I installed the HRVP44 and the numbers were better. 580 hp and 1,107 lbs torque. Hope this helps.

Mundo

 

[jimmyivy]

I was running the H. O. injection pump with Jammer IIIs then I switched to Mach 5s. It ran a little bit better but not as good as I expected. Last week I installed a Hot Rod VP44 and the truck woke up. The throttle response is excellent and very crisp. I was at 500 hp corrected with the Jammer IIIs. I'll dyno later this week when the snow melts a bit more. The new pump made a big difference. I just wasn't getting enough fuel.

do you have the jammer III for sale? i am looking for some.

 

[RGutierrez]

Sold 'em. Thanks for asking!

 

[KLockliear]

I dynoed last night. The last dyno I did was with Jammer IIIs and the H. O. VP44 and I got 496 hp and 1,017 lbs torque. I changed the injectors to Mach 5. 5s without a noticable seat of the pants meter increase so I didn't dyno. I installed the HRVP44 and the numbers were better. 580 hp and 1,107 lbs torque. Hope this helps.

Mundo

Too bad you didn't dyno with just the injectors OR pump mod. One thing at a time when trying to pinpoint your mod gain.



Back in the day, our HRVP44 was good for 70-75rwhp on a HO, and 40rwhp on a SO truck.