Doug, why would there be no gain in this case going from 4's to 6's? Are you already dumping all the fuel available into the cylinder so bigger injectors don't help? Or was he limited by the amount of airflow he had available?

I'm running a drag comp (5x4), smarty, HRVP44, and just went from M4's to M6's and am now considering M7's or bigger... Am I wasting my time?

I'd say once the pump dies go to an SO pump an jump to Mach 6's or 7's and you will have some big numbers. I made the dyno runs in my sig with my smarty on and TST on 9/9 for the first dyno and 3/9 for the second dyno. the biggest difference was twin trubo tunning. I have dynoed the TST on all setting from 5 up and I get my best dyno on setting 9. I found out that I only had a TST PM3 and sent it back and now have a TST Comp and need to get back on the dyno.

I think so. Don's told me that the mach 6 is making the most power with the hrvp currently. As far as I know the highest hp on a hrvp from regular posters in this room is Tiger Rag with 615 uncorrected with mach 6's and bd twins.

I put down 610 with a old piers hrvp, redline and a 40- ht4c set of twins and mach 7's a few years ago. This was on a Isaacs load dyno with 4.10 gears.

I did 696 uncorrected with an I.I. hrvp, SPS62, TST/EZ, and nitrous.

That's awesome.

Makes me want to put the old NOS kit in the garage to use.

Go for it, you have studs and o-rings. No reason not to ;)

This is an interesting thread.

The whole concept of a HRVP makes me wonder. From what I understand, it's basically an SO -27 B&P assembly with a more aggressive HO cam ring in most cases. This would change the rate of discharge curves.

I'm not sure that I think a HRVP is the answer--I mean, we saw Nathan take an SO pump to 700hp on fuel only with twins year ago (03? 04?). What does the HRVP do that the SO can't?

I think the HRVP is one of those things that needs more refinement to work well. For example, I'd say it probably needs a little higher pop-off on the injectors to work properly. I'd want to know exactly WHAT is done to make a pump a "HRVP" so that I could see how that would impact the rest of the system and correct for it.

We all know that HO pumps make more power from a given injector size up to their fueling limit. But maybe it's not JUST all from higher fuel discharge. What if a bigger injector is more optimal as part of the HO "system" as a whole? What if the rate-of-discharge from a bigger stick is better matched to the HO's pump?

What conclusions can we draw from the fact that a M6 won't make more power than an M4 with a HRVP? Perhaps that the rate-of-discharge of an M4 is more optimal with a HRVP? Perhaps it's atomization?

If nothing else, this surely seems to point to the M4 as a more *efficient* injector with the HRVP.

Yet we can turn around and drop that M6 into a standard SO pump and pick up 70hp or more over the M4. Perhaps the HRVP is actually a step backwards relative to making big power? I mean, we've seen a pretty fair amount of 650hp+ 24V trucks, and how many of them were running HRVPs?

Until someone shows me a dyno run where a HRVP of some kind increases fuel-only power with an M8 over an M6 over an M4, I'm not convinced they represent a step forward over an SO pump and a fueling box.

Personally, I'm suspecting that Quad's new race box and a plain old SO pump will be the new bar to meet over any stack for max fuel-only 24V power.

JMO

The more I think about it the more I think this II pump responds to bombs just like a HO pump, but has worse manners [verymad]

We just need a Smarty program to smooth out that horrible idle!!![yuk][yuk][yuk]

[QUOTE=CarcajouCummins;1583110]Yes, the Smarty kills the upper rpm horsepower.QUOTE]


The smarty does decreases high end HP but I wouldn't say it kills it. When I last dyno'd my 01 it wasn't even a 10rwhp diff between smarty and no smarty. What I did like about the smarty is the HP came on sooner in the RPM range. IMO, I'll loose 10 RWHP if the HP is coming on 300 rpm sooner.

There was some software tested, but it didn't help :(

If you turn the tst comp up all the way do you get a ticked off big block kind of idle? Btw who is nadp?

Until recently mine idled fine, but now I get a real choppy idle after the thermastat opens :confused: Started some time after I got the tst comp working good *smacks self in forehead*