chances are that the electronics on my factory HO vp are not worth a bag of d!cks anymore, forcing me to replace my enitre injection pump. my question is... should i replace my HO vp with A SO vp for more power or just stick with another HO vp? Ive heard that the HO's cant handle as much hp once you start adding on goodies like the ones in my sig.

Also, i live in CA where i myt have to smog my truck one of these days. will an aftermarket vp like Blue chips automaticly fail me? I can immagine a hot rod vp would, but not sure if they check. Im guessing that if i throw my stock injectors in, it couldnt burn too much dirtier with a hot rod or monster vp than stock? will they be able to scan for this and do they check the vp visualy?
Thanks!

 

I am not sure on the California smog thing, although all VP44's look the same. I would only recommend an SO pump in place of an HO pump if you are shooting for 600hp or more. I think the HO pump runs out of juice about there...
I have an SO pump on the truck in my sig. I am happy with it, although I did lose a fair amount of power on the low end. Of course the top end more than makes up for it as far as I am concerned...

 

are the injectors from my HO going to be compatible or do I need to get the pop off pressures dropped due to the SO pump being lower pressure? it seems like this would really change the duration and timing of the injection by keeping the injectors the same and switching pumps, but i havent heard of it being an issue.

 

Not sure really, I already had aftermarket injectors when I switched to the SO pump, and didn't notice any issues...

 

Injection pressure is determined by the injectors, not the pump. The pressure of the injectors sets the pressure at which the injection pulse will begin, and the "restriction" of the injector determines peak injection pressure. With a higher flow injector, you have lower peak injection pressure.

That's why you'll notice white smoke and such with larger injectors when cold (like I have with my Mach 4s). The larger nozzles drop the injection pressure down to where atomization isn't as good. Also, the rapid rate of discharge sucks a lot of heat out of the charge as it does atomize, which is why the clean up a bit when the engine warms up (white smoke tends to go away).

My M4s always haze a tiny bit-- it's the nature of the beast with a large nozzle and comparatively low pressure/flow to support it.

The key advantage of an SO pump is that it has larger plungers in it which can pump more volume. This, in turn, means that it can meet the flow demands of a larger injector before it runs out of flow capability.

So now it should be clear why HOs have smaller injectors from the factory (which causes them to operate at higher pressures). It's also clear why HOs run out of steam around 500hp, while an SO pump can make up to 700hp with a well-tuned combination.

JH

 

A VP from blue chip will pass CA, smog we have a couple special X VPs from chip with no problem passing

 

just wondering I dont live in Cali, but has anyone ever did a smog test with a smarty on half power. wonder what the result would be on the test.

 

Don't suggest a Hot pump for street driving. SO and chip perform very well.