sleds

Any H.O pump has more aggressive timing than the S.O pump.

Ph4tty

I've tried that and the only thing I noticed was higher cruise egts, but I never did romp on it hard on sw8 though.

Great thread- keep it coming

signature600

I know that...but how does a HR VP "get" that more aggressive timing of the HO pump?? I would have thought it was in the software...not a mechanical aspect.

If it was due to a difference in where the keyway is located in the shaft compared to the internals of the pump, that would make good sense...a higher static timing, yielding a higher dynamic timing as well!
Who knows for sure??

Chris

getblown5.9

just to see what heppens i ran SW8 yesterday so my only timing was from the HR pump...with the TST off i didnt notice much difference. a little quieter it seemed.

turn the TST on and things got ugly, i did a WOT blast on the highway and it was a turd, wouldnt get out of its own way, smoke all the way thru 3400rpms (silver bullet will clear up SW9 and TST-9) and the egt's at that point were knocking on 1600's door.

needless to say i went back to SW9 when i stopped to pick up a fuel filter and I drove home like that. same stretch of road going the other direction i did a WOT 5th gear blast and the top end was back and the smoke was gone. also EGT's were 200* cooler with the timing. so i have to say that the timing is definitely needed on my truck which should be around 550-575hp.

Tiger Rag

This is actually how I've been running my truck (even sw's). It is quieter and seems smoother to me. I don't notice the smoke. I also have only been running 8 on the dyno though....4 mostly for daily driving. Now I can add timing at the push of a button with the Edge Comp. On the dyno I made more horsepower with the timing from the Comp but the guys standing around said the timing rattle made them all cringe. Those are my observations anyway.

GB, I'm guessing that the odd SW's on the Smarty help you spool that single turbo better......and well If I remember correctly the timing was worth about 60hp on the dyno.

bnold

Just a guess but I would venture to say that the 85# of drive pressure is killing the HGs.. timing might not be helping, but 85#of drive for 60# of boost is poor... IMHO of course

signature600

Just curious...but have you checked yours to see how they are?? Don't take that as a slam or anything, but it would add to the thread

85lbs is high...but shouldn't be high enough to blow a HG by itself. There is something else going on here, IMHO!

Chris

getblown5.9

it may help spool the turbo better, but im talking after its lit, the top end just wasnt there, it didnt have the grunt it normally does to just pull thru the gears, it was sluggish. but thats with 200hp sticks, the smarty fueling, and the 120+hp worth of fuel from the TST box. thats alot of fuel with no timing advance.

bnold

Yep checked mine over the course of a week. pressures are less than 1:1 up to 55psi of boost (55# drive = 55# boost). at 60#of boost = 61# of drive

signature600

Cool...those are good numbers, and fairly normal from what I've seen!

Chris

Tiger Rag

I wouldn't say no timing advance, the HRVP adds a lot of timing. The additional fueling you have also adds timing. Not doubting your observations though. Like I said I noticed better hp (around 60) after adding Edge Comp timing. I didn't make any pulls with the Smarty doing timing. I didn't have time to make all the changes I wanted to. For daily driving, I think the HRVP puts all the timing in that my truck needs.

getblown5.9

with the TST off the HRVP added enough timing to run smooth and ok power...but with the TST on it had no top end pull and EGT's were way up.

eventually i may pick up an edge EZ to stack and see if there is a noticable difference

JLand

How a HRVP gets its timing from the HO componants is something I agree is key here. If it is software, which I always assumed, then it may be controllable by Smarty-type programmers. Maybe less so by add-on boxes like a Comp. BUT, if it is mechanical and therefore static, you may be on to something as to why different stacks of fuel/timing software work or don't work at higher HP and RPM levels and therefore create very harsh cylinder conditions. I'm surprised in the 6 years of HO pumps we haven't had that posted before if it is a mechanical difference. Whish someone would clear it up for us...

blackdiesel

If a hrvp has the mechanical of a SO and the elecronics of a HO. and the timing is in the elecronics, then it looks llike you would have the same problem with a HO pump, wouldn't you? Is there more to a HRVP than that? I don't know that's how they make a HRVP for sure, that's just what I was told.

signature600

It's not the mechanics of one with the electronics of another...it is the head of one pump mated to the rotor of another!!!

You get the bigger plungers (7.5mm vs 7.0mm) of the SO pump, with the higher pressure of the HO pump. That in itself might create a little timing bump, but shouldn't be that much...the electronics will limit the timing advance.

BUT...is the truck having problems an original HO??

If the static (mechanical) timing of the HO's are higher (which they are), then you go putting the bigger plungers in the pump, it will advance the timing a bit, because the injectors will pop sooner from having more volume (bigger plungers) Add to that the dramatic dynamic timing advance from the Smarty, and you could run into some problems in some trucks...I don't think all of them because as some BOMB's have shown, every truck is a little different!

Just shooting from the hip at this point...I'm just talking Some of this might be true, but I'm defiantly not an expert
Chris