SAC vs VCO

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SAC vs VCO

Postby spencerdiesel » Wed Nov 04, 2015 5:20 pm

Pros, cons, at what size/lpm one is better than the other? At what size does startability take a dive, biggest size for a DD with HX35 or equivalent?
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

Fuel: THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw bottomed @ 3 turns, timing bumped 3/16"
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Re: SAC vs VCO

Postby RCCUMMINS89 » Wed Nov 04, 2015 6:45 pm

Stock injectors can max out an hx35. I like to match 6x10 or 5x12 with the "smaller" sized turbos. If one has big future plans, things can be altered.


As a general rule of thumb.........13 thou orifice holes and larger I generally (note generally) recommend sac over vco for cleanliness and power. Below that vco will be noticeably cleaner.

Startability has more to do with timing needed with large injectors. Depends where you live etc..... but once one starts running injectors 100% larger than stock and above (5x16-5x17 and above) things will be harder to start in cold weather (30 and below).
89 RC on shortened 92 diesel frame - NV4500 w/dual disc/4.10s on 37s. - Self built pump, "hot screw", lots of timing, True high volume low pressure lift pump, 62fmw/68/.7gated, 77lpm SAC Inj., Studs/O-rings,- 423/1220 Mustang - 11/16/2013 http://www.TheHungryDiesel.com full line dealer, if you don't see it please ask.
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Re: SAC vs VCO

Postby spencerdiesel » Wed Nov 04, 2015 7:35 pm

Thank you sir. If you have two injectors that flow the same lpm (say a 5x14 edm, and the other flow honed to 5x12), and they both dyno the same power. Will the flow honed 5x12 have better/cleaner street manners? Possibly better mpg?
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

Fuel: THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw bottomed @ 3 turns, timing bumped 3/16"
Muffler delete
spencerdiesel
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Location: Brevard, NC
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Re: SAC vs VCO

Postby RCCUMMINS89 » Wed Nov 04, 2015 7:42 pm

Depends on how the honing was done, what size they were to start, etc.... It also depends on the overall mods, and how the truck is used.

What year is your truck? How do you use it? What are your goals? Auto or manual?
89 RC on shortened 92 diesel frame - NV4500 w/dual disc/4.10s on 37s. - Self built pump, "hot screw", lots of timing, True high volume low pressure lift pump, 62fmw/68/.7gated, 77lpm SAC Inj., Studs/O-rings,- 423/1220 Mustang - 11/16/2013 http://www.TheHungryDiesel.com full line dealer, if you don't see it please ask.
RCCUMMINS89
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Re: SAC vs VCO

Postby spencerdiesel » Thu Nov 05, 2015 5:28 pm

Sorry how do I fill the sig out? IC 5 speed with 4.10s, your pin and 366 spring. It will likely never (or very rarely anyway) tow, and is my DD. Ultimately I'd like 350 rwhp without having a bottomed fuel screw to do it (that part may not matter). And hopefully without having more than 6 degrees over stock static timing advance. Tall orders ha....
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

Fuel: THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw bottomed @ 3 turns, timing bumped 3/16"
Muffler delete
spencerdiesel
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Location: Brevard, NC
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Re: SAC vs VCO

Postby spencerdiesel » Thu Nov 05, 2015 5:33 pm

Oh and zero idle haze if possible. Doesn't HAVE to be super clean at WOT ( cuz I know it takes a LOT of good air to do that at 350 rwhp).
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

Fuel: THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw bottomed @ 3 turns, timing bumped 3/16"
Muffler delete
spencerdiesel
14mm rotor
 
Posts: 1022
Joined: Tue Oct 27, 2015 4:02 pm
Location: Brevard, NC
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Re: SAC vs VCO

Postby RCCUMMINS89 » Thu Nov 05, 2015 5:52 pm

What turbo do you plan on?

If a super quick spooling turbo, 5x12 vco would do the trick. They are a little more affordable than the next choice, which would be my choice on a super clean setup. Which would be 6x10 vco, and then doing a mild extrude hone on them to open them up to about a 55lpm. Which would be pretty close to a 5x12 flow.
89 RC on shortened 92 diesel frame - NV4500 w/dual disc/4.10s on 37s. - Self built pump, "hot screw", lots of timing, True high volume low pressure lift pump, 62fmw/68/.7gated, 77lpm SAC Inj., Studs/O-rings,- 423/1220 Mustang - 11/16/2013 http://www.TheHungryDiesel.com full line dealer, if you don't see it please ask.
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Re: SAC vs VCO

Postby spencerdiesel » Thu Nov 05, 2015 5:58 pm

An s300 based charger (60mm cold side) may be a pipe dream, he351 more likely. That's good to hear I was thinking around 5x12. Would it be of any advantage to have 5x11s flow honed to 5x12? Instead of just straight EDM'd 5x12s?
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

Fuel: THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw bottomed @ 3 turns, timing bumped 3/16"
Muffler delete
spencerdiesel
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Location: Brevard, NC
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Re: SAC vs VCO

Postby RCCUMMINS89 » Thu Nov 05, 2015 6:03 pm

Normal edm'd 5x12. Would be very clean with an he351cw. On an S300 type charger, they are almost always slower to spool, therefore for a really clean sub 1700rpm range, 6 hole would be cleaner.

Either injector will be idle haze free, assuming timing and other things are in good shape and healthy.
89 RC on shortened 92 diesel frame - NV4500 w/dual disc/4.10s on 37s. - Self built pump, "hot screw", lots of timing, True high volume low pressure lift pump, 62fmw/68/.7gated, 77lpm SAC Inj., Studs/O-rings,- 423/1220 Mustang - 11/16/2013 http://www.TheHungryDiesel.com full line dealer, if you don't see it please ask.
RCCUMMINS89
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Re: SAC vs VCO

Postby spencerdiesel » Thu Nov 05, 2015 6:55 pm

Awesome info, thanks.
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

Fuel: THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw bottomed @ 3 turns, timing bumped 3/16"
Muffler delete
spencerdiesel
14mm rotor
 
Posts: 1022
Joined: Tue Oct 27, 2015 4:02 pm
Location: Brevard, NC
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Re: SAC vs VCO

Postby spencerdiesel » Tue Nov 10, 2015 8:07 pm

Hey Eric how would those EDM'd 5x12s be compared to a flow honed 5x11 VCO?
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

Fuel: THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw bottomed @ 3 turns, timing bumped 3/16"
Muffler delete
spencerdiesel
14mm rotor
 
Posts: 1022
Joined: Tue Oct 27, 2015 4:02 pm
Location: Brevard, NC
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Re: SAC vs VCO

Postby RCCUMMINS89 » Tue Nov 10, 2015 8:19 pm

In that particular size....... wouldn't be much of a difference, if any. Assuming the 5x11 vco would be honed to flow the same as 5x12.
89 RC on shortened 92 diesel frame - NV4500 w/dual disc/4.10s on 37s. - Self built pump, "hot screw", lots of timing, True high volume low pressure lift pump, 62fmw/68/.7gated, 77lpm SAC Inj., Studs/O-rings,- 423/1220 Mustang - 11/16/2013 http://www.TheHungryDiesel.com full line dealer, if you don't see it please ask.
RCCUMMINS89
14mm rotor
 
Posts: 4825
Joined: Mon Oct 03, 2011 4:19 pm
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Re: SAC vs VCO

Postby spencerdiesel » Wed Nov 11, 2015 11:45 am

Ok so cleanliness/atimization would be similar? wouldn't be worth it to go the flow hone route?
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

Fuel: THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw bottomed @ 3 turns, timing bumped 3/16"
Muffler delete
spencerdiesel
14mm rotor
 
Posts: 1022
Joined: Tue Oct 27, 2015 4:02 pm
Location: Brevard, NC
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Re: SAC vs VCO

Postby RCCUMMINS89 » Wed Nov 11, 2015 7:10 pm

Depends on the setup. But in that case, no.
89 RC on shortened 92 diesel frame - NV4500 w/dual disc/4.10s on 37s. - Self built pump, "hot screw", lots of timing, True high volume low pressure lift pump, 62fmw/68/.7gated, 77lpm SAC Inj., Studs/O-rings,- 423/1220 Mustang - 11/16/2013 http://www.TheHungryDiesel.com full line dealer, if you don't see it please ask.
RCCUMMINS89
14mm rotor
 
Posts: 4825
Joined: Mon Oct 03, 2011 4:19 pm
Location: Spirit Lake, ID
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Re: SAC vs VCO

Postby spencerdiesel » Thu Nov 12, 2015 7:43 pm

Thanks. While back I read a thread saying *roughly* 375 rwhp was attainable w/ 4x13 in a non I/C motor. Since 5x12s have a similar cross sectional area, would that be a rough expected max for them as well?

Is a 5x12 big enough to eliminate popping the FSS?
1992 W250, 5 speed, 4.10, Ext. cab Ext. bed, 12.5k winch, 75 gal. fuel tank

Fuel: THD 12 psi piston pump, THD fuel pin, 366 spring, fuel screw bottomed @ 3 turns, timing bumped 3/16"
Muffler delete
spencerdiesel
14mm rotor
 
Posts: 1022
Joined: Tue Oct 27, 2015 4:02 pm
Location: Brevard, NC
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