Saw these pulleys get mentioned by another member in this thread:

https://www.f150online.com/forums/su...ody-tried.html

Is there any truth to getting those boost increases with just the pulley swap?
here is the link to the pulleys and the claimed increases for each size:

http://www.stage3motorsports.com/c=i...ey-System.html

 

I would think that is correct. 6PSI on top of whatever it makes stock would be bottom end explosive.

 

what do you mean by bottom end explosive? Does this mean right off the line but will not hold at WOT? My charger runs about 7lbs stock and I would like to be in the 10-12 range at WOT. Sorry if that was a dumb question.

 

I think he means that the Pistons ,rods and crankshaft ccan't handle that much boost , and will explode.

I'm still running stock boost now, so I can't comment on the realibility off these. I started that thread.

 

I see, I am assuming you did not purchase this pulley then? Id have to disagree with him if that is the case. I see a good amount of members on here with 10 lbs of boost and all the same stock internals with no issues. 10 is where I want to be, gave the 10-12 as just a range. 10 at the least...pushing 12 at the most, I figure there will be some movement in the boost level with how hot it gets here in FL during the summer compared to the cool nights in the winter.

 

I understand that with the 10-12psi can be done with the right tuner. Hopefully someday I can get to Troyer and get a similar kit with everything and a dyno tune.

 

your saying that with the pulleys and a good tune you can get the 10-12 correct? It sounded like you were saying that I good tuner would get you 3lbs just from a tune.

 

After I reread it I see what you mean.

The 10-12 psi would come from the pulley.

A good dyno tune is what you need with the pulley.

The e- mail I received when inquiring about the dub pulley system http http://www.southfloridapulleyhq.com/ indicated that if you have long tube headers your boost would drop 1-2 psi so the 6 lb pulley would put you in the 11-12 psi range

look in the ford roush nitemare set-up http://www.southfloridapulleyhq.com/...m_products.htm

 

You can run 10-12psi on the stock internals, however you will need supporting mods. Headers, true duals (at least 2.5") and a fuel system. You can get by on the stock pump but you will pop the motor in time. You can do those inline fuel pump upgrades but I'm the type that likes to do it right. The inline pumps are a bandaid in my opinion. Also I would highly recommend you give Troyer a call. He can make your Roush truck scream!

 

No I was thinking you were at 8 PSI thus making it 14PSI total (8+6). If you are at 7 PSI adding 6 more PSI is 13 and still just as explosive. A real good tune and 12PSI the truck will stay together depending on your right foot. 10PSI shouldnt be an issue.

Also you cant really look at a boost gauge and say "ok it reads 5PSI I can add another 5 PSI for 10 Psi "even though it already has a 8PSI pulley on it. Boost is actually just shows how inefficeient the motor is at letting the air through the motor, its almost a back pressure guage. Actually to my understanding what you want is to set the pulley or pullies up to whatever PSI you want the blow to be at, say 20. Then with amazing flowing heads, intake and exhaust if you can get it to read zero on the guage it would be that every ounce of air the blower pushes in is perfectly unhindered from entering the cylinder and exiting out the tail pipe. Same reason you do install headers and boost drops. Its not that the truck makes less power, its that the air is flowing better allowing the engine to operate more efficient. I would talk to Troyer as he is the Roush guy and tell him you want to do a 10PSI upgrade.

 

Not exactly. On a forced inducted motor the gauge reading zero would be a good indication of 100% volumetric efficiency. Theres no vaccum present so the cylinder is not pulling in more air, no boost indicates there's no pressure. The goal of any naturally aspirated motor is to achive 100% volumetric efficiency. This can be done with a wise selection of intake, heads, & cam. With supercharging you are overfilling the cylinder. In otherwords, you completly fill the cylinder and then force additional air in. For example I am reading 9-10psi on the boost gauge and my volumetric efficiency is at 149%. This means that instead of flowing 5.4 liters of air I am flowing around 8.1 liters.

 

hnmmmmm

 

This is a common misconception.. The person you were responding to is correct. You can't just look at "boost"... What you are really looking at is the actual AIRFLOW, which is usually measured in pounds of air(NOT pounds of pressure).. Just because you are putting in 10PSIG of boost into your engine, doesn't mean you are at 149% or whatever number you want to conjure up, efficiency. Lets say your air intake temps NA are ambient(lets say 80degrees), but your 10psig boost intake temps are 400*.... I don't want to go into the math(it's out there) but it's not a direct correlation.

Also look at people that have a blower running 15psi, and they add heads, intake, exhaust etc, and see a reduction in boost.. This doesn't mean they're loosing power, it just means they actually using the additional airflow the blower is providing.

 

The 149% isn't conjured. It is likely load (VE) as measured at 1.49, mine's 1.6. We all know boost #'s drop with more flow and less restriction.

 

I didn't conjure up anything! Those are the numbers straight from Troyer performance. And I don't know what the hell else you wrote cause it dosen't make any sense. For one thing I never said you could look at boost, nor did I say 10% meant 149%. I simply gave an example of what my truck is particular is doing. And where in the hell did you come up with intake temps of 400? You started an equation you can't finish cause you don't have any facts nor any numbers that make any sense.