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PHAZER TURBO HEAD SHIM

Powder Muncher-
You are mistaken. The calculations are based on Absolute pressure in the engine. That is boost pressure plus atmospheric pressure. The loss in atmospheric pressure makes the difference.
This is the reason that the MCX kit comes with the PCV to raise the boost pressure to compensate for the loss in atmospheric pressure and maintain the same horespower as at sea level.
This is also the reason we can run higher boost levels or less race gas or less engine mods.
 

i think you have one black piece connected at tube to intercooler, under stering in front of engine, a bosch recirculating bov?
 
I guess it would depends on the turbo system, I have a waste-gate that is controlled by a spring , I am sure the spring does not care about atmospheric pressure, just straight boost pressure I f I set it up for 14 pounds it does just that at any altitude.
 
powder muncher said:
Everyone always talks about it is OK at altitude....
With al due respect that is bulls------ on a turbo sled.

10 psi of boost is 10 psi no mater what altitude you are at , that is why turbos work well at altitude. ( the turbo makes up for the thinner Air and takes you to what ever boost level you set it at ) All things correct it will make exactly the same amount of power at 10 000 feet or sea-level.

Just because super-charger or any normally aspirated 2 or 4 stroke loose power and runs richer( at altitude) = less change of detonation ETC does not make it the same on a turbo.

Even a turbo engine at the same boost level looses some at elevation because of the ambient air pressure difference. At sea level, the average air pressure is 14.7psi and you add 10psi from the turbo for absolute pressure of 24.7psi total.
At 10k ft the air pressure is 11psi on average and you add 10psi from turbo for total of 21psi. That is 3.7psi less total pressure. To produce the same power it would require 13.7psi at 10k ft. So for us here running 10psi at 10k ft, it is like running 6.3psi at sea level. that requires less octain.
That is why we can "get away with it" at elevation.l
 
Not trying to get into a pissing match here. I understand the concept of absolute pressure . With a spring pre-loaded waste-gate 10 pounds is what it is , so your ambient pressure is lower------ does not matter on this particular system, the spring will not allow the waste-gate to open until it overcomes the spring pre-load. The pre-load does not change with atmospheric conditions so if the differential pressure would be 13 pounds to overcome the spring pressure that is exactly what will happen.

You can get nit-picky and say that my waste-gate is vented to atmosphere and the reduced pressure an the backside of the waste-gate makes it easier to open the waste-gate so yes there is some loss there. That is on my TRX1 !!!

Reality is a 160 hp Phazer turbo was totally whooping anything up to 1000-cc mod 2 strokes at just around 6000- 7000 feet . A normally aspirated engine tuned properly will loose about 10% for every 1000 meters or roughly 3000 feet of altitude, so most of the twin pipe ported 900 to 1000 cc 2 strokes should come in just under 200 hp take of 20% for the altitude and guess what--------they will be just around the same power as the little Turbo Phazer so for it to be competitive the turbo must be relatively efficient.

Just a hunch I have
 
The waste gate will not compensate for elevation on its own! If it is set at 10 psi, it will only ad 10 psi above what ever the ambient air pressure is. It is a "dumb" system. When the pressure in the compressor or charge tube reaches what ever it takes to overcome the spring pressure, it opens. The only system that compensates for elevation is the MCX phaxer and apex kit. It will bleed pressure off of the waste gate so that the boost can go up as you go up in elevation. Phazer kit makes 140 hp at 12psi at see level and the apex makes 260. With out changing any thing, the alitiude compensating boost controller will rise the boost to 16 to maintain 140 hp and 260 hp at 10,000 ft. There are many turbo web sites out there that explain this in great detail.
http://www.2-stroke-porting.com/altiden.htm
http://www.turbobygarrett.com/turbobyga ... ch103.html
 
I think we are talking past each other.

In your example the 16 pounds at 10000 feet are the exact same manifold pressure as the 12 pounds at sea - level ------------ the difference is only the reduced outside air pressure at altitude.

Pressure inside the Manifold does not change yet we drop a theoretic 4 psi of outside air pressure thereby increasing the Pressure-differencial to 16 psi to maintain the same amount of power.

I installed a closed loop on my waste-gate, where nothing is open to atmospheric pressure anymore, that of course also allows me to adjust boost-levels

Did I get it right this time??



:o| :o| :o| :o| :o|
 
The manifold pressure is not the same, it is what the guage reads, 12 and 16. The absolute pressure is the same because you have to PHYSICALLY turn the boost up. The waste gate will not increase the boost pressure on its own. It can only ad to what the ambient air pressure is. Other wise you would see a rise in boost with all turbos as you go up in elevation. You have to use a boost controler, manual or electric (in the case of MCX), and physically turn the boost up. That requires input from the rider(turning the boost control knob in) or input from the ECU in the case of MCX. Without physically altering the system, you loose total pressure as you go up in elevation because the boost level does not change. My point is that the turbo does not compensate for elevation on its own. You must physically increase boost pressure as you go up in elevation to keep the same hp. You should take the time to read the garrett turbo tech info. it is very good and it has a high elevation example that explains this concept very well!
 
Ok I get your point you have to change your setting , manual or automatic.

However there is actually no difference in the amount of Air the turbo puts into the engine (on our examples) 12 pounds at sealevel or 16 pounds at
10 000 feet all we did is make up for the drop in ambient pressure your engine at that point makes the same power has the same stress needs the same Octane or motor mods.

In essence you need to turn down boost on a MCX system if you want to run less octane or less motor mods. Altitude does not effect it. :o| :o| [/code]
 
powder muncher said:
We have one here with 2 head-gaskets instead of the shim, the difference is dramatic way better response and top end. However needs better fuel don't be fooled .

Can I install 2 head gasket with MPI supercharge too

MPI tell me that don't do this...it can be hard to tune!!!!

help me
 


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