88mm supercharger pulley

Jinxx · 03-08-2016, 08:38 PM

Quote:

Originally Posted by pokeyl

PR------Air Flow----RWHP Tgt------Stock HP
1.53------0.35----------400------------------300
1.73------0.38----------450
1.92------0.43----------500
2.01------0.44----------525
2.11------0.46----------550
2.20------0.48----------575

I don't do math, Excel is my friend.

This is using the Rotrex install information.
There are many other factors but it is a start
Use the compressor maps and find the intersection of the lines, that is the speed you have to spin the unit.
There is heat energy loss (that is % in the compressor map), intercooler pressure drop, intercooler temp drop

I can't even begin to understand how to read this lol

theDreamer · 03-09-2016, 10:08 AM

Pressure ratio on the compressor maps refers to the ratio of boost+atmosphere over atmosphere. so 1.0 on the map is ambient air pressure 14.7 + 0/14.7 or 1.0

so in terms of boost pressure:
1.0 = 0psi
1.5 = 7.3psi
2.0 = 14.7psi
2.5 = 22.0psi
3.0 = 29.3psi
etc

So if the 88mm pulley produces 11-12 PSI, you are at 1.5 to 2.0 Pressure Ratio, so for the c38-81 you are in the middle of the Compressor map just below the 70k line.

On the c38-91/92 compressor map you are at a similar spot but by the looks of it, the c38-91/92 compressor actually has a lower top spinning rate where the 81 can go a bit farther.

pokeyl · 03-09-2016, 10:30 AM

I think so, I am doing the math at all RPM's at all the pulley sizes. It may take some time.

Compressor Max Pressure
On the map, find the top-most point on the graph. The vertical coordinate is the max pressure ratio. For example, 2.8 pressure ratio at sea level is 1.8 times the atmospheric pressure, 1.8x14.7psi=26.46 psi.
Compressor max pressure is limited by compressor wheel speed. It's physically impossible to boost higher than this max pressure for one particular turbo. Plus the pressure drop in the intercooler system, the actual max boost reading from a boost gauge that's plugged into the intake manifolds maybe a few psi lower than this max pressure.

Yes, PR of 2.0=14.7 PSI of boost that is at the compressor outlet and very hot. You loose some of that as pressure drop across the intercooler.
More as the volume shrinks when the are is cooled by the intercooler.

Jinxx · 03-09-2016, 02:12 PM

So would the airflow at the bottom be rpm ? And since I'm running the 38-91 84mm would be the lowest I should go if I'm understanding the chart

pokeyl · 03-09-2016, 04:10 PM

Jinxx · 03-09-2016, 07:37 PM

Now that's a chart I can read lol that helps a lot .....so for the stage 1.5 charger the 84 would be best IMO. ANd for the stage two 88mm would be best IMO

Jinxx · 03-09-2016, 08:29 PM

I did find this 159-99-8507 - Pulleys - Performance / Accessories - KraftWerks USA
It's a 85mm with 6 bolt pattern for 85 bucks that might work out for my situation Any thoughts ?

pokeyl · 03-09-2016, 08:29 PM

Quote:

Originally Posted by Jinxx

Now that's a chart I can read lol that helps a lot .....so for the stage 1.5 charger the 84 would be best IMO. ANd for the stage two 88mm would be best IMO

I think so, I hate math. You can apply all the numbers to the 38-91 rotrex (stage 2) as well. I still need to do the math for the 82mm pulley I have. I just do not run to 7500RPM the motor might pop!

Jinxx · 03-09-2016, 10:08 PM

Quote:

Originally Posted by pokeyl

I think so, I hate math. You can apply all the numbers to the 38-91 rotrex (stage 2) as well. I still need to do the math for the 82mm pulley I have. I just do not run to 7500RPM the motor might pop!

There are some Dyno charts with the 84mm ran to 7500 .... And was at like 523 hp ... I'm thinking I could use the 85mm .... I don't like running high rpms so 6k-6.5k I feel better at

pokeyl · 03-10-2016, 08:08 AM

Quote:

Originally Posted by Jinxx

There are some Dyno charts with the 84mm ran to 7500 .... And was at like 523 hp ... I'm thinking I could use the 85mm .... I don't like running high rpms so 6k-6.5k I feel better at

No dyno near me, sorry

Zat_Zuma · 03-10-2016, 10:07 AM

I ran the upgraded stage 1.0 to a stage 1.5 with meth injection to 640 WHP and the 84mm pulley. Ran around 12 lbs of boost. Unfortunately, I have no proof and no record of it. The supercharger has since been removed and sold.

On to the next project

theDreamer · 03-10-2016, 10:09 AM

Quote:

Originally Posted by Zat_Zuma

I ran the upgraded stage 1.0 to a stage 1.5 with meth injection to 640 WHP and the 84mm pulley. Ran around 12 lbs of boost. Unfortunately, I have no proof and no record of it. The supercharger has since been removed and sold.

On to the next project

How hard is the install going from the 1.0 to 1.5?
I should have "all" the new pieces which include, 2 new intake pipes, intake filter pipe (I believe?), 1 engine mount, and a few accessories to re-route PS line.

Anything else I am missing or should know?

Zat_Zuma · 03-10-2016, 10:17 AM

Quote:

Originally Posted by theDreamer

How hard is the install going from the 1.0 to 1.5?
I should have "all" the new pieces which include, 2 new intake pipes, intake filter pipe (I believe?), 1 engine mount, and a few accessories to re-route PS line.

Anything else I am missing or should know?

Yes I remember how much of a pain it was to remove the stage 1 intake pipe.
Recommend the you drain all the oil out of the supercharger before doing that job.

theDreamer · 03-10-2016, 10:21 AM

Quote:

Originally Posted by Zat_Zuma

Yes I remember how much of a pain it was to remove the stage 1 intake pipe.
Recommend the you drain all the oil out of the supercharger before doing that job.

Oh that is already done, both steps.
My SC seized because we lost all the oil for it.

pokeyl · 03-10-2016, 11:41 AM

Quote:

Originally Posted by theDreamer

How hard is the install going from the 1.0 to 1.5?
I should have "all" the new pieces which include, 2 new intake pipes, intake filter pipe (I believe?), 1 engine mount, and a few accessories to re-route PS line.

Anything else I am missing or should know?

Do you have the 1.5-SC housing, I have a spare,

What injector are you running, 650cc or larger.

If you need the PS parts, I have a full kit, and the Fuel Pump voltage kit I'll make you a super deal.

I can mod your base tune to work any injectors, If you stay with the 600cc injectors you may run lean and pop the motor. Do you have WB O2?

03-09-2016, 10:30 AM	#33 (permalink)
pokeyl Track Member Join Date: Nov 2010 Location: DFS Posts: 891 Drives: ??? Rep Power: 54	I think so, I am doing the math at all RPM's at all the pulley sizes. It may take some time. Compressor Max Pressure On the map, find the top-most point on the graph. The vertical coordinate is the max pressure ratio. For example, 2.8 pressure ratio at sea level is 1.8 times the atmospheric pressure, 1.8x14.7psi=26.46 psi. Compressor max pressure is limited by compressor wheel speed. It's physically impossible to boost higher than this max pressure for one particular turbo. Plus the pressure drop in the intercooler system, the actual max boost reading from a boost gauge that's plugged into the intake manifolds maybe a few psi lower than this max pressure. Yes, PR of 2.0=14.7 PSI of boost that is at the compressor outlet and very hot. You loose some of that as pressure drop across the intercooler. More as the volume shrinks when the are is cooled by the intercooler. __________________ It's not my fault I'm old, I was born a very long time ago! Last edited by pokeyl; 03-09-2016 at 11:13 AM.

03-09-2016, 04:10 PM	#35 (permalink)
pokeyl Track Member Join Date: Nov 2010 Location: DFS Posts: 891 Drives: ??? Rep Power: 54	__________________ It's not my fault I'm old, I was born a very long time ago!

03-10-2016, 10:07 AM	#41 (permalink)
Zat_Zuma A True Z Fanatic Join Date: Nov 2008 Location: Edmonton, Alberta ...eh Posts: 1,171 Drives: 2017 Touring auto Rep Power: 18	I ran the upgraded stage 1.0 to a stage 1.5 with meth injection to 640 WHP and the 84mm pulley. Ran around 12 lbs of boost. Unfortunately, I have no proof and no record of it. The supercharger has since been removed and sold. On to the next project __________________ [B]2009 & 2017 370Z Touring Sport Autos SOLD

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03-09-2016, 02:12 PM	#34 (permalink)
Jinxx Track Member Join Date: Dec 2015 Location: South Carolina Posts: 699 Drives: 2017 nismo 370z Rep Power: 3375	So would the airflow at the bottom be rpm ? And since I'm running the 38-91 84mm would be the lowest I should go if I'm understanding the chart

03-09-2016, 07:37 PM	#36 (permalink)
Jinxx Track Member Join Date: Dec 2015 Location: South Carolina Posts: 699 Drives: 2017 nismo 370z Rep Power: 3375	Now that's a chart I can read lol that helps a lot .....so for the stage 1.5 charger the 84 would be best IMO. ANd for the stage two 88mm would be best IMO

03-09-2016, 08:29 PM	#37 (permalink)
Jinxx Track Member Join Date: Dec 2015 Location: South Carolina Posts: 699 Drives: 2017 nismo 370z Rep Power: 3375	I did find this 159-99-8507 - Pulleys - Performance / Accessories - KraftWerks USA It's a 85mm with 6 bolt pattern for 85 bucks that might work out for my situation Any thoughts ?