Drift-Office : Vortech / Perrin Combo Installed & Tuned!

[Dimman]

Originally Posted by OrbitalEllipses

Well this is a heavily moderated thread. @Dimman, see that?

Nothing to see here. Move along. Heh...

[sw20kosh]

Originally Posted by Adeets

I still don't know how you got to 10/11 psi, I over reved my stock pully and got 9.1psi 3.48 = 8.5psi @7400

U doing something special? Something hush hush?

As someone pointed out recently, cam overlap and exhaust modifications can significantly change boost pressure on a supercharged engine (with no boost limiter valve).

[Foobar]

Originally Posted by Adeets

I still don't know how you got to 10/11 psi, I over reved my stock pully and got 9.1psi 3.48 = 8.5psi @7400

U doing something special? Something hush hush?

What are you measuring boost with? Do you have logs that you can check what ECUtek saw via the ECU for that run?

Sent from my Nexus 4 using Tapatalk 2

[charged86]

Originally Posted by Foobar

What are you measuring boost with? Do you have logs that you can check what ECUtek saw via the ECU for that run?

Sent from my Nexus 4 using Tapatalk 2

the 3.125 pulley netted me 10psi at the manifold. also my vacuum boost gauge read 10psi with stock pulley but it prolly was 8.5 to 9 at the manifold per the map sensor.

[Wonderbar]

Originally Posted by Adeets

I still don't know how you got to 10/11 psi, I over reved my stock pully and got 9.1psi 3.48 = 8.5psi @7400

U doing something special? Something hush hush?

Mine hit over 10psi too, without over-revving. 10.11 I think is where mine stopped.

[Wonderbar]

Originally Posted by sw20kosh

As someone pointed out recently, cam overlap and exhaust modifications can significantly change boost pressure on a supercharged engine (with no boost limiter valve).

Lighter pullies/crank also.

Essentially anything that allows the supercharger to spin easier, the extra energy from less rotating mass is gonna go somewhere.

[sw20kosh]

Originally Posted by Wonderbar

Lighter pullies/crank also.

Essentially anything that allows the supercharger to spin easier, the extra energy from less rotating mass is gonna go somewhere.

The extra energy goes to the wheels not to extra boost. You'll gain more power with the same boost. These things have set spin rates due to being pulley driven.

Boost is a measure of back pressure between the compressor and the intake valves. Boost is raised or lowered via how much the engine acts as a seal/wall or by changing the pulley (which changes the speed of the compressor).

[Wonderbar]

Originally Posted by sw20kosh

The extra energy goes to the wheels not to extra boost. You'll gain more power with the same boost. These things have set spin rates due to being pulley driven.

Boost is a measure of back pressure between the compressor and the intake valves. Boost is raised or lowered via how much the engine acts as a seal/wall or by changing the pulley (which changes the speed of the compressor).

Based on several resources, a free flowing exhaust can actually lower boost. Granted, a centrifugal has different characteristics than a roots/screw. It's pretty tough to find a lot of data on centrifugal.

KB tech help, pg 4, "exhaust".

http://kennebell.net/KBWebsite/Commo...esAndCures.pdf

[Wonderbar]

Although, I can't find anything to back up my claim about weight being a factor. Ill test that idea when I get to NC.

[sw20kosh]

Originally Posted by Wonderbar

Based on several resources, a free flowing exhaust can actually lower boost.

http://kennebell.net/KBWebsite/Commo...esAndCures.pdf

Yes exactly. The more the engine acts as a barrier to the airflow being produced by the supercharger, the higher the boost will read in the intake manifold.

A free flowing exhaust will, in most cases, lower boost pressure seen because the exhaust gases are being evacuated from the cylinder more efficiently. This allows more of the air being pumped by the sc to enter the combustion chamber which will show as a drop in boost pressure, but often times an increase in power (or just the ability to run more timing).

[sw20kosh]

Originally Posted by Wonderbar

Although, I can't find anything to back up my claim about weight being a factor. Ill test that idea when I get to NC.

Rotational weight is totally a factor, just not in how much boost you will see. You'll see an efficiency inscrease of the overall motor in putting down power to the ground.

The rotors and or compressor wheel have a set physical flow. This flow is governed by the actual physical shape/tolerances of the unit and the speed. Weight of the unit or pulley doesn't affect flow of the unit at a given RPM and thus boost pressure at a given rpm will not increase.

That is the way I understand the physics of it all. I could be wrong.

[Adeets]

Originally Posted by Foobar

What are you measuring boost with? Do you have logs that you can check what ECUtek saw via the ECU for that run?

Sent from my Nexus 4 using Tapatalk 2

Just a ole fashion boost gauge I'll have to get the fully dyno map from moto east.

[Adeets]

Originally Posted by Wonderbar

Lighter pullies/crank also.

Essentially anything that allows the supercharger to spin easier, the extra energy from less rotating mass is gonna go somewhere.

I have a LWCP, cf drive shaft, and the 9" tcn105's which all make my drivetrain incredibly light but weight on your drive train doesn't effect rotational values like max rpm, just gets there faster.

For flow I have borla UEL and perrin catback, stock down/mid/up/whateverthefuck pipe.

[Adeets]

Originally Posted by Foobar

What are you measuring boost with? Do you have logs that you can check what ECUtek saw via the ECU for that run?

Sent from my Nexus 4 using Tapatalk 2

This is bobs thread so I'm not gonna post my dyno I'm here, but at 8.5 psi on WAWA gas, I dunno how people are getting 10psi on the 3.48 pully.

Dyno link