[Future1LE]

Originally Posted by radz28

absolute pressure channel?

Yea the Manifold Absolute Pressure is 30 on the log, so it is as JSH said.

[radz28]

Originally Posted by Future1LE

Yea the Manifold Absolute Pressure is 30 on the log, so it is as JSH said.

Ah. If you take away air pressure in psi, from that, then you have your boost

[Future1LE]

Originally Posted by radz28

Ah. If you take away air pressure in psi, from that, then you have your boost

Since I am not good at posting pics on forum here is what the channel looks like:

Barometric Pressure : 13.9 PSI
Manifold Absolute Pressure: 30.7 PSI
Supercharge inlet vacuum: 0.7 PSI
Supercharge inlet pressure: 13.1 PSI
Boost/Vacuum : 16.3 PSI
Intake Manifold Absolute Pressure: 30 PSI

[JSH]

The 2650 supercharged 6.2L V8 LT4 in the Corvette C7 Z06 makes 15# boost and that's basically what you have, so... I didn't know that.

So, back to your first question on pullies. Mine has a 9.18 lower which is popular, and 2.625, 2.75, and 3.00 upper pullies. You could try 3.00 or 3.25 upper, but I would and did ask KaTech or LPE or Vengeance or some reputable shop about pullies

[Future1LE]

Originally Posted by JSH

The 2650 supercharged 6.2L V8 LT4 in the Corvette C7 Z06 makes 15# boost and that's basically what you have, so... I didn't know that.

So, back to your first question on pullies. Mine has a 9.18 lower which is popular, and 2.625, 2.75, and 3.00 upper pullies. You could try 3.00 or 3.25 upper, but I would and did ask KaTech or LPE or Vengeance or some reputable shop about pullies

Thanks JSH! I will definitely look more into it. I guess I am just trying to find the "safe" limit of how much boost I can throw at the stock heads and cam lol. I know its not efficient as KingLT said, Boost is just a measurement of restriction. Heads/cam will bring the boost down and the car will be more efficient, making more power with less boost. I just don't know if the current 16# is too much already or if its still considered low boost for the stock heads/cam if you have the fuel to support it. Any change will probably requires a tune so not sure if I will change anything but be interesting to find out.

[JSH]

Originally Posted by Future1LE

Thanks JSH! I will definitely look more into it. I guess I am just trying to find the "safe" limit of how much boost I can throw at the stock heads and cam lol. I know its not efficient as KingLT said, Boost is just a measurement of restriction. Heads/cam will bring the boost down and the car will be more efficient, making more power with less boost. I just don't know if the current 16# is too much already or if its still considered low boost for the stock heads/cam if you have the fuel to support it. Any change will probably requires a tune so not sure if I will change anything but be interesting to find out.

No need to reinvent the wheel on this topic which has been experienced by many shops and people here. KaTech is a sponsor here.

[Joshinator99]

Originally Posted by Future1LE

Since I am not good at posting pics on forum here is what the channel looks like:

Barometric Pressure : 13.9 PSI
Manifold Absolute Pressure: 30.7 PSI
Supercharge inlet vacuum: 0.7 PSI
Supercharge inlet pressure: 13.1 PSI
Boost/Vacuum : 16.3 PSI
Intake Manifold Absolute Pressure: 30 PSI

So you’re just about 17# now. How does your fueling look? Need to log commanded/actual low pressure, rail pressure and injector pulse width. Then look to make sure you have no knock (probably won’t with E50+). If that all looks good then bump the upper pulley down a size (or lower pulley up a size) and then data log the changes and see where you’re at.

[Camaro1973]

Originally Posted by Joshinator99

So you’re just about 17# now. How does your fueling look? Need to log commanded/actual low pressure, rail pressure and injector pulse width. Then look to make sure you have no knock (probably won’t with E50+). If that all looks good then bump the upper pulley down a size (or lower pulley up a size) and then data log the changes and see where you’re at.

Honestly should just log everything in kpa. Log the manifold absolute pressure in kpa, barometric pressure on kpa.

Subtract max MAP from baro and use the calc in windows for pressure and it will convert kpa to psi.

In my case: 220 kpa MAP, 98 kpa baro 220-98 = 122kpa = 17.69 psi

When my car was stock with just boltons and a 2650 with a 90mm pulley I was hitting 16 psi easily in cooler weather.

[Future1LE]

Originally Posted by Joshinator99

So you’re just about 17# now. How does your fueling look? Need to log commanded/actual low pressure, rail pressure and injector pulse width. Then look to make sure you have no knock (probably won’t with E50+). If that all looks good then bump the upper pulley down a size (or lower pulley up a size) and then data log the changes and see where you’re at.

Hey Josh, here is what the fuel looks like. I don't know much on tuning so maybe the port injection affected how some of these looks but here they are. These are WOT

Fuel pressure requested : 73 psi
Fuel pressure (sae): 73-77psi
Fuel rail pressure: 3285 - fluctuate but always above 3k
Injector pulse width bank 1: 4.2ms
Injector pulse width bank 2 : 4.2ms
Alcohol percent: 67%
No knocks as you said.

[Camaro1973]

Originally Posted by Future1LE

Hey Josh, here is what the fuel looks like. I don't know much on tuning so maybe the port injection affected how some of these looks but here they are. These are WOT

Fuel pressure requested : 73 psi
Fuel pressure (sae): 73-77psi
Fuel rail pressure: 3285 - fluctuate but always above 3k
Injector pulse width bank 1: 4.2ms
Injector pulse width bank 2 : 4.2ms
Alcohol percent: 67%
No knocks as you said.

You have plenty of fuel. What’s driving the low side?

With a good low side you can make over 1300whp on port injection. I’m
At 1000 with the triple fore system on 70% E and still plenty of fuel left.

[Future1LE]

Originally Posted by Camaro1973

You have plenty of fuel. What’s driving the low side?

With a good low side you can make over 1300whp on port injection. I’m
At 1000 with the triple fore system on 70% E and still plenty of fuel left.

Currently just a DSX aux pump for the low side. If I plan to push into the 1kwhp I will do a bigger intank pump.

[Joshinator99]

Originally Posted by Future1LE

Hey Josh, here is what the fuel looks like. I don't know much on tuning so maybe the port injection affected how some of these looks but here they are. These are WOT

Fuel pressure requested : 73 psi
Fuel pressure (sae): 73-77psi
Fuel rail pressure: 3285 - fluctuate but always above 3k
Injector pulse width bank 1: 4.2ms
Injector pulse width bank 2 : 4.2ms
Alcohol percent: 67%
No knocks as you said.

Looks good! Time for more boost.

Originally Posted by Camaro1973

You have plenty of fuel. What’s driving the low side?

With a good low side you can make over 1300whp on port injection. I’m
At 1000 with the triple fore system on 70% E and still plenty of fuel left.

Agreed, be interested to know what @Future1LE’s low side is as well.

I’m with you on the Fore Triple my man! Tough to beat. We pretty much make identical power and the Fore Triple is rock solid. I need to add port…