JRSC C38 with an RS Pulley

[JDMChris]

Originally Posted by RevoG

Yes, larger intercooler was installed. IAT is around 2-4C higher than ambient for normal driving. Also installed a water /meth kit to run on track to keep the temps down.

Did a boost leak down test and all good there.

This is why you are showing lower boost.

[CSG Mike]

Originally Posted by RevoG

Yes, larger intercooler was installed. IAT is around 2-4C higher than ambient for normal driving. Also installed a water /meth kit to run on track to keep the temps down.

Did a boost leak down test and all good there.

Bingo

[Irace86.2.0]

If this was a turbo then boost would just continue to build regardless of the IC until the wastegate opened at the predetermined boost dictated by the spring, right? But since the compressor rpm is limited by/ tied to the engine rpm, any reduction in resistance will decrease boost. In this case, the IC reduces the pressure by reducing temperature of the air and be acting as a larger reservoir, which reduces back pressure, right?

[ML]

Originally Posted by Irace86.2.0

If this was a turbo then boost would just continue to build regardless of the IC until the wastegate opened at the predetermined boost dictated by the spring, right? But since the compressor rpm is limited by/ tied to the engine rpm, any reduction in resistance will decrease boost. In this case, the IC reduces the pressure by reducing temperature of the air and be acting as a larger reservoir, which reduces back pressure, right?

"Science Bitch"!

[Irace86.2.0]

So should he be making more power though? Even with lower compression and without E85, should he be making more power? Is his tuner not being aggressive enough on timing or something or is everything normal?

[86joe]

Originally Posted by RevoG

Yes, larger intercooler was installed. IAT is around 2-4C higher than ambient for normal driving. Also installed a water /meth kit to run on track to keep the temps down.

Did a boost leak down test and all good there.

This entire conversation has gone way too far lol. You made 320whp with the RS pulley at 10.0:1 compression on 98 fuel. That is right where you are supposed to be. Your boost is less than 15psi because of the larger intercooler. There is a larger volume to fill now and you are experiencing a bit of a pressure drop. This happens a lot with centrifugal supercharger setups because we cannot turn our boost up anymore. Whereas with a turbo guy who gets a bigger intercooler can just use a boost controller to increase boost back to where its supposed to be or just let the wastegate maintain its spring pressure and keep its boost level. That is what is happening. With that said, your power level is normal. If you ran 12.5:1 compression and E85 you'd see more power. Its usually best to not lower compression with the Jackson Kit but I understand some people don't have access to higher octane fuels or e85.
This is a common problem I see constantly on the Gen 3 Dodge Vipers where people run the Paxton centrifugal supercharger kit which is rated at 6psi but then people get afraid of IATs and upgrade to intercooler to find out their boost gets reduced to around 2psi and then start going on an endless hunt for boost leaks and other issues.

[86joe]

Originally Posted by Irace86.2.0

If this was a turbo then boost would just continue to build regardless of the IC until the wastegate opened at the predetermined boost dictated by the spring, right? But since the compressor rpm is limited by/ tied to the engine rpm, any reduction in resistance will decrease boost. In this case, the IC reduces the pressure by reducing temperature of the air and be acting as a larger reservoir, which reduces back pressure, right?

Whoops, Sorry did not see you already answered this. Working on a small computer monitor this morning and didn't see the reply lol.