Boost Cut

Reply Subscribe

Thread Tools

Jul 5, 2011 | 09:52 PM

#11

Suzuka_Joe

Joined: Nov 2004

Posts: 7,061

Likes: 64

From: Oklahoma

9psi is less likely to creep up than 14psi

Jul 6, 2011 | 10:59 AM

#12

chris2k03

Thread Starter

Registered User

Joined: Apr 2007

Posts: 348

Likes: 0

Thanks for the input guys. RealStreet, I think you're right about it being creep. I'll look into getting a bigger wastegate. Would a 44mm be sufficient?

Jul 6, 2011 | 11:19 AM

#13

chris2k03

Thread Starter

Registered User

Joined: Apr 2007

Posts: 348

Likes: 0

Quote:

Originally Posted by Spoolin

It may just be that you could be running too small of a wastegate like a 38mm instead of a 44mm and you are experiencing a boost spike before the wastegate is able to control the pressure. Try raising the wastegate duty cycle on the boost solenoid in the AEM, if thats what you're using to control boost. This may help it a bit to overcome the slow responses. Otherwise and if that doesnt work, it may be best to upgrade to a larger wastegate. I'm sure this is the main culprit of the spike.

I'm running KPRO. Here are my current boost settings.

Jul 6, 2011 | 11:59 AM

#14

siadam

Registered User

Joined: May 2008

Posts: 3,791

Likes: 1

From: Around

Quote:

Originally Posted by Suzuka_Joe

9psi is less likely to creep up than 14psi

Wrong blanket statement is wrong. All depends on motor, manifold, wastegate, turbine size and exhaust.

Jul 6, 2011 | 11:59 AM

#15

siadam

Registered User

Joined: May 2008

Posts: 3,791

Likes: 1

From: Around

Quote:

Originally Posted by chris2k03

Thanks for the input guys. RealStreet, I think you're right about it being creep. I'll look into getting a bigger wastegate. Would a 44mm be sufficient?

I would swap my manifold while I was at it.

Jul 6, 2011 | 12:05 PM

#16

chris2k03

Thread Starter

Registered User

Joined: Apr 2007

Posts: 348

Likes: 0

Quote:

Originally Posted by siadam

Quote:

Originally Posted by chris2k03' timestamp='1309978768' post='20752487

Thanks for the input guys. RealStreet, I think you're right about it being creep. I'll look into getting a bigger wastegate. Would a 44mm be sufficient?

I would swap my manifold while I was at it.

If I get lucky on some instant scratch tickets I might just do that.

Jul 6, 2011 | 05:09 PM

#17

camuman

Joined: Oct 2002

Posts: 8,044

Likes: 6

From: South Florida

Quote:

Originally Posted by siadam

Quote:

Originally Posted by chris2k03' timestamp='1309978768' post='20752487

Thanks for the input guys. RealStreet, I think you're right about it being creep. I'll look into getting a bigger wastegate. Would a 44mm be sufficient?

I would swap my manifold while I was at it.

x2 but i am biased rofl. hey siadam, i took the long way but i must say, TURBO + divided + external dump + big turbo FTMFW

Jul 6, 2011 | 07:17 PM

#18

spectacle

Joined: Sep 2004

Posts: 4,894

Likes: 9

From: Tampa, FL

Turn on boost by gear and give it less boost in the gears and rpm ranges where its creeping

Jul 7, 2011 | 05:35 AM

#19

chris2k03

Thread Starter

Registered User

Joined: Apr 2007

Posts: 348

Likes: 0

Quote:

Originally Posted by spectacle

Turn on boost by gear and give it less boost in the gears and rpm ranges where its creeping

I might just do that. Here's a datalog I took showing WOT in 3rd gear. When the rpm (red) just drops off is where it cuts. At that point I was as 18.2psi. What would you set your boost by gear at spec?

Jul 7, 2011 | 08:44 AM

#20

chris2k03

Thread Starter

Registered User

Joined: Apr 2007

Posts: 348

Likes: 0

How's this look spectacle? Anything I'm missing?

Reply Share

First
Prev
2 / 3
Next
Last