Boost Spiking?

ZuMBLe · 07-26-2006, 07:54 PM

Is a spike ever acceptable? Of course its best if we never saw a spike. But if it happens and the AFRs stay stable, is it okay? If the AFRs do stay stable and there is a spike what exactly happens to the engine? I have a knocklite and there is no knocking from the spike.

WolfPlayer · 07-27-2006, 05:09 AM

I would say it depends on how big the spike is. Be specific. What is happening?

t

ZuMBLe · 07-27-2006, 07:33 AM

When I got on the throttle at 4k in 4th and 5th I see spikes up to 20psi when the boost target maps call for 18.6 (I'm slowly raising it to see how the car reacts). The spike happens for a second or less.

I've since lowered my WGD Low table a bit in hopes the ecu will learn better. I had the table set so the values were 2-3% apart but now I have it set so they are 5-6% apart.

Quote:

Originally Posted by WolfPlayer

I would say it depends on how big the spike is. Be specific. What is happening?

t

crystal_Imprezav · 07-27-2006, 09:52 AM

At lower rpm's (under 5k) it is best to set the WGDC's about 10% from the high map. It will only get worse in the winter when it is cooler out and you will spike even more. Mine are lower until about 5200rpm when the are back to 5% within the high map.

ZuMBLe · 07-27-2006, 11:28 AM

Nice tip. I'll whip up a new realtime with those settings. ST makes these things so easy..

Quote:

Originally Posted by crystal_Imprezav

At lower rpm's (under 5k) it is best to set the WGDC's about 10% from the high map. It will only get worse in the winter when it is cooler out and you will spike even more. Mine are lower until about 5200rpm when the are back to 5% within the high map.

07-26-2006, 07:54 PM	#1
ZuMBLe Senior STI Driver Car: 05 CGM FXT Location: NY Posts: 323 Join Date: Feb 2006 Trader Rating: (2)	Boost Spiking? Is a spike ever acceptable? Of course its best if we never saw a spike. But if it happens and the AFRs stay stable, is it okay? If the AFRs do stay stable and there is a spike what exactly happens to the engine? I have a knocklite and there is no knocking from the spike. This ad is not endorsed by this member. Please register or login to hide this ad. Last edited by ZuMBLe : 07-27-2006 at 07:44 AM.

07-27-2006, 05:09 AM	#2
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,698 Join Date: Jun 2004 Trader Rating: (6)	I would say it depends on how big the spike is. Be specific. What is happening? t

07-27-2006, 09:52 AM	#4
crystal_Imprezav Spec C Club Car: Slow 05 STi Fav Mod: Loping Idle Location: Chewy's Garage Posts: 1,873 Join Date: Mar 2005 Trader Rating: (11)	At lower rpm's (under 5k) it is best to set the WGDC's about 10% from the high map. It will only get worse in the winter when it is cooler out and you will spike even more. Mine are lower until about 5200rpm when the are back to 5% within the high map.