Stage 1 boost to high?

Atomic · 03-09-2008, 09:54 AM

Flash stage 1 yesterday with a Cobb AP ('06 STI) and went out today to do some testing. I have a Defi boost gage installed. At stock my peak was a little high .11 MPa (15.95 psi calculated with 14.5psi = .1MPa which is supposedly stock boost). That is peak on a hard pull in higher gears. Just thought I was lucky

. I mean Defi's are supposed to be accurate, right? If I screwed up the install (very straight forward) you would think I would have lower readings, right? (a crimped vacume hose).

Now with Stage 1 I am hitting .125 MPa (18.13 psi). While the increase seems in line with stage 1 over stock (.025 MPa = 2.2 psi) the peak seems high. Like I am stage 2 or something.

My questions:
Is this maybe a false high based on my ECU needing to do more learning?
Am i hurting anything by running like this? or is everything "ok" if I am under the 19psi limit on the VF39?
FYI - I plan on getting a downpipe, catted in the future

Thanks guys.

fourseasonsandles · 03-09-2008, 10:06 AM

How long have you had the map on the car? Mine took some adjusting of about a week or 2 for it to settle down to target. Give it about a week and check it again with the AP. If you are still reading too high, you might have to go to the LWG map. Each car is different, but I would bet that it will be fine if you give it some time to learn.

Atomic · 03-09-2008, 04:19 PM

Quote:

Originally Posted by fourseasonsandles

How long have you had the map on the car? Mine took some adjusting of about a week or 2 for it to settle down to target. Give it about a week and check it again with the AP. If you are still reading too high, you might have to go to the LWG map. Each car is different, but I would bet that it will be fine if you give it some time to learn.

Hey thanks for the quick response. Flashed yesterday. I will give it some time and see what happens. I forgot I could check boost the the AP - that will be a good way to get a second number to compare to the Defi Boost gage.

Should I worry about the motor seeing 18psi?

will12345 · 03-10-2008, 08:50 AM

i would say its your gauge..some defis have been known to not read exact

Atomic · 03-10-2008, 12:41 PM

I will drive it a week recheck the peak on the Defi and check that against the AP realtime boost readings (or something like that, have not done it yet).

Then see were I stand on boost. I thought I was paying extra for an accurate gage, not so? I had not heard that.

Atomic · 03-16-2008, 02:27 PM

-1 for Defi boost accuracy. still boosting high on the defi, so did the live boost on th AP. AP says 16.8 max reading, amost 1.5 psi less than defi I expected better from defi (assuming the AP is more accurate)

**evilSTi7** · 03-16-2008, 02:32 PM

Quote:

Originally Posted by Atomic

-1 for Defi boost accuracy. still boosting high on the defi, so did the live boost on th AP. AP says 16.8 max reading, amost 1.5 psi less than defi I expected better from defi (assuming the AP is more accurate)

make sure the sending unit in your engine bay is installed correctly. if it's not it can cause inaccurate readings.

That part sticking up on the unit that the hose is connected to should be facing straight down.

03-09-2008, 09:54 AM	#1
Atomic Silver Member Car: 06 OBP STI Fav Mod: dedicated snows Location: MA Posts: 180 Join Date: Apr 2006 Trader Rating: (0)	Stage 1 boost to high? Flash stage 1 yesterday with a Cobb AP ('06 STI) and went out today to do some testing. I have a Defi boost gage installed. At stock my peak was a little high .11 MPa (15.95 psi calculated with 14.5psi = .1MPa which is supposedly stock boost). That is peak on a hard pull in higher gears. Just thought I was lucky. I mean Defi's are supposed to be accurate, right? If I screwed up the install (very straight forward) you would think I would have lower readings, right? (a crimped vacume hose). Now with Stage 1 I am hitting .125 MPa (18.13 psi). While the increase seems in line with stage 1 over stock (.025 MPa = 2.2 psi) the peak seems high. Like I am stage 2 or something. My questions: Is this maybe a false high based on my ECU needing to do more learning? Am i hurting anything by running like this? or is everything "ok" if I am under the 19psi limit on the VF39? FYI - I plan on getting a downpipe, catted in the future Thanks guys. This ad is not endorsed by this member. Please register or login to hide this ad.

03-09-2008, 10:06 AM	#2
fourseasonsandles Silver Member Car: 06 CGM Wingless Fav Mod: The Newest One! Location: Ra cha cha NY Posts: 3,129 Join Date: Sep 2005 Trader Rating: (0)	Re: Stage 1 boost to high? How long have you had the map on the car? Mine took some adjusting of about a week or 2 for it to settle down to target. Give it about a week and check it again with the AP. If you are still reading too high, you might have to go to the LWG map. Each car is different, but I would bet that it will be fine if you give it some time to learn.

03-10-2008, 08:50 AM	#4
will12345 Senior STI Driver Car: 04 subaru sti Fav Mod: 35r turbo kit Location: sunny san diego Posts: 307 Join Date: Apr 2007 Trader Rating: (1)	Re: Stage 1 boost to high? i would say its your gauge..some defis have been known to not read exact

03-10-2008, 12:41 PM	#5
Atomic Silver Member Car: 06 OBP STI Fav Mod: dedicated snows Location: MA Posts: 180 Join Date: Apr 2006 Trader Rating: (0)	Re: Stage 1 boost to high? I will drive it a week recheck the peak on the Defi and check that against the AP realtime boost readings (or something like that, have not done it yet). Then see were I stand on boost. I thought I was paying extra for an accurate gage, not so? I had not heard that.

03-16-2008, 02:27 PM	#6
Atomic Silver Member Car: 06 OBP STI Fav Mod: dedicated snows Location: MA Posts: 180 Join Date: Apr 2006 Trader Rating: (0)	Re: Stage 1 boost to high? -1 for Defi boost accuracy. still boosting high on the defi, so did the live boost on th AP. AP says 16.8 max reading, amost 1.5 psi less than defi I expected better from defi (assuming the AP is more accurate)