I recently had a vacuum line replaced due to there being a leak. Prior to the replacement, i was running about 7-9psi. After replacing the line, i found myself running 18.3psi in 4th gear. I know thats definitely higher than what its supposed to be. Anyway, as i let the rpms climb, i noticed that the boost would build to 18.3, then suddenly dip down to 9.8psi for a second, then fluxuate back to 17psi, 9psi, 18psi, etc. Anyone have any ideas on whats going on here? Thanks for any help.

Heres my info:
2002 WRX
HKS DP/UP/CBE
AEM Intake
Cobb AP Base Map at Stage 2 91Oct, but Real time map at Stock married mode at time of testing.

 

idea as I haven't dealt with Cobb for years. I got tired of waiting for products that were a year (or more) late. I also didn't appreciate purchasing products they said they'd support just to find out they changed their mind. They're not as bad as Perrin, but I really won't look to Cobb for performance products.

San

 

first of all what is your base map. is it stage 2 or is it your stock map?

if you married it with the stock map what's the point of you getting an accessport? if this is true and you're running your stage 2 on your real time map as soon as someone pulls the - (negative) terminal of your battery... bye bye stage 2, stock setup here i come!

if that's how you're running it i suggest you unmarry and remarry with the stage 2.

regarding your boost spiking... do you have a boost controller hooked up somewhere in that equation?

how are you monitoring your boost spikes? accessport? gauges?

i'd suggest you take off your CAI since stage 2 isn't mean to be run with a CAI.

Jon

 

My base map is at Stage 2, 91 Octane. The reason i set the Real-time map as the stock map is because i wanted a baseline reading on what my boost was running at before and after the line change.

After the line was changed, i reset the ecu, bringing it back to stage 2, then real time flashed it back to stock mode. And no, i dont have any boost controller.

All boost readings were taken off of the live readings from the accessport.

I'll be installing my stock airbox soon, but i dont think, based off my limited knowledge, that it could be the problem here.

Thanks!

 

BTW, nice to finally meet you San. I met you at Vakamon and we were talking about "Why get a STI when you can have a WRX?" You made a very interesting argument.

 

have the stock airbox if you need it. I don't sell my old stuff, I give it away. If I ain't using it, (oh no, the ain't word) I might as well hook someone up.

San

 

Thanks for the offer San, but i already bought one (doh!) from this guy in Cali.

 

well it's good to start somewhere you know?

it's hard to say if there is anything wrong or not. the accessport isn't a true reading since it's not reading any air lines it's simply getting it's info from the ECU itself. I myself have never gone on what the accessport says and have a DEFI gauge mounted in my car for my boost readings. it's more accurate that way!

also since your car is flashed with stage 2 it assumes stage 2 values. however when you're running the stock real time map i think the parameters are not exactly the same as stock.

you should post on cobbs forum and see what they say about it. remember when dealing with cobb you need to be as detailed as possible so take a buddy you can trust with you and have him/her notate the values and record them if necessary. this way when you post you can give them the most information in your first post so they can start helping you out more quickly than them having to play 20 questions with you...

Jon

 

Okay, heres an update.

I think the factory boost controller may be bad, since the previous owner had a EBC installed in the past. With that in mind, im gonna install a MBC to take place of the FBC and set the boost within the parameters of the stage map im running, in my current case, Stage 2. Hopefully that'll shed some light on whats going on with my car.

-Andrew