[Chromey]

Hi guys I am curious and I know a log is the answer so if I had one I would post but I don't. Certain times I'll do a wot and the cobb will say max boost 18.1 or 16 plus...., I'm running cobb stage 1 agressive. I feel terrible but I want to know if the spike is a boost leak or a potential issue. Perhaps without the log you can't say but what are some of the issues.

[Digitalism]

Is there a reason why you can't go out and save a datalog?

As you've already stated a datalog is the best way to diagnose if you indeed have a problem.

[Chromey]

3rd gear pull is a lose your license speed and they are on summer hunt right now downtown Victoria etc.... I haven't had time to get to the out skirts to get some rd way.... I just noticed the odd over boost max lately when flooring 1-2 into 3.... It's crazy how fast and what stretch of clear rd you need to do a 3rd gear pull from 2-2500rpm...

[Digitalism]

You don't have a highway close to you? Otherwise a dyno is your safest option.
Without logs it is pointless to diagnose what the cause is.

[Seymour Boost]

Originally Posted by Digitalism

You don't have a highway close to you? Otherwise a dyno is your safest option.
Without logs it is pointless to diagnose what the cause is.

A 3rd gear pull to 90ish is very quick and easy. Hit an on-ramp and let 'er rip.

I have the Stage 1 Aggressive map loaded and I spike anywhere from 15-15.5 and settle at 14.5. The logs would definitely tell your story.

Be safe.

[Chromey]

Figured I needed logs lol... I'll try.. Not sure about the states but anything over 40km is called excessive speeding in bc Canada the limit is 80km 3rd gear is around 140km plus I think... Lol . I know crazy but they have gone big time stupid in canada on speeding you get caught twice your licence goes by by for a year.

http://www.pssg.gov.bc.ca/osmv/road-safety/speed.htm

[jpsimon]

just don't get caught!

[Give_Em_The_DD]

Logging a proper 3rd gear pull only takes a few seconds.

If you are worried go out extremely late when the tollway is dead.

I used to do all my logging at like 4 AM on Sunday morning.

[2Times]

I thought everyone did that in Mexico? It's not that far... about a 20 min drive from Massachusetts.

[Allen@MOTIV]

Like everyone else has said, we need a log to help.

[e92_enthusiast_1]

Well since it's on the same topic. Is there suppose to be a hard max? Im on 2+ FMIC Sport and you can see I hit 16-17psi for a split second on two diff logs:

http://datazap.me/u/e92enthusiast1/c...data=3-4-16-17
http://datazap.me/u/e92enthusiast1/c...0&data=3-16-17

Should i have concerns like OP?

[Allen@MOTIV]

Originally Posted by e92_enthusiast_1

Well since it's on the same topic. Is there suppose to be a hard max? Im on 2+ FMIC Sport and you can see I hit 16-17psi for a split second on two diff logs:

http://datazap.me/u/e92enthusiast1/c...data=3-4-16-17
http://datazap.me/u/e92enthusiast1/c...0&data=3-16-17

Should i have concerns like OP?

The TMAP sensor(where the DME pulls boost from) is located before the throttle plate and whenever there is some throttle trimming going on it will create an artificially high boost reading. Your boost spike readings are occurring during these events. All in all your logs look good.

[Chromey]

I'll pull a log I know .... Hit 20.2 psi max today so I put it to sport map instead of aggressive. I need a FMIC bad .. Temps are around 154 peak and 120 just resting... Car feels slow.. Anyhow thanks guys I will post a log a soon as I can

[JStang]

Just boost spikes. Would need logs to confirm why they are occurring.

[Subaru335i]

Listen to allen. Throttle closures will cause these spikes, your engine never actually sees this much boost.
This question has been asked like a million times people, do you not read about how your car works before modifying it?

[V8bait]

Originally Posted by 2Times

I thought everyone did that in Mexico? It's not that far... about a 20 min drive from Massachusetts.

+100000

[924er]

you know i get a lot of throttle closures running cobb maps due to over boosting. idk why it happens. stage 1+ is worse. i guess custom tuning is the best way

[ajsalida]

Definitely throttle closures as others have said.

But wanted to point out you do not need to do WOT runs to redline or lose your license to log data and see this happening. Good exercise regardless just to get familiar with software plus you'll see the boost spikes. Just drive around normally and see what you get.

[Jeff@TopGearSolutions]

It's probably a boost spike from throttle closure.

Boost is measured pre throttle body so any throttle closure will induce an inflated boost pressure reading but your engine is not actually seeing those boost pressure.

If one wants to see the actual boost the engine is seeing you need a reading from inside the intake manifold and / or the throttle must be open 100%.

[Chromey]

Cheers guys makes sense ... I'm heading up island tomorrow where I can do a bunch of logs near cowichan river ..... I'll have sport map logs and aggressive .... That way we can see how things look.

[Chromey]

Something is wrong as sport is way faster feeling than agressive.. I have 94oct fuel in Victoria bc with no ethonal but I hear USA gas is much better in regards to octane... Perhaps agressive is to much after a bit of heat soak for my fuel here... Car feels like it is retarding itself which in past logs I posted I think some of you had mentioned... Do octane boosters work????

[cstmx_ryder]

Originally Posted by Chromey

Something is wrong as sport is way faster feeling than agressive.. I have 94oct fuel in Victoria bc with no ethonal but I hear USA gas is much better in regards to octane... Perhaps agressive is to much after a bit of heat soak for my fuel here... Car feels like it is retarding itself which in past logs I posted I think some of you had mentioned... Do octane boosters work????

Maybe your car is pulling timing due to the aggressive map and heat soak?

Sometimes more isn't always better....