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needforspeed6

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07 Mazdaspeed 6
What causes an overboost condition? I have the hypertech tune which users are saying they hold at 17-18psi, although some say they see spikes to 21 psi. What causes these spikes? I don't have a boost gauge yet, but I am planning on getting one so I would like to know where I should set my alarm for an overboost condition. Thanks in advance for the help!
 
the two main types of over boost:

Fairly common. Boost Spikes occur when going WOT in modified cars, can even occur on stock. you would see a quick spike in higher boost, which should then drop back down to a "held" PSI level, like 18, 16, 14, 14, 14, 14.... it is normal when starting to mod beyond what the stock tune was set for, meaning you start changing intake diameter sizes, bpv types, it plays with the pressure and it almost guarantees boost spike. It isnt necessarily a bad thing until you start seeing insane boost spikes like over 21 psi regularly, or if it holds too high a boost at those levels.

To avoid spikes (if you see too high boost held/spiked all the time), you can install an electronic boost controller or invest in advance engine management like the COBB AP.

Less common. Boost Creep can also occur in modified cars. it is when not enough exhaust is passing through the waste gate so that means TOO much exhaust is passing through the turbines so the boost you SHOULD hold like 14 psi would build continuously like... 14, 14, 14, 15, 16, 17, 18, etc... the risks of this are more dangerous than periodic spiking cause it means you no longer have any control of boost levels. uncontrolled boost can lead to pretty serious problems like blown turbo, blown engine, etc etc...

To avoid creep, you can port out a larger opening for the wastegate or work out a whole new setup with an external wastegate. it is on the mechanical level so no amount of engine management or electrical can help.

Our cars run about 14.6 PSi stock. IF it can hold that pressure at WOT, probly after a quick spike to 18, than you are just fine still.
If you are spiking EVERY time and higher like near 21 PSi, than you got issues and need EM right away (engine management) as explained above.
hope this helps you understand things!

cheers

EDIT: just realized you mentioned HT tuner. i dont know too much about that new EM device, but i cant say whether or not 17-18 reliable boost will be held or if it has spike/creep problems specific to that tuning device.
 
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I had them the worst I ever saw was a 25 psi spike.. Worst thing I ever did was unplug my battery now my car idles low and does not run as good after my mods.. Literally the idle will almost die when your driving and come to stop then it goes back up but it feels like it wants to die and it sounds like there might be a miss.

Never had this problem till I disconnected my negative on my battery..
 
uh, that isnt right. If you reconnected your battery right away, it means the ECU didnt have time to reset.
Resetting the ECU can often help as it "re-learns" fuel trims. This will should be auto adjusted with mods like intake, etc.

id say try again, disconnect the battery. Wait at LEAST 10 minutes to be safe (ECU should reset in 5 min), reconnect.
Then turn your car on, let it sit idle for 5+ minutes, then turn on all electrical components to make sure it can handle the power load.
than after another 5-10 minutes, take her for a spin!
 
yea gonna try that thanks.. Im pretty sure I waited at least 5-7 minutes.. Gonna do that recheck all my hoses make sure I have no leaks etc.. Gonna check my plugs too just to be sure. Not throwing any cells or anything


EDIT: Also should I give it some time to re-learn? And should I hook my BOV back to Recirc? IT ran fine in VTA mode before idled perfect etc.
 
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oh you running VTA? that could be a part of it... did you install a new mod when you disconnected the battery or was it just superficial work?

i would run recirc again, reset ECU, idle, and do light driving to let it relearn fuel trims and whatnot agian.
if you have an EM device, i would also look into finding a tuning map for BOV, wont run so great otherwise...
"ran just fine" before simply means it ran without obvious problems, but long term? i wouldnt trust it without a tune.
 
batou079 said:
the two main types of over boost:

Fairly common. Boost Spikes occur when going WOT in modified cars, can even occur on stock. you would see a quick spike in higher boost, which should then drop back down to a "held" PSI level, like 18, 16, 14, 14, 14, 14.... it is normal when starting to mod beyond what the stock tune was set for, meaning you start changing intake diameter sizes, bpv types, it plays with the pressure and it almost guarantees boost spike. It isnt necessarily a bad thing until you start seeing insane boost spikes like over 21 psi regularly, or if it holds too high a boost at those levels.

To avoid spikes (if you see too high boost held/spiked all the time), you can install an electronic boost controller or invest in advance engine management like the COBB AP.

Less common. Boost Creep can also occur in modified cars. it is when not enough exhaust is passing through the waste gate so that means TOO much exhaust is passing through the turbines so the boost you SHOULD hold like 14 psi would build continuously like... 14, 14, 14, 15, 16, 17, 18, etc... the risks of this are more dangerous than periodic spiking cause it means you no longer have any control of boost levels. uncontrolled boost can lead to pretty serious problems like blown turbo, blown engine, etc etc...

To avoid creep, you can port out a larger opening for the wastegate or work out a whole new setup with an external wastegate. it is on the mechanical level so no amount of engine management or electrical can help.

Our cars run about 14.6 PSi stock. IF it can hold that pressure at WOT, probly after a quick spike to 18, than you are just fine still.
If you are spiking EVERY time and higher like near 21 PSi, than you got issues and need EM right away (engine management) as explained above.
hope this helps you understand things!

cheers

EDIT: just realized you mentioned HT tuner. i dont know too much about that new EM device, but i cant say whether or not 17-18 reliable boost will be held or if it has spike/creep problems specific to that tuning device.
Click to expand...

Thanks for the explanation. I appreciate it. Also, if you have an aftermarket tune (i.e. Hypertech), when adding additional mods, do you just unplug the battery for the tune to learn the new mods like you would with the stock tune?
 
It was superficial work I redid my coupler hoses the one at the TB and the Turbo to Intercooler because the clamps looked crooked. I also Fixed my MAF I noticed it was not pushed all the way down into the Maf housing so I pushed it in all the way and tightened it back down. But I disconnected my Battery before I fixed the maf thing.

Ok... Gonna do that tommorrow.. It will run fine in Recirc though right even without tune?
 
KrGsMrNKusinagi said:
It was superficial work I redid my coupler hoses the one at the TB and the Turbo to Intercooler because the clamps looked crooked. I also Fixed my MAF I noticed it was not pushed all the way down into the Maf housing so I pushed it in all the way and tightened it back down. But I disconnected my Battery before I fixed the maf thing.

Ok... Gonna do that tommorrow.. It will run fine in Recirc though right even without tune?
Click to expand...

Check your hoses, losing power like that might be a vacuum leak, or maybe the hoses are leaking at a connection. Clean the MAF while you're at it. It does take some time for the ECU to relearn if you're just driving around, there are steps it has to go through to reset everything and you don't necessarily hit all of them driving around the block.

And, our engines prefer to run in recirc, running VTA almost always seems to be an issue.
 
aha thanks man! i forgot to mention that a MAF cleaning sounds like it is needed too... cheers.

needforspeed6 said:
Thanks for the explanation. I appreciate it. Also, if you have an aftermarket tune (i.e. Hypertech), when adding additional mods, do you just unplug the battery for the tune to learn the new mods like you would with the stock tune?
Click to expand...

Not quite. A tune map is geared towards a certain amount of mods (even brand specific due to different parts designs). The stock maps that the HT would come with should say what kind of intake and brands are tuned for. I do not know how extensive their tuning maps are, but you will have to research that yourself.

In other words, if you install a new engine performance mod, it would be best to see if they already have a map created to include that mod for a proper tune to the ECU. If they don't i believe you are out of luck of a proper tune until they release a map that includes that mod. That is why the Cobb AP is so popular, it allows for highly customized tunes so people can adjust on the fly to what their car runs.

If you do install a new engine mod, ECU reset should be natural since the battery should have been disconnected anyway. THEN you still need to load up the proper HT map tune.
 
batou079 said:
aha thanks man! i forgot to mention that a MAF cleaning sounds like it is needed too... cheers.



Not quite. A tune map is geared towards a certain amount of mods (even brand specific due to different parts designs). The stock maps that the HT would come with should say what kind of intake and brands are tuned for. I do not know how extensive their tuning maps are, but you will have to research that yourself.

In other words, if you install a new engine performance mod, it would be best to see if they already have a map created to include that mod for a proper tune to the ECU. If they don't i believe you are out of luck of a proper tune until they release a map that includes that mod. That is why the Cobb AP is so popular, it allows for highly customized tunes so people can adjust on the fly to what their car runs.

If you do install a new engine mod, ECU reset should be natural since the battery should have been disconnected anyway. THEN you still need to load up the proper HT map tune.
Click to expand...

Thanks again for the info. From what I was told, the hypertech tune can learn new mods, just didn't know if I could just unplug the battery or would have to reinstall the tune. The mods I was thinking of adding are an aftermaket BPV and a cat back exhaust.
 
I had some MASSIVE boost creep on my car (Spiking to 20, then settling to 17 then creeping to 22) due to my open exhaust. Tim at Surgeline dialed me back to 15psi and now I'm sitting at the numbers that are in my sig, which were WAY more than what I was making before :)
 
well damn, those are some nice numbers then!! gives a better idea of street power than the dynapak that i ran on.

i was 267awhp/305tq... so mustang would be somewhere below that.
 
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