[Joesuby]

Ever since I installed my Maddad shorty DP with stock cat I've had a loud whooshing sound coming from the engine bay. It happens during WOT throttle pulls after 8-9PSI and is consistant in every gear. I doubt it's an exhaust leak because it is only audible under these conditions. Has anyone else experienced this? Any suggestions or ideas are appreciated?

[Turninconcepts.com]

Possible boost leak. Check the turbo to IC hose.s

[Joesuby]

Thanks for the reply, I suspected this so I checked the boost feature on my A.P. and it's reading 18.5 PSI (not in 1st)under these conditions. Also checked my AF ratio and read 11.1; seems lean doesn't it?

[caveguru]

Originally Posted by Joesuby

Thanks for the reply, I suspected this so I checked the boost feature on my A.P. and it's reading 18.5 PSI (not in 1st)under these conditions. Also checked my AF ratio and read 11.1; seems lean doesn't it?

That's not the actual boost. ECU can only read out to AP up to 18.4-18.5, but actual boost may be higher and can be seen if you have Cobb's tuning software. Cobb also told me AF ratio target is low 11's, can't remember if it was that low.

[GhoSStRyda]

i hear that the af reading from the ap isn't accurate tho?

i hear a swooosh sound from the dp installed... thought it was normal... unless you're loosing boost, you should be ok? do you feel a loss of power from the dp install?

[Joesuby]

Originally Posted by caveguru

That's not the actual boost. ECU can only read out to AP up to 18.4-18.5, but actual boost may be higher and can be seen if you have Cobb's tuning software. Cobb also told me AF ratio target is low 11's, can't remember if it was that low.

I am using the Accessport to read boost what software are you referring to?
18.5 +/- .8 is target boost for stage 2 so I thought it was right on.

Originally Posted by GhoSStRyda

i hear that the af reading from the ap isn't accurate tho?

i hear a swooosh sound from the dp installed... thought it was normal... unless you're loosing boost, you should be ok? do you feel a loss of power from the dp install?

Did the swoosh sound almost like a CAI? And was it prevalent under the same conditions?
Thanks.

[WRXGuyInUSA]

Mine made considerably more boost noise after DP install as well... I think that's fairly normal!

[GhoSStRyda]

Originally Posted by Joesuby

Did the swoosh sound almost like a CAI? And was it prevalent under the same conditions?
Thanks.

sounded more like a bov. its not too loud on mine tho but its audible when i have my passenger side window open a lil. are you protuned or ots tune?

[Digitalfiend]

Originally Posted by Joesuby

I am using the Accessport to read boost what software are you referring to?
18.5 +/- .8 is target boost for stage 2 so I thought it was right on.


Did the swoosh sound almost like a CAI? And was it prevalent under the same conditions?
Thanks.

Does the MadDad have an O2 port for a wideband? If it does and you're not using a wideband, check that the plug bolt is tight. Sometimes the DP to turbo bolts will back themselves off.

As for the boost reading on the AP, the ECU is limited to 18.5 for that parameter. If you want the actual boost reading, I believe this can be determined by reading the "manifold absolute pressure" variable and subtracting 14.7 (barometric pressure at sea level). That won't be 100% perfect, but it will be pretty close and definitely read higher than 18.5.

Oh, the noise you're hearing could also just be the increased exhaust flow as the pressure increases. Many aftermarket downpipes are noisier than stock. So unless it wasn't making this sound before, it could be normal.

[Joesuby]

Originally Posted by WRXGuyInUSA

Mine made considerably more boost noise after DP install as well... I think that's fairly normal!

I thought so too at first but lately it's been bugging me and after a passenger recently mentioned it I got to thinking.

Originally Posted by GhoSStRyda

sounded more like a bov. its not too loud on mine tho but its audible when i have my passenger side window open a lil. are you protuned or ots tune?

Mine sounds very much like the K&N typhoon I had on my 04 but only after 8-9 PSI. I'm not protuned just OTS.

Originally Posted by Digitalfiend

Does the MadDad have an O2 port for a wideband? If it does and you're not using a wideband, check that the plug bolt is tight. Sometimes the DP to turbo bolts will back themselves off and this can cause exhaust gasses to escape.

Yes it does as a matter of fact and I had a muffler shop install a plug for me before installing it, the plug doen't impead the flow but I have'nt checked it sine install 2 months ago. Good idea! I should also check turbo to DP bolts. But if it were a leak wouldn't it be noticeable at all RPM and boost level?

I was using AP primarily to measure if there was a drop in boost during said conditions @ WOT. There didn't appear to be any drop in boost or inability to make boost.

[Joesuby]

Originally Posted by Digitalfiend

Oh, the noise you're hearing could also just be the increased exhaust flow as the pressure increases. Many aftermarket downpipes are noisier than stock. So unless it wasn't making this sound before, it could be normal.

Good point! It didn't make any noise before, and at first I thought it was just a result of divorced wastegate design.
When I get a chance I'll double check for exhaust leaks and also IC for leaks up top.

[Digitalfiend]

A divorced wastegate DP definitely makes a different sound (at least in my opinion) than a bellmouth or catted. I had a Crucial Racing shorty DP which was a divorced design and it made a noticeable "whooshing" sound as the boost increased.

[Digitalfiend]

Originally Posted by Joesuby

I was using AP primarily to measure if there was a drop in boost during said conditions @ WOT. There didn't appear to be any drop in boost or inability to make boost.

A post-turbo exhaust leak shouldn't really affect the turbo or your car's overall performance. If your header/uppipe is leaking, sure, that'd cause issues. Intake/compressor side leaks can definitely screw with performance.

[fullerton]

FWIW- I wouldn't 100% rule out a boost leak just because you are reaching your boost target. Your turbo can flow more psi than a OTS stage 2 map requests. It may just be working hard and just making the target, but being highly inefficient at the effort.

[Joesuby]

Originally Posted by Digitalfiend

A divorced wastegate DP definitely makes a different sound (at least in my opinion) than a bellmouth or catted. I had a Crucial Racing shorty DP which was a divorced design and it made a noticeable "whooshing" sound as the boost increased.

Yes it is a whooshing CAI type sound, very wind tunnel like, it's been driving me crazy because the other DP's I had on my 04 never made a sound.
Actually, they did but it was the expected turbo spool up whine, which I wish this DP had.

Originally Posted by Digitalfiend

A post-turbo exhaust leak shouldn't really affect the turbo or your car's overall performance. If your header/uppipe is leaking, sure, that'd cause issues. Intake/compressor side leaks can definitely screw with performance.

Yea I've experienced post turbo leaks before and they're present at all RPM's with little affect to performance. If it's a turbo to IC leak wouldn't the drop or lack of boost be noticeable via AP's boost guage?
thanks for the help