DDP - To recirc, or not to recirc.

[rtrdpenguin]

I thought it would only open at high oost when the wastegate was fully open but stupid me didn't think about the fact that the wastegate slowly opens throughout the boost range, not just when max boost hits. Hopefully the EBC I have on the way will help though =)

 

[NashMan]

teh best way to get power whould be to add in a cut out to the dp that you have

weldeing in divder is all the best thing you can do to meag mouth dp
i did this on my exhuast and the best setup i have ran yet and i have tried them all

 

[Doward]

I'd go recirculated, but that's just because I see zero reason to attract more attention than necessary.

Putting on a bigger exhaust does not increase boost pressure. It is physically impossible for it to do so. I went from a stock exhaust, to a 3" elbow + 3" catless pipe, and guess what my boost pressure went to, according to my VDO gauge? 6.8psi.

 

[87witmoreboost]

I'd go recirculated, but that's just because I see zero reason to attract more attention than necessary.

Putting on a bigger exhaust does not increase boost pressure. It is physically impossible for it to do so. I went from a stock exhaust, to a 3" elbow + 3" catless pipe, and guess what my boost pressure went to, according to my VDO gauge? 6.8psi.

Right - this would make sense. So, why do people get boost from better flowing downpipes? When I was open-test pipe, I was at 9psi.

Does the wastegate orifice flow enough air to slow the turbine to below 8-9 psi with low back-pressure exhausts?

 

[bluezone]

thanks doward for clearing that up.
it should be said that bigger turbo exausts improve power by reducing back pressure and also tend to improve spool up of the turbo.

 

[88tsupra]

I had the non recirculated DDP and yes I agree it was loud and got attention.

But I didn't care because I went with the rsr exhaust and yeah thats loud too.

Maybe it was just me but my boost creep when I added the BIC. Fuel cut FTL

 

[87witmoreboost]

Update to initial post:

Installed my MBC, set to 10psi. It restored the boost I lost from welding the exhaust and no longer running open test pipe.

Boost lag on the other hand will only be achieved from going DDP.

Anyone ever run an open DDP and stick a motorcycle muffler on the open wastegate dump? I bet it would sound really good and silence it up well.

 

[Quin]

Armando did.

 

[plaaya69]

Great thread.

I would like to know though with the people with the non recirculated downpipe how are the exhaust fumes? How are they at idle and driving?

I know when I had a exhaust maniflod leak and everytime I turned on the air you can smell those exhaust gases which was very bad and I took care of that asap.

 

[87witmoreboost]

Great thread.

I would like to know though with the people with the non recirculated downpipe how are the exhaust fumes? How are they at idle and driving?

I know when I had a exhaust maniflod leak and everytime I turned on the air you can smell those exhaust gases which was very bad and I took care of that asap.

Should be fine. Wastegate is only open when air is diverted around the turbo to slow it down.

At idle, it shouldn't have flow. No noise. No fumes.