Not sure if this is correct. I'm reading about 10.5 psi using the Torque app on my Android phone. This is pretty consistent at WOT.
My mods include LT EC headers, primary and sec cat deletes, x-pipe. Still have stock resonator and mufflers.
I've read that less exhaust restriction will result in lower boost pressures. I've read for a VRP 175mm pulley the boost rises around 4psi to around 14.2psi. Just curious is 3.7psi drop is inline with my mods.
thx
My mods include LT EC headers, primary and sec cat deletes, x-pipe. Still have stock resonator and mufflers.
I've read that less exhaust restriction will result in lower boost pressures. I've read for a VRP 175mm pulley the boost rises around 4psi to around 14.2psi. Just curious is 3.7psi drop is inline with my mods.
thx
MBWorld Fanatic!
That doesn't sound right. Your mods are nearly identical to mine and I see 13.5-14.5psi depending on the revs. My pulley is slightly larger ( 178mm ) but a 2mm difference in pulley is barely noticeable.
MBWorld Fanatic!
Here is a log with "180" asp pulley which is actually 178mm where the belt rides. Kleeman headers, no cats and exhaust.

EDIT: Log is from the man above.

EDIT: Log is from the man above.
Where should start looking? Belt, clutch? Any common areas where leaks happen?
thanks in advance
thanks in advance
MBWorld Fanatic!
Quote:
thanks in advance
Maybe the app? Originally Posted by Silverr1
Where should start looking? Belt, clutch? Any common areas where leaks happen?thanks in advance

MBWorld Fanatic!
Quote:
What are the numbers in the columns? Where are the RPMs?Originally Posted by Silverr1
Here is a quick log from mine.
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ExploreI attached another one from today with the labels. I also included the MAF which reads 422 g/s which work out to .94 cfm or 26.624 lts/m. I also checkout my vacuum at idle and it's steady 20 inches of vacuum. I hope some of this data helps.
MBWorld Fanatic!
Quote:
Sorry but those logs don't seem to make much sense. I think it's your logging application that's not right.Originally Posted by Silverr1
I attached another one from today with the labels. I also included the MAF which reads 422 g/s which work out to .94 cfm or 26.624 lts/m. I also checkout my vacuum at idle and it's steady 20 inches of vacuum. I hope some of this data helps.
Super Moderator
Stock vs. 178:

image credit Marcus Frost

image credit Marcus Frost
Super Member
Agreed. I haven't had good luck with it either. Try using intake manifold pressure since the vacuum/boost option has been problematic for me too.
Quote:
Originally Posted by skratch77
The torque app sucks for logging boost
Did another run using manifold pressure and got up to 26.4 psi or 11.7 psig. A little better but still not what others are seeing. Maybe just not the best logging tool. 

Senior Member
hey
My 190mm pulley made 1 -1.1 bar boost
Around 14.5 to 15.7 psi
acid
My 190mm pulley made 1 -1.1 bar boost
Around 14.5 to 15.7 psi
acid






