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View Full Version : 3" exhaust...now major boost. Need advice please.



rainman01
20th October 2012, 08:47 PM
G'day all,
I finally managed to save up the bickies and get the Roo Systems 3" exhaust and chip package, the research data has been phenomenal and I haven't been bias to the team from 4WD Action (love those magazines and DVD's).

I have decided to trial bit by bit, and have just finished replacing the stock exhaust with the 3" and WOW!!! The increase in torque is just phenomenal, and only from the exhaust, still no chip. However, this is where my problems come in to play and I seek advice please.

Before I put the 3" exhaust on, I was getting up to 16 Psi (thank crickey I just finished fitting the boost gauge recently) and when maintaining speed at around 100 km/h, the boost was sitting comfortably at the 2-3 Psi. Now however, I am boosting up to 20-22 Psi....what concerns me more is that when I maintain 100 km/h, the boost is sitting between 10-12 Psi, not really under load.

Additionally, when I got up to the 20-21 Psi mark, it felt like the turbo was 'cutting out'. I am guessing that there is some govern or other similar safety function with the turbo that I'm not aware of.

So to summarise, the power has increased phenomenally, but also the boost at a constant speed and this 'cut out' is coming into play. Has anyone had this sort of issue before, or can provide advice on whether there is something that I should do? I really don't want to fit the chip until I can be confident in not blowing up my engine.

My many thanks in advance...
Andrew

threedogs
20th October 2012, 08:51 PM
You're over boosting and need to fit a DAWES valve asap. firstly you need guages boost and EGTs
10 psi at 100k is ok

what year and motor

rainman01
20th October 2012, 08:57 PM
G'day mate and thanks for the prompt reply. Sorry I should have put this detail in my first post:
GU III
2002
KM = 223 000

What is a DAWES valve mate?

rainman01
20th October 2012, 09:00 PM
Ooops..forgot this bit. ZD30 Y61

threedogs
20th October 2012, 09:04 PM
PM sent, check the search engine top right hand side of this page, heaps written on this subject
What you're looking for is any article written by Chaz Yellowfoot {guru}.this explains everything you want pics, links everything.
You have an early grenade these mods will NAD your ride, just made that up cool eh.

threedogs
20th October 2012, 09:06 PM
OH mate we all knew that, very common problem on this forum. will help out as long as you want tonight

rainman01
20th October 2012, 09:07 PM
You're a legend mate...thank you ever so much. Research time :-)

threedogs
20th October 2012, 09:14 PM
You'll find its not a big job, if you know what parts are called and where they are, the best mod ever to do to a Z30 Di

rainman01
20th October 2012, 09:49 PM
Good as gold mate...and again, my many thanks for the advice. I am extremely happy that I have the boost gauge fitted, I'll be able to monitor everything whilst getting the rest of the NADS equipment and Dawes valve. I only really need the EGR gauge and oil catch can now. Ahhh cars / trucks, bloody money pits but worth it when you are watching a ripper of a sunset in the middle of nowhere...

threedogs
20th October 2012, 10:10 PM
can't beat that X 2 on the sunset somewhere

Maxhead
21st October 2012, 06:44 AM
what he said...hahah

Its funny that, not all people seem to overboost with a 3" but some do.

Get the dowes valve and even a needle valve and you'll be right mate

snewin
21st October 2012, 06:53 AM
Good as gold mate...and again, my many thanks for the advice. I am extremely happy that I have the boost gauge fitted, I'll be able to monitor everything whilst getting the rest of the NADS equipment and Dawes valve. I only really need the EGR gauge and oil catch can now. Ahhh cars / trucks, bloody money pits but worth it when you are watching a ripper of a sunset in the middle of nowhere...

Not being picky, just clarifying.....EGT gauge, EGR blocking plate. Good luck mate.

Rob