http://www.youtube.com/watch?v=NMi4HmpULyg


So I got the bnr tuned. I like it but at about 5500 boost falls from 26-27 to 20. Its also a little slow on spooling.

What could it be from? Should I put more preload on the wga? I want that top end!

 

That dam 30psi tune killed your **** You sure you don't have any boost leaks?

 

Ill have to check. The thing is it holds 26 psi for a bit, then tapers to 20.

 

What'd the tuner have to say about the noise? That didn't sound right, could be the wastegate like you had mentioned, may attribute to the noise you've been hearing too.

 

He didn't say anything. Lol. I was his first turbo swapped lnf. He's a fantastic tuned tho.

 

I'm no turbo expert, and don't want to act like one, but I'd maybe forward that video to whoever made the turbo and ask for their opinion, it wouldn't hurt.

 

Yea ill do that tomorrow.

My tuner said an mbc could help too.

 

hopefully everything works out for you man. I have my bnr2871 sitting in a box waiting to be installed. i'm trying to get as much info before i put this turbo on.

 

k heres the solution... mbc.. the stock solenoid is garbage when i swap 58/57 my boost was fine then it started tapering off from 24psi-20 a wot .. went to mbc no more issues

 

This sounds like a characteristic of a smaller turbo? Quick spool but won't hold high psi up top?

 

Ill try that. Hope it works, I have no top end.


This turbo has proven to hold up to 6700 or so with only like 1-2 psi drop, not 5-6

 

bump for more help. OP updated with a video.

 

lol try the mbc.. lol that exactly what happened to me

 

hope your right, this is frustrating. lol

 

**** looks like it moves tho.. That speedo isnt lying ..

 

Even though it's dropping in boost, it's definitely moving more air than the stock turbo. The tiny stock turbine/housing is going to choke up on the top end, no way around it except a bigger one.

 

It is a bigger one. The BNR has a gt2871r compressor housing. Its plenty bigger than the k04 one.

 

Sorry have to ask, what's MBC?

 

manual boost controller

 

Manual boost controller.

Dude, you should have just made one thread, I'm totally up to date on the progress of your car and I only had to read thread titles

 

Lol. I know. I get info hungry and searching has yielded poor results.

 

I thought manual boost controllers were bad...

Hmmm.... maybe I should consider one

 

What MBC did you use?

I found a TurboXS one, is that any good?

 

i got the one from dejon

 

Right, but the turbine side is still the stock housing. While the bigger compressor will still make more power, it is limited by the small exhaust side.

An mbc would definitely make a much smoother boost curve but it would still fall off a little bit up top just due to backpressure.

Maybe I'm misinformed, but this has always been my understanding of turbos.