now, I am not really sure that this is an issue, but it sure it puzzling.

When i got the turbo installed a month ago, I noticed that while I was in 5th gear and build boost very slowly from 55mph and up, that when the boost got up around 17psi, it sounded like the turbo was skipping/fluttering....this is very hard to explain. Then after it reached 21psi in the higher rpm's it went away. So i have been pretty much been hearing this since the turbo was installed, but the other day for some reason or another i looked at my boost gauge while it was making this noise, and sure enough the gauge rapidly goes up and down loopy and not linerally, then enventually it pushes through it and everything is fine. Again, this only happens in 5th gear while building boost slowly.

My car and performance mods:

2003 GSR
20g9lt from buschur - stock 9 WGA
272 hks cams
680cc
UR 3" TB - no cat
hallman boost controller - cabin controlled
ported and coated exhaust mani from buschur
ss o2 housing from buschur
buschur intake and filter - older version
walbro 255
arp head studs
Buschur FMIC with upper and lower piping

Anyone have any similar issues or suggestions as to why it is doing this? I will try and post a video.

Thanks for the help

 

Could the turbine be unbalanced? Pardon my newbness but those characteristics sound just like what happens to high speed fans when they are not balanced right.

 

Surge???????

 

sounds like it's surging

 

Come on down and I will look at it no charge - I will be in till at least 10 pm tonight and Mon - Sat next week

Al

 

Surge!

 

my car has done that since i installed my mbc licp uicp intake and forge dv, then i switched to the jdm mr dv and it did the same thing i wish someone could fix it lol

 

What you described is classic compressor surge.


Eric

 

Sounds like DV flutter. Does it occur at light throttle openings? No doubt, Al can diagnose the problem.

 

Classic compressor surge.

Partial throttle application at higher gears is the reason.


I believe there have been a couple of threads regarding this in the past.

 

Are you full throttle when this happens?

DV flutter would not occur if you are full throttle but surge could still occur at full throttle and low RPM/boost.

 

i dont think it is the dv...i have a stock 1g crushed...and it did not do this before the 20G install. This ONLY occurs when I floor it in 5 gear from like 3K rpm....of course on the highway. It only happens briefly then after hit gets around 5k its gone.

Al, I talked to Jimmy via email and I am going to bring the car in next week. Also, I am going to go with alky too...hehe

thanks for the responses everyone.

A side note...when jimmy was installing the o2 housing he said that the o2 housing that i had from buschur, there was issues with...i wonder if that can be the problem???

I will keep you all updated.

 

It is surge, seems like some people with the WR were having the same problem. My 30r would do it at part throttle in 3-4-5th. Not much you can do about it as far as I know.

 

go see al

 

sounds like it is surgin in 5th at low rpms cause of the extra load that fifth puts on it. The turbo spooling quicker and builds boost alot higher causing the surge. On stock turboed evos with mbc rolling into the throttle in 5th cause a spike in boost that is alot higher do to the load. My tuner has a log of hitting 28psi in fifth while flooring it at 3000 rpms. but in other gears only hitting 23psi. What do you guys think.