wilkija

Not to take over the thread, But this is the most information on rear turbo's I have found. And most likely the most experience to help me with my problem. The only difference is I have a charger SRT8, I have a rear mount setup that I put together and everything is working fine but when I do a WOT pull, I build boost to like 6 PSI and the waste gate keeps opening from the exhaust pressure. I have a 10 PSI Spring in now. I know I need to probably get a 14 psi spring to get boost higher. My problem is that when I hit that mark the boost is very unstable and my boost gauge needle flutters really bad. it does not hold stable at 6. I do not know if a bigger spring will fix the unstable flutter or just make it flutter in higher boost. If anyone has any idea as to how this can be fixed please chime in thanks.

JAX04

iTrader: (17)

Throw you on a manual boost controller. Also, how is your wastegate plumbed? Any pics of the setup?

AND TRUST ME, dont keeping adding springs to achieve your goal until you find out the real reason you arent building any. (boom)

SERIESIIV6

Make sure to route the wastegate pressure signal directly to the manifold instead of the turbo. That will take care of your issue.

wilkija

I have the turbo on the right side of the car and the waste gate on the other. I will post pics at lunch. Also i have the boost reference from the manifold. I have a boost controller but its the exhaust pressure opening the gate not boost pressure. Right now i have a needle valve teed off the boost line going to the top port of waste gate. It got to 10 psi but ithe boost need shakes like crazy. Will post a video later today to show what its doing.

wilkija

Here is a Pic of my build



So right now with the boost controller turned basically all the way down and bleeding some boost off to the top port of waste gate. I get to 10 pounds, But the gauge shakes back and forth wildly from I would say 9 to 12 pounds. I hear either the waste gate open and closing or the turbo surging don't know for sure. I would assume it's the waste gate.

HRHohio

What boost controller are you using?

JAX04

iTrader: (17)

Looks like a regulator from an air compressor.

So how exactly is it plumbed?

from where to where?

wilkija

It is a air regulator. So at first I had it plumed the regular way straight from the intake manifold to the bottom port on the waste gate. the waste gate kept opening at 6 or 7 PSI. so now I have it plumed like the picture below but instead of electronic solenoid I have a regulator and going of the intake and not the turbo. Im thinking that having the waste gate by itself it is building to much pressure in that one pipe and nowhere to go but to open the gate.

wilkija

I'm wondering if I get an electronic boost controller to regulate the top port better that it can keep it shut until 10 PSI.

wilkija

So I think I have it figured out. Witch sucks! Since I have the waste gate on it own pipe, I think that the exhaust gas is compressing in the pipe so when the waste gate opens it decompresses releasing just the pipe pressure causing the waste gate to flutter. I'm thinking I'm going to have to move the waste gate to the other side by the turbo.

SERIESIIV6

Wastegate should be close as possible to the turbo for proper venting.

wilkija

well that sucks. its gonna be a real pain to move that gate over

1toofastlt1

iTrader: (4)

My set up is a 383 LT1 220/230 .544int .544exh 114lsa, GT45 80mm, coated bbk shorties, with 3inch exhaust. I would like to make around 700rwhp but Im still trying to figure out some spark issues so I havent dynoed it. Should I stick with the 3 inch exhaust or go to something smaller? I will wrap the exhaust once I make sure I have the right size for my set up.

1320

iTrader: (6)

Stick with the 3 inch.