Turbo surge while trying to build boost

[Rzorsky]

Hey just as an intro my name is ryan. New to this forum. I tries searching info on turbo surge and found alot of info on surging when getting out of the throttle. My issue is trying to build boost I start to surge i will get up to about 22 psi and start to surge. I'm running a fully built socal motor and a river city lb71 turbo. Can't seem to figure out what's happening or how to resolve the issue. Any help would be greatly appreciated!

 

[ironmax]

what are you doing that requires that much boost to launch? what's your fueling upgrades? I'm going to guess your way out the turbos map range and building to much drive pressure. manual or automatic ? fill out your sig so we know what to account for?:welcome8:

 

[Rzorsky]

Not quite sure on how to make a significant yet. But I have a stage 1 socal motor bored .30 over with bullet mains and a heavier cam. Socal stroked cp3, air dog 165, 60 over sticks, mbrp intercooler pipes, mbrp downpipe and 5" exhaust, upgraded turbo mouth piece, and a river city diesel lb71 turbo running a 71 compressor wheel and 71 exhaust side. Bd wastegate, built Trans, and efi

 

[NC-smokinlmm]

Cam affects spool. Which cam?

 

[Rzorsky]

And it's not during a launch its during normal driving the turbo is supposed to handle 55 psi. I just finished the build and normal driving iLloyd go and easy into the throttle and boost will build to 25 and start chopping and jumping

 

[Rzorsky]

I can't really recall which cam. I now it is not the cam from the normal socal build it was the next step up. I think it's the hot street and tow cam for ported heads

 

[Harbin_22]

Wastegate adjusted properly? What's it do if you go WOT?

 

[Rzorsky]

Haven't really gone wot yet low gears it just kicks out I'm set at 30 psi right now just to break everything in but now I'm afraid to bring it up if it's chopping like this

 

[Harbin_22]

What is it set at right now while surging? How and where are you measuring boost from?

 

[Rzorsky]

its set by the banks big head wastegate to 30-32 psi. im taking the reading off the intercooler pipe passengers side. some time under a little heavier throttle it goes up to 30 psi. but cruising and slow rolling into it in a higher gear it starts to chop around 20-25 psi and jumps around about 5-7 psi swings.

 

[Harbin_22]

Crank the waste gate down and see if it still does it in that area. More boost is not going to hurt your engine for break in. I watched a puller engine go over 1200hp on a break in tune.

 

[Rzorsky]

So your saying it may be because I'm not letting it run where it needs to be?

 

[Harbin_22]

I'm saying the gate might be opening at part throttle and you aren't driving it hard enough to run with the gate open in that area. It opens, dumps drive pressure, not running it hard enough to stay on top of the charger, boost falls, gate closes, and it all starts over again. When the gate is open and you are WOT, you are driving the turbine hard enough to stay on top of it, but at part throttle, just isn't enough. Gate should only be opening if you are being hard on it. Shouldn't be trying to control part throttle boost with the gate. Hope that helps.

 

[Rzorsky]

It does thank you I'll try that out and see what happens