how high does your boost spike, where does it fall of to?

[kazzam]

Like the subject sais, how high does your turbo spike and where does it fall off to and stays? What kinda of turbo do u have and what kind of wastegate you have?

Mine is a ete32(50 trim) with internal wastegate and spikes to 20, settles down to 16 and holds to redline. I sometimes hit fuel cut during spike, but thats rarely. Any input would be awsome.

Another questions: can someone tell me what compressor surge is and why it happends?

 

[nine5raptor]

Originally posted by kazzam
Like the subject sais, how high does your turbo spike and where does it fall off to and stays? What kinda of turbo do u have and what kind of wastegate you have?

Another questions: can someone tell me what compressor surge is and why it happends?

14b--goes to 18 and stays there w/ stock internal wastegate.

Compressor surge is when you have the compressor too far out of it's efficiency range (either it is spinning too slow or too fast) and it becomes unstable. This sounds more like a screech instead of the normal whistle. Think of a boat propeller spinning too fast to 'catch' the water (I know, I know...one is axial flow and the other is radial, but it is the same concept ).

This is not the same as a boost spike.

Also, some call it surging when the bov does not open fast enough or far enough to allow the pressure in the piping to drop sufficiently (and the pressure surges). This sounds like a chink-chink--chink.....

 

[Agent Ezzard]

Ported Big16g, regular wastegate, ported 02 housing, Profec A, No spike or creep at any PSI.

 

[kazzam]

Originally posted by nine5raptor
14b--goes to 18 and stays there w/ stock internal wastegate.

Compressor surge is when you have the compressor too far out of it's efficiency range (either it is spinning too slow or too fast) and it becomes unstable. This sounds more like a screech instead of the normal whistle. Think of a boat propeller spinning too fast to 'catch' the water (I know, I know...one is axial flow and the other is radial, but it is the same concept ).

This is not the same as a boost spike.

Also, some call it surging when the bov does not open fast enough or far enough to allow the pressure in the piping to drop sufficiently (and the pressure surges). This sounds like a chink-chink--chink.....

when i am in 5th gear and floor it, the boost starts to build at about 2500rpm, at 3000 i already have about 14-15psi and then my bov just starts fluttering and the car does the rodeo. Would that be compresor surging? I have heard that large turbos surge, but i am not formilier with the concept yet, so i am trying to learn so i can fix it or minimize it somehow. Its a greddy type s bov and its set somewhere in the middle. I have tried tightening it and loosening it, same thing. Any help would be awsome, thx

 

[90AWDTalon]

16g, stock waste gate, no spike.

On my previous 14b I would spike to 18psi then fall to 14psi. The turbo was bad and as soon as I replaced it with my 16g I no longer had boost spike.

 

[doodie]

Originally posted by 90AWDTalon
16g, stock waste gate, no spike.

On my previous 14b I would spike to 18psi then fall to 14psi. The turbo was bad and as soon as I replaced it with my 16g I no longer had boost spike.

how big is your downpipe?

 

[nine5raptor]

Originally posted by kazzam
when i am in 5th gear and floor it, the boost starts to build at about 2500rpm, at 3000 i already have about 14-15psi and then my bov just starts fluttering and the car does the rodeo. Would that be compresor surging? I have heard that large turbos surge, but i am not formilier with the concept yet, so i am trying to learn so i can fix it or minimize it somehow. Its a greddy type s bov and its set somewhere in the middle. I have tried tightening it and loosening it, same thing. Any help would be awsome, thx

It sounds like you need to tighten it, but I haven't used the type s, so I wanna let someone else comment on it.

 

[a351must2]

ported FP Big T28, ported 02 housing, spikes to 15psi falls off to 15psi, Ric Gillis ball and spring boost controller. Basically, I've never had a problem with spike using a ball&spring type boost controller.

 

[DCsGST]

Big28 Killer internally gated, stock O2 housing, TurboX DMBC.... Spikes to 22 then settles to 16psi.

 

[90AWDTalon]

Originally posted by doodie
how big is your downpipe?

Stock downpipe until three or four weeks ago, now it's 3". The change of downpipes didn't effect anything except I now get some creep, but no spike with either one.

 

[kazzam]

Originally posted by DCsGST
Big28 Killer internally gated, stock O2 housing, TurboX DMBC.... Spikes to 22 then settles to 16psi.

Do you ever hit fuel cut? sometimes it helps if u put an aditional spring on the wastegate arm to pull it back, i got my fp big t28 ported to spike at 19 then settle down to 17, it was nice, now this spike i killing me, but hopefully that helps

 

[DCsGST]

Originally posted by kazzam
Do you ever hit fuel cut? sometimes it helps if u put an aditional spring on the wastegate arm to pull it back, i got my fp big t28 ported to spike at 19 then settle down to 17, it was nice, now this spike i killing me, but hopefully that helps

Never hit fuel cut, but it's funny. When I had it hooked up to the stock BC it would only spike to 14 before settling back down to 13. Now that I have a ball and spring type MBC I get crazy spikes but my datalogs still look fine.

I plan on doing some porting this winter, and possibly going with a O2 dump. I heard that usually helps.

 

[greyforestgst]

mine goes to 17psi and stays at 17psi

if i set it lower though it eventually creeps back up to around 17psi anyway

so i figure wtf