Turbo surge
 

When my turbo is coming on boost in 4,5,6th, around 3/4k it starts to chuff like a train, stops after bout 4k.
Bin told by mapper its turbo surge.
What causes this and how to stop it without having map altered.

Any help, thanks

What turbo, what car, what mods, what power output?

Tony:)

Do you have an aftermarket silicone turbo intake pipe and induction kit?

did the mapper not advise what needs doing to solve it?

Car is a 53 STI,
2.1 stroker
MD321T
650cc
RCM pump
GT spec tubular headers and up pipe
Fmic
Silicone intake pipe with alloy tube inside to stop it collapsing.
3" full decat
3 bar map sensor
Simtek
CAIK in wing
Was told by mapper that a taper inlet to the turbo would help speed up the axial gas speed?
Would anyone like to explain that to me coz I don't no what that means.

Hope this helps.

Ok its probably compressor surge, in which case the turbo is drawing in air faster than engine can spit it out so the charge systEm backs up on the turbo compressor, which in turn slows the compressor down allows the engine to catch up again, this happens over and over in a very short time frame until the air produced from the compressor can be managed by the engine and the surging stops, to cure it you need to reduce the internal diameter of your intake pipe to find the balance point of air in to exhaust out :)

Cheers Iain

I'm guessing this be made worse by changing the intake pipe from the oe to the silicone 1?
If I was to reduce the intake diameter to slow the air down to stop this surge, would it cause loss of power in the top range?

cheers

Yes the less restrictive silicone hose allows the turbo to draw air in faster than the oem pipe, but faster in this case is not better, the gains you will see in acceleration will far outweigh any drop in power at the top end if there is any, look at it this way by reducing the size of the intake to resolve compressor surge you are actually improving performance as compressor surge itself is a huge restriction.

Cheers Iain

Hi mate I had loads of this around 3-4 thou on light throttle acceleration asked jase at 52 what to do to cure it he alterd the map slightly I assume on the wastage duty I probably opens earlier hi didn't say really just my thought but it did cure it