turbo surging/sneezing under boost?

[Roc87]

FWIW, I have a larger TB and plenum and still have the part throttle surge, but the "gimmick" did work on the WOT surge...

4-71/Z-28; let me know if you want to use the MAF, don't know when I'm getting the engine back for the elky, so until then the GN has to remain parked anyways:frown:

 

[MidGaGN]

FWIW, I have a larger TB and plenum and still have the part throttle surge, but the "gimmick" did work on the WOT surge...

4-71/Z-28; let me know if you want to use the MAF, don't know when I'm getting the engine back for the elky, so until then the GN has to remain parked anyways:frown:

Interesting, I might have to check it out.... Thanks!

BTW: what size TB are you running?

 

[Roc87]

an old Kenne Bell 70mm throttle body & plenum.... Not really sure if it's a huge improvement over stock or not, bought it before I found this website right after I bought the car...But I guess it can't hurt

 

[4-71/Z-28]

i also have a 70mm throttle body. my piping goes 3" from turbo to 3" intercooler inlet/outlet and 3" to throttle body.
87roc, i think i ruled out the maf being bad with eric's reply about the free-revving , especially since i can see the maf counting with the scanmaster, i really appreciate the offer its good to know someone around these parts thats so willing to help out. ps im gonna shoot for monday at the dyno, again also how do you have youre tornado installed, couplers on each end? i plan on getting one and was thinking about having a friend tig it to the end of the up pipe.

 

[Roc87]

I have a 3.5" MAF pipe and I put the tornado in the rubber coupler from the pipe to the turbo as close to the turbo as I could, the Tig welding sounds like a great idea.

 

[4-71/Z-28]

So it goes preturbo?

 

[bmackinnon]

Yes, the tornado goes preturbo.... but if you are getting the sneezing/snorting ('surge', in technical terms) WOT, the tornado may help a bit, but likely won't cure the problem. It helps cars that have the surge problems at part throttle, where the turbo is operating way out of it's flow map. Your case seems to be the result of way too big of turbo for your engine's airflow capabilities, causing the turbo to operate off the map everywhere. The cure to your problem will be to port your heads, and increase the airflow capacity of the engine in every way you can. Once you get the airflow up into the range the turbo is sized to operate in, the surge will disappear..... or get a smaller turbo.... :frown: My O2....