Boost drop in higher rpm (top end)

[ColoradoST]

I have a Pumaspeed x37, that I am getting E30 tuned. My tuner days that the boost is dropping in the top end (25psi in the midrange and 16 psi in the top end). The tuner thought it could be a boost leak. I got the smoke test done and no leak at all. I was told to pressurize the whole system to 25 psi and see if there is a leak but a few performance shops told me that this would yield the same results as the smoke test. What could my issue be here? I am thinking that my 17psi Turbosmart wastegate could be preloaded incorrectly.

 

[Zormecteon]

I believe they drop off some boost as the rpms go up. ... It's a feature not a bug.

 

[Erbarry]

Get a new tuner. Most cars wth stock, hybrid/stock frame turbos will drop boost up top.

 

[Butterybunz]

Who is your tuner?

 

[ColoradoST]

Pd tuning. If this is normal then I'm happy because I don't really want to mess around with the preload...

 

[ColoradoST]

I'm looking at the data and it looks like the psi slowly drops after 5000 rpm. There is not a huge sudden drop.

 

[Butterybunz]

Pretty much all tunes are going to hit peak boost and then boost will level down as the rpms climb closer and closer to redline. If your tuner is trying to hold 25 psi to redline and the car isn't, that could be an issue but to me it sounds like you need a new tuner.

 

[ColoradoST]

Thanks. The car runs fine so I think I'm just going to leave it how it is and not mess with anything.

 

[TyphoonFiST]

So what ever happened after this? Just curious !


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