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Where did my power go?


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I went to the drag strip and am trying to figure out why my car ran the same times as it did the last time I went to the track even though the temperature was 61 degrees with low humidity rather than 103 degrees with 100% humidity like the first time I went.

The boost looks to be a constant 1bar but I read that even with a boost leak that can rob you of big power you may still see normal peak boost because the computer is demanding it. So basically the Turbos are working harder to get it?

I have the stock diverter valves with a softronic tune so that is why I am thinking maybe the DVs are not up to the task? They are not honking or anything. I do hear a loud wing gushing noise at wide open throttle but I just figured that it was the normal sound of the turbos or something.

The 2 other guys who went to the dragstrip with me both times were running 0.7 seconds faster with 6mph more when compared to the first super hot day which is to be expected.

So I guess my question is can you actually have a boost leak that will cost you about 100hp and still see normal peak boost?


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You need to check for both a boost leak and you need to see at what psi your wastegates are opening at.

When I switched over to the K24/18G setup I found a lot of boost leaks and ended up having to swap the intake hoses to silicone and even had to have the intake plenum strapped down to keep the boost from blowing the small rubber gaskets out that fit between the intake track and the engine. You have to buy special silicone connectors that fit over the Turbo air inlets and they have a air chuck on them that allows you to pressurise the system and then listen for leaks or spray soapy water over the engine and look for bubbles. As far as the wastegates go, I took a bicycle pump with a gauge and a air release button, and made a hose to fit the wastegate air niple. Then you pump the bicycle pump up and watch the gauge and the wastegate rod and note at what psi the rod starts to move and what psi the wastegate is full open. It will tell you if your dumping off too much boost.

The other problem can be the oem boost selenoid. Even with a softtronic tune it cant really overide the factory boost controller nor I dont think the boost map.

And even with a Softronic, the factory safety mechanisms are in place, so if your octane isnt high enough and the car detects ping,it will still pull back timing and detune the car.

The diverter valves arent an issue until you change turbos and are running way more cfm and psi. Its a myth that the people that sell diverter valves like to propogate to sell parts. With oem turbos and boost levels they work just fine.

Edited by Dus10R
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