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Car: Nissan Skyline R33 GTS-T s2 , RB25DET

Hey guys I was driving my Skyline r33 gts-t tonight and I noticed that I wasn't really getting the amount of boost I think I should be. From a standstill when I give it some rev's and then launch it gives me the correct amount of boost but when driving I found from 3 to 4th and to 5th the boost was less than usual.

so I changed the boost up two notches on my turbo smart boost controller an noticed minimal difference, although I'm not sure what the notch to psi ratio is.

Then I was finding that in 3rd gear I would accelerate and the turbo would start fluttering and the boost needle would be knock around like crazy then I could ease off and go and it would be fine. The thing is though that this only happens some of the time. I'm still learning so not really up to par with all the lingo. If anyone could help me out it would be nice.

Thanks!

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when you say the bost needle knocks around like crazy does your boost increase or nothing happens? from what your saying my assumption is your hitting a boost spike... and if there is no boost throughout 3rd- 5th i would throw out there you have a boost leak somewhere or your turbo is giving up or has given up on you

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so ur hearing flutter and ur boost gauge needle is all over the show under acceleration?

that sounds weird. btw flutter is the noise of the air running back through the turbo when u close the throttle it shouldn't be doing it under acceleration

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a boost gauge needle bouncing up and down and turbo flutter on acceleration sounds just like surging to me, caused by restriction on the compressors inlet. causes of the restriction could be the stock rubber inlet pipe sucking closed if you still have it (its a common problem), or something simple like a dirty air filter. i think you'll find the is more engine load in 3rd than in 1st and 2nd, hence why you only start seeing the problem in 3rd.

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