bad vibration at about 3k rpm

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With a swap usually you go after market engine mounts...which are usually stiffer which transfers all the engine vibration to your dash or car chassis it self but it also usually makes a lot of vibration at idle...you might also want to check your torque mounts or the rear tranny mount....does it vibrate on exceleration or just when you hit 3000 rpm???
 
It was only at that specific rpm it would vibrate hard. But like I said, it pretty much worked itself out, it feels fine now. Believe me, I know what the vibration from the engine mounts feels like and I'm used to that, it didn't have to do with the mounts.
 
Did you modify your downpipe to add spring bolts ? How's the vibration now ?

I have the same problem since i've put the turbo this spring on my B18... I have the flange and the spring bolts on, but my piping set-up is really stiff. The vibration started at 4000 RPM and dropped to 3000 RPM as you've experimented. The vibration made crack the bracket holding the turbo and also one branch of the header (equal lenght type). After repairing the cracks (I've removed the header from the car to do the job), the vibration disappeared completely for a few rides, but reappeared then.

I was thinking to add a flex pipe before the cat to remove some rigidity to the piping... But before removing the downpipe and have the job done, I'm looking at others experiment... I want to resolve this problem before pushing the turbo over 7 psi....

Thanks for giving some news...
 
Like I've said before, I no longer have the problem anymore. Once I swapped out the turbo manifold (header) and had my exhaust redone, the vibration went away. I'm pretty sure it has to do with the turbo manifold, it might have been slightly warped. Right now I am running a custom cast iron log manifold, and haven't had a single problem with it (no cracks, vibration etc.) and the flow is fine. I would recommend getting a cast iron manifold, those things will never crack, they may look ugly and may not look as cool as those ram style stainless steel ones, but I've had nothing but bad luck with those. My friend just bought a Blox ram style manifold and has only had it for a few days and it already has a crack. Not saying all those are all bad, but it seems like the cast iron manifolds are a little more reliable. Anyway, my recommendation to you is you should definitely get a flex pipe first of all, and get a whole new turbo manifold. Also, do some more research, find out what manifolds are good quality and such....I heard you can give your manifold a ceramic coating, that would also definitely help out. Another thing you can do, is get some custom built supports built for your manifold that bolt up to your engine block and reach up to your manifold and get them welded to it, for extra support. Hope this helps.....
 
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