I'm confused on how to get rid of the boost drop off @ 5k rpm
do you have to flash the ECU or get the piggy back system?
or a blow off valvue, boost gauge.......

Please help.
Thanks,

 

You need a boost controller. You can get one for real cheap- around $50 for a manual boost controller.

 

Any type of re-flash will solve this problem . And an Xede will also decrease this also a Boost controller will either manual or electronic. I had the Dynoflash on my last Evo with turbo back and air filter and it would go to around 1.5bar then at around 5500rpm start dropping to around 1.21 bar till new 7800 rpm red line it did not hold full boost to redline but did keep it higher as the rpms go as far as what stock was 19.5psi the drops to 16psi after around 5500rpm. Plus you can get a basic flash that will do this from Dynoflash for around $200.00 and an Xflash for Vishnu for around $399.00. Either way you have many choices good luck.

 

Another sure way to help solve this problem is an intercooler upgrade. The stock intercooler has a 3psi pressure drop across the core when enough air is trying to flow through it (higher boost levels). Many aftermarket intercooler kits will drop this number to 1psi across the core. That pressure difference will allow 2 more psi of boost to be sustained throughout the powerband. This additional sustained boost will all but eliminate your problem, especially with the mods suggested by the previous posters. Good luck!