Originally Posted by Appauldd

I just reach my hand down, grab the rod and pull it back onto the flapper mount. (after adjusting of course).

Originally Posted by buchnerj

Let me start by saying that I had the exact same setup as you. HTA Green 64mm, APS Twin vent, and 18psi WGA. I was getting TERRIBLE surging during spool up and boost spiking up high. It was a combination of the compressor cover and the BOV. My BOV would flutter and couldn't hold up to the 35 psi I was running with the HTA. Your only option is to either turn the boost down significantly to cut down on the compressor cover surge or at least change up the compressor cover. Once I switched to the 84mm Flow advancement port and the Tial QR Recirculating BOV I have had 0 issues. It is a night and day difference. The HTA is prone to these problems since it is using a standard 64mm stock flowing inlet and flowing significantly more air than the stock turbo. This causes spool up to be very rough and surging issues. I am telling you, I tried every solution, 25psi WGA, ECU boost, everything, nothing solved the problem until I purchased the 84mm port and a new BOV. Now it is flawless. Perfect DD combination and the spool up insane and smooth as butter.

I saw you said you don't want to upgrade, but I exhausted all options before I did and nothing worked... Sorry but your going to have to sink some money into her...

Originally Posted by nonschlont

now its "creeping". Some ppl like creep. You can use it to your advantage, as long as u run reasonable boost levels before it creeps, and tune your fuel/timing, to compensate.
to eliminate the creep, you need to port the wastegate hole in the o2 housing.
https://www.evolutionm.net/forums/ev...bs-thread.html

Originally Posted by 94AWDcoupe

embrace the creep. it means your wastegate is not flowing that well. this forces the pressure over turbine where it can do work. a little bit of creep is a good thing. lower rpms is where engine is most likely to detonate. higher rpms the piston speeds are so high there is no time for it to occur. those who are aware of this try to make the boost curve creep.

Originally Posted by cij911

Exactly...I always wonder why folks don't have the "boost spike" set lower (e.g. 27 psi @ 3500 - 4000 range and gradually increase the boost e.g. 32 psi at 7800 rpm - the shock to the drivetrain would be less (good thing), you'd have a flatter torque curve (easier / better for racing), and great hp up top...

I'll will be testing this in a few weeks with my new HTA Green and psi based boost control ....

Originally Posted by 94AWDcoupe

I have apexi AVCR on my evo 1. with wastegate boost on HTA green I get 17psi falling to 15psi. I currently have boost at 20 creeping to 21. The difference in powerband is lovely. My goal is 23 creeping to 27.

Originally Posted by sparky

Is this with the 18# FP actuator?

Originally Posted by I4UnderPressure

Well I finally did the compressor cover and 18psi actuator. I didn't think it was the aps bov, so I kept that. I went ahead with the fp intake and cut the hose to fit the perrin intake heatshield/maf. Took it out today and did a 3rd gear pull. Boost hit 22psi and literally stayed there like it was stuck, all the way to redline. I couldn't believe how steady it was. It was like someone reached in and held the needle so it wouldnt move. I can't believe the difference. And the ported compressor cover sounds much more wicked than the stock ported one. Thanks for the helpful info buchnerj. Gonna go ahead and set up the tune. Will keep ya posted.