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Boost controller problem (really tough one)!

372 Views 7 Replies 3 Participants Last post by  Supreme
G
I'll try to explain the problem I am having as best I can. Hopefully someone can help out.

I currently have the HKS-EZ boost controller and the new SP-70 turbo kit w/ HKS 60mm wastegate.

In short, we know the wastegate spring is a 1.5 bar spring, because with the hoses pulled, the car pulls 1.5 bar running just off of the wastegate every time. Now, we are 98% sure the EZ is hooked up correctly as all 4 people who have looked at it and installed one themselves have inspected it. The solenoid is clicking as well and there are no vacuum leaks. We also swapped a solenoid for another one yesterday, and got the same results.

Now for the problem...

The car pulls 1.5 bar on the dyno with the EZ at the 7 o'clock minimum position. You would think with such an aggressive spring, the EZ would be extra sensitive and a slight turn should crank up boost a lot. However, I have to go to 12 o'clock to get to even 1.8 bar on the dyno. Then the fun ends. Even if we bury the EZ to the 5 0'clock position, we still get 1.8 bar. So it's like the EZ is working but is extra insensitive, and won't run past 1.8 bar at all.

Peter B. has told me the EZ is supposed to correlate with the wastegate spring in the neighborhood of 250%, meaning this spring should be capable of 40psi or so. So then, why is the EZ being so insensitive? And more importantly, why are we being limited to 1.8 bar when we should easily be able to get 2.0 bar on the dyno?

Any help is much appreciated as even some of the more knowledgable Houston guys I know are stumped on this one.


***I re-posted this in Tech, but can't seem to delete it. Please delete this post.***
1 - 8 of 8 Posts
G
the ez can only hold like 23-25psi

Billy
G
SMGTurbo said:
the ez can only hold like 23-25psi

Billy
not true. I heard the EZ can hold up to 2 bar. or 36 psi.

from mvp motorsports also:

HKS EVC EZ Boost Controller
ITEM # HK 4503-RA008
Boost controller ideal for sequential turbos (i.e. Supra TT). This unit does not have fuzzy logic and does not attempt to learn your turbo(s). It has the quickest reacting solenoid controller & works great even on single turbos as it can control up to 35 PSI!!
MSRP $395.00 Your Price $328.95


well....supreme..to answer your question. a Buddy of mine with a 93 anthracite T66 also an automatic is running through the same problem with his HKS Ez. he can only hit about 18 lbs or so on his boost gague...no matter how high you turn the dial. However, if he bleeds the wastegate he is able to boost more...or so i believe. We have yet to figure out this problem.
23-24 psi, you're crazy. Boost controllers are rated to hold/make a certain percentage of a wastegate spring. The EZ is rated to hold 250% of the WG spring. My EZ ran 2 bar EASILY on my black car (at the 12 o'clock position).
Peter
1_MAD_DAWG said:


not true. I heard the EZ can hold up to 2 bar. or 36 psi.
2 bar is 29.4 psi. if you didnt mean it like that, my bad, im incredibly tired...but im a dumbass and wont sleep.
G
Problem is solved. When we pulled the wastegate, the one of the port on the back was left open and capped. We capped the port and went to a lighter spring. EZ is working like a charm now.

Thanks guys.
Amen to that, Joe.
What is your WG boost now??
14-16 psi would be great.

Tommy
G
anthracite said:
Amen to that, Joe.
What is your WG boost now??
14-16 psi would be great.

Tommy
1.1 kg/cm2 ~ 14 psi at 7 o'clock. 1.3 at 8 o'clock. 1.5 at 10 o'clock. Didn't go past there because I had 93 octane in the tank. Pretty sure it's fixed judging by boost response from the controller and the spring. Will lekely go to 2.0 kg around 12-1 o'clock position.

BTW, I know I bothered the hell out of you and Peter with questions, so thanks again for all of your help. I really appreciate it. I'm so glad to have it working right now, and I can't wait to stick it back on the dyno and tune for ~30psi.
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