I just bolted up and drove the s5 turbo to my 87 rx-7 and theres a problem or two. First off, it didn't idle when I first started it up, so I capped off a vacuum nib on the front of the cold side of the turbo that leads around to the output and goes into the turbine. I didn't have it on my s4 turbo so I capped it off and it idles for a while then dies randomly.

However, that's not my main problem. My main problem is that for some reason i'm running 10 lbs of boost for no apparent reason and I don't have an FCD. Possible causes, the air injection pump has a few things disconnected that WERE disconnected before and it was fine, secondly the O2 sensor is out. I'm still running full stock exhaust and it's STILL going to 10 lbs.?????????????

Any ideas?

 

are you saying you disconnected the wastegate?

 

Well the s5 wastegate is big enough. Sounds like your wastegate isn't opening enough or at all. Make sure the shaft for the wastegate is not touching anything. As for that nipple make sure it's capped or it won't build enough pressure for the wastegate actuator.

Also if you don't have an FCD then you should hit full cut. So maybe the guage is wrong. Your idle issue is probably due to something not being capped off.Theres another vacum for the gate inside the s4 manifold(scroll actuator). Make sure it is capped as well. Do you plan on getting rid of the emmissions?

 

Ok well wastegate is fine, didn't touch it. I capped off two more vacuum lines and the overboost problem has gone away. However the idle problem is still there and I can't figure it out. The only thing thats actually different from before with the s4 turbo is that the O2 sensor is no longer connected, unfortunately the wire snapped when the downpipe fell. Other than that, there's a vacuum line or two that don't fit too snugly, so i'll have to seal those off. If it means anything my idle adjustment doesn't work for *****.

 

You can use any wire to reconnect the O2 sensor. A new O2 sensor is pretty cheap.Just use some extra wire or buy some (cheap) and reconnect it.

I used small zip ties to make all my vac lines fit snug. Also you need a new gasket between the turbo and manifold.

You should've ported the wastegate as well. That way you can put a downpipe on and have NO boostcreep problems.

 

haveing no O2 sensor will cause problems with idle and make your gas milage go to ****