Hey everyone,

Hopefully I can get some help here. I recently finished installing a T25 on my 1999 1.8. It has an ebay manifold, with custom intercooler piping, and a custom downpipe. I am using a Flyin' Miata Voodoo Box for engine management. I tuned it following the instructions that came with the Voodoo Box.

The car runs great when it isn't in boost, however after hitting boost and letting off the gas, the rpms drop and sometimes the car cuts off and dies, other times, the rpms will drop and go back up and idle very high around 2k. After cutting off, the car will turn back on normally. My boost gauge is telling me I am hitting 6psi.

The only thing I could think it is, is when installing the downpipe, I accidently snapped one of the bolts off, so only four bolts are holding the downpipe on to the turbo. Could a small exhaust leak be the reason this is happening?

Please help!

 

What kind of blow off valve setup are you using?

 

I am using a Bosch recirculating BOV. Thanks for responding!

 

As long as it is recirculating back after the MAF it should be fine. That was my only guess.

 

Here is a picture of the engine bay the BOV is right after the MAF

 

LOL. BOV is plumbed wrong.

 

Where is that BOV hose going to?

 

I'm extremely embarrassed. What is wrong with it?

The hose is going to a nipple that was welded on a few inches after the throttle body

 

Does it idle?

 

BOV mounted onto the intake side of the turbo? Poscat to you sir.

 

Wtf is going on

 

You were pretty close, man. Here, I drew a sweet picture that should explain.

 

Also what's up with the washers on the exhaust manifold?

 

Your first diagram should work just fine. That's essentially how BEGI routes theirs, except with the BOV fipped. It's common to use that BOV flipped, as boost pressure helps it seal shut.

 

In that case, he'd still have to swap the "direction" of the BOV.

 

Direction of the BOV doesn't matter. It's just a piston that opens and allows air to flow. What he needs to do, is route that pre-throttle.

 

IIRC soviet was using a similar BOV, he had it mounted halfway between the intake and cold side plumbing

 

Where is your idle valve connected?

 

As long as that longer, ~1" diameter hose is going into the correct end of the BOV, this set up will work just fine. Where the BOV is mounted matters none, except for its sensitivity/response. It would operate better mounted on the charge pipe.

 

Flip this the other way

Put it closer to the charge pipe on the cold side.

I'd swap your T fittings locations also, put them closer to the intake manifold and just side by side so manifold==t=t======emissions thingy