Hey everyone,
I have just obtained a 04 RX8 and I have fallen in love with it. Here is a pic of it...



I'm knowledgeable of automobiles but I'm still learning about rotary engines. My question is... what is this? Is this a blow off valve. It resembles the GReddy blow off valve I had on my 99 Eclipse GST awhile back. Here is a pic of the item in question.



PS> pic is not my engine bay... I stole it off of here.

But anyways... if in fact this is a bov, is the rotary engine under pressue while normally aspirated? Does in fact the air in the "system" pressurized slightly (~2-4psi) and the pressure air blown off for better throttle response? On the Eclipse, I had a GReddy BOV and the throttle response and less turbo lag was well worth the $200 for the BOV. If in fact this is a BOV, anyway replace it yet? I have searched on this forum and have not found anyone doing so? I'm not looking to make big hp numbers but it would be nice to get a bit better throttle response (and a cool sounding psssstt... sound. )

Thanks everyone...

Ed

 

I can't say for sure what that is in that pic,but the RX-8 does not have or need a BOV.It is normally aspirated so therefore no need to blow anything off.If indeed that picture is a turbo charger kit on a RX-7 which I highly doubt then maybe it is a BOV,but again I doubt it.

Oh yeah welcome to the club.Now go out and drive!!!!

 

How can that be a BOV on a naturally aspirated car?

After consulting my trusty service manual, I think it's the secondary air injection control valve.

 

Umm, I don't know exactly what it is but I'm certain it is not a blow off valve.
If you're curious, why not disconnect the hose and give it a few revs?

 

not even close to a BOV, or even a BPV (By Pass Valve) for a turbo, they look a lot different with a different set up all together.

That looks like some sort of pressure release valve....

 

pressure release valve? hum... sounds like a blow off valve.... The blow off valve can be called mant things. I've heard it called a pop off valve, pressure valve... etc... :p If it is not a bov... anyone know what it is then?

Reaper man> no... the set up is EXCATLY the same as the set up in a 2g (or 1g) DSM. the by passed air must be recirculated back into the crank case due to the MAF sensor.

 

meh- my experience with all that is with Subaru FI mainly- every other car I've ever seen wasn't like that.

we had something like that (it was smaller) on the wrx that was a pressure relief valve, I just can't think of exactly what it was for again, that's what it looks like to me- dammit, It's going to bother me that I can't come up with the name....

 

You figure someone would read the RIGHT answer.

I'll change my answer. It IS the secondary air injection control valve.

 

.....and that does precisely what?

 

The secondary air injection control valve controls the amount of air provided by the secondary air injection pump (above and to the left of the circled area in the picture above) to the exhaust manifold. The secondary air injection system is used to provide addional air to the catalytic converter to help it oxidize exhaust emissions during engine start and warm up. The belt driven "smog pump" on other cars provides the same function, the RX8 uses an electric pump instead of a belt driven one.

 

Thanks!

 

You learn something new here everyday, that's for sure.

 

Then there's the tertiary air injection valve which is about to fitted retrospectively to all RX-8 in Australia. The Tertiary valve is connected to the induction throttle body and in theory will give the 13B Renesis (yes the Renesis is a 13B engine..have a look at the epitrochodal block for 13B stamping...did you know that!) extra response through a 10% improvement in torque. This was determined by the inventors of the Hyclone air turbulance system devised by an Aussie some 20 years ago. Mazda in OZ are about to fit this to improve the pitiful torque of the Renesis engine. The fitting will be around $150 with no labour charges. I have this on extremely good authority. IHALOY

 

what about the rest of us? find out more man! we'd be excited to find torque for $150

 

yes yes of course. tertiary air injection- should have been done in the first place IMHO( sorry i forgot your age that's- "In My Honest Opinion") off hand do you know why it is still a 13b?

 

do you think the rx8 is turbo?

 

LMAO! that looks just like a thermostat...

 

My God, what a load of.....

You are either mixed up or misinformed, sorry. The valve in the picture is the secondary air valve, it has a diaphragm valve which opens to allow secondary air pumped by the secondary air pump into the engine. There is also a reed valve in there, to prevent exhaust gasses from coming back up the hose and damaging the pump.

There is also a jet-air system, which allows BARO (atmospheric air pressure) into the primary ports, aiding fuel atomisation at low rpm/temperatures. Maybe that is what you are trying to tell us????