Camel, check out my sig and get back to me :-)

I went with the R out of necessity. My compressor base diameter is 89mm, bigger than a T88.



The Supra thing sounds like it needs to be adjusted.



Vosko, believe me I'd like to run more boost but I'm still breaking the engine in!



I'll just use a smaller BOV for low boost stuff. If I didn't think it would hurt the turbo, I'd leave it as is. I hear those shockwaves hitting the compressor and it makes my hair stand on end! Once the engine is ready to rock and roll, I may not ever need it but who knows.

 

Is their a softer spring you can get for it? I've never tried the Greddy TypeR, but the Tial I have required the softer spring to prevent compressor surge at low boost.. fixed it 100%. At least that is a cheap option, springs are less than $20 usually?

 

Yeah I thought of that option and I may try it next before attaching an additional BOV that I have lying around. I threw the box away but I don't recall seeing any spring identification markings. They make two for the type R.

Michel

 

Just talked to GReddy USA. They said don't worry about it. Apparently in Japan, most don't even use a BOV with the 78/88. Just something else to go wrong. I guess the turbo is strong enough to handle the shockwave. Either spring will cause flutter at low boost so there's no real solution. I'll just leave it be! Won't be too much longer before I'm running "real" boost levels.

Michel

 

more driving and less posting!!!!

 

Guys, It's suppose to make the "flutter" sound! If you go to Japan, you'll see that most BOV's do that.

 

If you go to GReddy's web site, they specifically state that there should be one, clean blowoff when the valve opens. When it stutters/flutters, it's partially the piston opening/closing rapidly and/or shock waves travelling backwards in the intake piping and slamming into the compressor wheel. GReddy techs said not to worry about anything below 5 or 6 psi. And they tend not to use BOV's in Japan according to the GReddy tech. Just one more thing that could go wrong.

 

The only time I have every heard of people not running BOV are with ball bearing turbos....

 

God I love these, 'if you go to Japan' posts.. the only time you should consider running without a BOV acceptable is with the IHI turbos, possibly other durable BB turbos as well. Compressor surge at low boost isn't the end of the world, but it certainly isn't the best idea in terms promoting turbo longevity.. especially on non BB turbos including the T78/88. What does one more thing to go wrong mean? It doesn't get much simpler mechnically than a BOV.. worst case scenario it gets stuck open. No big deal, at least it won't blow your motor.. if anything not using a BOV is asking for one more thing to go wrong. That is unless you find redoing your IC pipe clamps all the time something amusing.

 

hey, don't shoot the messenger just what I heard straight from the GReddy tech's mouth who happens to be Japanese. Apexi used to brag about the fact that one didn't need a BOV with the RX6 IHI series. I'm with you, I always thought it was a necessity, hence my haste to solve the problem.



Just did a quick thumb through of Hyper Rev Vol. 54 from Japan (all about the RX7) and it's about a 50/50 split between BOV/No BOV. Some of the pics are small and the BOV could be on the IC end tanks, but there are several that have none running T88's. Take a peek if you have the magazine.