Yesterday, TheSpeedFactor provided me with and installed a new Forge RS DV that Forge sent for testing purposes. I already have a great setup that has worked for me on both pump gas and race gas, but I was interested in seeing if there was anything to gain from having the Forge unit. Here is what I've found so far, and I will continue to provide feedback as I make more adjustments, and also after I've done some testing at the track on both pump and race gas. For this test, all I did was replace my JDM MR DV with the new Forge RS DV.

What I can tell you is that I installed it with it turned all the way out to minimum stiffness, then went to test it. The boost appeared to hold just as well at minimum stiffness as my JDM MR DV, but I was only able to test in 2nd gear. I was getting a quick spike to 22psi that would drop close 20 almost immediately, but then it would stay just above 20 all the way through 7k rpm, which was good - I also was unable to induce any surge in 5th or 6th gear whether it was 2psi or 10psi built then released - there was also no purge noise at this setting. I then did 2 full rotations and tested again. I ended up doing this 5 times total, and each time the boost actually seemed to spike HIGHER initially, then hold a little higher after the spike - also, the BOV became more and more audible each time (stock airbox) and it became easier to induce surge in top gear. Again, the boost test is only 2nd gear, but I went from a 22psi spike to a 24psi spike. Higher than I want, but if I'm seeing more boost with the same MBC setting, then this BOV is telling me something.

I stopped adjusting it after 5 tests (10 full rotations), because I think the boost is holding strong as hell, but I'm also much more prone to surging. I can even cause surge in 4th gear if I build just over 10psi. In 5th and 6th, all it takes is a brief low throttle blip, then letting off quickly, and it will surge. To me, this means I need to now back the knob out to find a happy medium between solid boost holding and minimal surge. What's great is that I will be able to crank the knob down when drag racing so that I have maximum stiffness, but then loosen it up for daily driving. Hell, it holds boost as well as the JDM MR DV even on minimum stiffness, so I have nothing to lose really. Oh, also, at its current stiffness, it is VERY AUDIBLE when it purges, which is another telling sign of how stiff you can make it, because I have the stock airbox that muffles all intake/bov sounds, and the valve is fully recirculated. When I say "audible," I mean I can hear it from inside the cockpit even with the radio on. My JDM MR DV was inaudible even with the radio off...I only knew it made some noise when other Evo owners drove beside me and told me they could hear it when shifting. I'm not mentioning this for the cool sound factor; I'm mentioning this in relation to how stiff the valve can get.

I will provide more feedback after loosening it some to find a happy medium between holding boost and not surging. The racing results will have to wait until racing season begins.

 

I agree 100% w/ your review. IMHO, it is the best DV on the market. Even w/ the stock air box you can hear a little whistle sound.

 

I think I run mine at 6-7 full rotations for daily driving. It holds boost great and I only get occassional light surge in 5th gear when I tip in throttle light and let off.

 

Good feedback. Mine is at 10 rotations right now, so I would expect 6-7 to be a good spot.

 

I've been experiencing a lot of that surge you're talking about, which is why I am DEFINITELY making this investment in a couple of weeks. I'm glad someone went into detail about using the RS so when I get it I'll have detailed information to go on.

 

I sell and love the RS BOV from Forge - simply the best there is - period

You can set it soft like a sotock one and then wehn you go to the track you simply turn it down a few screws to get max bov performance

Ideal BOV solution

NOTE - ONLY get the recirc version on a MAF equiped evo

Those who may want one PM me for special evom pricing

 

What are the pro/cons of going from a soft to a hard spring?

 

This valve only has one spring that is applicable for it. There is no need to change springs as is done with many of our other valves.

The adjustments are done by turning the knob at the top of the valve.

Thanks for the kind review Mr. Talon and the kind words Al!

 

We still have a few RS valves in stock and ready to ship, pm me for a price.

 

will adjusting the bov from soft to hard affect power and tune results? is the soft setting - and + for hard?

 

Holy thread revival batman.

 

you realize this thread is from 4 years ago?

 

My sweet ninja edit skills covers me...that newbie though its his fault

 

Yeah I know its prehistoric, but I figured Id continue on this thread rather than making a new one.... so, anybody have an answer for me?

 

x2