Hey (first post! )...I just want to say that I've been an avid Subaru enthusiast for the past year and a half. It's time to get rid of the WRX and move on to better things: EVO MR or STi. I liked the recent review by Motor Trend and was shocked when the dyno showed the true power of both - both were basically equal (give or take a few hp). I know the Subaru world inside-out, but have a couple of questions about EVO's:

1. How many whp would the EVO put out with proper tuning and catless turboback?

2. It seems like the EVO's ECU is no where near as complex as Subaru's. It seems like the big thing to do is go S-AFC with a means of boost control. Is that the best tuning method for optimal power or is something like the reflash or Emanage better? With Subaru's, the optimal way to get power is through a reflash basically...

3. With the Subaru's, CAI's and BOV's are enemies unless used with a custom tune or high psi. With the EVO's, are CAI's terrible for the car? What is the stock intake system good up to hp wise? With the BOV, what is the stock BOV/bypass valve good up to before needing to go 100% atmospheric?

That's all for now. I'm sure I'll have more questions soon. Thank you!

 

1. I got 315WHP with turboback cat(NO WAY) AEM intake, S AFC and 21PSI of boost. STOCK ECU
2. Get a flash and a S AFC for fine tuning(if u have EGT, and wideband)

3. Drop in filters give u good HP people run 11s with stock airbox with drop in. VTA isnt a good idea on the evo unless u buy a HKS EIDS. STOCK BOV SUCKS its plastic and it leaks like shyt
after a awhile.

 

Thanks for the quick response...VTA = ???

 

VTA = Vent To Atmosphere

 

read post 11 and 25.
I have had this car for a yr and loveit. could not be happier.
An exhaust and a good tune or flash should net around 50whp. give or take a bit
https://www.evolutionm.net/forums/sh...&highlight=VTA

 

So basically CAI is your own decision as long as you get it tuned it seems. I am still confused about the BOV situation. So no VTA but don't keep the stocker?

 

Exactly For example: The Greddy Type S BOV(which I have) is the same style as the stock bov u can still Recirc with this BOV. WIth the HKS u have to buy an Adapter or u can just buy the GO fast Bits BOV that does both and wont cause issues.

 

Nice...So the CAI is the same as with the Subaru's. Probably only gives about 10hp max too when tuned right?

So hypothetically speaking, if I were to go and buy the Type S right now and bolt her on, it would be perfectly fine with a tuning? I wouldn't need anything else special? I've heard them and they're pretty loud, making them a VTA too right? The rule with the Subaru's is never put one on unless youre running 18-19psi and higher and can get it tuned...It seems like the EVO situation is different.

 

If your going to upgrade the DV get a JMD-MR valve(the metal one). It has a stiffer spring and is constructed of better materials. There is NO reason to vent to the atmosphere with a maf based car, so doing so would be a ricer move only. An intake will make your stock DV PLENTY loud. Go with a reflash for best whp on stock ECU. Bolt ons and a flash will sit you safely in the lower 300whp region. Cams can get you into the 350whp region although about 335whp is average.

 

Alright makes sense. I think tuning wise, I might go S-AFC and tune it with my cousin. We would street tune it, and he has been tuning AFC for awhile and is exceptional at it. I heard that since we would be street tuning, we could get more hp than a flash or dyno tuning if done correctly. Is this true?

 

Yes, if you or someone you know is experienced with tuning an S-AFC, then go that route. It's what I use, and I tend to do better than those who rely on a flash. On the flipside, a flash can give you things that I sorely miss, such as a raised rev limit and removed fuel cut. My fuel cut is delayed by the S-AFC negative settings, but I still hit it occasionally.

Hopefully, my sig gives you a good idea of what the MR is capable of doing on minimal mods and decent tuning...

 

Interesting...I never knew that street tuning would give more hp than professional dyno tuning (AND SAVE MONEY!!!) if done right...

But back to the CAI...I think if the tuning would go perfectly, I can settle with a one.

And for the VTA...I heard that the Greddy Type S would be fine with a tuning...Is that true and are any others that are fine once tuned?

 

It's not a matter of professionals not being good at tuning, but rather an issue of liability. Al @ Dynoflash can tune your car to the edge of danger, but he's not going to, because he doesn't want your car to blow up. Therefore, he tunes it in a manner that gives good hp gains, but that will be acceptable in all weather conditions, so it's not as aggressive as you can tune yourself on an S-AFC. Flashes add a few extra features and change AFR along with timing...something the S-AFC can only do indirectly (timing).

CAI/BOV - Do a drop-in filter and JDM MR DV. There is no reason to even ask about a VTA BOV, whether it's "fine" or not with tuning. If this is what you're interested (sound/bling), then I can't help you beyond this point...

 

Good deal I like the honesty. No, I am not interested in bling at all. I want pure performance. I am just trying to learn the EVO here because Im learning that its setup is very different than Subaru's (obviously)...

JDM MR DV > USDM MR DV = ???

 

Yes, all USDM Evos (including the MR) come with a crappy, plastic BOV that I found to start opening at 13psi when doing a pressure test. The JDM MR DV is exactly the same shape, size, and appearance, except that it is metal and has a stiffer spring. It's a direct bolt-on that recirculates and really makes no more noise than stock, which is almost nothing to begin with.

Due to my stock intake and MR DV, I make only barely audible spool noise and almost no blow-off noise en route to 12.2@111 in the 1/4-mile. The only thing you hear from my car is a nice exhaust note, which is how it should be. Don't get me wrong, I love the sound of the turbo and a little bit of blow-off, but I won't pay to hear it unless it makes me faster...