Yes remove the down pipe and see if your power increases. If you do a boost leak test and the BOV leaks that could be the problem. That appears to be a stock 9 BOV.

 

Yes, that looks like a stock 9 valve. That's the same valve I was running and my EF3 was blowing it open. The only 2 ways I can think to test it are:

1. Build a boost leak tester and start pressurizing your setup. Keep turning the pressure up on your air compressor and look/listen to see if you can hear your DV venting. I think mine was venting around 20-22psi.

2. Buy a new DV. Get a good one... not a GReddy clone or Ebay $30 valve.


And if the DV is the culprit, use caution when you install the new valve because your boost might be tuned in a lot higher than you think. When I swapped in my new valve, my boost shot up past 30psi because we had been turning up my MBC only to have the stock DV venting pressure.

Good luck.

 

I can try that. My tuner said he did a pressurized boost leak test and smoke tested the system with no leaks. But would a BOV leaking actually show up in a pressurized test since it is recirculated? If it vented I could see it showing up easily.

 

Flip the bov over. It will surge yes. But it will stay shut. I picked up 40hp by doing this. They really wont hold much over 25. Some do. But mine did not.

 

Ok, so I was going to maybe try the crush trick and see if that would help with the spring pre load and maybe give me an improvement in power so that I knew I was going in the right direction with this. I pulled off the bov and checked the diaphragm integrity with a vacuum pump. It held. Then another guy in the shop came over and was looking at it with me and said lets check the valve operation. He took shop air at 120 psi and applied to the vacuum port on the top of the bov before I could stop him. So now I have a crushed evo 9 bov with a destroyed diaphragm. So it looks like I have to get another one.

 

What an idiot. Sorry about your luck. Although my car made 550whp at 28psi on a stock metal BOV. It was a JDM EVO8 MR valve.

 

You are better off with a new valve anyway. Even if your OEM valve isn't the problem, a new, tighter valve isn't going to cause any additional issues. Plus new ones don't cost much anyway. Just don't cheap out.

 

Yeah, so my buddy that works with me that blew the other valve up is replacing it for me with another stock 9 valve that's new. It'll have to do for now. I'll save some funds to get a new one that's better. Those things aren't cheap. Lol. With the cash I just spent on everything else, the wife isn't too keen on anything else right now. Especially with our vacation coming up next week. Just sucks now the car is rendered useless. New valve won't be here till the day we leave next week . I just hope this shows some improvement on my situation. This is pretty frustrating to say the least. I've been racking my brain since last week trying to figure out what else could be causing me to come up short on my power goals. Especially since my tuner said that he kept adding boost and the car just wouldn't build anymore power, that it actually started losing power at a certain point. He said I have enough fuel, plugs are new and firing fine, just for some reason the car won't make anymore than what it is now. Driving me nuts. Thanks for all the input guys.

 

Update. Got the replacement valve this past Saturday. Tested it by adding vacuum to it, ok. Did the crush trick, re tested it for vacuum, ok still. Installed the new valve, with new clamps. Re checked all of my coupler connections and vacuum lines and fittings, ok. Test drove the car, feels the same as before this whole fiasco started. So this wasn't my issue. On vacation now, so I guess when I get back, when I get some time, gonna pull the head and go through it just to be safe and eliminate it as a suspect. That's what my tuner thinks is the problem. Guess I'll go back and have it on the dyno one more time after this to see if it was the problem or not. If not, I'm totally lost. Keep you guys posted. Feel free to throw any more ideas or checks and tests my way if you think of any.

 

like i said before im having the same problem you are having and im starting to think it may be a transmission or transfer case issue not getting the power to the ground, havent started pulling stuff off yet but just thought i let you know what im doing

 

^^^Pretty sure I don't have any trans or transfer case issues. Car has never had a problem pulling before. My issue is the tune, I'm pretty certain of it now. So I built my own boost leak tester finally and double checked my tuner's work. He said he tested the car and had found no leaks. I started adding pressure to the system and got a huge leak from the throttle shaft seals at 4 psi. YES, 4 psi. I say to myself, how could this be right if he checked it? Whatever, I ordered new high pressure seals and installed them. Fixed that leak, found 2 other small ones and fixed those as well. Now I can pump it up to 26 psi and it bleeds off nice and slow like. Re drove the car and it feels a little better, but I'm sure it's got to be re-tuned to be fixed. Going in on Monday to try this one more time. If it still doesn't yield the power I'm looking for, might try to tune it myself or somewhere else.

 

I say find a new tuner. I wouldn't trust him after he said he did a boost leak test and it was fine and you found leaks at only 4psi.

 

Yeah, I agree. Problem is the closest other tuner with a really good rep is about an hour and a half away. Since this is my daily driver, it's tricky to accommodate driving there and dropping it off for however long they need it to try and tune it. Plus the extra money of paying for the tune, since I just paid for one here. Then I have to try and plan if they tell me I have to do any engine work that I'll be able to afford it. I'm hoping this trip will yield better results. I don't know how much those boost leaks could've affected my power outputs. Also I want to get as much detailed info from the tuner during this run as possible to help with input here on the forum as well as for Adam at MAP. Been talking with him trying to figure out the issue. They are very helpful and willing to do their best to solve any performance issues you may have with their products. Keep you guys posted

 

Message Tscomp especially if youre on stock ecu

 

Ok guys, so I ordered new upper and lower hard intercooler piping. Talking with Adam from MAP, he suggested ditching the stock upper for something better and to get a better BOV. So I have ordered this stuff. I already had the gaskets to pull the head and check it out to make sure I didn't have any issues with it. So I pulled the head tonight. Found out the head gasket that was installed is almost 3 times the thickness as the factory OEM one I bought. Wtf!? Now like I said in an earlier post, my tuner had told me that some people did this back in the day thinking it would help improve boosting ability by lowering compression, but that it actually cost power. Has anyone had any experience with this? Or does anyone think this is just another stab in the dark at my issue as to why I can't build power? I was able to figure out what cams are in the head finally. Ran these numbers 8-tx272, turns out they are Kelfords like the previous owner said. So I know I got some good cams in there. Going to check the valves and leakage tomorrow.