how you doing guys I have a evo 9 currently my modifications are ets intake, ets intercooler, ets stock route intercooler piping, walbro 255, 3 port grimmespeed, precision 1200 cc, turbo timer, megan 02 housing, hks catchback and piping. I have a stock 9 turbo and the stock bov. I want to change the BOV but I don't know the best for my evo. I heard the aftermarket bov gives the evo problem on boost and tune. I want to know recommendations and also I have to change my wastegate if I change the BOV this is base on my stock route intercooler piping. thanks for the help.

 

how much will you be boosting? stock 9 is a solid bov designed to minimize flutter at partial throttle, which is great for DDing. A crushed 9 bov is good for ~28psi +/-

I rock an adjustable Forge recirc. Some people complain about it, but I have had zero issues with it. Just make sure its setup correctly and included in your tune.

 

with all of this I did in a dyno on 91 362whp and e85 401 at 25 psi. I just did my tune two days ago.

 

^^ not bad numbers on dj.so why u want to change the bov?

 

if see I can improve my numbers. I am waiting for this week for my GSC cams 2 with the springs and retainers. So I was looking that can help a little more. thanks

 

How much boost is the stock BOV good up to anyways?.. before it starts to see problems?

 

BOV shouldn't change how much power you make, unless it's leaking/not holding boost.

 

as far I my knowledge it holds 25 psi. people if you crush the bov you make a little more 28psi

 

If you do end up buying an aftermarket bov just get a tial with the proper spring. They are little spendy but by far the most reliable. The only issue this should cause with you tune is if you get a vent to atmosphere like the tial q, and don't have speed density. If you are still running the stock maf and a recirc setup you can use the tial qr. Then if you decide to go to speed density and want to use a vent to atmosphere bov you just swap the bottom half for a tial q bottom half and your golden. I've use a forge bov (non-adjustable) and it just could not handle even the stock boost level. it would open up at wot and cause my car to buck violently and loose power. Switched to an aps adjustable bov and the bucking went away but I still have issues with it opening at partial throttle (I may just not have it adjusted right. But because of that I am looking to just swap to a tial and stop fighting with the bov. And as for the wastegate the only reason you should need to replace that is if you are looking to boost to a higher psi the wga only controls when your wastegate opens, which controls the amount of pressure your turbo creates.

 

Interesting. Thanks all for the helpful information.