Issues with surge/bucking under partial throttle with aftermarket BOV's
Sep 3, 2019, 11:48 AM
#16
EvoM Guru
iTrader: (1)
Originally Posted by razorlab
I use a Tial QRJ bov with 1.5psi spring on my 10 and there is zero part throttle bucking on street or track. It's super smooth and literally the best BOV I have ever used. I stayed away from aftermarket BOV's before because of the bucking.
Sep 3, 2019, 01:23 PM
#18
I ran a stock slightly crushed metal BOV to 30psi and it worked well on a fast spooling stock frame turbo. It did not hold well over that .
I've tried a few different springs in my Tial QR and it doesn't drive as good as the stock BOV did but its held 40psi.
I've tried a few different springs in my Tial QR and it doesn't drive as good as the stock BOV did but its held 40psi.
Sep 3, 2019, 02:34 PM
#19
Evolved Member
Eh disagree, for 98% of us out there, dealt with this for a whole season of testing back in 2011. Removing the MAF forces you into a TiAL like BOV which absolutely does not have part throttle availability. Couple that with the "SD Patch" that the oem ECU uses and you go from bad to worse. Tried all sorts of springs, but that doesn't solve the problem. As you said these other setups have adjusted driving style and most of those are running uber power levels that mask it. The ONLY setup that gives you NA like part-throttle drivability is a dual vent, recirculating, BOV. Only two on the planet achieve this to my knowledge. First is the APS TwinVent which of course doesn't exist anymore and the used ones go for retail prices for this reason, I have used it for 8 years now. It doesn't hold more then 31ish-lbs however. Second from what I've seen and heard is the GoFastBits Response I think it's called now, used to be called GFB twin vent. There is also rumor that the COBB twin vent can do this as well but I've yet to see feedback on that.
Sep 3, 2019, 08:37 PM
#20
Eh disagree, for 98% of us out there, dealt with this for a whole season of testing back in 2011. Removing the MAF forces you into a TiAL like BOV which absolutely does not have part throttle availability. Couple that with the "SD Patch" that the oem ECU uses and you go from bad to worse. Tried all sorts of springs, but that doesn't solve the problem. As you said these other setups have adjusted driving style and most of those are running uber power levels that mask it. The ONLY setup that gives you NA like part-throttle drivability is a dual vent, recirculating, BOV. Only two on the planet achieve this to my knowledge. First is the APS TwinVent which of course doesn't exist anymore and the used ones go for retail prices for this reason, I have used it for 8 years now. It doesn't hold more then 31ish-lbs however. Second from what I've seen and heard is the GoFastBits Response I think it's called now, used to be called GFB twin vent. There is also rumor that the COBB twin vent can do this as well but I've yet to see feedback on that.
Sep 4, 2019, 05:10 AM
#21
Eh disagree, for 98% of us out there, dealt with this for a whole season of testing back in 2011. Removing the MAF forces you into a TiAL like BOV which absolutely does not have part throttle availability. Couple that with the "SD Patch" that the oem ECU uses and you go from bad to worse. Tried all sorts of springs, but that doesn't solve the problem. As you said these other setups have adjusted driving style and most of those are running uber power levels that mask it. The ONLY setup that gives you NA like part-throttle drivability is a dual vent, recirculating, BOV. Only two on the planet achieve this to my knowledge. First is the APS TwinVent which of course doesn't exist anymore and the used ones go for retail prices for this reason, I have used it for 8 years now. It doesn't hold more then 31ish-lbs however. Second from what I've seen and heard is the GoFastBits Response I think it's called now, used to be called GFB twin vent. There is also rumor that the COBB twin vent can do this as well but I've yet to see feedback on that.
I'll have to disagree, my SD setup and Tial 50MM has NA like part throttle. It behaves better than OEM. Not a single buck, stutter, boost building issue at all.
It's in the spring and tune.
Any after market recirc with MAF that I used had part throttle bucking, comes with the turf.
Sep 4, 2019, 09:21 AM
#22
Evolved Member
Sep 4, 2019, 09:53 AM
#23
I've been eyeing the Tial QRJ but i'm a bit skeptical as i'd rather not spend $200+ and find out the hard way that its going to give me the surging issue. I spoke to my friend who I sold my old crushed 9 bov to 6 years ago and he still has it, so I get to have it back 
Sep 4, 2019, 10:28 AM
#24
EvoM Community Team Leader
I'm wondering if anyone knows if the "Intake Reversion AFS Reset Control" tables are meant to deal with this issue?
Sep 4, 2019, 01:18 PM
#26
I have an 05, came with plastic POS BOV. Swapped in a JDM metal BOV almost first thing. The evo 9 had not dropped yet so it was my only option. Last year when I got tuned Boostin crushed it for me. Holds 30psi. That BOV plus SD my car is smooth as silk. Can part throttle and decel just fine. Only bucking i get is really low RPM due to cam I believe.
Sep 4, 2019, 03:56 PM
#27
Stock uncrushed DV here. No issues at all. Smooth as can be. I only run 27 psi though.
I ran a Turbosmart recirc style before and nothing but surging and bucking when getting off the throttle. It was horrible. But now that I am on SD, I may try it again. Maybe...
I ran a Turbosmart recirc style before and nothing but surging and bucking when getting off the throttle. It was horrible. But now that I am on SD, I may try it again. Maybe...
Sep 4, 2019, 04:16 PM
#28
I have an 05, came with plastic POS BOV. Swapped in a JDM metal BOV almost first thing. The evo 9 had not dropped yet so it was my only option. Last year when I got tuned Boostin crushed it for me. Holds 30psi. That BOV plus SD my car is smooth as silk. Can part throttle and decel just fine. Only bucking i get is really low RPM due to cam I believe.
