2MUCHKW Member 350 Member For: 18y 10m 18d Posted 17/12/06 08:17 AM Share Posted 17/12/06 08:17 AM Installed 4" dump pipe and removed factory BOV.←Hi Jason,Sounds like it was an exhaust restriction partically causing the lack of power!Great to hear you've got it sortedCheersJustin Link to comment Share on other sites More sharing options...
Romulus Donating Members 1,279 Member For: 20y 2m 6d Location: Perth Posted 17/12/06 10:40 AM Author Share Posted 17/12/06 10:40 AM Installed 4" dump pipe and removed factory BOV.←Hi Jason,Sounds like it was an exhaust restriction partically causing the lack of power!Great to hear you've got it sortedCheersJustin←Thanks Justin,IMHO it was the BOV causing the bulk of the power loss. I had the factory BOV plumbed into the Cobra kit, which I suspect was bleeding off a huge amount of boost before the t/b, recirculating the air back to the air intake. Put it another way, the wastegate DC tables have dropped from 80-90% to 30-40%. Says a lot about what was going on. I've also been able to add an extra 6 degrees of spark without any detonation.With this knowledge I'm sure 400+ rwkw will easily be achievable. Link to comment Share on other sites More sharing options...
2MUCHKW Member 350 Member For: 18y 10m 18d Posted 18/12/06 12:24 PM Share Posted 18/12/06 12:24 PM Installed 4" dump pipe and removed factory BOV.←Hi Jason,Sounds like it was an exhaust restriction partically causing the lack of power!Great to hear you've got it sortedCheersJustin←Thanks Justin,IMHO it was the BOV causing the bulk of the power loss. I had the factory BOV plumbed into the Cobra kit, which I suspect was bleeding off a huge amount of boost before the t/b, recirculating the air back to the air intake. Put it another way, the wastegate DC tables have dropped from 80-90% to 30-40%. Says a lot about what was going on. I've also been able to add an extra 6 degrees of spark without any detonation.With this knowledge I'm sure 400+ rwkw will easily be achievable.← why are you still running the OEM BOV????Nizpro kits dont run a BOV at all ... no need.I assume the induction noise annoys you on deaccelerationCheersJustin Link to comment Share on other sites More sharing options...
Romulus Donating Members 1,279 Member For: 20y 2m 6d Location: Perth Posted 18/12/06 10:48 PM Author Share Posted 18/12/06 10:48 PM why are you still running the OEM BOV????Nizpro kits dont run a BOV at all ... no need.I assume the induction noise annoys you on deaccelerationCheersJustin←You assume correct, the trailing throttle noise sh*ts me - makes the car sound like a boy racer car. Not desireable on a FPV IMO, hence I fitted the factory BOV.Oh well, I can't have it all my way, and will live with the noise - and extra power - removing the BOV has created. Link to comment Share on other sites More sharing options...
exahsix Member 296 Member For: 19y 5m 7d Location: Monterey, NSW Posted 19/12/06 01:46 AM Share Posted 19/12/06 01:46 AM What about replacing the factory BOV with an aftermarket one (still vented into the intake) but capable of holding more boost. Maybe a turbosmart one or such. Surely that's prefereable to having your turbo try to shear it's intake wheel off every time you back off under boost. Link to comment Share on other sites More sharing options...
Romulus Donating Members 1,279 Member For: 20y 2m 6d Location: Perth Posted 19/12/06 08:21 AM Author Share Posted 19/12/06 08:21 AM What about replacing the factory BOV with an aftermarket one (still vented into the intake) but capable of holding more boost. Maybe a turbosmart one or such. Surely that's prefereable to having your turbo try to shear it's intake wheel off every time you back off under boost.←I'm told by the experts I don't need to use one Part of the reason I want to retain the BOV is for the exact reason you describe.Now, why would companies advocate not to run one when the problem you describe can occur? Link to comment Share on other sites More sharing options...
2MUCHKW Member 350 Member For: 18y 10m 18d Posted 19/12/06 08:56 AM Share Posted 19/12/06 08:56 AM What about replacing the factory BOV with an aftermarket one (still vented into the intake) but capable of holding more boost. Maybe a turbosmart one or such. Surely that's prefereable to having your turbo try to shear it's intake wheel off every time you back off under boost.←I'm told by the experts I don't need to use one Part of the reason I want to retain the BOV is for the exact reason you describe.Now, why would companies advocate not to run one when the problem you describe can occur?←Hi Jason,Believe the experts for I've driven my old Nizpro stage II XR6T for the last 3 years now without a BOV and the turbo's end float is still like new ... Simon @ Nizpro knows his stuff!Actually now you dont have a BOV; go for a good fang up your nearest tight twisty mountain range road and see the massive throttle responce difference accelerating out of corners! Its so fuc..ing good not having a pesky BOV bleeding all your boost away the second you lift the throttle As for shearing your intake wheel off exahsix you are pumping a "GAS" with your turbo not a liquid! Gas is compressable so please tell me how your going to shear an intake wheel off or do any damage to a turbocharger at all not running a BOV???? BOV's are only utilized for emissions & induction noise suppression ... no other reason! They actually reduce allot of throttle responce upon tight twisty mountain range roads and I'll never run one ever! BOV's are Cheers Link to comment Share on other sites More sharing options...
exahsix Member 296 Member For: 19y 5m 7d Location: Monterey, NSW Posted 19/12/06 09:19 AM Share Posted 19/12/06 09:19 AM 2muckw I can see plenty of sense in what you're saying. As for compressing a gas....hmmmm....I guess a gas can still compress pretty hard and have a hell of a lot of force. Just like the exhaust gas does to the other wheel of the turbo. If they are fighting each other there could be opportunity for what's in the middle to break. Then again, one side of gas just fights against the other side of gas until they're equal. I dunno - I sell poker machines for a living so happy to be corrected by the experts.But hey, a couple of years of driving a stage 2 with no BOV and your turbo is perfect is pretty damn good evidence of the real world. I might give it a try then........... Link to comment Share on other sites More sharing options...
2MUCHKW Member 350 Member For: 18y 10m 18d Posted 19/12/06 09:43 AM Share Posted 19/12/06 09:43 AM 2muckw I can see plenty of sense in what you're saying. As for compressing a gas....hmmmm....I guess a gas can still compress pretty hard and have a hell of a lot of force. Just like the exhaust gas does to the other wheel of the turbo. If they are fighting each other there could be opportunity for what's in the middle to break. Then again, one side of gas just fights against the other side of gas until they're equal. I dunno - I sell poker machines for a living so happy to be corrected by the experts.But hey, a couple of years of driving a stage 2 with no BOV and your turbo is perfect is pretty damn good evidence of the real world. I might give it a try then...........←exahsix you cant compress a gas much at all with the standard turbo before the compressor wheel slips and cant grip / hold the air hence the gobble gobble sound! I forget the intake air charge PSI that his happens ... Simon @ Nizpro did tell me.Cheers Link to comment Share on other sites More sharing options...
Romulus Donating Members 1,279 Member For: 20y 2m 6d Location: Perth Posted 19/12/06 09:49 AM Author Share Posted 19/12/06 09:49 AM (edited) I guess the reason for the BOV's goes back to the days of bushed-bearing turbo's, and their slow spool up speed. Hence the need for one to keep the turbo spinning whilst changing gears.As for the extra throttle response - that's more than likely due to the extra 6-8 degrees of ignition timing over what it had.....did I mention the 408rwkw it pulled?Gonna have to see what I can squeeze out of it Friday. Edited 19/12/06 09:50 AM by M6 XR6T Link to comment Share on other sites More sharing options...
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