Discussion
Hi folks,
Just fitted a Forge BOV (Yellow spring) as per the instructions on the GTO3.com website. Took the car out for a run but didn't hear anything different other than the usual noises coming from the air filters. Checked that I was getting over 0.5bar of boost with no indication of it dropping. Everything seemed fine performance wise but I can't tell if the valave is working correctly. I've read back some of the previous threads and some guys reported that the valve can be 'lazy' to begin with.
Just looking for some reassurance that everything is fine really.
I appreciate that everybody's probably a bit tired of this subject but would appreciate any feedback that anybody has time to give.
Cheers,
Graeme
Just fitted a Forge BOV (Yellow spring) as per the instructions on the GTO3.com website. Took the car out for a run but didn't hear anything different other than the usual noises coming from the air filters. Checked that I was getting over 0.5bar of boost with no indication of it dropping. Everything seemed fine performance wise but I can't tell if the valave is working correctly. I've read back some of the previous threads and some guys reported that the valve can be 'lazy' to begin with.
Just looking for some reassurance that everything is fine really.
I appreciate that everybody's probably a bit tired of this subject but would appreciate any feedback that anybody has time to give.
Cheers,
Graeme
Naso Grande said:
Hi folks,
Just fitted a Forge BOV (Yellow spring) as per the instructions on the GTO3.com website. Took the car out for a run but didn't hear anything different other than the usual noises coming from the air filters. Checked that I was getting over 0.5bar of boost with no indication of it dropping. Everything seemed fine performance wise but I can't tell if the valave is working correctly. I've read back some of the previous threads and some guys reported that the valve can be 'lazy' to begin with.
Just looking for some reassurance that everything is fine really.
I appreciate that everybody's probably a bit tired of this subject but would appreciate any feedback that anybody has time to give.
Cheers,
Graeme
Just fitted a Forge BOV (Yellow spring) as per the instructions on the GTO3.com website. Took the car out for a run but didn't hear anything different other than the usual noises coming from the air filters. Checked that I was getting over 0.5bar of boost with no indication of it dropping. Everything seemed fine performance wise but I can't tell if the valave is working correctly. I've read back some of the previous threads and some guys reported that the valve can be 'lazy' to begin with.
Just looking for some reassurance that everything is fine really.
I appreciate that everybody's probably a bit tired of this subject but would appreciate any feedback that anybody has time to give.
Cheers,
Graeme
If the air filters are at the bulk head then its hard to hear, I'm never sure which sound is which on mine. Some of the other types of BOVs are a lot louder (I know mine is working as the lag was reduced between gear changes).
0.5bar, interesting is this a 2.5L I only ask as mine when running off wastegate is 0.75 (o.77 was factory) and then a bit more as I have a vairiable boost switch. I belive I have some kind of factory control valve in the line someware any ideas where this might be (or what it looks like , as I think I've found it).
Bondy
If the BOV is installed in the correct place and hooked up properly (and is venting to the atmosphere), it will have nothing whatever to do with the inlet air filters. It's purpose if to "blow off" excess pressure in the pipe feeding the throttle body, and thereby it reduces the back pressure on the compressor side of the turbos. You should hear it when you "lift" the throttle on any upshift.
Thanks guys. 0.5bar seems to be as much as get indicated on the gauge and it's a GTO-3. I don't hear it on every upshift and it is installed as on the GTO3.com website but maybe as Bondy says its hard to distinguish that noise and the noise you usually hear coming back through the air filters. This is where I find it confusing as I would have thought the usual sound would have stopped as when the BOV open all the air would exit through the Dump Valve and none would make it back through the turbo.
Cheers,
Graeme
Cheers,
Graeme
You should be reading .8 to .9, something is wrong.
I do not think you are building up enough pressure to get the BOV to open, not 100% sure about Turbos, look for leaks in the pipework, look at the pipework that connects to the intercooler, they tend to split on the bend.
May also be a sticking wastegate, someone will come along and correct me if I am wrong.
Basically you are getting around half boost. Get someone to look at it and as far as a lazy BOV is concerned, I have never heard that.
All the best.
Ash.
I do not think you are building up enough pressure to get the BOV to open, not 100% sure about Turbos, look for leaks in the pipework, look at the pipework that connects to the intercooler, they tend to split on the bend.
May also be a sticking wastegate, someone will come along and correct me if I am wrong.
Basically you are getting around half boost. Get someone to look at it and as far as a lazy BOV is concerned, I have never heard that.
All the best.
Ash.
Ash 996 GT2 said:
You should be reading .8 to .9, something is wrong.
I do not think you are building up enough pressure to get the BOV to open, not 100% sure about Turbos, look for leaks in the pipework, look at the pipework that connects to the intercooler, they tend to split on the bend.
May also be a sticking wastegate, someone will come along and correct me if I am wrong.
Basically you are getting around half boost. Get someone to look at it and as far as a lazy BOV is concerned, I have never heard that.
All the best.
Ash.
Ash, wrong I am afraid.... gto-3 is between .65 and .7 , M400 is .8 to .9.I do not think you are building up enough pressure to get the BOV to open, not 100% sure about Turbos, look for leaks in the pipework, look at the pipework that connects to the intercooler, they tend to split on the bend.
May also be a sticking wastegate, someone will come along and correct me if I am wrong.
Basically you are getting around half boost. Get someone to look at it and as far as a lazy BOV is concerned, I have never heard that.
All the best.
Ash.
Also remember that the boost gauge is not the most accurate...have you tried running it on the road with a lappy plugged in?
As I mentioned earlier, the noble seems to be 0.5 off the wastegate. Daddysummo's is and then 0.9 once the switch is flicked (Noblemotorsport conversion). A fellow 2.5 also hits 0.5. I have noticed that I have a small cylinder in my line (from factory) that I think is some king of restrictor (it has power) that allows the car to boost to 0.7ish.
So it maybe possible that this device is missing out of the car so its just working off the wastegates directly?
I'm trying to find out if this is true as I want to remove mine so my variable boost trim switch can run from 0.5 to 0.9 rather than 0.7 to 0.9 as it will give me more adjustment due to weather conditions.
Bondy
So it maybe possible that this device is missing out of the car so its just working off the wastegates directly?
I'm trying to find out if this is true as I want to remove mine so my variable boost trim switch can run from 0.5 to 0.9 rather than 0.7 to 0.9 as it will give me more adjustment due to weather conditions.
Bondy
Ash 996 GT2 said:
You should be reading .8 to .9, something is wrong.
I do not think you are building up enough pressure to get the BOV to open, not 100% sure about Turbos, look for leaks in the pipework, look at the pipework that connects to the intercooler, they tend to split on the bend.
May also be a sticking wastegate, someone will come along and correct me if I am wrong.
Basically you are getting around half boost. Get someone to look at it and as far as a lazy BOV is concerned, I have never heard that.
All the best.
Ash.
There seems to be some confusion about how a BOV works.I do not think you are building up enough pressure to get the BOV to open, not 100% sure about Turbos, look for leaks in the pipework, look at the pipework that connects to the intercooler, they tend to split on the bend.
May also be a sticking wastegate, someone will come along and correct me if I am wrong.
Basically you are getting around half boost. Get someone to look at it and as far as a lazy BOV is concerned, I have never heard that.
All the best.
Ash.
See this link for more info:
http://en.wikipedia.org/wiki/Blowoff_valve
(especially the section--and associated figures--under the heading of Operation).
The point is, the BOV is opened by manifold vacuum and not boost pressure. The spring in the valve body is only there to keep the valve closed under boost.
Edited by JLSELAN on Tuesday 12th August 05:50
alex s said:
Ash 996 GT2 said:
You should be reading .8 to .9, something is wrong.
I do not think you are building up enough pressure to get the BOV to open, not 100% sure about Turbos, look for leaks in the pipework, look at the pipework that connects to the intercooler, they tend to split on the bend.
May also be a sticking wastegate, someone will come along and correct me if I am wrong.
Basically you are getting around half boost. Get someone to look at it and as far as a lazy BOV is concerned, I have never heard that.
All the best.
Ash.
Ash, wrong I am afraid.... gto-3 is between .65 and .7 , M400 is .8 to .9.I do not think you are building up enough pressure to get the BOV to open, not 100% sure about Turbos, look for leaks in the pipework, look at the pipework that connects to the intercooler, they tend to split on the bend.
May also be a sticking wastegate, someone will come along and correct me if I am wrong.
Basically you are getting around half boost. Get someone to look at it and as far as a lazy BOV is concerned, I have never heard that.
All the best.
Ash.
Also remember that the boost gauge is not the most accurate...have you tried running it on the road with a lappy plugged in?
Thought they were all the same.
I knew someone would be along to put us all straight
While this is on the topic of boost pressure might i ask a question,
It is mentioned above and elsewhere that the M400 should run about .9 bar of boost, however the gauge in my car is showing that it peaks around 1.4 then sits around 1.2-1.3 bar till i lift.
My question being, should i be concerned or will it have been adjusted when the exhaust was done? i know the previous owner fitted the Roush system and handed me a print out showing 426bhp and roughly 410 lb/ft (hard to tell on the graph).
Oh and could someone please tell me why the interior light in my footwell comes on when the boost gauge is showing 1 bar or more of boost, its comical
thanks
Graham
It is mentioned above and elsewhere that the M400 should run about .9 bar of boost, however the gauge in my car is showing that it peaks around 1.4 then sits around 1.2-1.3 bar till i lift.
My question being, should i be concerned or will it have been adjusted when the exhaust was done? i know the previous owner fitted the Roush system and handed me a print out showing 426bhp and roughly 410 lb/ft (hard to tell on the graph).
Oh and could someone please tell me why the interior light in my footwell comes on when the boost gauge is showing 1 bar or more of boost, its comical
thanks
Graham
Edited by hollowpockets on Thursday 4th September 16:01
hollowpockets said:
While this is on the topic of boost pressure might i ask a question,
It is mentioned above and elsewhere that the M400 should run about .9 bar of boost, however the gauge in my car is showing that it peaks around 1.4 then sits around 1.2-1.3 bar till i lift.
My question being, should i be concerned or will it have been adjusted when the exhaust was done? i know the previous owner fitted the Roush system and handed me a print out showing 426bhp and roughly 410 lb/ft (hard to tell on the graph).
That sounds a bit high to me, although as mentioned it might just be an inaccurate gauge (especially give the interior light somehow being connected to it).It is mentioned above and elsewhere that the M400 should run about .9 bar of boost, however the gauge in my car is showing that it peaks around 1.4 then sits around 1.2-1.3 bar till i lift.
My question being, should i be concerned or will it have been adjusted when the exhaust was done? i know the previous owner fitted the Roush system and handed me a print out showing 426bhp and roughly 410 lb/ft (hard to tell on the graph).
I seem to remember that daddysumo had a case of one turbo being overworked to compensate for some kind of failure or lack of power from the other, but I think that one was still limited to 1 bar.
What does your gauge say when you're not accelerating?
sounds like you have had a remap on your car - an m400 never made 425 bhp from the factory
where was it rolling roaded - there are some very optimistic dyno's out there that quote 50% transmission losses
what did it make at the wheels ?
lots of people in the usa run big boost with standard valve springs
"Oh and could someone please tell me why the interior light in my footwell comes on when the boost gauge is showing 1 bar or more of boost, its comical"
that is quite funny - perhaps the extra power is pulling the doors open (only kidding)
where was it rolling roaded - there are some very optimistic dyno's out there that quote 50% transmission losses
what did it make at the wheels ?lots of people in the usa run big boost with standard valve springs
"Oh and could someone please tell me why the interior light in my footwell comes on when the boost gauge is showing 1 bar or more of boost, its comical"
that is quite funny - perhaps the extra power is pulling the doors open (only kidding)
Edited by gadgeroonie on Thursday 4th September 17:19
When its idling the gauge shows -0.7
Due to the interior lights flashing on when i boot it i'd guess a dodgey connection or readout from the gauge but will make a few phonecalls first, the previous owner doesn't know if the fuel pump was re-wired when the exhaust was fitted.
Thanks for the info guys
G
Due to the interior lights flashing on when i boot it i'd guess a dodgey connection or readout from the gauge but will make a few phonecalls first, the previous owner doesn't know if the fuel pump was re-wired when the exhaust was fitted.
Thanks for the info guys
G
Edited by hollowpockets on Friday 5th September 11:05
Spoke to the West tuning who fitted the exhaust and mapped it,they said around 1 bar was what it should have been at but it was done a year ago and that the 426bhp is what to expect with the exhaust and re-map as they never made claimed outputs from the factory, another company told me it should make 475 with a re-map and the roush exhaust, i find this hard to believe, thoughts??
the gauge could be 'out' or i may have an issue in the fusebox causing lights to come on and the maybe affect the gauge readout. They also said my car should have had the wiring on the fuel pump done, does anyone have before and after pictures so i can look and check?
Iv booked the car into a local specialist who can do a diagnostic check on the interior lights issue, check the boost level and find out if there is infact a problem at all.
again thanks for the time and help folks
Graham
the gauge could be 'out' or i may have an issue in the fusebox causing lights to come on and the maybe affect the gauge readout. They also said my car should have had the wiring on the fuel pump done, does anyone have before and after pictures so i can look and check?
Iv booked the car into a local specialist who can do a diagnostic check on the interior lights issue, check the boost level and find out if there is infact a problem at all.
again thanks for the time and help folks
Graham
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