BOCU Anyone had decent results ?
25 December 2002, 08:57 PM
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G'day all
These boost oscillation units are gaining popularity over here. I was wondering if you guys have had much experience with them ?
The one way valve allows improved pick up when off boost, spooling the turbo quicker apparently.
Easier to fit with the reversed manifold but the remote adaptor under the manifold keeps it nice and stealth !
Bruce
These boost oscillation units are gaining popularity over here. I was wondering if you guys have had much experience with them ?
The one way valve allows improved pick up when off boost, spooling the turbo quicker apparently.
Easier to fit with the reversed manifold but the remote adaptor under the manifold keeps it nice and stealth !
Bruce
25 December 2002, 11:27 PM
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Correct John, quite often referred to as PMSLOL - Power Modulating Systems Limiting Overrun Lag.
I have read that a number of these have been fitted to cars in the UK and was looking for some feedback
I have read that a number of these have been fitted to cars in the UK and was looking for some feedback
25 December 2002, 11:51 PM
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This is a quote from a user on NASIOC
We all know USA horses are a bit weaker 
than UK/Auz horses, still a fair result though.
Bruce
Got to say, results are proving to be very interesting over established tuning methods.
Have now got converted T67 Greddy turbo on board and 1 bar of boost occurs at 2600rpm with no loss of pressure even up to 7500!!!
The little known intercooler company *PerformAir* has achieved incredible results which just goes to show how well, true engineering always shines through.
At a solid 1.4 bar boost across the rev range, this car achieves an incredible 395Ib ft of torque with 385 flywheel bhp.
Have now got converted T67 Greddy turbo on board and 1 bar of boost occurs at 2600rpm with no loss of pressure even up to 7500!!!
The little known intercooler company *PerformAir* has achieved incredible results which just goes to show how well, true engineering always shines through.
At a solid 1.4 bar boost across the rev range, this car achieves an incredible 395Ib ft of torque with 385 flywheel bhp.
than UK/Auz horses, still a fair result though.Bruce
26 December 2002, 12:39 AM
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Bruce,
I think you should point out that this system needs to be run with water injection !!!!! This can clearly be seen on your engine, and you really need to let people know ALL the details.
Just for you Wallis
Mark.
[Edited by R19KET - 12/26/2002 11:15:40 AM]
I think you should point out that this system needs to be run with water injection !!!!! This can clearly be seen on your engine, and you really need to let people know ALL the details.
Just for you Wallis
Mark.
[Edited by R19KET - 12/26/2002 11:15:40 AM]
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26 December 2002, 10:00 AM
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Correct Mark, There is a slight risk of detonation unless the engine is fully remapped to compensate for the increased airflow.
Water injection can indeed overcome this.
The car in the pic is not my RA, it is clearly a 99- from the throttle body/bodyshell design (intercooler hose through inner wing)
May I also mention that this system can only be used with a Link/Motec/GEMS or similar ECU which uses MAP as the load reference, the air flow meter is temporarily bypassed during turbo spool up phase via the additional reed valve controlled intake port.
More info on this system can be viewed at
http://www.boyesen.com/products/snowmobile/index.html
good night
Bruce
[Edited by 96 Rex RA - 12/26/2002 10:04:19 AM]
Water injection can indeed overcome this.
The car in the pic is not my RA, it is clearly a 99- from the throttle body/bodyshell design (intercooler hose through inner wing)
May I also mention that this system can only be used with a Link/Motec/GEMS or similar ECU which uses MAP as the load reference, the air flow meter is temporarily bypassed during turbo spool up phase via the additional reed valve controlled intake port.
More info on this system can be viewed at
http://www.boyesen.com/products/snowmobile/index.html
good night
Bruce
[Edited by 96 Rex RA - 12/26/2002 10:04:19 AM]
26 December 2002, 10:31 AM
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Bruce,
I do find that with the LINK the oscillation can get out of control - so I am using the MF2 to both control the water and an air injector valve to control the oscillator. With this approach I can get the MD309 to produce 1bar of boost in around 14ms at 1700rpm - right up to the redline at 9,000 rpm. Its amazing how the oscillator helps you increase the redline - why didn't you mention it!
Anyway - on the rollers I got 478ft lbs of torque and 415bhp at the top end - mind you the boost was tailing off there to around 0.8bar.
Trout
I do find that with the LINK the oscillation can get out of control - so I am using the MF2 to both control the water and an air injector valve to control the oscillator. With this approach I can get the MD309 to produce 1bar of boost in around 14ms at 1700rpm - right up to the redline at 9,000 rpm. Its amazing how the oscillator helps you increase the redline - why didn't you mention it!
Anyway - on the rollers I got 478ft lbs of torque and 415bhp at the top end - mind you the boost was tailing off there to around 0.8bar.
Trout
26 December 2002, 01:01 PM
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WTF?
Could somebody explain what this actually does, because at the moment my "Snake Oil" light is flashing, especially seeing the above (and highly suspicious looking) pic.
Could somebody explain what this actually does, because at the moment my "Snake Oil" light is flashing, especially seeing the above (and highly suspicious looking) pic.
26 December 2002, 01:18 PM
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I think this thread should be one of the first for the 'Advanced Technical" forum...It would make a great start for the new year.
Anyone else agree?????
Think I'll go have another drink now
[Edited by ustolemyname??stevieturbo - 12/26/2002 1:19:57 PM]
Anyone else agree?????
Think I'll go have another drink now
[Edited by ustolemyname??stevieturbo - 12/26/2002 1:19:57 PM]
26 December 2002, 03:02 PM
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Deep, the url relates to the special high pressure carbon reed valves which form the key part of the BOCU. They are also used on racing 2 stroke engines such as snowmobiles.
Trout I think you are making fun of me ? why ? Do you not understand ?
Here is a better link which will go some way to explaining the theory
http://www.boyesen.com/products/moto.../radvalve.html
Bruce
[Edited by 96 Rex RA - 12/26/2002 3:08:13 PM]
Trout I think you are making fun of me ? why ? Do you not understand ?
Here is a better link which will go some way to explaining the theory
http://www.boyesen.com/products/moto.../radvalve.html
Bruce
[Edited by 96 Rex RA - 12/26/2002 3:08:13 PM]
26 December 2002, 03:09 PM
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I believe it is very real. Isnt this what has made THOMO's car so fast??? It wasnt the 2.7 18valve legacy/wrx conversion, or the ported and flowed Evo spark plugs, or even the STI 25 ecu, it was the BOCU he also didnt mention that was fitted by his mechanic.
26 December 2002, 03:55 PM
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There will be at least 3 cars at Well Lane 4 using a similar set up to this. Harvey's, Alan.G's and my own
I find it amusing just how little people actually know or understand about these systems.
Andy
I find it amusing just how little people actually know or understand about these systems.
Andy
26 December 2002, 04:11 PM
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AndyF,can you please tell me if one of these can be run with a car using Ecutek and WI(2s) or is a MAP based ECU essential.Also where can you purchase them from?
Many thanks,Deep
Many thanks,Deep
26 December 2002, 04:51 PM
#21
This would actually work btw. It's just a valve that allows the engine to draw air straight in (ie not through the turbo) when driving off boost.
The WI hokum is nonsense, unless you feel you need WI at 2000rpm with no boost....
The picture above looks like a fake, as there appears to be no reed block, unless it magicallly fits in the filter, but then the thing would be rather small.
Probably more at home on a low emissions, low power, high efficiency concept car.
Paul
The WI hokum is nonsense, unless you feel you need WI at 2000rpm with no boost....
The picture above looks like a fake, as there appears to be no reed block, unless it magicallly fits in the filter, but then the thing would be rather small.
Probably more at home on a low emissions, low power, high efficiency concept car.
Paul
26 December 2002, 06:44 PM
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Bruce,
you are right - I don't understand how it works. I got mine set up complete from Andy.F - I think he has most testing in the UK.
However I do think that Pavlo understands less than I do - as a proxy anti-lag system you will find that you do need the WI as the EGTs skyrocket at low rpms destroying turbos as the boost is rising.
Before fitting I was only getting 346bhp and even less torque. I think that anyone who needs help in the UK should speak to Andy - he really understands how this works.
Trout
[Edited by Trout - 12/26/2002 6:48:47 PM]
you are right - I don't understand how it works. I got mine set up complete from Andy.F - I think he has most testing in the UK.
However I do think that Pavlo understands less than I do - as a proxy anti-lag system you will find that you do need the WI as the EGTs skyrocket at low rpms destroying turbos as the boost is rising.
Before fitting I was only getting 346bhp and even less torque. I think that anyone who needs help in the UK should speak to Andy - he really understands how this works.
Trout
[Edited by Trout - 12/26/2002 6:48:47 PM]
26 December 2002, 07:24 PM
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I'm not sure I believe in all these 'bolt-ons' but perhaps it goes some way to explaining why andyf has made 370 hp for under £1000 when others seem to have spent fortunes for much lower output figures ?
26 December 2002, 08:33 PM
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Bruce, I have managed to get this working with a MAF based ECU today with a few tricks with a microcontroller. Details remain under wraps for now until the next rolling road day. Needless to say there will be some eyebrows raised when I operate the control unit
26 December 2002, 10:17 PM
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Just spoke to a friend(who does'nt post here) who had this mod fitted a few weeks ago on his STi7.Reckons that he's getting 1 bar boost at 2000rpm,and 1.3 bar boost by 2600rpm all the way to 6000rpm then tails down to 1 bar by 7000 rpm.In other words no lag at all!! I'm ordering mine on Monday!
27 December 2002, 11:16 AM
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C'mon guys...you at least have to admit how these work?
The website makes no reference to anything other than high airflow on NA, Carbed, small displacement engines. Totally irrelevant to a scooby, then?
What is Boost Oscillation? Does the engine not recieve a smooth constant flow of pressurised air? Does fitting a flap on the injection manifold (which presumably loses all that compressed charge when it pops open) improve things? How?
Is it the resistance of the engine that prevents a turbo from spooling up quickly, in which case there are much better ways of achieveing this result than a flap on the inlet manifold! (think dump-valves with light springs, think ISCV people)
Until I see some real technioal information, this will remain a work of fiction, guys.
The website makes no reference to anything other than high airflow on NA, Carbed, small displacement engines. Totally irrelevant to a scooby, then?
What is Boost Oscillation? Does the engine not recieve a smooth constant flow of pressurised air? Does fitting a flap on the injection manifold (which presumably loses all that compressed charge when it pops open) improve things? How?
Is it the resistance of the engine that prevents a turbo from spooling up quickly, in which case there are much better ways of achieveing this result than a flap on the inlet manifold! (think dump-valves with light springs, think ISCV people)
Until I see some real technioal information, this will remain a work of fiction, guys.
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