Procharged 350z uprev / maf / bov
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From: Odessa
Procharged 350z uprev / maf / bov
Hey guys , approximately in December I've bought a used c-2 procharger kit for my 350z. The Previous owner sold it to me along with procharger intercooler,7 psi pulley, 560cc injectors,
turboxs blow off valve , aem A/F gauge , Map sensor (his vehicle was running both map and maf sensors due to HKS F-Con engine management),
also some walbro fuel pump( i've changed it immediatly for the new one) etc .
I've started my supercharged project from rebuilding my engine with forged internals , but decided to keep the high compression with
Wiseco 11:1 pistons in order to swap back easily for N/A mode without loosing any power. May be its controversial but anyway...
My car was already prepared for some good supercharger mode-i mean full cat-less exhaust with tomei headers and tomei 264/264 camshafts...
My N/A Z was tuned with Osiris Uprev before so i believed to stay with it supercharged and gave it to authorised Osiris dealer in my local place to retune it.
Forgot to say that the kit came without any EFMU or whatever it calls , so i went with aeromotive fuel pressure regulator and handmade fuel return system.
Turboxs bov was changed for Tial Q bov cuz its sounds peachy. The first problems i've started to expierence - were the ripped belts during the dyno tune..
i had a big headache with it but due to my350z forum i've found solutions for it : handmade bracket that attaches the engine to the procharger bracket right
in the middle and some engine damphers from the both sides cuz it moves and flexes under the load.Frankly speaking the aluminum quality of those Procharger mounting
brackets is extremely poor .I'm looking forward to have it CNC milled from the alluminum alloy used in aircraft industry.Its lightweight and extremely durable.
I'll attach some photos if needed. Finally those problems were solved so we dyno tuned it and got some poor but result. 301 rwhp.The stock Maf sensor was out already
at 6000 rpm...so i knew i'd change it for Maf Gt by uprev somehow...My N/A build showed 235 rwhp on intake / exhaust modes with tomei camshafts.Anyway these are just the
numbers and different dyno-stands show different results ,also different tuners use different gears, thus we get different numbers i guess.
anyway my tuner finished its job ,so i took my Z back home and the first weird thing i've noticed was that it was really hard to start up the engine especially in the morning
after a long period of no-use and also my car started to stall after some hard kick-downs...I was told its smth wrong with the injectors ...so i've ripped apart the manifold to
make another leak and pressure test,changed the gaskets again...The injectors were just fine...Now i guess there is nothing about the injectors but the tune....Many of you may argue
that BOV wont work on centifugal supercharges thats why the kit comes with bypass valve that recirculates pressure back to intake before the SC head unit. On the Bov valve that vetns to atmosphere,
MAF has already accounted for the air that is in the intake manifold, and if it was allowed to escape to the atmosphere, the car would run overly rich due to the fact that
the ECU still believes that the air is in the intake tract ...I forgot to mention another terrible error that our tuners let to happen...They put me a
stiff 10 psi spring into the Tial bov...Now as we know that supercharger is belt driven blower and even at idle its makes big pressure that doesnt utilize thus causes compressor surge
and also a huge rise in temperature under the hood....Once my car was even taken by evacuator because of overheat...Since then i've tried different kind of springs also
those for superchargers 2-3 psi spings...They dont work...at idle they are wide opened - its makes my idle sick and during the acceleration its doesn't hold the boost almost
until 4000 rpm. Then i've tried to make it semi-closed with some wastegate spring ...6-8 + psi springs...works better...idle became more stable...but i've notice that during the acceletion
at idle it still lets the air to escape under 2.500-3000 rpm...smth like that... Do u think guys that the only way to keep it vented to atmosphere is to switch for the map sensor?
But actually i dont see it working anyway while the problem is with the spring...Map sensor could only help not to get rich under the high load...or am i wrong ?
Now if there is no way i can use those bov valves - i should switch for the bypass valve ,which one to choose ? springs are related to vacuum as we know...Do i still have to measure the vaccum
before making any steps toward the bypass...And u guys probably heard smth about those dual-port Bov valves...As i understand they could help by bypassing and venting at the same time - vortech sells smth like that .
Sorry for asking the same f...g questions, for the foreigner its a bit heavier to understand ) Also all of the mechanics and tuners here know nothing about SC , everybody here goes turbo,but it shouldnt be that easier.Dont get me wrong , i payed a lot of money and didnt get any result.Switched for another workshop ,guys here are trying to
help and they are honestly saying they dont know much of superchargers configuration/tuning...every errors that had been made - were found by myself searching on forums, articles etc...
There are different suggestions about it -one of them is to put the MAF sensor right after the air filter...now i have it 6-10 inches from the throttlebody...dunno whether it has to be there or
it has to be on its stock position ( guess it used to be couple of inches after the stock air filter... ) Any thoughts ? Let's take a look at the quote from Wikipedia above:
"An alternative method for utilizing both a MAF and a blowoff valve is to have the MAF located down stream between the intercooler and the throttle plate. This is known as Blow-through rather than the traditional Draw-through set up. Care must be taken as to the position of the MAF to prevent damage to the sensitive element. For example, on a SR20DET engine, the MAF must be at least 12" from the throttle plate, and the blowoff valve must be 6" from the MAF sensor. By using a blow-through method, the MAF won't be affected by the blowoff valve opening as the pressure is vented before the air reaches the MAF"
Basically it's the same setup I have ...
Another thing i'd like to ask u guys is about the silicone hose that goes from fuel regulator to one of the intercooler pipes . I'll try to describe what my tuner explained to me . The regulator is connected to the place where it only sees the boost , and no vacuum in order to keep the Ecu working the stock scheme in no-boost zone.the stock Ecu doesn't regulate the pressure with vacuum so we have left it working the same way ,in the boost mode - the regulator loads the pressure by the boost and keeps the pressure proportional ... Hope I get it translated right )
Thank y'all in advance , stay boosted )
Victor
turboxs blow off valve , aem A/F gauge , Map sensor (his vehicle was running both map and maf sensors due to HKS F-Con engine management),
also some walbro fuel pump( i've changed it immediatly for the new one) etc .
I've started my supercharged project from rebuilding my engine with forged internals , but decided to keep the high compression with
Wiseco 11:1 pistons in order to swap back easily for N/A mode without loosing any power. May be its controversial but anyway...
My car was already prepared for some good supercharger mode-i mean full cat-less exhaust with tomei headers and tomei 264/264 camshafts...
My N/A Z was tuned with Osiris Uprev before so i believed to stay with it supercharged and gave it to authorised Osiris dealer in my local place to retune it.
Forgot to say that the kit came without any EFMU or whatever it calls , so i went with aeromotive fuel pressure regulator and handmade fuel return system.
Turboxs bov was changed for Tial Q bov cuz its sounds peachy. The first problems i've started to expierence - were the ripped belts during the dyno tune..
i had a big headache with it but due to my350z forum i've found solutions for it : handmade bracket that attaches the engine to the procharger bracket right
in the middle and some engine damphers from the both sides cuz it moves and flexes under the load.Frankly speaking the aluminum quality of those Procharger mounting
brackets is extremely poor .I'm looking forward to have it CNC milled from the alluminum alloy used in aircraft industry.Its lightweight and extremely durable.
I'll attach some photos if needed. Finally those problems were solved so we dyno tuned it and got some poor but result. 301 rwhp.The stock Maf sensor was out already
at 6000 rpm...so i knew i'd change it for Maf Gt by uprev somehow...My N/A build showed 235 rwhp on intake / exhaust modes with tomei camshafts.Anyway these are just the
numbers and different dyno-stands show different results ,also different tuners use different gears, thus we get different numbers i guess.
anyway my tuner finished its job ,so i took my Z back home and the first weird thing i've noticed was that it was really hard to start up the engine especially in the morning
after a long period of no-use and also my car started to stall after some hard kick-downs...I was told its smth wrong with the injectors ...so i've ripped apart the manifold to
make another leak and pressure test,changed the gaskets again...The injectors were just fine...Now i guess there is nothing about the injectors but the tune....Many of you may argue
that BOV wont work on centifugal supercharges thats why the kit comes with bypass valve that recirculates pressure back to intake before the SC head unit. On the Bov valve that vetns to atmosphere,
MAF has already accounted for the air that is in the intake manifold, and if it was allowed to escape to the atmosphere, the car would run overly rich due to the fact that
the ECU still believes that the air is in the intake tract ...I forgot to mention another terrible error that our tuners let to happen...They put me a
stiff 10 psi spring into the Tial bov...Now as we know that supercharger is belt driven blower and even at idle its makes big pressure that doesnt utilize thus causes compressor surge
and also a huge rise in temperature under the hood....Once my car was even taken by evacuator because of overheat...Since then i've tried different kind of springs also
those for superchargers 2-3 psi spings...They dont work...at idle they are wide opened - its makes my idle sick and during the acceleration its doesn't hold the boost almost
until 4000 rpm. Then i've tried to make it semi-closed with some wastegate spring ...6-8 + psi springs...works better...idle became more stable...but i've notice that during the acceletion
at idle it still lets the air to escape under 2.500-3000 rpm...smth like that... Do u think guys that the only way to keep it vented to atmosphere is to switch for the map sensor?
But actually i dont see it working anyway while the problem is with the spring...Map sensor could only help not to get rich under the high load...or am i wrong ?
Now if there is no way i can use those bov valves - i should switch for the bypass valve ,which one to choose ? springs are related to vacuum as we know...Do i still have to measure the vaccum
before making any steps toward the bypass...And u guys probably heard smth about those dual-port Bov valves...As i understand they could help by bypassing and venting at the same time - vortech sells smth like that .
Sorry for asking the same f...g questions, for the foreigner its a bit heavier to understand ) Also all of the mechanics and tuners here know nothing about SC , everybody here goes turbo,but it shouldnt be that easier.Dont get me wrong , i payed a lot of money and didnt get any result.Switched for another workshop ,guys here are trying to
help and they are honestly saying they dont know much of superchargers configuration/tuning...every errors that had been made - were found by myself searching on forums, articles etc...
There are different suggestions about it -one of them is to put the MAF sensor right after the air filter...now i have it 6-10 inches from the throttlebody...dunno whether it has to be there or
it has to be on its stock position ( guess it used to be couple of inches after the stock air filter... ) Any thoughts ? Let's take a look at the quote from Wikipedia above:
"An alternative method for utilizing both a MAF and a blowoff valve is to have the MAF located down stream between the intercooler and the throttle plate. This is known as Blow-through rather than the traditional Draw-through set up. Care must be taken as to the position of the MAF to prevent damage to the sensitive element. For example, on a SR20DET engine, the MAF must be at least 12" from the throttle plate, and the blowoff valve must be 6" from the MAF sensor. By using a blow-through method, the MAF won't be affected by the blowoff valve opening as the pressure is vented before the air reaches the MAF"
Basically it's the same setup I have ...
Another thing i'd like to ask u guys is about the silicone hose that goes from fuel regulator to one of the intercooler pipes . I'll try to describe what my tuner explained to me . The regulator is connected to the place where it only sees the boost , and no vacuum in order to keep the Ecu working the stock scheme in no-boost zone.the stock Ecu doesn't regulate the pressure with vacuum so we have left it working the same way ,in the boost mode - the regulator loads the pressure by the boost and keeps the pressure proportional ... Hope I get it translated right )
Thank y'all in advance , stay boosted )
Victor
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