Plumb Back Blow Off Valve

[Liiger]

Well the factory BOV is fully plumb back. I'm guessing nissan wouldnt do that unless they thought it wouldnt harm your engine or the BOV. Dunno if thats the case just my logic behind it.

[Munkyb0y]

Has anyone had any definitve results regarding fuel economy being increased by replacing an atmo bov with a plumb back bov?

I've heard all sorts of things, like atmo bovs cause the engine to run richer coz the air measured isnt all there once blown off, but fuel is still pumped in according to air intake, blah blah blah.

I dunno, it's all a big grey area to me.

I've got a GFB Hybrid BOV. Currently hooked up 50/50 atmo. So it is plumbed back, but also blows atmo 50%. I can just plug the trumpet and make it full plumbed.

By the way, if anyone has the screw in plug for my bov, let me know. I havent got one. Emailed GFB, not sure if they're available separately.

[Liiger]

I've got a similar BOV to yours Munky. The Deceptor Pro. Usually drive around with it on full atmo and get over 400k's a tank just about always. Havent tried full plumb back for the tank tho.

[Munkyb0y]

Ive only had my R33 for less than 2 weeks.

Should i reset my ecu? Would this perhaps remove the previous owner's driving style, and maybe give me better fuel economy?

As i understand it, reset ecu by disconnecting battery (positive) and hit the brakes or lights a few times to drain any remaining power.

[Madaz]

Ive only had my R33 for less than 2 weeks.

Should i reset my ecu? Would this perhaps remove the previous owner's driving style, and maybe give me better fuel economy?

As i understand it, reset ecu by disconnecting battery (positive) and hit the brakes or lights a few times to drain any remaining power.

it was my understanding that u left it disconnected for 12 odd hours maybee sum1 could clarify this

[Liiger]

Woah the ECU actually learns?

[Munkyb0y]

Can anyone confirm?

Is it wise to reset the ecu when you first get the car (R33) ?

How do you go about reseting the ecu ?

[Munkyb0y]

I just got this email from GFB:

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As for fuelling issues, whilst it is possible that atmosphere-venting blow-off valves can increase fuel consumption, it is important to note that they do NOT change the air fuel mixture when they are closed, which is any time you are driving and cannot hear it venting. When they vent, this is when it can cause a rich spike, but fortunately a well set-up valve will make no measurable change in economy. Since your valve is a Hybrid, 50% of the air is being recirculated, which in itself will cut any potential extra fuel use straight away. Second, if the spring pre-load is set correctly so that the valve only vents when lifting the throttle after boosting (instead of every time you lift the throttle regardless of boost), this will also ensure excess fuel is kept to a minimum. It is also important to note that most modern ECUs will cut the injectors on a trailing throttle to conserve fuel, which means about half a second after you lift off the throttle, the injectors will cut regardless of what the valve is doing.

So to summarise, yes, an atmo valve can cause an increase in fuel consumption, but with the size, spring adjustment range and configuration of the 50/50 venting of the Hybrid, it is unlikely. Either way, if you are plugging off the trumpet, you will eliminate the concern altogether.

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[Madaz]

still doesnt awnser your question about resetting ECU

after reseting your ECU and your drive hard so the ECU learns a hard drving style is it allways going to give you more spray in the injectors cuase the car thinks you allways want to drive hard ?

i get dredfull fuel econo but im 88% of the time on the boost

and by dredful i mean this week i got a little under 300km for the tank but could of squeezed 25-35 maybee more out of it dont want to run it dry

[Liiger]

Dang man, whats the hurry? Just change before that needle hits 3k. Saves me heaps of fuel. Now getting near constant 450k's per 50L. And hoping its gonna go up soon as I get a Power FC.

[Munkyb0y]

still doesnt awnser your question about resetting ECU

after reseting your ECU and your drive hard so the ECU learns a hard drving style is it allways going to give you more spray in the injectors cuase the car thinks you allways want to drive hard ?

That's what i want to know.

Also, how do you reset ecu ?

Is it even advisable to do so ?

[Munkyb0y]

Found this thread about resetting ecu, benefits etc.

http://www.skylinesaustralia.com/forums/in...ST&f=10&t=13711

[Liiger]

Well just ran a week with my BOV closed and got about 460k from 51L, when Bov was open and same driving patterns (shifting before 3k) got about 420k's from 53L.

[Freddy Kruger]

can anyone recommend a cheap plum back bov? i got this loud ass one on my new r33 and its amazing i havent been pulled over yet... even somewhere i could buy a standard one...

Edited June 18, 2006 by Freddy Kruger

[Liiger]

Yeah just buy a stock one, they do the job quite nicely. what sort of BOV do you have atm? You should be able to make it plumb back by piping it back into the standard hose.

[dd4321]

Yeah just buy a stock one, they do the job quite nicely. what sort of BOV do you have atm? You should be able to make it plumb back by piping it back into the standard hose.

That's right. I just converted my HKS SSQV from atmo to pulmb back. Too early to tell if it improves fuel efficiency, but early indication is pretty good though. The car is not running as rich as before.

Got the kit from BD4 for $35... money well spent...

[Madaz]

Well just ran a week with my BOV closed and got about 460k from 51L, when Bov was open and same driving patterns (shifting before 3k) got about 420k's from 53L.

thats awsome economy i think mine is going down hill rapidly so hard to drive under 3k when it sounds soo good above that

but even when i do pussy foot it i dont get much over 300 from a tank ... but that isnt my full tank over until warning light comes on i dont drive it till fuel light goes on i normally drive till the 1/4 of a tank mark

on a side note how many ppls got funny fuel guages where u mioght say get 200km's b4 the guage moves then it drops quickly the next 100km

[Liiger]

Heh awesome fuel economy will be past 500k's to 50L. Should make it happen when i get my Apexi FC. Will keep ya posted. But if your jsut driving to work or whatever, keep your BOV closed and when your having fun open it. Love this deceptor, well worth it in the end.

Yeah I think the fuel gauges on all Nissans are warped. My old Exa did that, my mates silvia does it and so does my mum's blurbird.

[Munkyb0y]

Yeah plumb back might be the way to go.

I've got a GFB Hybrid bov. U can plumb back full, half, or have full atmo.

It's just a matter of replacing the trumpet with the screw in plug.

I actually prefer the flutter sound it makes now rather than the loud pshhhhht blow off sound.

I think you only really get that if you are running a pod and maybe exhaust.

As for fuel economy, cant say yet, only plumbed back yesterday.

And yes, looks to me too like the nissan fuel gauge is not proportional.

On a crappier note, the f*cker that sold me my car claimed the timing belt and 100k service had been done.

After chasing him up for the receipt he promised he'd dig up, he finally spits out that it hadnt been done.

So i'm getting it looked at today, coz now I have now idea what it actually needs.

I've heard others say, when you get the car, change everything regardless. Sounds like good advice.

Hoping it's got old plugs. Coz if it does, that might explain fuel economy too.