how can i get wastegate chatter on a 350zx

O'dear....

I thought it was standard issue to plug the re-circs when fitting BOV's???

What should be done then to combat this if you still want to keep the BOV's?

I used to run the re-circs as well as the BOV's but was told this was wrong and that I should remove them...

well there on a tip somewhere now so shall I go foreging for some new ones to replace them with???

Or is the fact that I have BOV's fitted mean that It doesnt reallly make any difference now as the fueling could technically be incorrect for the first few seconds or re-application of the throttle? :confused:

 

Ta

O'dear....

I thought it was standard issue to plug the re-circs when fitting BOV's???

What should be done then to combat this if you still want to keep the BOV's?

I used to run the re-circs as well as the BOV's but was told this was wrong and that I should remove them...

well there on a tip somewhere now so shall I go foreging for some new ones to replace them with???

Or is the fact that I have BOV's fitted mean that It doesnt reallly make any difference now as the fueling could technically be incorrect for the first few seconds or re-application of the throttle? :confused:

 

Ta

 

Nooooo Bov's do the same job as the re-circs just its venting to air, as long as you have one or the other your ok.

 

Cossies running about 22psi with a cone filter and no BOV's is the sort of sound your looking for you will never get a z to sound as extreme as that unless you block off the re-circs and up the boost (but I aint trying it )

Nooooo Bov's do the same job as the re-circs just its venting to air, as long as you have one or the other your ok.

PHEWwwwwww

CheerZ there :duffer:

My dumpvalves make a "woop" noise. Is this how they are supposed to sound? It gets a bit irritating, especially if you are running at a speed where the woop becomes constant.

Are you sure its the dump valves making that noise?

Have you still got re-circs fitted?

My re-circs used to make a GooseHonk noise at constant high speeds...so i pulled them out and plugged them.

i pulled them out and plugged them.

 

And what did u replace with bud ?? bov's ?

And what did u replace with bud ?? bov's ?

no bud....

I had some alloy caps made up and had them inserted into the empty tubes where the re-circs used to plug into and blanked of the vacuum pipes coming from the re-circs

(well...i say i did..i didnt really it was me bud bud chris aka Krsmayo)

My dump valves are fitted just in front of the throttle bodies on the top of the engine bay...See RIDES :cool:

They should work more effectivly there as this is the point at which the pressure will build up first instead of half way round the system like the old re-circs :smash:

plugging the re-circs and having no BOV causes the air to stop flowing through the MAF when you lift off sharp after accelerating, and it stalls (usually going into a corner fast!) which, on an auto, leaves you with no power steering and a brown mark on the seat.

 

effectively, wastegate chatter is the compressor going into surge, which will wreck it and on big turbos, over time the stress on the impellor shaft can cause it to shear, resulting on the nut getting drawn into the engine.

plugging the re-circs and having no BOV causes the air to stop flowing through the MAF when you lift off sharp after accelerating, and it stalls (usually going into a corner fast!) which, on an auto, leaves you with no power steering and a brown mark on the seat.

I have never had it stall on me bud ;)

well not yet anyway :rolleyes:

my apexi's (probably along with most other types of bov) make different noises depending on the boost level they are dumping. at high boost (say 10+) they give a loud PSSSSSTTT (or a TISSSHHHH when the Z was automatic), but at low boost (5 and below) it gives a quiet but not too quiet WHHIPP-T-T-T-t-t-t :D

 

[cough]

Good sound effects there mate :tongue:

Good sound effects there mate :tongue:

 

lol, cheers. [drinks glass of water]

I have never had it stall on me bud ;)

well not yet anyway :rolleyes:

 

But you have BOVs :tongue: Ergo no problem (in fact, the opposite - the turbos will still be sucking in air, the MAF metering it, but all that air will be wasted.. so the ECU will inject wayyy too much fuel..)

k...thanks :tongue:

So does that mean I will be loosing power on the initial re-application off the throttle after a gear change coz its running rich for those few secounds?

Mine stalls now and again if i boot it coming up to a corner or junction and just dip the clutch

k...thanks :tongue:

So does that mean I will be loosing power on the initial re-application off the throttle after a gear change coz its running rich for those few secounds?

 

no i dont believe so because when you change up and take your foot off the pedal closing the throttle butterfly the throttle position sensor will tell the ECU that the throttle is closed, if it did continue to inject fuel as if you were wide open throttle then i imagine the engine would stall. Either way it would not be a case of rich for a few seconds the unburnt fuel would be ejected down the exhaust immediatly you will certainly not notice any performance loss.

stalling is more likely to be due to air leaks whether you have BOV's or not.

go ch ch ch ch ch ch(say it fast)!

 

Isn't that a dance?

 

Dave, I think that's CHA CHA CHA yer on about!! :rofl: ;)

no i dont believe so because when you change up and take your foot off the pedal closing the throttle butterfly the throttle position sensor will tell the ECU that the throttle is closed, if it did continue to inject fuel as if you were wide open throttle then i imagine the engine would stall. Either way it would not be a case of rich for a few seconds the unburnt fuel would be ejected down the exhaust immediatly you will certainly not notice any performance loss.

Good Good...just what I wanted to hear :dance:

Thanks fellas :bow:

so if the recirc valves dump back air to the intake side of the turbo... is that air that was under pressure and metered and had the right amount of fuel chucked in still taken into consideration by the ecu even though it hasnt passed back thru the afm to be metered by the ecu ???????? any one with me on this ?????