Turbo lag, when does your turbo hit full boost??

[terra88]

Tried to search as I thought this would have already been covered??

I want to know what RPM everyones ZD30 hits full boost (15psi)

Mine only hits 15psi at 2500rpm, although mine does have a top mount cooler so it might have a bit of lag compared to a stock motor. Just seems a bit high in the rev range to be hitting full boost??

 

[tweak'e]

sounds about right.
exhaust improves it a bit.
however what you have is not turbo lag. its simply under fueling in the low rpm's.

 

[04SilverSTR]

however what you have is not turbo lag. its simply under fueling in the low rpm's.

Tell us more wise one!

 

[-JOSH-]

+1 for more information

 

[Dave]

Mine comes on full boost around 2200-2500rpm.

 

[Dave]

Its the way the Maps are written for the computer.

 

[outback dreaming]

Good to know. Never ceases to amaze me what you can learn on this forum

 

[tweak'e]

just ask anyone that has chipped theirs, it picks up a lot of power in the low rpm.
i think its just to do with emissions. egr is normally on heavily in the low rpm so it pays to limit the fuel.

 

[4x4 ST-R]

How do I check what boost mine is running at? Probably with a boost gauge installed I suppose??

 

[ben85]

that would be the easiest way i believe.

 

[terra88]

sounds about right.
exhaust improves it a bit.
however what you have is not turbo lag. its simply under fueling in the low rpm's.

Well I always assumed that "turbo lag" is the delay or lag before the turbo hits full boost... my bad, and also how come when I over fueled my previous turbo Terrano or Surfs the low down power suffered until the turbo hit full boost to burn the extra fuel.... Doesn't make sense...

Anyway yes mine seems to hit 15psi boost at around 2500rpm but on the weekend and towing the trailer it hit full boost at 2200rpm so I guess its about normal compared to others...

Thanks guys for putting my mind at ease

 

[BP90]

Im hoping anyone can help me with this, i read this thread and was puzzled when reading that most of you reach max boost (15psi on your zd30) at around 2500rpm. As i didnt think mine reached it that early, so tonight on the way home i decided to check and see at what rpm mine reaches max boost. And it doesnt reach max until 3000rpm. So just after what you guys rekon would be the cause of this, would it be something like gauge error? Or maybe like an exhaust manifold leak or something to do with the intake side of things? Or something else?

Any help to try work out what is the possible cause would be greatly appreciated.

Cheers Bart

 

[qqc d22]

Could possibly be a slight blockage in the exhaust to? Cat cloged up or something

 

[tweak'e]

Well I always assumed that "turbo lag" is the delay or lag before the turbo hits full boost... my bad, and also how come when I over fueled my previous turbo Terrano or Surfs the low down power suffered until the turbo hit full boost to burn the extra fuel.... Doesn't make sense...

depends a bit on if its running a boost compensator or not. the other thing is changing fueling on a VE changes injection timing. my mem i think its increase fuel advances timing. you can get it advancing to much and loose power.
also pouring in to much fuel in the low rev's does tend to bog the engine down. i;ve had it with atmo diesels. more fuel means ton of smoke and no go.

....And it doesnt reach max until 3000rpm. So just after what you guys rekon would be the cause of this, ...

more than likely its because yours is stock standard.
blocking off egr, egr butterfly mod and exhaust all help bring the boost on earlier.

 

[pointblank5]

Mine can get to 15psi just under 2k. Cant remember if thats with watermeth on or not (set at 9psi)
Have got chip, exhaust and egr/swirl mods done and 80series airbox (dont think that makes much difference tho...

 

[BP90]

more than likely its because yours is stock standard.
blocking off egr, egr butterfly mod and exhaust all help bring the boost on earlier.

so is it 2200-2500rpm that it reaches max boost for people after they have done a few mods like exhaust and egr and intercooler? im just trying to work out if the 3000rpm for mine is normal or not before i go any further into like blocking the egr and geting and exhaust and intercooler and chip etc so that if there is actually a problem i can get it fixed before i do all that.

cheers bart

 

[tweak'e]

its been a few years so i'm trying to remember what it was like stock.
i'm pretty sure it doesn't get max boost till 3k in stock form.
egr butterfly doesn't turn off till 3k and they tend to come alive at 3k.
air flow and fuel is restricted under 3k so i would not expect full boost then.

if in doubt find someone with a stock engine and fit a boost gauge.

 

[Lawry]

Mine hits it around 2500 maybe a bit earlier 2400 is...
running 2.5 inch turbo back, xr6 front mount 2,5 inch system
pre filter removed, and EGR/Butterfly mod.
as of lag... well i really should of got the boost gauge before the intercooler mod... but it sits on 3-4 pound of throttle at 100... reaches 15 in a bit over a second.

Take your cat out... not sure what state your in but mine never needed one when going through nsw blueslip. An exhaust specialist said being pre 2006 or something and mechanical injection they dont need one by law...

thats a start?

 

[BP90]

Mine hits it around 2500 maybe a bit earlier 2400 is...
running 2.5 inch turbo back, xr6 front mount 2,5 inch system
pre filter removed, and EGR/Butterfly mod.
as of lag... well i really should of got the boost gauge before the intercooler mod... but it sits on 3-4 pound of throttle at 100... reaches 15 in a bit over a second.

Take your cat out... not sure what state your in but mine never needed one when going through nsw blueslip. An exhaust specialist said being pre 2006 or something and mechanical injection they dont need one by law...

thats a start?

In QLD, do you mean take it out because it might be blocked or just take it out as a way to increase performance?

 

[4x4 ST-R]

He means take out the cat as it restricts the exhaust flow.