1) What is spoolong up?? I know it's stupid question but why do have to be past a certain RPM to produce boost. If you stab the throttle say @ 2k your gauge will register boost - but is it really boost?
2) Is that lag just the time the system takes to pressurize.
3) When you stab the throttle at alow rpm and you see your A/F gauge peg to green is that a) Your ECU going into WOT mode OR b) Your Fuel Pressure Riser seeing boost (if it is boost) and raising the fuel pressure up a notch.

Thanks everybody

Alvin

Alvin

http://www.cardomain.com/id/96rst

1) spooling is what a turbo does in order to give you boost

2) Turbo lag is the time in between the turbo spooling up usually more present in larger size turbos, but can easyly be less present with a little shot of nitrous.

3) when it is showing green it means your burning rich which is good.

1-spooling is the compressor wheel spinning, which is like he said building boost.
2-lag is the time it takes between opening the throttle and the time it takes for the turbo to build pressure.
3-green means the AF gauge is reading a high O2 voltage .8-.99
AF gauges dont read throttle position.

1995 Eclipse GS - HRC Stage 2 - Retired.
2004 350z Enthusiast / 2008 Nissan Versa SL

> 1) What is spoolong up??

I dont know technically. I dont know how to explain any better than "spooling up" itself. spinning increasingly faster?

I know it's stupid question but
>why do have to be past a certain RPM to produce boost.

A certain amount of exhaust energy is required to turn the turbine fast enough to produce boost. Lower rpms=lower exhuast energy. In general the bigger the turbine side the more energy is required to spin it sufficiently, all other things being equal.


If
>you stab the throttle say @ 2k your gauge will register
>boost - but is it really boost?

Yes its really boost, its just not worth a damn. You probably read a few lbs of boost at 2200rpms but the turbine side is still restrictive enough to make such small amount of boost virtually useless. A tiny turbo would likely make enough boost at 2200rpms to make it worthwhile but sacrafice top end power (which small turbine would become restrictive at high rpms). In other words the benefit of boost has to overcome the backpressure of the restrictive turbine the exhaust has to pass thru before it produces any real power. NA there's no boost at 2200 but your also not trying to pass all the exhaust thru a tiny snail with a big ass blade clogging it up as well. At some point boost becomes beneficial despite the backpressure. With the star turbo appearantly its not happening yet at those rpms/boost levels your talking about. Also why supposedly there is no such thing as too big an exhaust for a turbo engine (in boost), because the turbine creates so much backpressure.

> 2) Is that lag just the time the system takes to
>pressurize.

lag=The time it takes to reach full boost once boost onset starts (taken from Corky Bells "Maximum Boost" ).

onset=when any boost is produced

because it produces boost and you are not feeling any power is not lag

> 3) When you stab the throttle at alow rpm and you see your
>A/F gauge peg to green is that a) Your ECU going into WOT
>mode OR b) Your Fuel Pressure Riser seeing boost (if it is
>boost) and raising the fuel pressure up a notch.

hard to say. you can blip the throttle with no FMU and without ever achieving WOT and peg it at green momentarily before the ECU begins to cycle. On the other hand theres also a momentary rich spike caused by the FMU as well when you 1rst lay into the throttle at boost producing rpms (you wouldn't get that from a quick stab at the thottle at low rpms, not with your turbo anyway. no time to build any boost). A slow reacting FMU might cause the oposite, a momenetary lean spike until it catches up with boost. If you are talking about it being pegged at green with your foot planted at low rpms (like in 5th gear at 2400rpms with 2lbs of boost)its the ECU in WOT closed loop operation. Of course without the FMU it might be pegged in yellow.

I could be wrong on alot of this sh*t, dont bet your life on any of it. hahn, corbin, armond, murix, jason, dino, rick or somebody can make the appropriate corrections.

:farfrommugen:
Yes I still own a 2gnt.
Damn right I've been here longer than U
klassic_liven@yahoo.com

Hmmmm..interesting, gotta check out the dsm page to even get more technical. So when you do punch the throttle at 2k in 5th gear and yo produce 2lbs of boost - the boost is not really there?..I thought boost is only produced when the turbo is spooled and the turbine is spinning fast enuff to spin the compressor to produce boost? I'm not directing it directly at you Stan, you just got me thinking bout stuff. Also I know that when you do use a Pressure dependent fuel riser there will be a dead spot at and around 0 vaccumm and wouldn't it produce a lean spot?...This turbo thing got my head spinnin...

Alvin

Alvin

http://www.cardomain.com/id/96rst

>Hmmmm..interesting, gotta check out the dsm page to even get
>more technical. So when you do punch the throttle at 2k in
>5th gear and yo produce 2lbs of boost - the boost is not
>really there?..I thought boost is only produced when the
>turbo is spooled and the turbine is spinning fast enuff to
>spin the compressor to produce boost

if your gauge is reading 2lbs at 2K its there. The gauge is reading pressure at the intake manifold, it wont lie. If your seeing 2lbs at 2K rpms then the turbo is spinning fast enough to produce it. Its there but its not producing any significant power.

Only thing I can give an analogy to is maybe a supercharger. If a supercharger is producing 2lbs of boost but requires 30hp to turn the supercharger boost is still there but its not helping power any. Well with a turbo instead of parasitic drag from a belt drive its backpressure from the restrictive turnibe housing. At some point the supercharger will be making 6lbs of boost which will outweight the 30hp it takes to turn. At some point with a turbo there will be enough boost to offset the restriction caused by the turbine. In your case its not happening at 2K. Your car probably doesn't feel any faster than a NA car at 2k rpm, maybe worse.

:farfrommugen:
Yes I still own a 2gnt.
Damn right I've been here longer than U
klassic_liven@yahoo.com