How to keep the turbo's spooled up?

[rweir]

Hi All,

Just been talking to a friend about this. Just had the KO4's put on my car, and, more turbo lag which I knew was going to be the case.

Sometime I have the problem when chaning gear the boost is lost, I would like to be able to keep the turbos spinning to stop this.

I realise that this is not the best for the turbo's, so would like some way if possible to do this via a switch or something. Idea being if I wanted to keep the turbo's spun up for a period of 10 mins say I could, and the rest of the time it would be back to normal driving conditions ...

Anyone got any ideas if this is possible??

Cheers,
Rich [img]images/graemlins/s4anogaro.gif[/img]

[wazza]

V dangerous IMO. [img]images/graemlins/frown.gif[/img]
You would be better off changing higher up the rev range.

[Nige_RS4]

You would stall the turbos by forcing them to spin continously when changing gear, this would not only give you more lag [img]images/graemlins/033102bad_1_prv.gif[/img], but you will eventually be visted by the turbo lady [img]images/graemlins/boohoo.gif[/img]

I'm not sure that K04's give that much more lag - Where's Jeff when you need him ?

You might actually have a problem that has only manifested itself after fitting the K04's - check the usual BPV's and TBB for damage ??

Nige.

[DAVIDP20V]

There is a thing a friend had on his escort cossie a few years back called anti lag, which removed all/most lag. [img]images/graemlins/clap.gif[/img] [img]images/graemlins/clap.gif[/img]

i dont know how this worked or what it did but it worked, i am sure someone here would have heard of something
like this [img]images/graemlins/1syellow1.gif[/img] help anyone [img]images/graemlins/1syellow1.gif[/img]
oh yea when using anti lag it sounded like a rally car, pop-bang-pop-pop-bang .............. huge flame..... bang

[Nige_RS4]

Here's how the Cossie Anti-Lag system works. Happy reading [img]images/graemlins/thumbs.gif[/img]

In my opinion, it is for big turbos that suffer from massive lag.

[DavidT]

Not sure if I understand you correctly. Are you saying you want the turbos to generate full boost (controlled by a switch) constanlty regardless of throttle position and RPM ?

Not possible.

Turbos generate boost by using engine exhaust gas flow and you have more lag with K04's that K03's because they are larger therefore need more exhaust gas flow hence higher RPM to generate boost. The turbo has no power source other then exhaust gas flow to make it spin.

A turbo has two sides, a turbine on the exhaust side of the engine is turned by the exhaust gases leaving the engine. This is connected to a pump on the inlet side of the engine that pressures the air entering the inlet manifold - this is boost.

THe nearest thing to what you want is the anti-lag system used on rally cars. It works by making the air-fuel mixture very rich when the throttle is closed, then igniting this unburnt fuel in the exhause manifold when the throttle is opened again. This creates exhaust flow which in turn spins up the turbo and produces boost much more quickly than without the system. It is not practical for road cars because a) the exhaust manifold has to be extremely strong to withstand the heat/pressure produced b) not fuel efficient at all and c) it's expensive.

Your problem may just be the bypass valves not opening correctly to allow the turbos to spin during gear changes.

Hope this helps.

[rweir]

Thanks all for your input, Nige I read that link, that is exactly what I was looking for and very informative as to the different types ... somehow I don't think it is going to happen since I am certainly not going to be the first person to have it done to my car! Not rich (no pun intended!) enough for that!

But interesting stuff, now I know where that pop-bang-splutter noice comes from! [img]images/graemlins/smile.gif[/img]

So take it no one has had this fitted to their S4, RS4?

r [img]images/graemlins/s4anogaro.gif[/img]

[Prawn]

Hi rich,
First off anti lag kills turbo's, no two ways about it.
It is only a real possibility for competition cars.
With a FBW throttle it would be fairly easy to program in you just need to keep pumping fuel through the system when the throttle is closed but it is a bit like smacking the turbines with a sledge hammer to crack a nut.

Re the lag, when my K04's were put on I did not see any increase in lag but I also had the lightened flywheel added at the same time.

[DavidT]

when my K04's were put on I did not see any increase in lag

That's good. I assume you get initial boost a bit higher up the rev range though ?

[Joshie]

I can still remember the first time I drove my S4 with the KO4's fitted and I remember thinking how little turbo lag there actually was. I was very impressed.

I wonder if there is something else which is causing the lag such as dodgy DV's [img]images/graemlins/confused.gif[/img]

[jeffw]

There was very little increase in lag from a K03 set-up to a K04, at least with mine....which I was surprised about.

Anti-Lag systems are fine for WRC cars who can afford to change turbos every 300-400 miles but not for road cars...The mileage you get from an anti-lag car is less than 8mpg your pumping fuel into the exhaust after all.

Not recomended .....

[kiwi_mtm]

This sounds strange. Asking an obvious question, I assume you have had the ECU remapped for the Ko4's?

Antilag wouldnt be a daily drive solution. Take the car to an Audi Tuning Specialist, and get some feedback.

[Prawn]

David,
certainly not to any noticable extent.

[DavidT]

certainly not to any noticable extent

Excellent, it's the future. Now when does my warranty expire [img]images/graemlins/smirk.gif[/img]

[chris22]

seems a bit too much lag as said before.
I have seen NOS fitted to big turbo cars before to reduce lag [img]images/graemlins/grin.gif[/img]
Im not clued up enough to give any advice on this but might be worth looking into.
Bass