As John says - no engine load. If you are doing 6K RPM, and not moving, then you must have the clutch depressed (or in neutral)?? You are only turning over the engine (i.e transmission not engaged) which is different to actually shifting a tonne of car down the road at 6K RPM.

Chris

[Edited by Chris L - 7/3/2002 12:00:08 PM]

 

Just curious. The thought came to me while I was reading another post mentioning anti-lag launch control. I was trying to figure out why you'd need anti-lag on a hard launch as you'd be giving it welly anyway and there shouldn't be any. The only thing I could think of was that it somehow let the car build boost while stationary. Don't know if that's right but it got me wondering why you can sit there and rev away and no boost builds up? (not how, just why)

Is it a safety thing? What would be the benefits and disadvantages to letting the boost build?

 

Lack of engine load and hence exhaust gas for a sufficient time is the reason.

 

Hmmm. If you're sitting still running the engine at 6000rpm are you not still burning the same amount of fuel etc and therefore creating the same amount of exhaust???

 

If you are not under load then the only way to keep it at 6000 RPM is to use less throttle and hence flow less air.

 

I wouldn't say you need anti lag to launch the car hard from standstill, blipping the throttle gives enough airflow to spin the wheels (or clutch ) from a standing start ok.

Where the anti lag comes into its own is after lift off into a corner, as soon as you need power again it is there instantly with anti lag. Normally you would need to wait a few tenths of a second. It's worse with a bigger turbo and or FMIC.

Launch control on gravel, even tarmac to an extent, can provide more consistant launches as the software looks after engine power for optimum traction, you just mash the pedal

 

But John, people do manage it. In an auto (and a manual if its not your car) you can hold the car on power against the brake and build up the boost. This how all of the 0-60 times are done for auto cars (hence why there times are never as slow as they feel in comparison to an equivalent manual). On the (fortunately) still born Ford XR5i (a Granada Scorpio with an automatic box and Sierra Cosworth engine) we could get 0-60 times within 1/2 second of the two wheel drive Sierra Cosworth until the torque convertor broke.

One of my most memorable pieces of motor racing spectating was Shelsley Walsh in the 80's and watching Hans Stuck (spelling) in the early 4 wheel drive Quattro setting a new saloon record. The launch technique (all pre launch control remember) consisted of a heel and toe style full throttle/full footbrake and the other foot on the clutch, engine on the rev limiter, bring the clutch up beyond the biting point, drag the revs down to around 5,000 rpm with the clutch (at which point you could hear the wastegate opening - separate exhaust in the S2), then off the footbrake and the clutch at the same point. The launch he got was awesome - all 4 wheels spinning all the way in first and second (twin clutch tiptronic boxes meant no lifting on changes) and the speed into Kennel was faster than any of the single seaters that day. Downside was the most awful smell of clutch plate and only three runs before it gave in altogether.

Duncan

On a more serious note - when you rev and engine to 6,000 rpm and no load you are only running a fraction of the normal air through the engine, hence the turbo isn't spooled up. If you have a boost gauge give it a go, and see what boost you can get to by blipping the throttle.

 

Duncan

You may not build much boost but you spool the turbo sufficiently to spin at least 2 wheels from a standing start on a Subaru.
I see it on a number of cars every other week at Crail
My own car on Toyo's, any more than a steady 4500 rpm and it would spin all 4 as I lift the clutch and mash the throttle.

Sticky tyres, big turbo etc is a different case entirely

 

Different case? Different drivetrain, I'd say

Richard

 

Should that be 'broken case'

 

Lol @ Andy

To right - do that too often and you'll need a new transmission.

 

The anti lag launch control was in another post about which is the best ECU to bet. It's what got me thinking in the first place.

I know that the boost won't build as I've had a lot of turbo cars over the years. As for boost guage, this is the first turbo car I've had without one??? What's that all about anyway?
I don't like the look of an aftermarket item at all.
Come on you lot! someone develop a replacement set of clocks that have the boost guage in with the speedo

 

Std Scoob barely produces enough boost to register on a gauge, so no point fitting one