Whats anti lag? how does it work ?

 

If your refering to a turbo than lag is something thats sometimes felt by the driver of a turbocharged vehicle as a delay between pushing on the accelerator pedal and feeling the turbo kick-in. This is a product of the time taken for the exhaust system driving the turbine to come to high pressure and for the turbine rotor to overcome its rotational inertia and reach the speed necessary to supply boost pressure. Lag can be reduced "anti-lag" by lowering the rotational inertia of the turbine, for example by using lighter parts to allow the spool-up to happen more quickly. Ceramic turbines are a big help in this direction. Unfortunately, their relative fragility limits the maximum boost they can supply. Another way to reduce lag is to change the Aspect ratio of the turbine by reducing the diameter and increasing the gas-flow path-length. Increasing the upper-deck air pressure and improving the wastegate response helps but there are cost increases and reliability disadvantage. I think garret and borg warner both make a VGT turbo. A VGT uses a set of vanes in the exhaust housing to maintain a constant gas velocity across the turbine, the same kind of control as used on power plant turbines. Other designations for this type of turbo include Variable Area Turbine Nozzle, Variable Turbine Geometry, and Variable Vane Turbine. Such turbochargers have minimal lag like a small conventional turbocharger and can achieve full boost as low as 1,500 engine rpm, yet remain efficient as a large conventional turbocharger at higher engine speeds thus creating a very flat "lag-less" power curve.

 

do you drive the car or you fly the car...how the hell can you feel lag unless it is super charged!

 

LOL, didn't you say you worked on cars for a living?

Anti-Lag: http://en.wikipedia.org/wiki/Anti-Lag_System

Video of Anti-Lag in action: http://www.youtube.com/watch?v=A-bnBEpWu70

Launch - http://www.youtube.com/watch?v=vdwxM...eature=related


Moral of the story, unless you're racing the car (rally, drag, roadcourse), you don't want it. Daily Driving a car with Anti-Lag is going to eat through turbos like you would not believe.

 

yea thats not anti lag... anti lag mean you run really rich, and the exhaust cam and ignition is set so that it partially fills the exhaust header with raw fuel and just before the exhaust valve closes the spark plug fires to load up the turbo with burning fuel/ a new flame front. afterburner style i guess... the actual force that pushes the piston down is the boost and flame front then. you can litterally sit at idle making 26psi... its not recomended lol. most drag teams use it in conjunction with a traction control system off the line so theyre able to get as much direct power to the ground off the line... what doesnt make sence to me is ive seen installed on more awd cars like subbies and evos that fwd which its really more useful for... dsm and subbies have enough problems not blowing theyre transaxle/ transmission and center diff apart from too much power on launch, why risk it on a street car? idk...

your much better off going with a vgt but in my opinion twinscrolling is still supreme for street/strip use. nothing like a venturi affect and good old fasion scavanging exhaust system and individualizing pulses to ensure a good turbo really spool. and dont forget! turbos like high cylinder pressures so stroke out your bottom end and increasing bore 10 folds you to have less lag and more surface area for boost to go boom! also a lot of people forget to increase your combustion chamber volume... but not too big, for a better flow and better boom with boost... i personally like to think of the engine as a giant funnel or venturi. make it work! flow that air!!! lol

hybrid turbos (such as t3/t4s) do the trick that vgt does for half the cost. just buy 2 halfs of 2 turbos a rebuild kit and maybe new inducer housing to match up to a new inducer wheel to get the right a/r ratio and flow your looking for. high and hot trapt exahust pressures spinning a big cold inducer... kinda like torque multiplecation in a transmission only not...? lol

ive been reading a modifed mag about a subbie circuit team in japan that made (raw? idk the difference between raw and not raw but thats what they call it??) raw carbonfiber jacket for theyre intake manifold and some of the plumbing and they lowered intake temps substantially! ill have to find the article because the underhood shot made me hard... yea... and it was by a very suggnificant amount which got me thinking, if between the jacket and the manifold they ran flattish copper tubing and filled with co2 and relased it into a bar on the fmic they could have manifold temps as low at 30 degrees Farenheight on a 100 degree day in arizona... in march.... lol sorry...

in short there are a lot of tricks to making boost and making it fast but honestly... whats the fun in that?! i like getting the **** scared outa me!