VR-4 ECU with Anti-lag / Launch Control

[foxdie]

Hi folks,

Managed to secure another VR-4 ECU, this ones a H8/539 pre-facelift to facelift straddler ECU, it can run ECU mods and any ROM from a 7202 or 7203 and as such, anti-lag / launch control / no lift to shift / CEL-on-knock / switchable maps, however it needs MMCFlash to change the settings (something not everyone has).

It should work with every 8th gen VR-4 (1996-2003), manual or auto, TCL or non-TCL.

Looking for £150 + P&P :)

(Please note, this ECU is currently on a stock ROM and the mods have yet to be installed, ETA for this should be within the next 30 days)

[Gingerfish]

Out of curiosity and at the risk of making myself sound like a total div, what is Anti-lag?

[foxdie]

http://www.youtube.com/watch?v=U-x7aPn0x_U :thumbsup:

[Chris.W]

Gingerfish - An anti-lag system (ALS) or misfiring system is a system used on turbocharged engines to minimize turbo lag on racing cars. It works by arranging for fuel and air to be in the exhaust duct after the engine, and before the turbocharger. This ignites in the hot ducting and the combustion process that occurs there keeps the turbocharger spinning when the engine is not delivering enough exhaust gas.

An ALS requires an air bypass, generally done in one of two ways. The first method is to use a throttle air bypass; this may be an external bypass valve or a solenoid valve which opens the throttle 12-20 degrees. This allows air to bypass the closed throttle and to reach the engine. The second method is to use a bypass valve which feeds charge air directly to the exhaust manifold.

Retarding ignition

The throttle bypass/throttle solenoid system is combined with ignition retardation and slight fuel enrichment (mainly to provide cooling), typically ignition occurs at 35-45° ATDC. This late ignition causes very little expansion of the gas in the cylinder; hence the pressure and temperature will still be very high when the exhaust valve opens. At the same time, the amount of torque delivered to the crankshaft will be very small (just enough to keep the engine running). The higher exhaust pressure and temperature combined with the increased mass flow is enough to keep the turbocharger spinning at high speed thus reducing lag. When the throttle is opened up again the ignition and fuel injection goes back to normal operation. Since many engine components are exposed to very high temperatures during ALS operation and also high pressure pulses, this kind of system is very hard on the engine and turbocharger. For the latter not only the high temperatures are a problem but also the uncontrolled turbo speeds which can quickly destroy the turbocharger. In most applications the ALS is automatically shut down when the coolant reaches a temperature of 110-115°C to prevent overheating.

Inlet bypass

An ALS system working with a bypass valve which feeds air directly to the exhaust system can be made more refined than the system described above. Some of the earliest systems of this type were used by Ferrari in F1. Another well-known application of this type of anti-lag system was in the WRC version of the 1995 Mitsubishi Lancer Evolution III and Toyota Celica GT-Four (ST205). Brass tubes fed air from the turbocharger's Compressor Bypass Valve (CBV) to each of the exhaust manifold tracts, in order to provide the necessary air for the combustion of the fuel. The system was controlled by two pressure valves, operated by the ECU. Besides the racing version, the hardware of the anti-lag system was also installed in the 2500 "Group A homologation base WRC method car" street legal Celica GT-Fours. However, in these cars the system was disabled and inactive. The tubes and valves were only present for homologation reasons. On the Mitsubishi Evolution later series (evo 4-9, JDM models only) the SAS (Secondary Air System) can be activated to provide Antilag.

[Gingerfish]

Thanks for the explanation Chris.

:curtain: although, you could've just said that it reduces turbo-lag. lol.

[aboo]

Or this. http://www.youtube.com/watch?v=yV8qztxXA1o :)

[Gowf]

Chris, That is an interesting definition. Just to add to this (as someone who actually sets this up) ALS is something that you DO NOT WANT on your road car. As has been said it effectively moves your combustion from the combustion chamber to the turbo blades thus keeping them spinning which is not good for longevity and you will be replacing turbos with every engine oil service! We change the turbo once a year if we are lucky on the rally cars as it will be way past its best, and to put that into perspective that would be 9 rounds of 40 competitive miles each.

Its all well and good stating how it works etc, but what about how it drives and what the true purpose is. So, as you know, in order to generate boost (which we can loosley relate to power here) you need to open the throttle. Boost takes time to generate and so power is not instantaneous but is time dependent. Once you close the throttle, by any significant amount you will lose boost via one of two methods depending on how your induction system is set up. Clearly then when you open the throttle you have to wait for the boost to build again thereby losing you time. If you have ALS active yes you still lose boost (depending on what level you are at, in the evos I run from 2bar down to 1.6bar) but there is still a whole lot there. The implications of this are that even though you have come off the throttle the car does not want to slow down and it actually pushes you on, which is not something that you want on the road.

One thing to mention is that you can not have anti-lag if you run a dump valve as it clearly defeats the purpose for why would you want to release the pressure if you desire to keep it, so stock ECUs with the feature available were made so purely for the purposes of homologation and are not true versions of ALS. Infact all you end up getting are some pops and bangs, which again are not good for the engine, and all of this can be replicated by simply retarding the low load parts of the ignition map, but again this is not advisable. It does seem that everyone wants to drive a rally car on the road, but in reality you really dont unless you are willing to have a very short life on the components.

Just as an indication, With the ALS that we run on the E5 rally car it can generate just under 14psi of boost at idle (granted idle is around 2500rpm). Therefore we have 2 stage ALS which gives the driver an option to calm it down a little when its a little too slippy. The ALS system is also not just a simple on and off switch, it is controlled by fairly comprehensive strategies that activate and deactivate depending on certain conditions (and on some ECUs the likes of which are used in LMP1, you have 12 potentially different ALS strategies). EGT has to be measured and used as a safety threshold as otherwise you can fine pretty severe localised temperatures which is allowed to continue will see your exhaust valves dripping on the floor.

So all in all, road car ALS is mere snake oil. It does not work as intended and really is just a bit of popping and banging to keep teenage girls heads turning when cruizin the high street on a sat afternoon.

[dutch driver]

and this from the exhaust
http://www.youtube.com/watch?v=iJZI3cAFb-4

[foxdie]

Despite the nay-saying above, this is still for sale without the ECU mods (so its just a stock H8/539), you'll need someone like Davezj to flash it for you if you want the anti-lag etc. Price reduced to £100 + PnP.

[funkstardelux]

hi jason has it got manual or auto on there at mo

[Davezj]

Despite the nay-saying above, this is still for sale without the ECU mods (so its just a stock H8/539), you'll need someone like Davezj to flash it for you if you want the anti-lag etc. Price reduced to £100 + PnP.

i always have the culbs best interest very close to my heart.

[foxdie]

I think I still have this for sale, it can be supplied and fitted at the dyno tuning day tomorrow (http://www.clubvr4.com/forum/showthread.php?72668-2014-Dyno-tuning-meet-22nd-Nov-in-Nottinghamshire) if anyone wants it?