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Discussion Starter #1
im getting a fair bit of work done on my 32 at the end of this month, but it seems the fcon s is getting binned in favour of the hks fcon v pro instead (something to do with it not being that good for cars over 400bhp, doesnt stop ecu from re-learning etc apparently).

two features of the v pro that sound particularly cool are anti-lag and launch control. i had LC in my e46 m3, which meant fiddling with buttons for it to work.

how does it work in a GTR?
and how does anti-lag work, what exactly does it do?

as you can guess from my post, my technical knowledge is limited :D , so can anyone explain in basic laymens terms please?


for example, i always thought anti-lag buggered turbos( the gt-ss turbos im getting aint cheap so dont wanna knacker them), so in what circumstances would it be used? on a drag strip? do i have to press a button for it to work, or is it automatic? my gtr is purely for road use.

sorry for the basic questions, who knows, one day i may ask about something REALLY technical... and have an idea what im talking about :D
 

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A friend of mine has anti-lag and launch control set up on his Evo 4 ECU. There's a small button you press which sets your idle at 2000 when stationary (this is how his works anyway). We're also assuming that it massively overfuels at the same time, as when he sets off from the lights using launch control he just does an ordinary "fast start" (but not a clutch-eating launch) and it tears away, spitting 4 foot long flames on every gearchange. When you change down it pops and bangs like a [email protected]@rd (hence the assumption that massive overfueling is part of the anti-lag/launch setup).

Dunno if that's any help :smokin:
 

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I had Anti-Lag on my Cossie.

Theres a lot of bullshat about how it works, and a lot of "Anti-Lag" setups which would do nowt but the noise, but heres basicly how it really works...

Basicly with it switched on it will behave normally on throttle, but off throttle it retards the ignition hugely, around 30degrees in most cases, adjust the fueling accordingly (this depends how viscous your ALS is), and most importantly it opens a throttle bypass valve for the air.

What it would do on mine, is you could flick it on at idle or whatever and itd be totally normal, itd only engage once it senced over 15degrees of throttle movement, tho i dont know how complex your one would be.

The ign timing being so retarded basicly ignites the fuel when you got the exhaust valves open, and the resultant explosion into the manifolds n turbos helps keep em spinning, and the air still has a way of getting into the engine past the closed throttle via the air bypass valve, and so on.

Most road car setups ive seen are crap, using std ISCVs (or just nothing) as a throttle bypass and having no real effect but the noise.
My car had a mountune WRC ALS Air bypass valve fitted, and from size alone id estimate it could flow at least 5 times the amount the one used to regulate idle speed could, and the airways to and from it were similarly enlarged.
On a GTR you got SIX throttles to bypass, and the std idle speed regulator thing will not be good enough for REAL ALS, just the homo pops n bangs n nowt else like most people with ALS on road cars have.
Wouldnt take much thought, if you know what you doing.

My one, i could blip the throttle upto about 5-6k in neautral, let off throttlke totally, and the boost would stay sat at 23psi.
While on the move if you was hitting full boost, 2bar, and let totally off for a while, itd either stay there, or not drop massivly.
Totaly changed the drive of the car, esp thru corners, felt like driving a 8litre n/a engine rather than a 2litre turbo, almost totally linear throttle responce, esp at part throttle when cornering fast n hard.
Wont change your driving experience in straight line acceleration unless your pathetic at changing gear, or your turbo/gearing is so totaly mismatched your drop off boost on every gearchange.
Tho my cars boost stayed very high, thats not nececerily (sp?) needed, when it comes down to it, the speed boost increases in general from 0-1psi to full is very fast anyhow, its when its showing vacumn it takes time, so even if the boost dropped to almost nothing, the acceleration when you put foot back down would be much more instant.

The rapidfire machinegun sounds you could here over 2.5miles away (we tested, lol) and flames longer than the car were fun too, lol.
The 750pound total fine i got (endangering the public, etc etc) for one "offence" alone was worth it for 2years of ALS.

Shame most people have it just for the noise and the fun of watching old dears jump lean over walls and hedges thinking they back in WW2 :rolleyes: (Dont get me wrong, that is ace fun and i got some class sotries from it, but then is just a gimmick, i hate gimmicks on cars, if your not gonna use it properly, DONT HAVE IT)

Damage to turbos, well, i ran really viscous WRC spec ALS for 2years and had no turbo damage at all, even with EGTs in the downpipe of well over 1000degC, but then my car/turbo was built properly for it.
Absolutley no idea how long your turbos will last.
Its the temperatures that will kill them, but youl be suprised how long it takes to reach those temps.

I could go into much more detail and be typing all day about various stuff, but thats your basics.
 

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Antilag is more than just something on the ECU. You have to have some way of bypassing the throttle plates - and there's six of them on a GTR making it virtually impossible :(

Normally when you lift off the throttle, the throttles close which stops the flow of air into the engine. This means the turbo stops spinning, meaning you get lag when you plant your foot again.

Antilag works by bypassing the throttles and massively retarding the ignition so the fuel is practically being burnt in the manifolds, and the flow of air and heat keeps the turbo spinning up so you have instant boost when you come back on the throttle again :D
 

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Completely pwned by Steve's technical description :D
 

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Nice description Steve. Personally I can't stand those 'pretend' ALS systems. Max Idiot in my eyes.

I guess a single body makes things much easier though on a GT-R.
 

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Good job my GTR got single throttle eh.

Might be Max Idiot, but thats 95% of the "ALS" setups ive seen on roadgoing EVOs and Scoobys, ****y sytems that do nothing but make the noise and make them belive its removing the lag...

Only ALS ive seen/heard comparable to what i had on mine on a road car was that Icelandic Scooby at TOTB3, that brought back some memories :D

Regarding the Launch Control, well that depends, but i bet its just a 2-Step (no, nothing to do with UK Garage, lol).
Basilcy itl be an artificialy low ignition rev limiter.
Say its set to 5k, when its switched on you can put foot to the floor at a standstill and it will bounce off a 5k ign rev limiter, with lots of pops n bangs as the fuel is ignited in the exhaust/turbo, like most pretty serious modded turbo cars do when launcing at SantaPod etc (YES thats Launch Control, NOT anti-lag, tho some have both but thats not what you hear when they getting ready to launch).
On a n/a car it just helps keep your launches consistant, on a turbo, the bouncing off the limiter, as its an ign cut and not a fuel cut, works in a similar way to ALS does (but ONLY at a standstill), and after a few secs, your boost will begin to rise, so you can have boost off the mark, providing you got the grip and strong transmission to make use of it.

There is a more complex one that changes the fuel n ign maps, but most ECUs launch control is a simple 2step rev limiter, which is good enough really.
 

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Launch control function is built in to the Omex shift light unit I got.

Except it wont work on the GTR cos it has 6 ign coils, instead of the one coil and a dizzy like on my Civic (and 99% of all cars)
 

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heres how mine work. btw, this is for drag launch use only. its nothing like those rally anti-lag system.

HKS v-pro anti-lag and launch control are 2in1 function.

1. set the # of rpm u want to launch with. ex.9000rpm.
2. press the button, give it full throttle. (it will hold on 9000rpm as set and give u active on-boost ready. ex.0.8-1bar)
3. release the clutch and the button.

thats about it. i can give more details if u like..
 

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Thats just a 2step rev limiter, launch control, no idea why they call it anti-lag cause its not.

I remember once a vid of an evo and the big fuss was all about its "anti lag" and all it had was launch control, just they get told its anti-lag as it makes the customers happy if they know no better
 

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This is the first time i've ever seen an acurate and proper description of Anti lag V Launch control ..

nice, clear and easy to understand explanation Steve ..

Well done m8

Steve
 

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anyway HKS never call it anti-lag or launch control.

they call this function "Pro-Start"
 

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Discussion Starter #13
thanks steve and rock, well explained and much appreciated!

pops, bangs, huge flames and doesnt necessarily shag the turbos asap! cushty! bring it on!:D :D
 

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Been talking at length with various people about this sytem for anti lag and SteveN,s description is one of the easiest to understand!

whilst i am still unsure whether it is a good idea for a road car i am now left with a burning question!!

Are you having anti-lag on your skyline when its finished SteveN :D :smokin:

JAY
 

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blueskygtr said:
Been talking at length with various people about this sytem for anti lag and SteveN,s description is one of the easiest to understand!
Thankyaaw. Nah, its jus cause I ran ALS for years (Nearly 5 years ago now!), used it properly, got all the parts and fitted (and repaired, lol) myself (a proper ALS setup isnt just an ECU function), and I also never buy anything without knowing how it works and that it really works and not just all talk and a gimmick.
Most people who are tuning experts still dont know about it as they have little or no experience with it, just what they hear, which is understandable as its not common barring rally cars.
Also I was one of the first ROAD Cosworths (or any UK road car really) with it running properly so used to get asked the question 10 times a day so get good at explaining it, lol.

blueskygtr said:
whilst i am still unsure whether it is a good idea for a road car i am now left with a burning question!!
All depends if youl USE it (most people just use it for the pops n bangs, and seems pointless jus for that), and also depends if the ALS function on your chosen ECU (which is?) is PROPER anti-lag with a decent size air bypass for the throttles (most "ALS" setups on road cars dont, they pathetic, do nowt and give AntiLag a bad name...), and not some crappy function that like the D-Jetro version where you have to manually keep the throttle open by having your foot on the gas! :rolleyes:
You are running risk of damage too, but IMO the damage caused is greatly overhyped...

blueskygtr said:
Are you having anti-lag on your skyline when its finished SteveN :D :smokin:
Probably (not like its hugely important to me, but it does make the car a lot more fun to drive if you drive like me), but it will be a proper setup like on my last car, not some crap like the ones you usually see which are either non-existant and just the Launch Control (ie that GT-Art vid and loads of people with modded Scoobys, EVOs, etc etc who just have LaunchControl/2Step but the tuner has kidded them thats AntiLag....), or some mild setup that pops n bangs slightly on the overrun but does nothing to help keep the boost up...
 
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Steve,

I am with you on this one.

1, Launch control (i.e HKS Pro and Power FC pro)
2, Anti lag

these are 2 totally different things. Not even in the same league in my opinon.

The launch control as in the Power Fc and the HKS F-con are not bad as the tool
they are designed for. But a Steve say proper Anit-lag is in a different world.

Yep a GTR with a single throtle body does make it a little easier.........
 

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The throttle bodys have 'air bypass' for idle speed control so you could make something to go on that. It's much easier with all the idle speed control gubbins removed.
 
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