first ever scooby

how can i get more 'pops and bangs' without anti-lag? if i change gear at 3k on a sensible drive, i always get one loud bang on gear change, sometimes so loud, one unfortunate old man ducked for cover when i went past. proper p****d myself! however, if i get a little more adventurous it won't do it. i love the sound of the anti-lag system but still can't love the price. is there anything i can do to get extra pops and bangs? thanks

JimmyBFC

Negative timing added when being re-mapped.

chrisdicko

iTrader: (21)

As above. Fully de-catted and a VTA dump valve.

V5RLTD

iTrader: (5)

That works for me

MK2VTR8VALVE

Is negative timing bad for the engine at all? Does it affect performance as well?

I'd love some pops 7 bangs too, got decat & VTA but no pops that Im aware of.

Cheers..

first ever scooby

[QUOTE= got decat & VTA but no pops that Im aware of.

QUOTE]

same here. i've heard a lot of people say that a de-cat and vta does this but i only get a few. very strange! i don't have £650 for a mappable ecu and configuration so i guess there's nothing i can do?! i have the hks ssqv which does vent to air. i will try and get a photo up to see if its connected properl but i have never had any probs the way it is.

mshill

iTrader: (4)

I had pops and bangs mapped in with my last map, only had it for 1 month as pop went my O2 sensor into my turbo
bang my exhaust housing on the turbo was cracked,

2 seperate incidents exhaust housing cracked 1st, got that replaced then 2 weeks later the O2 sensor tip blew off and wedged in the compressor housing of the turbo causing blade damage, Full turbo rebuild required.

so be warned

ginge2719

i had mine mapped and it it pops and bangs like mad i get asked all the time if i have anti lag im no expert but my mapper said he put fuel in on the over run to get it to sound like trhat mabee someone can explain what that means???

Boyakasha

iTrader: (2)

Bore Wash

JimmyBFC

ecu'tek pops and bangs does not create borewash whatsoever, its a myth.

Neg timing of say -5 to -10 is put in on the fuelling, real anti lag is going on -40 so you can imagine the difference in harshness.

scoobyc

iTrader: (2)

overrun is where fuel is injected without the spark i.e. when uve lifted off the throottle, so this flamage gets booted out into the exhaust where it ignites.

This is my understanding of the overrun method. Im not sure if neg timing is required also??

shaggy6

iTrader: (2)

no spark on over run?? thought the timing just gets retarded?

scoobyc

iTrader: (2)

perhaps im wrong. and i probably am, i thought it just plowed fuel in when normally it wouldnt.

chris dt

iTrader: (3)

get an apexi pfc and ask JGM to map it.

you can turn them off too by turning the air con on.

sounds excellent on a tunnel run!!!!!!

first ever scooby

i'm just about to purchase a Z4 ecu. can some kind of mapping be bought for that, if so, where? thanks.

shaggy6

iTrader: (2)

yup it does put more fuel in but as the timing has been retarded not all the fuel get ignited.. or somthing along those lines lol

scoobyc

iTrader: (2)

ahh ok.

So the difference between the apexi and the simtek ALS is the amount of negative timing??

What does the extra 100 quid for als actually do on the simtek if you can already retard the timing on the apexi?

shaggy6

iTrader: (2)

Just nicked this off the net.. explains it pretty well.. i know what i mean in my head but i cant actually wxplain it in words if you know what i mean lol..

"When the driver lifts his foot from the gas pedal the ignition timing is altered with sometimes 40° or more of delay (retard) and the intake air and fuel supply mixture is made richer. The inlet butterfly is kept slightly open or an air injector, bypassing the inlet butterfly, is used to maintain air supply to the engine. This results in air/fuel mixture that keeps getting in the combustion chambers when the driver no longer accelerates. The ignition being severely delayed, the air/fuel mixture reaches the exhaust tubes mostly unburned. When the spark plug fires, the exhaust valve is starting to open due to the ignition delay mentioned above. Additionally, the exhaust temperature being extremely high, the unburned fuel explodes at the contact of the exhaust tubes"

Heretik

iTrader: (1)

What can you turn off by turning the air con on?

I've an Apexi Fc/ECU mapped by API and get a fair few pops and bangs once the engines heated on the overrun (most satisfactory too I might add!)- but turning on the aircon doesn't do anything other than turn on the air con as far as I know!?

Cheers

RobsyUK

iTrader: (2)

I dont know whats been done to mine but it pops very nicly. If i sit at the lights and rev it it bangs a treat. I actually hate it as its fuel that could be used elsewhere...

Whats a VTA?

M444GY

iTrader: (72)

decat , vta , and wrap the exhaust headers/downpipe . u will get mucho poppo

JimmyBFC

VTA = vent to atmosphere

Dumpvalves can come in a few types, recirc, normally standard, VTA, or dual port types, like the turbosmart ones - these recirc at low revs and then VTA on boost.

t7srt

iTrader: (2)

The 100 quid is to get the code from simtek to activate ALS, its already built into the ecm but has to be activated via an authorisation number, Also the mapper will fit a switch so you can turn it on and off,


Shaggy has hit the nail on the head with his explaination, The impreza uses the Idle speed control valve to let air into the system, too much use can burn exhaust valves out and bugger the turbo. great fun though,

shaggy6

iTrader: (2)

And give blue wrinses heart attacks

scoobyc

iTrader: (2)

yeah i figured that. i meant what does the extre 100 quid of unlocked software actually do.

I.e. whats the difference between pops n bangs n ALS provided by the simtek.

Is it just a case of that 100 quid lets you dial in more negative timing or is there another aspect required for ALS rather than just pops n bangs?

first ever scooby

thanks for all your info lads, but could one of you answer my question? if i get the Z4 ecu. what can i do to it to get the pops and bangs? can different map chips be bought for different tuning etc? cheers.

JimmyBFC

an aftermarket ECU will run "full blown anti lag" - what is used in rally cars on stages, the proper real deal, pops and bangs is merely a small timing change that is more of a gimmick effect.

Hence why aftermarket ecu's have "switchable anti lag" - using and abusing it a lot will eventually lead to turbo wear, nailed on, using in short bursts will prolong the life.