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Discussion Starter #1
I'm sure most of us have seen the videos on youtube of GTRs doing huge backfires and spitting flames all the time. I am currently at Stage 4.25 mapped by Litchfield and have the pops and bangs and shift pops. I'm not a chav but I do think the big backfires look pretty impressive and at my last visit to Litchfield I enquired as to why mine seem pretty tame in comparison to others I've seen (The Knight Racer ones seem particularly aggressive) and was told the aggressive pops and bangs maps aren't very good for your engine, well the words were "it destroys your engine". As Litchfield are experts in this field I'm happy to stay on a map that is safe for the car whilst still being able to make the odd bang here and there.

This got me thinking though, exactly how does the pops and bangs work, and the shift cuts? And how damaging is it to the various components in the car? I've heard crude explanations of unburnt fuel igniting etc, but is anyone able to offer a more in depth explanation as to how it works and how damaging it is to the car? I know many have had the KR650 conversions that have fairly aggressive maps, has anyone had any issues? One other thing I noticed is that Knight Racer seem to use a 'Racerom 5.2' version of Ecutek for their 4.25 conversions, does anyone know why?
 

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Call Ben Linney and ask, the KR maps come from him.
 

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You run rich on overrun so that unburnt fuel goes straight into the exhaust and ignites at some point in the exhaust, typically close to the exhaust outlet where there is available oxygen.

It's similar to boost off the line except that boost off the line is produced with an open throttle so that unburnt fuel is ignited in the presence of excess oxygen but in the turbo rather than in the combustion chamber.

It's bad for the engine in more extreme cases because running excessively rich at any point in time can cause ignition in the turbo which reduces the life of the turbine blades, but also excessive fuel in the combustion chamber causes bore wash, where the excess fuel washes away the oil on the cylinder bores which lubricates the movement of the piston. This increases piston and cylinder wear. Mild pops and bangs won't come close to causing this.

Personally I hate the idea of them, the GT-R is not a rally car. Pops and bangs are a relic of antilag which is used in rallying. The GT-R never was and never will be a rally car. It doesn't need antilag, especially with the speed of its gearbox.

It's totally out of keeping with the nature of the GT-R.
 

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Discussion Starter #8
You run rich on overrun so that unburnt fuel goes straight into the exhaust and ignites at some point in the exhaust, typically close to the exhaust outlet where there is available oxygen.

It's similar to boost off the line except that boost off the line is produced with an open throttle so that unburnt fuel is ignited in the presence of excess oxygen but in the turbo rather than in the combustion chamber.

It's bad for the engine in more extreme cases because running excessively rich at any point in time can cause ignition in the turbo which reduces the life of the turbine blades, but also excessive fuel in the combustion chamber causes bore wash, where the excess fuel washes away the oil on the cylinder bores which lubricates the movement of the piston. This increases piston and cylinder wear. Mild pops and bangs won't come close to causing this.

Personally I hate the idea of them, the GT-R is not a rally car. Pops and bangs are a relic of antilag which is used in rallying. The GT-R never was and never will be a rally car. It doesn't need antilag, especially with the speed of its gearbox.

It's totally out of keeping with the nature of the GT-R.
Thanks Adam that's a good explanation. I'm assuming your point around bore wash is something that would generally occur over a long period of time rather than through the occasional use of more aggressive pops and bangs? i.e. if people were in that map every time they drive the car then that's where the issue becomes much more prevalent?

How about the shift pops is that the same principle?

To those saying it's for chavs I do agree and I rarely do it, but come on it's fun sometimes to release your inner chav and just make some extra noise :chuckle: A lot of cars at the minute have the shift pops built in, just look at Merc/Audi/BMW/Jaguar etc, I think I'm right in saying that all of their top models do a crack/pop when shifting or on the overrun, although have to admit sometimes it can sound pretty artificial.

The video I watched that made me think it was pretty impressive was this one: https://www.youtube.com/watch?v=vEhUVS2ey_M

That backfire in the tunnel is crazy!
 

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I think the very aggressive pops are horrible, especially just sat stationary revving.

A few subtle burbles on over run can sound quite nice imho.

Obviously if you have cats, or decide to put them back in then they'll die very quickly with pops and bangs.
 

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I think the very aggressive pops are horrible, especially just sat stationary revving.

A few subtle burbles on over run can sound quite nice imho.

Obviously if you have cats, or decide to put them back in then they'll die very quickly with pops and bangs.
Depends what CATs you fit the ones AC fit are fine with pops and bangs.
 

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Occasional use is of course better.

The more aggressive and the more often, the more likely the damage.

Of course there's also damage to cats if you still have them.

Pops on gearchanges are more about noise than flames. I'd be surprised if a mainstream manufacturer released a car that spits flames.
 

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REPHRASE= pops and bangs on upshift and downshift i like,
sitting in a carpark reving the tits of it NARRR!!!!
 

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The only 'pops and bangs' that sound good are carburettor engined cars on overrun. Anti lag sounds shit. V6 engines trying to emulate either - even more shit. Each to their own and all that....
 

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"Pops and bangs" on the gear shift is ****, it only really works over 5krpm and on WOT, anything less than those two factors the shift is bloody awful and the car detects DET so not only are you going slower because the gear change is shite it's also pulling timing, waste of time!

Basically it leaves the injectors open and cuts the timing, same as pops and bangs in normal driving, total shit
 

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I have only ever used the pop's and bangs map a hand full of times and that's when I had some pals in a car behind me. I feel it doesn't feel right for the car and am scared to turn my turbo's into turbo soup
 

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"Pops and bangs" on the gear shift is ****, it only really works over 5krpm and on WOT, anything less than those two factors the shift is bloody awful and the car detects DET so not only are you going slower because the gear change is shite it's also pulling timing, waste of time!

Basically it leaves the injectors open and cuts the timing, same as pops and bangs in normal driving, total shit
Why does the car detect det?

Too much fuel reduces chance of det as does leaving the timing late. It's basically taking too the extreme the changes you would make to reduce det.
 

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Why does the car detect det?

Too much fuel reduces chance of det as does leaving the timing late. It's basically taking too the extreme the changes you would make to reduce det.
Because under 5k the effect of the change are so shit and brutal the engine detects false det, use it, try it and find out...... its ****! The check engine light flashes it's nuts off

I didn't say it was detting, I said it detects det!
 
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