pops and bangs
18 August 2010, 10:17 AM
#63
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Sorry harvey for getting confused: I think the ecu had been re-set, and obviously pulled all the advance back in, resulting in lower boost and slower pickup.... it's getting quicker and quicker again now... in fact it's properly flying. 
18 August 2010, 11:20 AM
#65
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On some cars, particularly those with carburettors, you can get a good explosion in the exhaust if you get it hot with some WOT, then leaving it in gear, switch the ignition off and on a few times. The length of ignition off (on a carburettor car) will determine how much fuel you can get in the exhaust and results can be very loud but be warned I have seen an exhaust box blown apart. This is not a good thing for your pocket. It does make a loud bang and is spectacular, probably even more so in the dark.
That happened on my AX GT when the coil started to fail. Also blew the insides out of the centre box!
It needed a new exhaust anyway
My mk2 Polo had a slight blow from the downpipe/manifold joint and that used to pop and bang beautifully on the overun
18 August 2010, 12:49 PM
#67
I had my car re-mapped after some bits and pieces were done. Car was running very nice..... Then I had fitted "gizzmo" for launch/flat shift and pops and bangs. The compression is now stuffed, and the car is off the road waiting till I can afford to fix the compression. It could be just bad luck but I found that "pops and bangs" aint good for the engine.
18 August 2010, 02:20 PM
#71
Now you tell me!
Until we have an internal inspection, I cant say. The compression test and leak test shows that the exhaust side is the problem. Gizzmo deny any repsonability, claiming that it could of been mis-fitted and the garage who reccomended and fitted "gizzmo" origionally, said they would fix it free of charge but then changed thier minds and said they would fix it at a cost.
Until we have an internal inspection, I cant say. The compression test and leak test shows that the exhaust side is the problem. Gizzmo deny any repsonability, claiming that it could of been mis-fitted and the garage who reccomended and fitted "gizzmo" origionally, said they would fix it free of charge but then changed thier minds and said they would fix it at a cost.
18 August 2010, 07:04 PM
#73
What degree of excess fuel is used will only be very small and what damage might be caused in mild form or any other form I havn't a clue and I don't know over what period of time this might happen. Obviously the longer you do it the more chance of damage and certainly increased wear rate. What I do know is that the engine is not running efficiently to cause the pops and bangs so as far as I am concerned it shouldn't be happening but like I said at the beginning of this, if this is what you like please don't let me influence your enjoyment.
19 August 2010, 11:48 AM
#80
It's a rev limiter, so when you flat foot shift, you don't bury the revs on the other side of the clocks. Keeps boost up during shifts also. And of course rev limiter for launch control. The electronic throttle cars can have this via the ECU, but obviously not the older cars.
Yes you are right about it being a completely different kind of pops and bangs that are discussed here though.
Antilag however is to keep the turbo spooled all the time, again completely different.
Yes you are right about it being a completely different kind of pops and bangs that are discussed here though.
Antilag however is to keep the turbo spooled all the time, again completely different.
19 August 2010, 12:07 PM
#81
It's a rev limiter, so when you flat foot shift, you don't bury the revs on the other side of the clocks. Keeps boost up during shifts also. And of course rev limiter for launch control. The electronic throttle cars can have this via the ECU, but obviously not the older cars.
Yes you are right about it being a completely different kind of pops and bangs that are discussed here though.
Antilag however is to keep the turbo spooled all the time, again completely different.
Yes you are right about it being a completely different kind of pops and bangs that are discussed here though.
Antilag however is to keep the turbo spooled all the time, again completely different.
That's what the Gizzmo does for the launch control.
19 August 2010, 12:14 PM
#82
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How ALS works
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. Luckily the turbo sits right there and the explosion keeps it turning (otherwise it would slow down since its intake, the exhaust gases, is cut-off). The effect is vastly lower response times with some downsides:
* A quick rise of the turbocharger's temperature (which jumps from ~800°C to the 1100°C+ region) whenever the system is activated
* A huge stress on the exhaust manifold and pipes (mounted on a street car a bang-bang system would destroy the exhaust system within 50-100 km)
* The turbo produces significant boost even at engine idle speeds
* The explosions which occur in the exhaust tubes generate important flames which can, sometimes, be seen at the end of the exhaust tube
* Reduced engine brake
The gizzmo on the other hand just keeps rotating the rev's up to the rev limiter thus artificially creating boost pressure.
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. Luckily the turbo sits right there and the explosion keeps it turning (otherwise it would slow down since its intake, the exhaust gases, is cut-off). The effect is vastly lower response times with some downsides:
* A quick rise of the turbocharger's temperature (which jumps from ~800°C to the 1100°C+ region) whenever the system is activated
* A huge stress on the exhaust manifold and pipes (mounted on a street car a bang-bang system would destroy the exhaust system within 50-100 km)
* The turbo produces significant boost even at engine idle speeds
* The explosions which occur in the exhaust tubes generate important flames which can, sometimes, be seen at the end of the exhaust tube
* Reduced engine brake
The gizzmo on the other hand just keeps rotating the rev's up to the rev limiter thus artificially creating boost pressure.
Last edited by scooby L; 19 August 2010 at 12:16 PM.
19 August 2010, 12:41 PM
#84
This is why i thought that the gizzmo launch control work on the same principle as als:
Gizzmo's New LI-2 Launch Control Interface integrates with the Gizzmo Shift Light to enable the fully adjustable launch control function. The launch control function induces sequential misfire events at the desired rpm set by the user.
The new LI-2 Launch Interface is the next generation of Launch Interface, housing the fastest processor we have ever used on anything. This time around, Gizzmo’s launch interface also supports Toyotas and Rotary Engines. In addition, the LI2 has adjustable timing retard and more triggering options to make launching easier and better than ever before.
So no need for the shout scoobydoo69
Gizzmo's New LI-2 Launch Control Interface integrates with the Gizzmo Shift Light to enable the fully adjustable launch control function. The launch control function induces sequential misfire events at the desired rpm set by the user.
The new LI-2 Launch Interface is the next generation of Launch Interface, housing the fastest processor we have ever used on anything. This time around, Gizzmo’s launch interface also supports Toyotas and Rotary Engines. In addition, the LI2 has adjustable timing retard and more triggering options to make launching easier and better than ever before.
So no need for the shout scoobydoo69
19 August 2010, 07:11 PM
#86
Apologies if I mislead a few people, sorry. I fitted gizzmo for the launch and flat shift only, NOT for the pops and bangs. The fitter told me that it induces a misfire (bang) to keep the turbo on maximum spool. The bangs therefore were a part of the "package".This is why I had it fitted. Although gizzmo`s launch interface version 1 didnt sound too reliable, I was told that all the problems had been fixed and version 2 was fine. I repeat that until we have the internal inspection, I cannot confirm that it caused the compression loss. It caused some other problems, but I wont confuse this thread..
All this said, if pops and bangs float your boat then go for it. These cars are for enjoying, but I wont be looking for pops and bangs after my car has been fixed.
All this said, if pops and bangs float your boat then go for it. These cars are for enjoying, but I wont be looking for pops and bangs after my car has been fixed.
Last edited by Hammer man; 19 August 2010 at 07:12 PM. Reason: spelling
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