Antilag + or - ??
05-04-2009, 10:26 AM
#16
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Myself I can't think of any situation where I would want more lag between the throttle and the turbo, less lag equals more control to me.
As for downsides there is a lot of heat generated which has to be taken care of, and don't think it would improve fuel consumption , to put it mildly...
Mine will be switchable aand we will use the egt sensor to protect the turbo through the ems
As for downsides there is a lot of heat generated which has to be taken care of, and don't think it would improve fuel consumption , to put it mildly...
Mine will be switchable aand we will use the egt sensor to protect the turbo through the ems
05-04-2009, 10:33 AM
#17
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Spend the money on some coaching and nail the LFB method! I actually started LFB for the uphill at the last club race and found the power was there sooner. Was doing it far from perfect and something I need to work on but could reep benefits!
05-04-2009, 10:46 AM
#18
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When Special tool used it at the drag strip it worked very well for his launch. The only problem was he was not familiar enough with it to get it timed right. He ended up sitting for 2 seconds waiting for the turbo to spool after the light turned green. He told me it slowed him down between shifts after that though, I didn't understand that statement.
As far as between shifts on the track I wouldn't use it. Personaly I have never needed it, and I run what I consider a very large turbo. I can shift so fast I don't even see how it would have started to work. Personaly DBB does an amazing job keeping the turbo spooled.
As far as damge yes it does. I have seen the effects. Not from actual antilag but from the same thing. When there is that much raw fuel burning in the hot side it eats away at the turbine wheel. The turbos I have seen, the wheel is visualy smaller, it looks eroded away.
I think rally cars use it because sometimes they are off the throttle for a long time (relatively), or because they will have ended up dropping to low in the rpm band. They also have small displacement so for the turbo size they run it also makes sense.
I also think there will be a lack of controle because it will effect your ability to modulate boost with your foot. If you have enough power you probaly don't want full boost to fast tracking out of a turn.
As far as between shifts on the track I wouldn't use it. Personaly I have never needed it, and I run what I consider a very large turbo. I can shift so fast I don't even see how it would have started to work. Personaly DBB does an amazing job keeping the turbo spooled.
As far as damge yes it does. I have seen the effects. Not from actual antilag but from the same thing. When there is that much raw fuel burning in the hot side it eats away at the turbine wheel. The turbos I have seen, the wheel is visualy smaller, it looks eroded away.
I think rally cars use it because sometimes they are off the throttle for a long time (relatively), or because they will have ended up dropping to low in the rpm band. They also have small displacement so for the turbo size they run it also makes sense.
I also think there will be a lack of controle because it will effect your ability to modulate boost with your foot. If you have enough power you probaly don't want full boost to fast tracking out of a turn.
05-04-2009, 10:48 AM
#19
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My current testing is mostly focused on the aerodynamics of our fine cars, not boost control or anything. It was actually mostly inspired by a conversation I had with Chris a few months ago.
I'm trying to quantitatively measure down force, and I'd also like to do some "wool tuft" testing at some point in the future.
That should be fun!
I'm trying to quantitatively measure down force, and I'd also like to do some "wool tuft" testing at some point in the future.
That should be fun!
05-04-2009, 11:13 AM
#20
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The typical anti lag (timing retard and really rich mixture) usually leads to uncontrolled (read explosive) combustion in the exhaust manifold. If you listen to the rally cars you can hear bangs and pops - thats the unburnt fuel exploding in the exhaust mainfold - and it sure spools up the tutbo (among other things)!
05-04-2009, 11:15 AM
#21
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My current testing is mostly focused on the aerodynamics of our fine cars, not boost control or anything. It was actually mostly inspired by a conversation I had with Chris a few months ago.
I'm trying to quantitatively measure down force, and I'd also like to do some "wool tuft" testing at some point in the future.
That should be fun!
I'm trying to quantitatively measure down force, and I'd also like to do some "wool tuft" testing at some point in the future.
That should be fun!
05-04-2009, 11:24 AM
#22
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The typical anti lag (timing retard and really rich mixture) usually leads to uncontrolled (read explosive) combustion in the exhaust manifold. If you listen to the rally cars you can hear bangs and pops - thats the unburnt fuel exploding in the exhaust mainfold - and it sure spools up the tutbo (among other things)!
Alot of guys run 2 step. I wouldn't be using that either. I was most intersted in the zero lag between shifts.
05-04-2009, 11:24 AM
#23
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05-04-2009, 11:26 AM
#24
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05-04-2009, 12:26 PM
#26
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To clear up some of the mis-conceptions...
The typical rally-car setup is much more aggressive then what a non-dedicated race car would use. These cars retard timing significantly (more than 10degrees ATDC!), add a lot of extra fuel, and even have an air-bypass to allow more raw-air into the exhaust. These systems are used mainly on decel, to keep the turbo spooled until you get back onto the throttle.
Check out this page for info on rally-car anti-lag: Click me
Anti-lag can be setup much less aggressive, and still be somewhat effective. Such as locking timing at 0BTDC, and no fuel enrichment. Just takes some experimenting to get the desired result.
Anti-lag is different than no-lift-to-shift (NLTS) setups, though one doesn’t exclude the other. NLTS is simply a second ‘rev-limit’ that is engaged when the clutch is depressed. This setup is used for upshifts only. Using NLTS drops RPMs to a point slightly below what the next gear requires. Some advantages are automatic ‘rev-matching’ for upshifts, quicker shifting (then non-matched shifts), and significantly less turbo-lag between shifts. NLTS can be setup using either ignition based secondary rev-limit or a fuel-based rev-limit (injector cut). Using the injector-cut will do no harm to the engine/turbo (assuming it works properly). In fact the factory motronic uses injector-cut during drop-throttle situations. Ignition-cut is a little more aggressive, as some fuel is being burnt in the exhaust manifold. However the system is only active for the time it takes to shift (few 1/10s), and in my own experience EGTs don’t change much.
A NLTS setup I don’t believe to be much harder on drivetrain… Because the secondary rev-limit is activated via the clutch-switch, the engine will not be providing any power/torque until the clutch switch is re-activated and the clutch is fully re-engaged. In fact, using NLTS should be easier on synchros due to the automated rev-matching.
On a track car, a NLTS setup can save you some time accelerating, assuming you aren’t already traction-limited. Obviously how much time saved depends on the exact setup. But in cars like mine with older-school turbos, it makes a huge difference.
FYI, I used an MSD 6AL-2. This unit has the second rev-limit built in, and is small enough to be installed where the cruise-control unit was (the normal 6AL doesn't have the built in second rev-limit nor is it small enough to be installed at the same location).
-Rogue
The typical rally-car setup is much more aggressive then what a non-dedicated race car would use. These cars retard timing significantly (more than 10degrees ATDC!), add a lot of extra fuel, and even have an air-bypass to allow more raw-air into the exhaust. These systems are used mainly on decel, to keep the turbo spooled until you get back onto the throttle.
Check out this page for info on rally-car anti-lag: Click me
Anti-lag can be setup much less aggressive, and still be somewhat effective. Such as locking timing at 0BTDC, and no fuel enrichment. Just takes some experimenting to get the desired result.
Anti-lag is different than no-lift-to-shift (NLTS) setups, though one doesn’t exclude the other. NLTS is simply a second ‘rev-limit’ that is engaged when the clutch is depressed. This setup is used for upshifts only. Using NLTS drops RPMs to a point slightly below what the next gear requires. Some advantages are automatic ‘rev-matching’ for upshifts, quicker shifting (then non-matched shifts), and significantly less turbo-lag between shifts. NLTS can be setup using either ignition based secondary rev-limit or a fuel-based rev-limit (injector cut). Using the injector-cut will do no harm to the engine/turbo (assuming it works properly). In fact the factory motronic uses injector-cut during drop-throttle situations. Ignition-cut is a little more aggressive, as some fuel is being burnt in the exhaust manifold. However the system is only active for the time it takes to shift (few 1/10s), and in my own experience EGTs don’t change much.
A NLTS setup I don’t believe to be much harder on drivetrain… Because the secondary rev-limit is activated via the clutch-switch, the engine will not be providing any power/torque until the clutch switch is re-activated and the clutch is fully re-engaged. In fact, using NLTS should be easier on synchros due to the automated rev-matching.
On a track car, a NLTS setup can save you some time accelerating, assuming you aren’t already traction-limited. Obviously how much time saved depends on the exact setup. But in cars like mine with older-school turbos, it makes a huge difference.
FYI, I used an MSD 6AL-2. This unit has the second rev-limit built in, and is small enough to be installed where the cruise-control unit was (the normal 6AL doesn't have the built in second rev-limit nor is it small enough to be installed at the same location).
-Rogue
Last edited by Rogue_Ant; 05-04-2009 at 01:19 PM.
05-04-2009, 02:01 PM
#27
Drifting
Just to clarify on 2 step here's a video for those who might be confused.
http://www.youtube.com/watch?v=wQrJ2HeRtZM
http://www.youtube.com/watch?v=wQrJ2HeRtZM
05-04-2009, 05:34 PM
#29
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Thread Starter
My current testing is mostly focused on the aerodynamics of our fine cars, not boost control or anything. It was actually mostly inspired by a conversation I had with Chris a few months ago.
I'm trying to quantitatively measure down force, and I'd also like to do some "wool tuft" testing at some point in the future.
That should be fun!
I'm trying to quantitatively measure down force, and I'd also like to do some "wool tuft" testing at some point in the future.
That should be fun!
I'll be interested in your findings Van as I'm sure many of us will.
05-04-2009, 06:38 PM
#30
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I'm thinking we don't 'need' this but it could be good if you got it working perfectly in harmony with some other features. The NLTS system could be utilised too but that sounds like a much easier retro fit.
