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Hi all, I have an fg barra with std hydraulic lifters, can I set up anti lag or do i risk pumping up the lifters?
Unsure how the barra reacts to anti lag and Andre Said some valvetrain don't like it if they run hydraulic lifters.
Most engines which run hydraulic lifters don't like antilag.
However, I have successfully run many cars (The likes of Mitsubishi's 4g63) with antilag and without pumping up the lifters.
A lot of it comes down to how aggressive you run the cut. The more cut, the more backfires and the more likely you're to pump up the lifters.
Having stiffer valve springs is a good start which will help combat the issue. Also running less cut and more retard will help as well. You won't get the full benefit like you can with a solid lifter setup .
This is also an issue with running launch control. With launch control I will tend to run more a fuel cut with ignition retard, over an ignition cut . Not as effective, although as soon as you run an ignition cut and start with the big back fires, with stock springs you will pump up the lifters every time.
You can always have a play and see how it reacts, creeping up on it and trying different strategies
I don't recall the seminar, but while hydraulics are basically a pure mechanically limited mechanism, I assume the problem is aggressive anti-lag causing presure spikes in the exhaust manifold/ports that lift/hold the exhaust valves off the seats, in conjuction with elevated rpm?
If so, it would seem the 'cure' is to run more exhaust seat pressure?
Chris's comments seem to support that?
Yes 100% correct, aggressive ignition cuts will cause backfires which results in spikes of EMAP (Exhaust manifold pressure) pushing on the back of the exhaust valve. While heavier springs/more seat pressure do help substantially (and I do recommend), I wouldn't say its a cure. The seat pressure required to keep the valve on the seat and not bounce during these conditions is so great that it will cause its own problems. Even the smallest amount of bounce/float etc will contribute to the lifters pumping up. Ideally the proper cure would be a combination of solid lifters, proper valve springs, cam profile and valves.
A fairly large cost for most enthusiasts. If you can make it work with more retard than cut and keep away from excessive Emap, that is the easiest and cheapest option. Although it won't be as effective. If you're needing it for competition use, I would suggest springs and solid lifters at a minimum.