Am I right about the AFR? Or completely full of it?
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Am I right about the AFR? Or completely full of it?
Lazy postwhore
I haven't seen your dyno so I can't say, but with our cars the best way to tune not leaning out the AFR, but rather increasing ignition timing to the point of knock and then reducing it until you're comfortable. That and upping the boost.
Fabrication Yoda
206.9kw is the biggest I've seen from a CES system with 3" MAF and XEDE, so 199.5kw is pretty good, 7kw difference isn't bad. If you had 189kw then I'd get a retune, but what you have should be save and reliable.
What boost are you running? 18psi?
As far as I understand, anything above 18psi and the turbo leaves its effeciency range.
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Lazy postwhore
I think 18 psi on a stock IC is as far as I would push it because of how hot the turbo gets and the fact I like to go WOT...a lot lol. But don't forget 18 psi on my car would mean the turbo is actually running about 2 psi lower than someone with a stock IC. In reality that would be only about 1 psi more than from factory which I feel (with no evidence to back me up) is relatively safe due to the fact that factory settings are not maxxed out in order to increase longevity.Originally Posted by 2XS
That's probably about the leanest AFR I've ever seen with our engine. All the dynos I can remember never push more than 12 and rarely come close to 12.5. I'm not sure whether to be impressed or shocked.
Nuliaj: Hatches are only really half a car anyway.
shinslinger66: And you forgot to add that they are also a girls car!
G Force Addict
Why? What is the standard AFR and what would be the recommended AFR for engine safety?That's probably about the leanest AFR I've ever seen with our engine
Forum Regular
She is hitting a different Dyno tomorrow to check on the AFR.That's probably about the leanest AFR I've ever seen with our engine
Lazy postwhore
Stock AFR under WOT will go as low as 9.5 - 10. Conventional wisdom says this is very rich. A theory as to why this is, is the cooling effect that the petrol has on the cylinder temperatures. I'm not sure if I believe that, given the tiny amount of time between the injection and ignition of that fuel. Regardless that has not got to be good for fuel efficiency.
On further research, I've found one other AFR chart which matches Crushers, but as I mentioned before, the others I've seen are all below 12.
As I understand it, our ECU either adds or removes fuel to try and maintain the targetted AFR. Since you're not tuning to get more air, all you're really doing is removing the amount of fuel used. This is not generating more power than a richer mixture. Now given the tendency of our engine to knock (whether real or false knock) and the already aggressive ignition timing from factory, I feel that an AFR of 12 -13 is probably leaner than I would be willing to go. This is all speculation and theory crafting, so I'm not saying that 13 isn't safe, but rather it is past my comfort zone.
Some people might be thinking leaning out the AFR might give you some fuel savings, but in actual fact it won't make too much of a difference. Reason being that when you're not under boost, which can happen even at high RPMs depending on load, the ECU is still trying to maintain stoich, which means 14.7 times the mass of air to fuel regardless of tuned or stock. So unless you're on boost constantly, the fuel savings will not be there.
Nuliaj: Hatches are only really half a car anyway.
shinslinger66: And you forgot to add that they are also a girls car!
Fabrication Yoda
Ok: update:
I have manifold, FMIC, CES SRI, CES TBE and HKS BOV. I don't have the fuel/boost cut. My car is still untuned. CES TBE does not cause boost cut, even with SRI. Each to their own I think.
IS NOT A
Thats what i wanted to hear 2xs
Zorst soon for me
Full Member
thing I want to know is how much can the turbo make before its inefficient? Alot of members are pushing 20psi as a daily driver with mods
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