Tuning for zero knock retard - how to?

[Alky V6]

Be careful with chips that richen only at WOT, AND above a certain boost level. There will undoubtedly be a transition point in the rpm and boost rise where the a/f mixture may be too lean and you will have the onset of knock before the WOT richening has had a chance to kick in. Hopefully more alky during that transition point will take care of that knock. Or maybe the chip could be sent back to richen the target a/f ratio at that particular engine operating point.

A very interesting thing to watch out for if you encounter this lean transition point during your tuning.
If your wastegate is setup that allows a certain amount of 'cracking' before the boost target, make sure the boost level is not set so low as to allow the boost level to linger in this fueling transition range. The longer you have knock during transition, the longer it will take for the WOT richness setting and the alky to bring combustion temps (egts) down to a no knock condition. Raise the boost control level to a point where the wastegate cracks above the fueling transition range. When the wastegate cracks at a low boost level, it slows the rate of boost climb and will cause the engine to linger in a fueling level that is not best for the engine.

 

[Timbuick]

Donnie, thanks for such a comprehensive review Maybe this should be a sticky?
currently, i'm not using alky, but I can see that the proces explained above still applies. My chip does allow me to add/retract both fueling and timing so i'll try and get some scantool numbers and then adjust accordingly.In the above info, are the figures you cite for WOT use? e.g.AF 9
If so, i'll start to collect figures for WOT in AF and 02mv and see what transpires.

 

[Alky V6]

Donnie, thanks for such a comprehensive review Maybe this should be a sticky?
currently, i'm not using alky, but I can see that the proces explained above still applies. My chip does allow me to add/retract both fueling and timing so i'll try and get some scantool numbers and then adjust accordingly.In the above info, are the figures you cite for WOT use? e.g.AF 9
If so, i'll start to collect figures for WOT in AF and 02mv and see what transpires.

Yes, those would be WOT numbers for chips such as TT where the programmable extra fueling only comes in at WOT. Pay very careful attention to that fueling transition point. That looks like a major stumbling block for these types of tuneable chips. Hopefully, that section of the map can be adjusted by the chip maker if you encounter that problem. IMO the fueling needs to be more ramped into the WOT fueling setting. It stays too lean up to the point where the WOT fueling finally comes in.

 

[Alky V6]

One last note before I eat my turkey,

Start at a known safe boost level until you get the fueling and timing worked out for that boost level. Only after you've found the best tuneup for that boost level should you start to increase boost. Depending on what boost level you've started your tuning at, move up 2 psi at a time, working to 1 or .5 psi at a time as you start pushing the envelope. At each step, you will need to go through the above mentioned tuning routine. In fact, it would be best that you started out at the new boost level with the timing backed off say 4 degrees, and if no knock is encountered start bringing the timing back in little by little.

Expect to have different fueling and timing targets at each level of boost. Keep records of your best tuneup for each boost level. Keep an eye on egts and plugs.

 

[Timbuick]

Thanks agin, Donnie, The last post helps clarify matters. Once the rain stops (!) i'll get some numbers recorded and report back in due course.

Do think that this would make a good sticky for any of the newer guys like me. Much appreciated

 

[Alky V6]

I have heard comments that suggested that some purchase a TT chip, slap it in, and it's good to go. Didn't have to adjust anything. All that's needed is to adjust the alky system.

Bad procedure.

When I took this recent car out for a baseline check of the chip setup, the mixture was horrendously lean at WOT. Try high 13s to one. The owner claims that the chip was set up for the size injectors that are installed. At the point I'm at with the tuning so far, I had to richen the WOT mixture 18% to get to a safe starting point.
This fella has already gone through a blown head gasket on a fresh engine because he and his previous engine builder assumed the chip was correct out of the box and gave the car back to the owner to drive tuned that way. Holy cow.

Never assume that the chip you purchased is right for your engine just because everyone else has told you that they never had to adjust their chip.

Check it out!

 

[Timbuick]

well got a chance to take the car out for some road testing for an hour or so today. noticed mainly that the AF is certainly too lean once i get into throttle in 3rd gear. came up with 14s.
02s were better showing approx 750-780, still a bit lean for street gas.
anyway, i decided it was too dangerous trying to read four different dials and be safe at speed, so Ive booked a rolling road session in a couple of weeks time. Idea is that I provide the figures i need (the ones you guys suggest) and we tune accordingly. I'll report back in time.