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I’ve never really been a fan of canned tunes, not because I don’t think they are good, but I’ve always liked to have a tune match a specific engine and mods. My car (07 C4S) came with the champion f77 kit which included a GIAC tune. I can’t say I disliked it but I’ve checked my afr’s a couple of times using a simple obd reader and it seemed to be running rich. Well I decided to go with a custom tune in order to get a more efficient engine and was not looking to squeeze any more power out of the car.
Here is the aftermath.
Sure enough the GIAC was sure running rich! Overall impression is the car is smooth like it should be.
It's good that you got the rich AFR cleaned up. IMO the price to performance ratio of these NA tunes are just not worth it. I think we get more out of our cars with lightweight wheels and smaller beer guts.
I don’t have any kind of pre-tune dyno so I can’t see how much hp a tune frees up. But I agree personal weight reduction (and mechanical) is way more cost efficient.
When the engine is under heavy load a little richer isn't bad. An AFR of 16 on your new tune is too lean under initial tip in. You really don't want to be any leaner than 14.7 unless just idling down the highway with essentially zero load and even then no leaner than 15.0.
AFRs of 12 or just higher prevent detonation under heavy load. The rest of the new AFR graph looks better, but I don't love the tip in point lean AFR #s.
When the engine is under heavy load a little richer isn't bad. An AFR of 16 on your new tune is too lean under initial tip in. You really don't want to be any leaner than 14.7 unless just idling down the highway with essentially zero load and even then no leaner than 15.0.
AFRs of 12 or just higher prevent detonation under heavy load. The rest of the new AFR graph looks better, but I don't love the tip in point lean AFR #s.
yes AFR’s in the higher range 15.5-16 sometimes will show a loss in power in the cruising range. However if you see the graph I am loosing no power as my engine and mods seem to like the lean mixture. As throttle is applied the afr’s drop accordingly. I should see better mileage (wasn’t the point) while making the same power.
yes AFR’s in the higher range 15.5-16 sometimes will show a loss in power in the cruising range. However if you see the graph I am loosing no power as my engine and mods seem to like the lean mixture. As throttle is applied the afr’s drop accordingly. I should see better mileage (wasn’t the point) while making the same power.
I agree that almost all 9f the mixture graph is better. I just worry about that 16 AFR for a few hundred RPMs right as you're putting the engine under load. You'll also notice that there's no power from 3k-3,300 rpm because the mixture is so lean and why the HP curve came in much earlier with the other tune that had a better AFR lower. Seems like there may be some additional tweaking possible to get the best of both worlds.
I agree that almost all 9f the mixture graph is better. I just worry about that 16 AFR for a few hundred RPMs right as you're putting the engine under load. You'll also notice that there's no power from 3k-3,300 rpm because the mixture is so lean and why the HP curve came in much earlier with the other tune that had a better AFR lower. Seems like there may be some additional tweaking possible to get the best of both worlds.
This was the final tune after a base pull to see where we were at, initial tune (followed by a dyno), tweaked some more then the final pull which is shown. Pearson (Hydra) did the tuning so not sure what timing he adjusted along with the other parameters. AFR of 16 seemed to be the sweet spot for my particular engine. I understand how seeing a higher afr may look odd esp compared to the crazy rich box tune! I’ll admit I’m not an expert at how dyno’s graphs work but this is making me more curious about looking into how we can tune our own engines (like we did with the e46 m3 platform). I think there is a lot of efficiency left on the table. What I don’t know is how beneficial a tune is to a stock car. I really wish I had the car on a dyno before the previous owner did the upgrades.
This was the final tune after a base pull to see where we were at, initial tune (followed by a dyno), tweaked some more then the final pull which is shown. Pearson (Hydra) did the tuning so not sure what timing he adjusted along with the other parameters. AFR of 16 seemed to be the sweet spot for my particular engine. I understand how seeing a higher afr may look odd esp compared to the crazy rich box tune! I’ll admit I’m not an expert at how dyno’s graphs work but this is making me more curious about looking into how we can tune our own engines (like we did with the e46 m3 platform). I think there is a lot of efficiency left on the table. What I don’t know is how beneficial a tune is to a stock car. I really wish I had the car on a dyno before the previous owner did the upgrades.
You know what would be interesting is to track and log bank 1 and 2 fuel trim live values as you're doing a pull on the street and see what the DME is seeing and adjusting as well as AFR values.
You know what would be interesting is to track and log bank 1 and 2 fuel trim live values as you're doing a pull on the street and see what the DME is seeing and adjusting as well as AFR values.
Good call! I was also thinking this would give the car time to adapt (short term fuel trim) and settle down. Let me see if the torque app will do this and I will report back. Will have to wait as I Iook outside and its snowing...
When the engine is under heavy load a little richer isn't bad. An AFR of 16 on your new tune is too lean under initial tip in. You really don't want to be any leaner than 14.7 unless just idling down the highway with essentially zero load and even then no leaner than 15.0.
AFRs of 12 or just higher prevent detonation under heavy load. The rest of the new AFR graph looks better, but I don't love the tip in point lean AFR #s.
Its 100% ok to be lean while it rolls into full power. Not going to melt anything.
01-14-2022, 05:42 PM
Canned tune vs custom tune
