When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Modification are ARH Long tubes (no cats), one step colder plugs, split cooling, HE, belt wrap kit and no other "power mods". It's a custom dyno tune that was done in the summer heat. 102,000 miles and runs incredibly well. Just got a comment about the AFR and wanted a few opinions
Tune is on the aggressive side from 3700 -4200 but rest looks pretty good. Cool graph!
as long as I have fueling and the car doesn't have a melt down at full throttle at the track. I'm fine doing 1/4 mile pulls but he consistent full throttle at AMP/Road Atlanta is what made me want to have a few opinions on this setup.
For the long pulls up top looks like you're in the 12.4 range. Not terrible but would feel better closer to 12. It would be very telling to do a full pull up top and shut down quickly for a plug read. I know, pain in the rear but it's a good snapshot to have.
On a side note... big fan of your car and love that you track it. Looks like a blast!
This is just me, but I'd go a full point richer on that AFR for road racing. Shooting for low to mid 11s. Will make no difference in lap times and easily be worth the piece of mind when you stay in the throttle.
I road race my SRT-6 and while it's not the same it sort of is. I've run leaner than your showing in the past but I was running with 100 octane at the track. More for piece of mind than anything else. Currently my tune has my car right where you are. As my car gets hotter the PCM enriches the mixture and I end up in the high 11 AFR's. I'm running 18 to 19 lbs. of boost. I've seen water temperatures of 245º after 20 minutes and IAT's at 165º in the summer heat. Blackstone labs gets oil samples when I change it and so far so good. All these words just to say you should be fine if your engine is anything like mine. For piece of mind you can mix 100 with what's left in the tank.
This is just me, but I'd go a full point richer on that AFR for road racing. Shooting for low to mid 11s. Will make no difference in lap times and easily be worth the piece of mind when you stay in the throttle.
I told the tuner the type of driving I did and he tuned accordingly. He may of forgotten or didn't understand "road racing". So you'd have it re-tune it and get it into 11-ish?
This is just me, but I'd go a full point richer on that AFR for road racin. Shooting for low to mid 11s. Will make no difference in lap times and easily be worth the piece of mind when you stay in the throttle.
I told the tuner the type of driving I did and he tuned accordingly. He may of forgotten or didn't understand "road racing". So you'd have it re-tune it and get it into 11-ish?
Exactly, I'd add more fuel. He may have got an extra 10 HP, but I'd rather have the piece of mind when exiting turn 12 @ RA, and burying the loud pedal. We could speculate that your ECU is adding fuel due to charge temps at the track, but would only be guessing w/out a wideband.
I'd also take a close look at timing. You're making a ton of power for the track and don't need a max-effort tune.
Exactly, I'd add more fuel. He may have got an extra 10 HP, but I'd rather have the piece of mind when exiting turn 12 @ RA, and burying the loud pedal. We could speculate that your ECU is adding fuel due to charge temps at the track, but would only be guessing w/out a wideband.
I'd also take a close look at timing. You're making a ton of power for the track and don't need a max-effort tune.
I'm currently gearing up for a data logger and wideband for the track. I'm trying to link up with Tony (former BIP) to have my car re-tuned but having issues coordinating with him. I've done many track days with his tune powering me and felt great. I'm a little uneasy diving into the track season with this tune.
I have a wide band and can see the AFR's in real time on track. When I first pull out I see 12.4 at WOT, more or less. If you have the same basic ECU (2.8) it can richen the mixture almost a full point and will when "sensor readings" trip a threshold in the ECU. It won't cost power being a bit richer. The difference between 11.8 and 13.0 AFR's on the dyno was around 5 hp on my car. If you have no cooling issues you'll be fine where you are, IMO. But if your worried run 100 octane or do as everyone else recommends which is run a lot richer. Stock my car was in the 10's.
Thanks for all the answers. I think I will take it back to the tuner and have them take a look at it again.
On another side. My 02 was fouled from what appeared to be carbon/soot. My exhaust shoots out a good bit of black smoke. I don't really drive it as hard as I do (mainly 6 miles commutes and barely gets it up to temp). I am tempted to lay into it a bunch of times and clear it's throat. I also feel this black smoke is tune related.
02-13-2016, 01:17 PM
