VTC_CiViC

And I mean REAL tuners i.e. you've tuned more than your own car, I'm curious, what A/F do you shoot for when you dyno tune a car? See I always thought of 12.5:1 as the "ideal" ratio, but I learned yesterday from Frank @ SFP that Honda's simply won't live at that lean a ratio, and he aims all his motors for 11.9-ish, mine was done at 11.8:1. I thought this was a pretty interesting little tid-bit since I'd always belived the in 12.5:1 rule.

So how about you guys? What do you shoot for?

X2BOARD

Don't get me started...

jinxproof99

i'm posting this as my experience and not to be told i'm an idiot.

speaking of ONLY turbo hondas w/comp ratio's in the 9:1 area.......my old car went to mid 13.8 on 116 octane. that lasted over 1 year. stock pistons/rods. my new set up runs between 13.0 and 13.5 on race gas. i've personally witnessed more than one race car go over 14.0 on dynos.

as for a safe, daily driven, pump gas car. 12.5 is ok, but anything richer will only be safer. a high 11 a/f ratio seems alittle safe for me, but if i were running a business and tuning customers cars, a 11.5-12.00 ratio is probably where i'd shoot for. just to be safe.

VTC_CiViC

13.0-13.5! Wow!! This on race gas I see, but that's still pretty damn lean! Well I guess if you've got the expereince and it works for you.. afterall, Frank was also the guy who called my car a "timebomb" before he touched it heh


[Modified by VTC_CiViC, 3:42 PM 5/8/2002]

VaporTrail

for street cars with 9-10:1 CR, I tend to shoot for high 11's a/f also on pump. Race gas burns much cooler, and therefor, you can run it much leaner and still be safe. Seems like Frank did a good job on tuning your car, should be safe and powerful for a while

VTC_CiViC

Awesome, thanks John and Jinx

c_penson

Some tunners do this because when the car is on the street the conditions are diferent and this causes some drop in air fuel ratio, on the dino the temperature is stable and cooler because of air conditioning and the fans that are put in front of the car cool the pipings and intercooler of your turbo.

VaporTrail

excellent point, but not quite accurate. At speed on the street, typically you'll see cooler intake temps, and thus the car sometimes runs leaner. Running it rich, you'll avoid running into a lean condition

X2BOARD

Good thread

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