I just got into the whole tuning bit first of all. I got hondata s300 on a b16 with cams/header. I am still fine tuning WOT too. My main question is about part throttle since this seems to be the hardest part of tuning for me.

I realized most people shoot for 14.7:1 but the problem im having is with very light throttle. Is it generally harder to tune this? It either seems to be way lean or way rich. Do small adjustments make a big change at part throttle?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SilverEk3dr &raquo;</TD></TR><TR><TD CLASS="quote">I just got into the whole tuning bit first of all. I got hondata s300 on a b16 with cams/header. I am still fine tuning WOT too. My main question is about part throttle since this seems to be the hardest part of tuning for me.

I realized most people shoot for 14.7:1 but the problem im having is with very light throttle. Is it generally harder to tune this? It either seems to be way lean or way rich. Do small adjustments make a big change at part throttle? </TD></TR></TABLE>

You shouldn't have a very hard time tuning partial throttle. What amount of load (.e. 20 inches of vacuum) are you having a hard time with ?

What software are you tuning with ?
Does your car have a full exhaust on it ?

 

Im using the hondata Smanager software directly from their site.

Its mostly -8.6 & -12 (column 1 & 2) at light cruizing speed. Although I took it out on the freeway and played with it for a while and seems to at least be getting close.

My main other concern is when you downshift or slow down with engine braking (zero throttle) how lean should it go? If I remember back when st00pid tuned my other car it would go 20:1 at times. Is this ok/normal?

BTW the car does have a full exhaust

Its a b16 with shortram intake, endyn bumpsticks, jdm itr header with 2.5" collector.



Modified by SilverEk3dr at 12:38 AM 6/8/2008

 

On decel with 0 throttle, even at stock tune, the injectors are disabled. Essentially all fuel is pulled.

Why do you want 14.7? Just because it is stoich doesn't make it the 'best'.

 

cause I beleive it to be safe.. and that what most people tune for at cruizing right?

 

we do mid 15's for very light load cruising, mid 14's for light tip in etc. on decel, its always really lean, almost no fuel going in

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Garage 808 Hatch &raquo;</TD></TR><TR><TD CLASS="quote">we do mid 15's for very light load cruising, mid 14's for light tip in etc. on decel, its always really lean, almost no fuel going in</TD></TR></TABLE>

Thats what I was looking for. Just needed some guidelines

 

at part throttle, you can lean it out until it misses and hesitates (not enough fuel to properly combust). The engine will bitch and complain before any damage is done in the light acceleration and cruising areas.

cruising speeds i am in the mid 15's and mid 14's for acceleration. In crome, i run a target AFR of 15 from 26" to 11".

I get 30+mpg in my h23vtec. almost 40mpg on the highway.

 

^^^ N/A I assume??? Not boosted right

 

a boosted motor is NA when out of boost

 

Touché, so why is it that some not all say it is best to be at 13.5afr on a boosted engine with light load??

And man that is good MPG I wonder what I could get on my b16a (yes, N/A and boosted) with that lean of an afr??

I think I will have to try it, are you running 0* cam timing at 16* of ignition timing??

Also what octane?

 

There is no definitive A/F Ratio which is best certain engines and setups like certain A/F Ratios. Yes there are guidelines of what to run in certain loads. You can have a lean mixture with a retarded ignition or a rich mixture with an advanced igntion making the same horsepower. It is the job of the tuner to decide the margin between them and what works best for power production and engine reliablity. Why not just save yourself the trouble and get it tuned. First off yes you can dial in you A/F ratio on the road somewhat but you will not be able to safetly tune you ignition as the only way to monitor that would be with you ***. Which is not exactly a precition machine!