[cjuetten]

I started tuning the car this week with the wide band. First off, all I can say is the wide band is the ONLY way to go...I started with the narrow band and made fair progress in cruising but WOT was a major challange. Since switching to WB it's been 10 fold easier. (69 camaro 461, headers, Lunati Bracket II cam, TKO-600 w3.70s, And Holley 950 commander TBI 75lb injectors w/WB O2).

Anyways I was wondering what and how others go about tuning. So far it seems to run best at 13.2 at WOT and partial throttle. And 14.0-14.7 for cruising. All seems good, except I still need some work on the "accellerator Pump".

1) Do these readings seem to fall in the normal range?

2) How lean can you safely go when cruising (fuel milage) ?

3) When working on the Accell Enrichment do you try to maintain 13.2(?) or should you see a rich spike as you hit the throttle?

4) Any other tips?


Thanks
Chris

 

[camcojb]

I started tuning the car this week with the wide band. First off, all I can say is the wide band is the ONLY way to go...I started with the narrow band and made fair progress in cruising but WOT was a major challange. Since switching to WB it's been 10 fold easier. (69 camaro 461, headers, Lunati Bracket II cam, TKO-600 w3.70s, And Holley 950 commander TBI 75lb injectors w/WB O2).

Anyways I was wondering what and how others go about tuning. So far it seems to run best at 13.2 at WOT and partial throttle. And 14.0-14.7 for cruising. All seems good, except I still need some work on the "accellerator Pump".

1) Do these readings seem to fall in the normal range?

2) How lean can you safely go when cruising (fuel milage) ?

3) When working on the Accell Enrichment do you try to maintain 13.2(?) or should you see a rich spike as you hit the throttle?

4) Any other tips?


Thanks
Chris

you are correct, the wideband is the only way to go. I've never tuned EFI without one.

1. readings look pretty normal.

2. I've gone into the 15's approaching 16:1 on the cruise areas, but it depends on the particular engine. Most are fine and run great that lean at a cruise, and others will have a slight misfire. Learned this a long time ago, give the engine what it wants.

3. You could actually be a bit leaner as you make your way towards wot, but there's nothing wrong with where you're at really. You might try richening wot to 12.8:1 or so just to see if it picks up any more, but somewhere in the 12.8 to 13.2:1 at wot with a naturally aspirated combo is usually what works best. A rich spike is common but can be tuned out. Not a big issue to me.

4. I get all my idle, cruise, and wot areas done first, then do a lot of datalogging doing my daily driving errands and smooth out all the transition areas, and blend everything together. Sounds like you're already real close, so you can maybe try a bit richer at wot, and also try leaning out the cruise and see what the engine will take. Timing is another area to play with. I usually run 20 degrees or more at idle and quite a bit at cruise/light load areas (45+) which seems to help the mileage.

Jody

 

[cjuetten]

Thanks for the Info...hopefully it'll warm up again and I can get out and fine tune.

 

[Mark .L.W.]

Hi Jody i just finished switching over to my wideband upgrade on my holley comander MPFI , yes it makes it way better to see it in real time , and i can now run closed loop . I may need your help with some questions later this year for the procharger install , i just finished buying the D1SC kit complete with the air to air , it will come all polished to add some more to clean all summer . i also just ordered a new set of J&E pistons i want to have everything and ready to go .
Mark.

 

[camcojb]

Hi Jody i just finished switching over to my wideband upgrade on my holley comander MPFI , yes it makes it way better to see it in real time , and i can now run closed loop . I may need your help with some questions later this year for the procharger install , i just finished buying the D1SC kit complete with the air to air , it will come all polished to add some more to clean all summer . i also just ordered a new set of J&E pistons i want to have everything and ready to go .
Mark.

you'll love that blower Mark, and the wideband is the only way to tune, especially with a blown motor.

Jody

 

[novaderrik]

another good tuning tool is a vacuum gauge.
for WOT tuning, tune for less vacuum. for cruising or idle, tune for max vacuum.

 

[Mwilson]

+1 wideband is an awesome tool

 

[whytry]

Just got my wideband installed on my Carbed 468 Procharged BBC, and now I get to join this club... Much easier to tune, any recommendations for tuning carbed?

 

[Mwilson]

Much easier to tune, any recommendations for tuning carbed?

take good notes each time you change, you have jets/IAB/HSAB power valves and disscharge nozzles.
I had a buddy (The owner of the Wideband) ride with me and take notes at different speeds and idle and wot

 

[camcojb]

the Dyno jet wideband can datalog which really helps. Did someone set up your carb, or are you doing the mods yourself? What a/f are you seeing under boost?

Jody

 

[cjuetten]

another good tuning tool is a vacuum gauge.
for WOT tuning, tune for less vacuum. for cruising or idle, tune for max vacuum.

Can I use the MAP sensor readings inplace of a vacuum gauge (more is less/ less is more), in otherwords.

Maximum MAP reading (more air) at WOT ?
Minimum MAP reading for Efficiency while Cruising ?

 

[novaderrik]

a good old mechanical vacuum gauge mounted under the dash is the best tuning tool you will ever get. for instance, if the cam starts to go flat, the needle will start to fluctuate a couple of ".
a MAP sensor will never give you that kind of heads up.

 

[camcojb]

a good old mechanical vacuum gauge mounted under the dash is the best tuning tool you will ever get. for instance, if the cam starts to go flat, the needle will start to fluctuate a couple of ".
a MAP sensor will never give you that kind of heads up.

but it won't tell him his a/f.

Jody

 

[novaderrik]

unless you are running a supercharged combo, the a/f ratio isn't as important as the vacuum reading under various conditions. it's not that it doesn't matter, but it is just one thing you need to watch.
i wonder how many guys went out and spent a few hundred $$ on a/f meters that aren't getting optimum power or mpg because they are tuning "by the meter" instead of what their engine wants. the optimum a/f setting on one engine in one car might be way different than a similar engine in a different car.
plus, it's just fun to watch the what the vacuum gauge does in different situations. i bet everyone on this board would find at least a couple of mpg if they had a vacuum gauge- it shows every time you move the gas pedal just a little bit, and you learn not to do that when you have a gauge bouncing in front of you.
as for power- if the vacuum gauge doesn't go down to zero when you are at WOT, something isn't set right. my Nova would actually go to a couple of pounds of POSITIVE pressure in the midrange under WOT

 

[camcojb]

unless you are running a supercharged combo, the a/f ratio isn't as important as the vacuum reading under various conditions. it's not that it doesn't matter, but it is just one thing you need to watch.
i wonder how many guys went out and spent a few hundred $$ on a/f meters that aren't getting optimum power or mpg because they are tuning "by the meter" instead of what their engine wants. the optimum a/f setting on one engine in one car might be way different than a similar engine in a different car.
plus, it's just fun to watch the what the vacuum gauge does in different situations. i bet everyone on this board would find at least a couple of mpg if they had a vacuum gauge- it shows every time you move the gas pedal just a little bit, and you learn not to do that when you have a gauge bouncing in front of you.
as for power- if the vacuum gauge doesn't go down to zero when you are at WOT, something isn't set right. my Nova would actually go to a couple of pounds of POSITIVE pressure in the midrange under WOT

I am a big proponent of giving an engine what it wants, especially in EFI tuning. Don't get hung up on the a/f numbers, but I still want to know what they are. Since this thread was about EFI tuning I think it's an important piece to have.

As far as reaching "0" vacuum, I have seen many combos not reach that at wot, generally because the throttle body/carb was not large enough, or there was another intake restriction (too small of an air filter, severe bends in the inlet, etc.) and no amount of tuning with a vacuum or wideband gauge will fix that.

Jody

 

[novaderrik]

it won't fix it, but it will tell you something isn't right.
you could set it up with the a/f gauge, and think you have everything all maxxed out an perfect, then put the vacuum gauge on it and see 3" of vacuum at WOT. this would tell you that there is a fairly large restriction somewhere that needs to be addressed if you want max perfromance. could be the throttle body/carb is too small, but it could also be as simple as not getting the throttle blades all the way open.
all i'm saying is don't get caught up in the hi-tech and forget about the low tech stuff. if you've got them, use them together.

 

[camcojb]

I have a vacuum gauge with all my forced inductions (boost gauge) and all the n/a efi setups have the map sensor which is the same thing. I can see a restriction there by logging map kpa, which I always do. Fluctuation at idle also shows.

I think with EFI I'd rather have a wideband and no vacuum gauge, vs a vacuum gauge and no wideband. I just see no way to tune wot with just a vacuum gauge. Just because the vacuum is low doesn't mean the a/f is correct or not far enough off to be damaging.

Jody

 

[cjuetten]

Thanks for all the info, I have both Vacuum gauge and MAP so I plan on using both. I guess I a little fuzzing on the WOT part. Will adjusting AFR and ignition timing have an effect on a Zero vacuum reading while WOT? If everything is sized right and no limiting restriction on the intake side.

Assuming the restrictions on the intake side is fixed in a non forced induction motor. Wouldn't a small vacuum reading indicate the motor is using air faster than you can supply it. And Zero reading would mean it is not using all the air that is availible? Are you using the guage to tune or just verify that there are no restrictions holding the motor back?

 

[camcojb]

Thanks for all the info, I have both Vacuum gauge and MAP so I plan on using both. I guess I a little fuzzing on the WOT part. Will adjusting AFR and ignition timing have an effect on a Zero vacuum reading while WOT? If everything is sized right and no limiting restriction on the intake side.

Assuming the restrictions on the intake side is fixed in a non forced induction motor. Wouldn't a small vacuum reading indicate the motor is using air faster than you can supply it. And Zero reading would mean it is not using all the air that is availible? Are you using the guage to tune or just verify that there are no restrictions holding the motor back?

generally you'd like to see "0" vacuum at wot, though it doesn't always happen for a variety of reasons.

Jody

 

[Mark .L.W.]

just put a blower on it and push past the restriction .
Mark.