chevymans 77

This is probably the best one thing I have done to help get better performance out of the vette. No more guessing if the mixture is correct and if the vette is running the best it can.
I welded the O2 bungs on and installed the sensors then I hooked the meters up adjusted the idle at 14.7:1 and went for a ride. Cruising the mixture is off the scale lean and soon as I hit the go peddle it goes full rich. I will be locking out the secondary and checking the primaries to see how for out they are and make adjustments. Once I get them set I will unlock the secondary
and tune them.
I can’t stress enough how this is the ultimate tuning tool it takes the guess work out of tuning the carb. For what it cost me to build it is probably the cheapest thing I have done.
Lasse
The readings on my two meters are as follows.
1 .11 1 .18
2 .22 2 .28
3 .33 3 .38
4 .44 4 .48
5 .55 5 .56
6 .66 6 .66
7 .77 7 .76
8 .88 8 .86
9 .99 9 .96
10 .1.10 10 .1.06

The last led on both meters will not light because the voltage required is to high it seems the 330 ohm resister is not enough I will be replacing it with a larger one to get the #10 led voltage down a little so it will be in the same range as the O2 sensor (needs to be 1.0 volts or just bellow).

Neal :hurray:


[Modified by chevymans 77, 10:35 PM 7/2/2003]


[Modified by chevymans 77, 10:37 PM 7/2/2003]

LAvetteman

:cool: :hurray:

Schmucker

How do you read your LED guage to know the mixture? I'm confused.

427V8

Did you put the o2 sensors in the collectors?

I tried puttin them in the headers but with my cam they get a real messy signal :U

chevymans 77

Schmucker
The O2 sensor sends out a voltage signal calibrated to operate in a range with 14.7:1 being near the center. The meter is a simple voltage meter that instead of displaying numeric values it lights up LED’s each LED represents a given voltage from 0.0 to 1.0 (lean to rich) if the meter is calibrated correctly 14.7:1 will be near .5 volts which will light up half or 5 LED’s. Hope this helps.

427 V8
The cam may mess up the signal at idle due to overlap but once off idle it should clear up. You could possibly dampen the signal more, this may slow the fluctuations from the sensor. I do not have headers, but Lasse has recently installed his O2 sensor at his collectors and it appears to work fine.

Neal
:)


[Modified by chevymans 77, 6:58 AM 7/3/2003]

Lasse

Neal - Good, really balanced figures btw the meters. Have you measured the two engine sides at the same time and compared the balance? It would be nice to hear how much they can differ. :cheers:

Schmucker - I used this graph to translate the led's to A/F ratio:

Value of led # in my case..


427 V8 - The leds on my meter jumps syncronized with the sound on idle (2-3 leds up and down), but on the road the leds lits steady on the values. You have my cam figures in the sig. I mounted the sensor right after the collector (~1 1/2 foot in front of the crossmember) and attached the A/F meter ground to the collector clamp and chassi ground. (one wire sond).

:thumbs:

Matt Gruber

A/F meters are great!
i never would have guesed my carb back barrels were 42% too rich. Only problem now is i use so little gas, i worry about it getting stale. :p:

427V8- did u have a ground wire direct to the sensor? i've not read about any cam causing a problem.
i get lean readings within 2 seconds on a cold start, if i don't pump it enough, non-heated sensor.

chevymans 77

Lasse
I mounted both meters and went for a ride. Both meters mirrored each other while cruising but while adjusting the idle I was able to separate the readings from side to side. The adjustment would affect both sides but it would alter the side I was adjusting more then the other.
:)

BSeery

what sensors are you using? (brand and part number and where you got them).

2 or 3 wire ?

87bob

How about some pictures? Sounds like a great set up. :hurray: :hurray: :hurray: :hurray:

chevymans 77

BSeery
They are Bosch sensors I bought off of e-bay for $15.00 I do not have the part #'s with me but I will post them as soon as I get home. They are the single wire sensor. You should be able to pick these up at the local parts house for $20.00 new.

chevymans 77

87bob
Here are some pic's of the meters.

:)

71'AirStrike

oooh drool .. This sounds like an efficent cool way to fine tune in your machine. I personally am tired of my 8MPG w/ my 454. PLease pose more info. mabie a how to?

thanks
chad

427V8

Chevymans
Mine were mounted right up next to the heads on the primary pipes, I think the fule is still burning there !

I haven't had time to move them to the collectors yet, but plan on it as soon as I finish the other 15 projects ahead of it!!

Lasse

They say that 10-12 inch are the optimum lenght from exhaust port.

71'AirStrike - We had a topic of the construction two weeks ago. Check out: http://forums.corvetteforum.com/zerothread?id=584319

We have follow http://www.markvanderkwaak.com/dbbp/tech-tips/mm.html building scheme.

BSeery

Trying for 9 MPG ?? :lol:

I think these would be very similar to the Nordskog brand meters sold through Summit or Jegs.

I think I need to go with a heated sensor since I have mine in the collector of my headers.


[Modified by BSeery, 1:34 PM 7/3/2003]

Lasse

They are the same as K/N's, but costs only $10 and two hours of work. :yesnod:

chevymans 77

BSeery
This is the part # on the Bosch O2 sensors. Part # 0 258 001 037

Neal

Matt Gruber

Tuning without an A/F meter is like flying a plane blindfolded! :cheers:
newbies see sig. link

BSeery

what signature ?


[Modified by BSeery, 9:17 AM 7/4/2003]