Firstgens.com

The question comes up so often about tuning a carb in timing etc etc.
Even just getting the engine to run better.
I have come to the firm conclusion to do so one can get in the ball park by the seat of one pants, but to get it right or damn near right, forget the old CO/HC sensors ..go for a O2 logger like the innovate LM-1 or 2... For tuning DO NOT use a led or gauge....spend the extra bucks

1st get the timing in the ball park...low intial around 8 to 10 deg, so as not to load batteies and starter motors and end up blaming hard warm starting on header heat.
A good stable idle , depending on your combo will be around 16 to 18 degs....so around 8 or 10 deg VA all in around or below the engine vac at the idle advance you have established....usually a VA around the 7 to 12 "
Then the curve its self old iron heads, lookingh around 36 to 38 deg max..modern Al heads/hi compression around the 32 to 34 deg max....all in around 3200 rpms
So cruise at 3200 you have a total of around 40 to 44 deg.
Thats a ball park,
Now put the O2 sensor in the exhaust, not at a low piont where condesation will get to it...
Set the sec butterflys so the idle speed screw amd idle mixture screws are in factory spec
Check the gaps and action on the accel pump is correct.
Check the power valve is correct for the engine vac.
Now adjust the idle mixtures to just lean of the AFR of the fuel u are using
Then set the jets also just lean of the AFR of the fuel u are using at cruise
Chances areThe power valve will be correct

Cant see what Im typing..will make a new post

Chances areThe power valve will be correct...
With a gauge or LED indicator it is not sensitive enough to check if it and the accel pumps richen the mixture enough....THIS is where the logging comes in to see the rich spikes...and if they are rich enough for your fuel.

Now you have the carb set up...back to the timing for minor adjustments...a couple deg here, a deg there will not be more than that.....recheck the O2 for the carb... very unlikely will need and changes other than minor changeof the idle mixture screws.

Im pretty good at the seat of the pants, bloody sight better tham most, but since tuning with the innovate LM1...I am astoded how in 1 1/2 an afternoon of tuning...my WOT power increased dramatically..enough t actually scare me cause was not expecting such a difference
And a 114 mile cruise of varing terain most open road, flat , up thru hills , winding roads and even gravel.....I picked up a huge near 30% economy....31.4 mpg.E to 96 octane petrol.

What I am kicking my head real hard for is I had thought about going to a logger many yrs ago.. after reading a comment ina post Jim made at TC on ECU mapping...even if I had done so 12 months ago..it would have more than paid for its self...
When it comes to injection..I know it doesnt have a carb...thats it lol

A couple warnings..locate the O2 sensor in a manner it will not get condesation on in the exhaust...the top side 10 to 2 oclock
Do not run the engine with the O2 sensor not connected up....Both eventaully stuffs them.
If running high rpms also have the tach hooked in..make sure u have enough CFM and enough fuel to supply the required energy (BTU)

The basic Innovate unit can be set up for many fuel types..from diesel, methanol, LPG, CNG, petrol, you custom settings.

Don't forget to adjust your valves before you do any of the above. Just to be sure you have maximum vacuum.

Jan

Sounds like for the less than the cost of dyno tuning you could do it yourself. Great post Steps.

u catch on quick for an American lol

Seriously thu, its like going out and buying yor own welder, dollies, compressor....its doesnt take a rocket scientist with 1/2 doz PhDs to make up and weld a few patchs...and it works out cheaper than sending the car off to prison for a few months...+ you have a well equiped workshop for the next project
Sure its time....
AND I bet the shop labour charge out rate is a a bloody sight higher than your NETT hourly rate.
And I would also bet the mark up on the parts is a bloody sight more expensive than your 'trade' price

The basic Innovate is just that...even so the data is an eye opener
Then add a couple more sensor to the O2, the AUX module to the Innovare and one is talking very serious tuning....AND trouble shooting tools....on old school engineering.....
There are built in forumla (and one can do custom also) creats 3 diamenstional live graphs, and from what I understand rather accruate HP and torque curves

Then if u have fuelinjection it eally comes alive...with the Aux units think its something like 32 sensors can plug in and log, map, etc.

I found a plug intermitently not fully fireing because it logs more than each cylinder fires....this resulted in the occassional low O2 spike (rich) no way would have I ever picked it up.

If u go here

http://www.innovatemotorsports.com/support.php
download logworks3 at top of the page, install and in the import under file onecan import some exaple logs.

hmmm, some old dog's been learning some new tricks?

Yup, tuning by capturing live data is the way to go, either during a dyno tuning session or on your own.
you need O2 and RPM, and... it's really nice to have throttle position, and oh yea, manifold vacuum.

I have those 4 gauges on my dash, it would be a great tuning tool if I didn't have to pay attention to the road, even better if I could actually remember all 4 data's for any length of time. Still, it's amusing to watch the gauges.

Much better to capture the logs and go back and replay and analyze later.

hmmm, some old dog's been learning some new tricks?

Yup, tuning by capturing live data is the way to go, either during a dyno tuning session or on your own.
you need O2 and RPM, and... it's really nice to have throttle position, and oh yea, manifold vacuum.

I have those 4 gauges on my dash, it would be a great tuning tool if I didn't have to pay attention to the road, even better if I could actually remember all 4 data's for any length of time. Still, it's amusing to watch the gauges.

Much better to capture the logs and go back and replay and analyze later.

WOW Steps. All that from a guy that touted for yrs about being able to make his own O2 sensor. I'm very impressed! Welcome to the dark side on this one mate. I looked at the Innovate tuner for quite some time but in the end found a great deal on the fast dual wide band and ordered the matching rpm mod. as well. In part because I'm still contemplating EFI maybe somewhere down the road. That and I liked the looks of the Fast monitor and the fact that I didn't need a laptop at the track to play back.

Old?? may God rot yor socks over night and other horrible curses like it


OK I have a innovate lm-1...basic unit
rpm logging on old school requires another add on part....
BUT doing deeper reseach on our old school carbed cars...forget even trying to get it to work...
And the newer model LM-2 apparantly works fine IF you have a ECU output tp hook into....Its my understanding it can be done, sometimes requiring a damaged forehead and a brick wall.

I can live with that because of my application, a straight street daily driver that happens to be ok quick because of hi compression and 105 octane fuel...without going over 5000 rpms...
All I need to know is at what rpms it does lean out.....
I can record diff sections of several short periods with known rpms on the dash tach.

For you guys with old school pionts/HEIs no ECU and hitting up in serious rpms with serious street track grunt
Take advice from Jim and Harley for something else
If running a ECU, tach output innovate is good.

P.S..cant find anywhere....the std Primary wave form for a ac delco HEI 4 tag module dizzy off the tach tap.