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Posted by: KaptKaos Mar 9 2012, 10:05 AM

I am planning to tune my carbs with an exhaust gas analyzer that I have access to at my weekly autoshop class. I have a 1.8 with a carb cam running dual weber 40s. I don't know the stats on the cam. I tried a few times to see if it was marked, and to measure the lift and duration, but neither was successful for a number of reasons. Regardless, it does run well, but I want to dial in the carbs better.

I will be running an SVDA dizzy, with vacuum advance. Timing at 30 degrees BTDC @ 3500, no vacuum connected.

I have access to an exhaust gas analyzer at my weekly autoshop class, and I intend to use it to measure my air/fuel ratio.

I have read that I want to be at about 13.5:1 to 14:1 at idle and cruise, and at about 12.5:1 at wide open throttle (wot). Does this sound about right?

Any advice or tips here are appreciated.

Posted by: McMark Mar 9 2012, 10:10 AM

Is it the style that you can drive around with? Unloaded tuning is worthless on the road.

Your ratio numbers are pretty much right, but listen to how the car feels more than the numbers.

Posted by: KaptKaos Mar 9 2012, 12:07 PM

Unfortunately not. It's stationary.

I had done this before and it was pretty good. What else do you recommend?

Posted by: Aaron Cox Mar 9 2012, 12:25 PM

Borrow an LM1/LM2?

Drive around/log data?

Posted by: brant Mar 9 2012, 12:38 PM

it has to be underload
you either have to drive around with it
or use a rolling dyno

borrow an LM1

brant

Posted by: jmill Mar 9 2012, 12:49 PM

I have one of these. Works great. You can find them on Ebay once in a while for about $150. There's one there now for way too much and even one on craigslist.

Heathkit EGA


Attached image(s)

Posted by: KaptKaos Mar 9 2012, 01:18 PM

Who the f__ are you?

Posted by: Elliot Cannon Mar 9 2012, 02:46 PM

Or welcome back?

Posted by: Aaron Cox Mar 9 2012, 02:55 PM

Joo meees me? lol...

Posted by: carr914 Mar 9 2012, 03:23 PM

Posted by: KaptKaos Mar 9 2012, 04:12 PM

Of course I did. How them brakes coming?

BTW: what was the deal with that guys comment on your brake picture? Out of line much? Geez....

Posted by: Aaron Cox Mar 9 2012, 04:17 PM

Not to threadjack..
but brake project is in progress. Studying for a final this weekend, so postponed a week.

Guy is a college buddy. NBD - nuked it!

Call me later.

Posted by: Elliot Cannon Mar 10 2012, 01:29 AM

So, this is what? Your seventh year of college?

Posted by: nsr-jamie Mar 10 2012, 06:17 AM

I had my car set up this way last year around october or so and it made a big difference..my car was actually running lean. I am running duel 40mm Dellortors. I had my local shop do it for me, they only charged me like 45 dollars which I think was too cheap and I helped out a bit...they attach it to the car and take it out on the roads for a while and make measurements and than set the carbs.

Some pictures



Before setting



carbs apart



after setting and another test run