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blodi

Weber selection and initial jet tuning

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Gentlemen, stupid question, how are you putting these graphs together?  Are you attaching something to your AFM?  I don't know if you are just taking readings and putting the graphs together, or creating them directly from AFM.  I want to create my own.

Love the thread!

 

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1 minute ago, duffman said:

Gentlemen, stupid question, how are you putting these graphs together?  Are you attaching something to your AFM?  I don't know if you are just taking readings and putting the graphs together, or creating them directly from AFM.  I want to create my own.

Love the thread!

 

I have an Innovate LM-2 that is hooked up to a wideband sensor in my collector.  The Innovate has a logging function that you can then pull up on their software on the computer.   It's not cheap (~$240) but the information is priceless.  

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Excellent data! Nice to see a crowbar at work and the high end raise!

215 to 238.JPG

 

I agree 165/225 should flatten it and give ~12.5 +/- 0.5.   You could then try 160  fuel  if you want a tic leaner.

 

There also seems to be a big change in the low end of the latest plot. It does not dive rich like it has done but instead it jumps lean.  What is your A/F when you cruise at 60mph now?  We may have to keep an eye on this region.

Edited by 240260280

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2 hours ago, 240260280 said:

Excellent data! Nice to see a crowbar at work and the high end raise!

215 to 238.JPG

 

I agree 165/225 should flatten it and give ~12.5 +/- 0.5.   You could then try 160  fuel  if you want a tic leaner.

 

There also seems to be a big change in the low end of the latest plot. It does not dive rich like it has done but instead it jumps lean.  What is your A/F when you cruise at 60mph now?  We may have to keep an eye on this region.

Ordered some 225's...we'll see where that lands. I notice the lean jump on this one too at the beginning....odd. I took two other logs last night as well...they were similar.  I didn't get a good eye at cruise....it's always been good at cruise in the past. I'll check it again. 

2 hours ago, 240260280 said:

Once you get the mains sorted did you want to circle back to accelerator circuit?

Yeah, we'll come back to that...not sure where to go with it now seeing how it changed with that last run. 

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I found out my AEM AFR meter (#30-4110) has the analog output capability for data logging, look forward to see how my numbers look in graph format!  So much tweaking, so much fun!!

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9 hours ago, duffman said:

How are you doing a repetitive test run to compare results on an apples vs apples basis?

Flat road, 3rd gear....pull from 3K rpm.  It's certainly not a dyno, but I try to get 2-3 pulls in so that I can make sure I'm getting repeatable results.  

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I'm gonna toss the 155 mains back in for a 155/225 combo. I'll report back tomorrow. 

Btw, cruise was dead on driving home today...~14.7 

Edited by blodi
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I tried 155/225...way lean..in the 14's, didn't get a log.

Threw in my 215 corrector....for a 155/215 combo....

36320007332_bee737ed7a_o.jpg81017 by blodi, on Flickr

I also ordered a 35 exhaust jet to start combating the accel pump jet at the low end. 

 

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14 hours ago, 240260280 said:

Do you think the meter's calibration was off for the 165/225 run posted above?

Maybe? I could reinstall that combo, recalibrate and then try again. Because to be honest...that combo should have made more sense looking at the latest results.  

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On 4/25/2017 at 2:53 PM, 240260280 said:

Because both throats are controlled by a single idle set screw, sometimes wear or manufacturing variations cause one throat to flow more than the other at idle.  The bypass is used to balance air flow between the two throats.

 

Normally the bypass valves are closed off but if one throat is flowing more air than the other at idle, you can balance the carb by opening the bypass on the throat flowing less air.  This procedure is only needed at idle.

 

FYI: The old way was to drill small holes in the throttle plate to balance (see photo below). (btw the holes solder-up nicely if over-drilled).

 

fuel-system_progression-1a.jpg

where is the bypass valve? im not seeing it

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Got the 165/225 combo back in as well as the .35 exhaust jet.  Removed wideband sensor and re calibrated it.  I'll report back later with results. 

 

 

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165/225 with 35 exhaust.....

oddly it's half a point richer than this same combo before. 4 pulls all confirm.  Back to 155/225? 

36568998096_9e1e4d3ec9_o.jpg81617-165225 by blodi, on Flickr

Edited by blodi

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