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Old 07-25-2009, 08:03 PM   #31
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Good read.

http://www.superchevy.com/technical/...ild/index.html
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Old 07-25-2009, 08:51 PM   #32
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Im still trying to understand why you would tune WOT first and not cruising? Your primaries affect WOT too. Personally, Id do cruising first, then ease into WOT.
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Old 07-25-2009, 10:15 PM   #33
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Tune how you want. Again, I'm not an expert and haven't written any articles on tuning carbs. I'm just your average guy who has learned to tune his own carb on his own car. I've already explained why I suggested it.
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Old 07-25-2009, 11:33 PM   #34
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Quote:
Originally Posted by 94cobra69ss396 View Post
Tune how you want. Again, I'm not an expert and haven't written any articles on tuning carbs. I'm just your average guy who has learned to tune his own carb on his own car. I've already explained why I suggested it.
If it works, it works. I havent touched a carb in quite a few years, so Im no expert either. I just know when I tune an EFI engine, Im going to tune idle and cruising speed areas first, then venture up and get to WOT. To me, thats much safer. My thinking is that if you cant drive 25 mph safely, how can you do WOT going 80?? Thats how I look at it. If you can tune a carb that way, then I learned something new.
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Old 07-26-2009, 12:42 AM   #35
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Quote:
Originally Posted by Damian View Post
If it works, it works. I havent touched a carb in quite a few years, so Im no expert either. I just know when I tune an EFI engine, Im going to tune idle and cruising speed areas first, then venture up and get to WOT. To me, thats much safer. My thinking is that if you cant drive 25 mph safely, how can you do WOT going 80?? Thats how I look at it. If you can tune a carb that way, then I learned something new.
So after reading his first post in which he says "It's about 10:1 under light throttle acceleration, 12.5:1 under part throttle acceleration, and I tipped into the boost real quick and it hit 15:1" you would worry more about getting the cruise ratio right first? Even after you broke a piston due to the WOT being too lean? According to your statement above you consider 15:1 under boost safer than 10:1 at cruise and would lean out the primaries further to get to 14.7:1 at a cruise and then worry about the ratio under boost. I'd be more concerned with breaking another piston than drivability and it looks like Adam felt the same because he corrected the ratio on the secondary side and it's now around 12:1 under boost.
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Old 07-26-2009, 12:48 AM   #36
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Quote:
Originally Posted by 94cobra69ss396 View Post
So after reading his first post in which he says "It's about 10:1 under light throttle acceleration, 12.5:1 under part throttle acceleration, and I tipped into the boost real quick and it hit 15:1" you would worry more about getting the cruise ratio right first? Even after you broke a piston due to the WOT being too lean? According to your statement above you consider 15:1 under boost safer than 10:1 at cruise and would lean out the primaries further to get to 14.7:1 at a cruise and then worry about the ratio under boost. I'd be more concerned with breaking another piston than drivability and it looks like Adam felt the same because he corrected the ratio on the secondary side and it's now around 12:1 under boost.
I understand your point. but one thing I'm sticking on a little bit, is that you don't have to romp on it right away for tuning. If you get the cruise right, then you go a little further and observe; in short you don't ever make WOT passes in the dark. You get cruise right then pass by pass work up through throttle positions.

To be honest I like your thinking in principle because it is fail safe. No moment of jack assery or simply loosing concentration will result in destruction.
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Old 07-26-2009, 01:02 AM   #37
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Quote:
Originally Posted by Vettezuki View Post
I understand your point. but one thing I'm sticking on a little bit, is that you don't have to romp on it right away for tuning. If you get the cruise right, then you go a little further and observe; in short you don't ever make WOT passes in the dark. You get cruise right then pass by pass work up through throttle positions.

To be honest I like your thinking in principle because it is fail safe. No moment of jack assery or simply loosing concentration will result in destruction.
How long has he been driving it like this, a year? You really think he's not going to jump on it if someone revs at him? Do you really think Adam has that much restraint?

I'm not saying that you shouldn't tune the primaries first but that should have been done after he built the engine the first time and was breaking it in. That's how I tuned the 454 in the Chevelle. I drove it around at light throttle and got the drivability tuned for the first 500 miles or so and then tuned the secondaries for WOT.

Anyone else with their vast knowledge want to tell me how my suggestion is wrong?
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Old 07-26-2009, 01:04 AM   #38
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Adam, did you do any more tuning today? How's the ratio now?
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Old 07-26-2009, 01:19 AM   #39
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Quote:
Originally Posted by 94cobra69ss396 View Post
. . You really think he's not going to jump on it if someone revs at him? Do you really think Adam has that much restraint?
This Adam?



Ya. No.

Quote:
I'm not saying that you shouldn't tune the primaries first but that should have been done after he built the engine the first time and was breaking it in. That's how I tuned the 454 in the Chevelle. I drove it around at light throttle and got the drivability tuned for the first 500 miles or so and then tuned the secondaries for WOT.
So we're talking about an Adam-safe procedure.

Quote:
Anyone else with their vast knowledge want to tell me how my suggestion is wrong?
It clearly isn't wrong. It's probably best for Adam's exact condition. It simply differs from the ideal procedure (basically the one you used for yourself).

That's my read.
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Old 07-26-2009, 01:41 AM   #40
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Yes, this was specifically for Adam who is the one tuning his car and asked. Now if he had posted that he just built an engine and wanted to know how he should go about tuning the carb my answer would have been different.
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