engine and drivetrain Weber 38 Wb Readings - Lean On Anything Else Than Wot?

[roadhog0]

Looks like you're getting pretty darn close there mate!

[GreenSwede]

Too much work, and too little play. But now I'm back at it again. Popped in 140 mains again.

 

Now. Well, now I believe there is more grunt. It feels quicker and hangs out around 13 a lot. But, at 3rd and 4th it leans out at 5500 rpm, hitting 13.5. Which seems a wee bit lean on those revs and WOT.

 

Cruise is leaner, 14,7 to 15. Don't like that either.

 

So, do I go back to 145 mains and try to be satisfied - or do I try smaller airs? I'm leaning (hehe..) towards smaller airs..

 

Another clip. Again, sorry about the glare but if you squint you can see the needle.

 

[ray_]

Wow. That looked pretty darn good to me. You were not really under heavy throttle at the end, right?

 

You need to add throttle position to your video, haha!

 

Cheers,

[GreenSwede]

No, not after I let go at 5500 at 4th. After that just rolling with clutch depressed, and revving a bit. I caught up with some one and couldn't pass. The speed was not quite legal either, but I'm restricted to testing on public road and I try to do it safely.

 

The issue of a throttle position was discussed, but I haven't gotten around to that..=) Hopefully my filming of afr is over soon!

 

But isn't 13.5 a bit lean? Ish?

Edited May 27, 2014 by GreenSwede

[ray_]

In my opinion (as a novice) I think 13.5 is a bit lean under load, but unlikely to damage anything. You just may be losing out on a bit of power.

 

Cheers,

[GreenSwede]

Ok, thanks. And I can assure you that I'm more of a novice.

 

Yes, I've been viewing the last two clips a few times… And I think it got just a tad sluggish on high revs with the 140 (last change). Also the cruise at highway speed is leaner 15+, mostly. I think I'll give smaller airs a go, and see if they richen up the high rev area. 

 

Then just maybe I'll have a look at idle again.. Is one ever done?=)

Edited May 27, 2014 by GreenSwede

[ray_]

I bet you are closer to done than 75% on this board!

 

 

Me, I took the easy way. All I need to do is type in the AFR I want and the fuel management complies!

 

 

Cheers,

[GreenSwede]

That's just cheating! And not period correct!=)

 I just popped in 155 airs (last run on 165) to see what happens. Even if 140 mains and 155 airs seems wrong, from what I've read.

There might come a clip..=)

Edited May 28, 2014 by GreenSwede

[GreenSwede]

155 airs did not do much, but richer high RPM's. Took a longer drive today and noticed the cruise is a bit lean now. Even with 155 airs cruise is lean around 4000 rpm. 14.5 +/-.5 but 15+ on light load, going uphill for example. Maybe I need the 145 mains to get cruise right.

 

But, I'm thinking maybe I'm doing this the wrong way? 

 

I tend to be a tad richer between 2000-4000 and end up around 13 at about 5000 RPM. I started fiddling with the mains, going upwards, maybe I should have started going downwards with the airs? Getting the high revs around 13 and then doing the mains? Just thinking, and I probably will not go that way..

 

I mean, if the airs control the whole register (at least to a certain extent), maybe I should do those first and correct the "between" with the mains? It seems smaller airs make me run richer at RPM's below 4000. 

 

165 airs will go back in and run for a while to see how cruise and such is doing, while considering if to go back to 145 mains. But I think I'll order 142 mains and maybe 160 and 170 airs to fiddle with. At least I'm getting quicker at shifting them..=)

 

Edit:

 

This is a bit too much. I now get the real point of a logger, cause I can't keep it all in my head. Viewing clips back and forth, thinking "that sounds better, but that seems quicker, cruise was lean but not as lean as..". Just now I even clocked it from 100 to 140 km/h on two different clips - did it a few times and on that particular section the 145 mains and 165 airs is quicker with 6 vs. 7 seconds. Tomorrow they go back in, I'll keep an eye on the cruise (which I believe was better with those) and do something else.. Like finishing off my brake cooling. And start booking track days.

Edited May 28, 2014 by GreenSwede

[GreenSwede]

Another clip. Still running 140 mains and 155 airs.

 

I get the feeling I need the 145 mains cause even with 155 mains I tend to lean out at high revs on 3rd and 4th gear. To me it seems the mains are at play there on top as well.  And, as I said, cruise is lean. I get the feeling the motor didn't feel and sound.. happy, or really comfortable with these jets.:-) Quite quick on WOT, but a bit nervous on cruise and deceleration. 

I'd like to get it leaner, closer to 13, on full throttle and lower RPM but maybe that just won't happen.

 

Edited May 29, 2014 by GreenSwede

[ray_]

I think you looked closer on the "02 on 140s" video. But maybe you driving more conservatively in that vid.

 

Re:

 

"155 airs did not do much, but richer high RPM's. Took a longer drive today and noticed the cruise is a bit lean now. Even with 155 airs cruise is lean around 4000 rpm. 14.5 +/-.5 but 15+ on light load, going uphill for example."

 

That may well be okay. I don't think you are in an area that is potentially damaging. I would say 15.2 or so on light load is okay.

 

Some dialogue here, fwiw: http://performanceforums.com/forums/archive/index.php/t-67234479.html

 

Others feel free to chime in!

 

Cheers,

 

Ray

[GreenSwede]

I think you looked closer on the "02 on 140s" video. But maybe you driving more conservatively in that vid.

 

 

Maybe you're right.. Maybe I'm in too big of a hurry making the changes and drawing conclusions=)

 

 

Re:

 

"155 airs did not do much, but richer high RPM's. Took a longer drive today and noticed the cruise is a bit lean now. Even with 155 airs cruise is lean around 4000 rpm. 14.5 +/-.5 but 15+ on light load, going uphill for example."

 

That may well be okay. I don't think you are in an area that is potentially damaging. I would say 15.2 or so on light load is okay.

 

Some dialogue here, fwiw: http://performanceforums.com/forums/archive/index.php/t-67234479.html

 

And maybe you're right about that, as well! I'm a bit chicken about walking the line. 

 

I'll do some reading, hoping it will direct my train of thoughts!

 

 

 

Others feel free to chime in!

 

Cheers,

 

Ray

 

And yes, please! Partially I see what I'm doing (AFR), but that does not mean I know what I'm doing.=) 

 

ANY thoughts very much appreciated!

Edited May 29, 2014 by GreenSwede

[kbmb02]

GreenSwede: Good work, and helpful.

 

I'm curious: Are you testing / making changes under the same weather conditions each time?

 

Data point: A difference of 10 degrees (F) will impact the corrected altitude (air density, basically) somewhere in the neighborhood of 600 feet. In my experience, that will impact your A/F mixture readings and carb/engine performance. Small aviation pilots and some racers adjust accordingly for optimum performance (and, so does an electronic fuel management system, which stock 02's don't have). -KB

[2002dean]

KB, great point and one I hadn't thought about.

Dean

[GreenSwede]

GreenSwede: Good work, and helpful.

 

I'm curious: Are you testing / making changes under the same weather conditions each time?

 

Data point: A difference of 10 degrees (F) will impact the corrected altitude (air density, basically) somewhere in the neighborhood of 600 feet. In my experience, that will impact your A/F mixture readings and carb/engine performance. Small aviation pilots and some racers adjust accordingly for optimum performance (and, so does an electronic fuel management system, which stock 02's don't have). -KB

 

Well, quite. The weather has been roughly the same this period, and I've stayed away from rainy days. But I'll have that in mind, thanks! Now, I don't know how much 600 feet would make in jetting as I have too little knowledge, but the difference I'd say have been about 5 degrees during my testing. At least the last ones, when the results have been closer to what I at least think I want. 

 

Right now, I'd like to lean out the bottom end at full throttle a bit and maybe richen the cruise. I just don't know how, as those things don't go well together as I understand the principals of jetting.

Edited May 29, 2014 by GreenSwede