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My Super is tuned for sea level and has a hard time breathing here at 6000 feet. Is there a source and part numbers available for high altitude jets for a 1750 with Webers? IAP and Centerline don't seem to offer them. Thanks.
 

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I buy jets routinely on ebay, but there are a number of suppliers out there. Just type weber dcoe into google and you will get a bunch. Of course you will need to know what jets you want. How is it currently jetted? I have a spreadsheet somewhere that shows jet correction values based on altitude. It came from Eliseo Carillo in Mexico. Not sure if he is on this forum.

Let me know what your main jets and air correctors are currently and I might be able to help.

Erik
 

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Mr, Wood...................here I am :D :D :D Missed you at Mid Ohio!!!

ALTITUDE COMPENSATION
0–1500->1500-2000->2000-3000->3000-4000
2.00->1.95-1.90->1.85->1.80
1.75->1.70->1.65->1.60
1.50->1.45->1.40->1.35
1.25->1.20->1.15->1.13
1.00->0.97-0.95->0.95-0.93->0.93-0.90

Alfonse22, if you say you are at 6000ft that would be 1828 meters. So what you do per the table is the following: You have 2.00 MAIN FUEL JETS for 0-1500 meters (I did this for Mexico) and you now go to 1828 (the 1500-2000) range so you go DOWN 5-10 jet points on jets.....to 1.95 or 1.90.

If you have 1.75 go to 1.70........see the chart.

All of this is a START POINT and use it as a reference!!! Verify this with the color of the exhaust and see the plugs.

At more Altitude less air so you have to change jets and make the mixture leaner.

Now you will also need to work with your air corrector jets....... I usually have higher air corrector jets than fuel jets: 20 points higher. Examnple: 170 Fuel Jets-190Air Correctors

Sources for jets:
www.piercemanifolds.com
www.webercarbs.com
www.webercarburetors.com

Good luck, REMEMBER TO VERIFY THE PLUGS!!!!!
 

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Eliseo, now I'll know to never say anything bad about you on a public forum. You are everywhere! Mark, the factory jetting for a 1750 was usually a 130 main jet with 200 air correctors. Based on Eliseo's spreadsheet, I would probably drop to a 125 main and 180 correctors and then check the plugs. You might want to go on down to a 120 main. Remember, to do a good plug check, you need to have the engine under load and at higher rpm when you shut down. Even if you get the mixture right, you won't have as much power at high-altitude.

And of course, don't forget, if you end up with a good mixture at 6000, you will be really lean if you ever come down from the mountains!

Erik
 

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ECARRILLO said:
All of this is a START POINT and use it as a reference!!! Verify this with the color of the exhaust and see the plugs.
That's very true. We've found that there is no "stock" suggestion that works for every engine at elevation, especially if the engine is not stock. And, sometimes things are just counter-intuitive at altitude as well, so you may need to try some things that don't make sense.

If you have access to a dyno shop that has a good selection of jets, you can get the exact mixture you are looking for within a very short time vs. weeks or more of experimentation/ordering jets/experimentation/ordering jets.

Joe
 

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Since your already in the hills, you can make a nice local virtual dyno:

Find a reasonably straight uphill stretch of 1/2 mile or more. With the car well warmed up and in a good gear to climb the hill (does not have to be too steep) all the way at a high throttle position, drive hard up the hill, press in clutch and shut off motor; pull over and chjeck the plugs. You want to find a light brown deposit. Black sooty is too rich, white or bare is too lean. Adjust main and air correctors 'till you're giddy. This will give you a good setting for full load.

Similarly, do the same on your normal commute or freeway (?) trip - check plugs at roadside. THis will help you decide if you have the right heat range for your plugs as well.

Then find a jet set that gives you good compromises.

R
 

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Discussion Starter #7
Erik, Eliseo, Joe, R --

MANY thanks. You all are just some of the many reasons this site and its people are the BEST!

This is obviously more complicated than I counted on. Fortunately, I have found a local mechanic who has quietly been working here for a long time on many different imports and enjoys this type of challenge. I will forward Eliseo's chart and all the other tips to him.

One more question: Is it important that the timing be re-adjusted when the proper jets are installed?

Thanks again!!
 

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Like all things, no engine is like other, all are unique. Yes, I would make sure timing is were you wanted, were is that? Were you want it........?? Just make sure, timing, plugs, jets, and good gas is in the car.

GOOD LUCK!
 
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