IDA jetting for 2332 cc

[neil68]

I have some jetting questions for you IDA gurus.  I haven't been able to put the Beetle on the chassis dyno yet, but will be in California for a few days and would like to pick up some more IDA jets for future experimentation.  Don't want to buy an entire set of jets, so I would appreciate any suggestions.  Here's my current engine/IDA set up:

-2332 cc, Web 86C, JPM 48 x 38 heads, MSD 6AL/dist, 10.6:1 CR, 1.75" header, seems to rev into the 7500 rpm range just fine
-3,600 ft elevation
-air density is poor: 4,800-5,200 ft most nights
-42 venturies
-3rd progression hole
-enlarged float bowls
-F7 emulsion tubes
-210 air correctors
-180 main jets
-120 idle jet holders and it also says 180F10 on "one" jet, but the others had the 180 number scratched off (I only have the larger jet gauge, so I can't measure the idle jet size)...these were prepped by Jaycee according to the previous owner.

Any suggestions appreciated.

PS:  Darren-the 86C works way better than the 226...can't wait to get to the track tomorrow

[Geoff]

Your engine is almost identical to mine but the difference in elevation from here to Calgary may not make for a proper comparison

[neil68]

Thanks, Geoff.

The engine runs a bit rich, so I'll probably pick up some smaller mains and maybe some F2's...

[Bruce]

-120 idle jet holders and it also says 180F10 on "one" jet, but the others had the 180 number scratched off (I only have the larger jet gauge, so I can't measure the idle jet size)...

Do you have a number drill set?  You can use them as ballpark gauges.
I doubt your idle jets say "180F10"  Maybe it's 80F10?  The 80 would be 0.80mm in diameter.  Even running alcohol, you would never use a 180 idle jet. 

If your jets are .8mm, throw them away.  It will be so rich with them you'll foul plugs right away.  Even a 70 will be pig rich.  I suggest a 65, but at your elevation, a 60 may be closer.  I've heard of guys making a 55 work, but the best I've succeeded with is a 60. 

The smaller the jet you can make work, the better the tuner you are. 
When guys tell me they use a 75, it tells me they know nothing about carbs.

[neil68]

Thanks, Bruce.  I'm in SoCal and will pop in to Veedub Parts tomorrow and pick up some 65 (and maybe 60) idle jets.  My engine does run very rich in Calgary!!

[RockCrusher]

Hey Neil....
Live my life mostly over at Samba but got the Forum upgrade notification so I jumped in here to see what's happening!

Anyway, based on your theoretical density elevation here is what I'd do:
175 main
250 air......yes that is not a typo
55 idle
F2 e-tubes

That should be a very good baseline setting and should run very well right there but you can tweak a little to get it just right.

RC