Jetting change 48 idas

[1LoWezl]

I set float heights to 5.5 on new 48 idas and was thinking about messing with the jetting a little. I have read about every thread possible on ida jetting and this is what i came up with. Please critique this:

motor: 2276, cb wedge ports 44x37.5, cam is a shop grind and dont have the specs now, A1 merged 1.75",1.25 rockers,9:1 pump gas 91 mixing in some 110. Have 200 miles on it. Timing i was told 28 at 2500rpm

48 idas current: F7 e tube, 155 main, 200 air, 70/120 idle 37mm vents, has 3rd progression drilled.

Defiantly smells rich and am getting about 12/14 mile/gal. I know running to rich is not good for cylinders and would like to get a bit better mileage out of the tank and not wash the cylinders.

Was thinking, F11 e tube, 155 main, 200 air, 60 or 65/120 idle and 37 vents. It pulls hard and feels/sounds great except for slight hesitation during change to mains. Slight hesitation.

Is it cool to just change the f7 to f11 with no other adjustments? And then mess with the idle jet after running the f11 to see if idle needs change? Have 60 and 65 idles to mess with right now. Appreciate the guidance and direction
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1963 ragtop type 1
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1963 ragtop
1962 convertible

[RCP Phx]

I'm doing just the opposite right now with a single carb, changing out the F11's for F7's because of a stumble at low rpm's!

[1LoWezl]

From what i have read, single carb better to go w/ f7, dual idas f11's, but im not totally convinced until i try it. Maybe one of the members will chime in eventually.
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1963 ragtop
1962 convertible

[QRP]

Definitely try the 60 idles, may still be on the fat side but 70 IMO are just to big.

You are running dual IDAs?? correct??

[1LoWezl]

yes
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1963 ragtop
1962 convertible

[stealth67vw]

I run a 2276 with IDAs. 42 x 46 Berg vents, 11.45:1 compression, F11 emulsion tubes, 170-175 mains, 190-215 airs depending on track elevation and 60 idles with 3 progression holes. 3.0-3.5 psi fuel pressure max. 3.75-4.0 psi overloaded needle and seat and ran super rich at idle.
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John Bates
JB Machining Services
1967 street Bug 2276 w/ 48 IDAs, 2020lbs with driver
7.76 @ 89.55mph 1/8 mile
12.34 and 108.10 mph 1/4 mile

[1LoWezl]

Right now I am running 3# on fuel pressure and gonna try the f11 w/60 idle, seems to be 1st move forward. Writing everything down to log changes. Will synch and set idles after car is warm. I had fuel at 3.5# but had a float problem, realized the floats were not adjusted so I set those. Maybe I need to push fuel back up to 3.5? This is mostly a driver but once I have some miles I will tack it to the track few times. Thanx again
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1963 ragtop
1962 convertible

[k-weaver]

[richierich]

I have a 2276 in my bus. C45 cam, Super Pro heads, 9.1 CR, 48 IDA's, Magnaspark 2 ignition.

I'm running the following:

37 vents
F2 tubes
55 idles
120 idle airs
160 mains
200 airs

I'd had enough with trying to smooth transition off idle onto mains with F7 tubes. Put the F2's in and changed jetting completely until settled on the above. Like a different motor to how it was previously. No stumble on transition at all.

I run 99 octane fuel.
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Blah.....

[1LoWezl]

I'm shooting for around 99-100 on the octane mixing the 91 w/110 at home. Will start with the idles considering almost everything i have been told or read points to at least 55-60's. Then ill adjust the e tubes if need be. Will take car for a ride first before switching idles and readjusting the mixture screws. The 28 timing was what i was told by the builder. I definatly have a good starting point and can mess with the timing later if need be. Motor seems close now, but im just starting to understand these 48's. Thank you both for the advice, appreciate your knowledge.
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1963 ragtop
1962 convertible

[74 Thing]

Why are you mixing with 110 octane and you are only running 9:1 compression ratio?

[richierich]

[1LoWezl]

So, i ran car up to temp on 30-mile run yup valley, came home and swapped the idles to 60's. Synced carbs, re set mixture screws and only had time for a short drive. At low rpm it seems more responsive and zero popping/spitting. Gonna keep it here for now until i can make another long drive to run it through the rpm ranges. As far as the fuel and adding the 110, no real specific reason other than was told it could wake it up a little more. Not dead set on anything unless it really helps. Anyone with pros/cons my ears are wide open. What's a realistic mpg with 3.88 pro street tranny? Car cruises at 3k/65mph, running 205/60 15, i know it depends on how heavy my foot is, but 20 to 25 realistic?
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1963 ragtop
1962 convertible

[74 Thing]

I would get the specs of the camshaft from your engine builder as well as info on the compression ratio if it is static or dynamic.

What are your gear ratios with the 3.88 R&P, and what is your rear tire size and what ignition are you using?

If you have a final drive ratio near stock and daily drive then depending on your timing and tuning you should be in the 20-25mpg range for sure.

[richierich]

[1LoWezl]

Ok drove the car around with first jet change for about a week,
48 ida 2276cc (details in first post)
37 vents
155 mains
200 airs
f7 e tube
changed 70/120 idle to 60/120 idle

Results were better on low end and weigh less rich! Plugs looked a lot better and smell too,but still had slight stumble in transition so....second change,

37 vents
155 mains
200 airs
now 60/120 idle
CHANGE f7 to F11 e tube, engine sounds great, runs great and transition is way better, zero miss fire, popping or stumbles, haven't totally opened top end up yet, but it feels like i lost so power from about 2k-4k. Question is now should i change the MAINS to 160-165's? or leave it and drive it. I am happy now except for small mid-range power loss. Thanx for any suggestions
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1963 ragtop
1962 convertible

[Bill Schwimmer]

Ditch the 37 vents and put some 40's in there. You are leaving some on the table. It will drive fine with the bigger vents. Adjust the jetting after the vent change.

[1LoWezl]

Ok so couple people suggest moving up a size in vents. Are the gene berge grooved vents ok for street application or mostly for racing? I would prefer to have the bottom end pull better than top speed. Or just regular 40mm jaycee billet style? With a vent change i have read need to start with little bigger mains, so maybe buy set of 160,s at same time? Thanx for the insight
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1963 ragtop
1962 convertible

[vwracerdave]

I'd suggest the Berg 35/40 vents for street driving. You can call them and ask for advice. I'd also keep the F11 tubes.

https://www.thesamba.com/vw/classifieds/detail.php?id=2201199
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2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK
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[1LoWezl]

Appreciate the advice. Just got back from 1.5 hr drive with the F11s and 60 idles. Engine feels great right now with this set up. No popping, farting, hiccups, etc. like i said before. Exhaust is a nice clean brownish color now with very little smell of fuel. Super drivable through all ranges with only that one down fall of some slight mid-range power loss. Seems the F7 tubes were little crisper and more responsive in the middle power range but could tell engine was still rich. Will call and talk w/ Berge Monday to talk about the grooved vents. Would still like to pull what power i can if it is sitting on the table for the taking. Thanx again for everyone's input and experience.
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1963 ragtop
1962 convertible