Weber Questions

[sb_hbackDX]

Hello! Hows it going? Well i have a few questions/recommendations about some parts for my weber...First is this fuel pressure regulator:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=MRG%2D9710&N=700+4294925239+4294839053+4294880914+4294891681+ 4294759208+4294849160+400330+115&autoview=sku
Should this be sufficient for the Weber 32/36 or Weber 38 ?
Next is this fuel pump:
http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_748050_-1_10307
Its the Carter in-tank fuel pump( the last one and cheapest lol)
Also what kind of A/F gauge do yall use? I have seen tons online and dont know which to get...have any recommendations?
Oh yea, I was searching through old posts and I saw postings for your weber jets...has anyone recently changed them for either the 32/36 or 38/38? Have to test out my Weber 38/38 progressive project....
Thanks for your time.:cheers:

[2ndGenGuy]

Well, I hear you want to run your Weber at 3PSI, ideally. So with that "super street" pump, and that regulator, you should be good to go. The stock pump will suffice to get you going though, and you may find it does the job just fine.

I also hear that regular A/F gauges are pretty useless. The only way to get good readings is with a Wideband O2 sensor. That lets you tune it more precisely. A regular A/F gauge pretty much just shows rich or lean, and isn't all that accurate.

Also, there's a thread that shows the jet sizes that everybody here is running:
http://www.3geez.com/forum/showthread.php?t=4223&highlight=weber+jet+sizes

Post your results there when you're done when you find what's best. :)

[sb_hbackDX]

Thanks for the reply

but for the Weber 38 would your still run 3psi ? Ah wideband o2 sensor...I supposed it functions relatively the same as an A/F ratio sensor just with better readouts? Yep accuracy is important when tuning...

"2ndgenguy" I notice you also operate with the Weber 38, I have been trying to get it to become a progressive carb using linkages and vacuum/mechanical secondarys...finally seeing some progress but I have to tune. Ever pondered that idea? My aim was to save gas initially for everyday use...

[2ndGenGuy]

I'm actually running the progressive 32/36. There's a 38 up at the wrecking yard I've been trying to get my hands on. I imagine that you could swap the linkage from the 32/36 onto the 38 and have a mechanical secondary like that. Good news is you can order individual Weber parts, so maybe you could do that, and put those on the 38? And yeah, you'd still want 3PSI. I'm pretty sure all Webers run at about 3PSI any more and you overload the float valve. You want high-flow, low pressure. So when the float valve does open, you can feed that bowl and keep it full! :)

[cygnus x-1]

Nice to see another Weber user! I've done a fair bit of tuning with my 38/38 so I can probably help you.

Fuel pressure should be 3PSI. I'm using the stock fuel pump with no regulator and it works fine. I have a Prelude though so you might get different results. But you might as well try the stock pump by itself and see if it works.

Watch the float level; it's absolutely critical. To start off set it exactly per the Weber specs. If you find that it stumbles or surges with light throttle you can raise the float level 2mm to try and bring the main circuits in sooner.

Honestly I don't think it's worth the trouble to convert a 38/38 to progressive. With a good tune you should be able to get 30MPG if you don't have a lead foot. A 32/36 might be slightly better but I doubt by much.

You appear to have almost exactly the same setup I do so I would suggest the following jetting for the 38/38:

1.47 Mains
0.55 Idle
2.10 Air Correction
0.60 Pump Jet
F50 Emulsion Tubes

All AFR gauges use the O2 sensor for measurement. Stock (narrow band) O2 sensors have a steep transfer function so they aren't very useful for tuning. They can really only tell you if the mixture is too rich or too lean, but not how much. Wideband O2 sensors are much more accurate so you can get a true air/fuel ratio reading. Tuning is immensely easier with an AFR gauge and wideband O2 sensor.

If you have any other questions about the 38/38 ask away. I have a 32/36 but it's kind of a junker and needs work. Oh, and you can check out the pictures of my build including the Weber.

http://bluegreenlabs.com/Prelude/Engine-build/

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