# Weber DGES 38 Tuning Help



## xPat (Aug 9, 2006)

Sorry this might be a little long. 
I'm trying to tune this carb and have a few questions. The carb is a bone stock Weber 38 DGES with the jets listed below. Engine is a 1.8 8v with TT 272 cam, G60 head, and 10.1 GTI pistons from a DX motor. Manifold from the G60 with a TT dual downpipe.
Main Jets 145mm
Air Jet 185mm
Emulsion Tube F50
Idle Jet 45mm
Pump Jet 70mm
I bought the carb kit on eBay and it claimed to be for a VW 1.8, turns out the carb is a bone stock Weber 38. But surprisingly the jets aren't fare off. The idles are to lean but I can make it run. It just has a hesitation at low rpms coming off idle. Under acceleration and at WOT its pretty much spot on reading 12.5~13 on the wideband commander. I've ordered larger idle jet so that will solve one problem. But I’m a little concerned that under high speed cruses it's running a little to lean at ~16.5. Low speed in town cursing is ok at 14~15.
Now I also have a starvation problem when I turn left so I’m going to have to raise the float level which I understand will richen my overall mixture. But how much? I think I’ll have to change the air jets but I’m not sure which way to go. I think I have to go smaller but I’m not sure pretty new to carb tuning.
Thanks in advance


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## xPat (Aug 9, 2006)

*Re: Weber DGES 38 Tuning Help (xPat)*

I guess nobody knows much about the Weber 38








Well last night I adjusted the float level and made two steps forward and one step back. The hesitation from light acceleration is gone; the starvation problem turning left is gone however the car is still suffers from this problem during hard left hand cornering. My step backwards is I now have a flooding problem on hard right hand turns. These problems do not exist if I take the corner under acceleration or WOT








I tonight I will again adjust the float level. I will try lower the float level to remove the flooding and decrease the float travel to keep more fuel in the bowl and prevent the starvation durning cornering.
I'm still looking for suggestion on tuning as I’m really new to this. I have the Haynes Weber tech manual but it's more of a tear down manual then a tuning guide.


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## B4S (Apr 16, 2003)

*Re: Weber DGES 38 Tuning Help (xPat)*

Set the float to specs and see what happens. It's important that you not mess with the float height until you get the rest of the jetting right, because 9 times out of 10...it's not the floats. Set the droop to spec too. If the car doesn't buck or surge under high speed cruise, then 16.5:1 is fine. Contrary to popular belief, lean doesn't mean high EGTs. It'll be hotter, sure, but unless your plugs tell you there's an issue with running that lean...then it's fine. I cruise at 16:1 on my duals, and no issues at all.
Going bigger numerically on the air correctors will start the main circuit sooner, and lean it out up top. Think of the air correctors as a modifier to the fuel curve. It won't change the curve, but it moves it up or down in the RPM range. Big airs = lean up top and main jet starts to flow earlier, and small airs = richer up top, and the mains come on later.


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## xPat (Aug 9, 2006)

*Re: Weber DGES 38 Tuning Help (B4S)*

Thank you this is just the kind of information I was looking for http://****************.com/smile/emthup.gif 
I set the float level closer to Redline weber's spec last night and it got better but still not perfect. I'll leave it like this until I get my new idle jets and then I’ll try another adjustment if it's needed.
Adjusting the float level has changed my cruise to 16:1 and the really improved the drivablity of the car. It doesn't surge and the plug overall look near perfect. I'll try pulling a plug right after a cruise to see how they look then.


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## gdaily (Aug 26, 2008)

*Re: Weber DGES 38 Tuning Help (xPat)*

I just ordered that setup offa ebay, how do you like it?
I guess i could use the above info to get it tuned if need be.
But please let me know what kinda experience you've had with this setup.
Thanks http://****************.com/smile/emthup.gif


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## johannlangner (May 13, 2016)

Hi you guys,
I know this is an old post, but I recently bought a Weber 38 DGAS (auto choke removed) and I came across this post.

I am going to put the weber 38 on a 2.25 4 cylinder aircooled VW motor.

Carb specs.
Venturi 27
Idle jets 45
Just got it, not 100% sure about the next.
Main jets 145
Air jets 190

Im gonna build a center mount intake manifold.

Some ppl say this will work and some swear it won't. So here I am, heading straight into this, head first lol

Any help would be appreciated

Thanks

... Vollswagens forever !!!


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