Another Jetting Post, 1911 short stroke motor. Options

[Alphaogre]

1970 914-4 "1.7"

Motor spec:
• 1.7 built into short stroke 1911cc motor.
• Stock 1.7 stroke, with 96mm KP pistons.
• Web 86 cam.
• 1.7 Heads machined by Headflow Masters.
• Tuna Can for extra oil.
• Carbs: Dual Weber 44's (i know should have 40's) Car came with them and always ran well with them.
• Idle Jet: 50
• Emulsion Tube: F11
• Main Jet: 115
• Air Jet: 200
• Lower Venturi: 28mm
• Upper intake above Venturi: 38mm
• Velocity stacks: 52mm tall, Upper Diameter:61mm / Lower diameter:40mm
• Electric fuel pump with a fuel pressure regulator at about 4.5lbs


Car use:
Sunday Funday canyon driving.
Intermittent AX (not trying to win a championship)
Intermittent Track time Trials (not trying to win a championship)
with that It has a front Adjustable Sway bar, rear has Adjustable Bilstine HD C/O's

The Questions:
• When Warm (driven hard) it has trouble keeping idle...I've adjusted the idle crews but 50 seems small right? maybe up to 60/65? (especially since thats your fuel flow up to 3K RPM's)

• I have A Lot of exhaust popping on throttle lift-off. I thought it was just over Jetted since it cam with the 44's when I bought the car as a project... but 115 seems low, right? but so do the 28mm venturi for a now 1911 motor? So, now I'm thinking it's under fueled? (IMG:style_emoticons/default/huh.gif)

I don't think the popping is exhaust leaks, I have the copper washers in the exhaust manifold with them all good and tight and stock exhaust manifolds. The popping really started after the motor build and lack of carb matching to the motor.

I never really messed with it too much because the car pulls well, no major complaints, and has gone through some pretty long/hot track days with no issues. I've just had an "if it's not broke..." attitude.

I've been distracted with other projects and have been driving it here and there, but have an itch to get back into some AX/track days. So, I'm trying to take a look at it now and go down another part of the car that I somewhat neglected in the past. I've been learning a lot with doing some research but thought some of the gurus here can school me some more (IMG:style_emoticons/default/biggrin.gif)

Any parameters suggestions or numbers to look at as target would be appreciated, I can then start working towards them. I don't want to just start buying jets and messing around with it all in vain because of a main facet negating everything...

I guess my main questions to start in the Idle Jet Number, Main Jet Number, and Venturi Number in relation to listed specs and applications.