uprated carb

[MADFIVE]

just a quick one guys ive got a uprated carb on my car it has a 29mm venturi what the maxuim amount of boost i could run? its got a 1.40 main with a 1.2 ac im told.

[Markey Mark (BD)]

29mm venturi!! :eek: Thats abit big mate. With a 1.4 main jet i bet thats running rich off boost

What the other jets like, 2nd stage in particular?

The sioze of the venturi doesn't limit the amount of boost you can run, its the jet sizes that you need to worry about

[MADFIVE]

29mm venturi!! :eek: Thats abit big mate. With a 1.4 main jet i bet thats running rich off boost

What the other jets like, 2nd stage in particular?

The sioze of the venturi doesn't limit the amount of boost you can run, its the jet sizes that you need to worry about
i dont know what the second stage is. i got it from a mate that was breaking an old ex 5gtt that was used on track. i gave it to justin from ep motorsports and hes putting a 27mm venturi in instead. he told me when hes finnished with it. it will be a great carb.

[Markey Mark (BD)]

i dont know what the second stage is. i got it from a mate that was breaking an old ex 5gtt that was used on track. i gave it to justin from ep motorsports and hes putting a 27mm venturi in instead. he told me when hes finnished with it. it will be a great carb.

For me 27mm is still to big, best one to fit is standard 25mm.

The second stage is the fixed jet in the main body, you can see it when you remove the enrichment body (triangular body on passenger side). This jet is what you need to mod to fuel for on boost, not moding this you run risk of running lean at high rev's.
If set right a carb on any venturi size will cope with any boost, using a standard venturi and main jet will fuel alot better off boost where as larger venturi's and bigger mains tend to over fuel alot.

Just to give you an idea my campus which puts out around 220-230bhp still uses 25mm venturi and 1.2mm main jet but has drilled 2nd stage and smaller ac