Hey there fellers just a quick question I know it may be a stupid one but here goes.I have an A15 that I am building and this is what I have done.I have a 4-1 branch the head has been very lightly ported and skimmed down to make 11.1 compression the fly wheel and crank have been lightened as well.I have also done the e15 electronic dizzy swap.The question I have is have I done enough to this motor to make using 38mm chokes worth while or shall I just stick to the 32mm ones.Oh the carburetors are 40DCOE32 Weber.Please fellers I am no mechanic so all your help is much appreciated.

Thanks Immy

Only a day on the dyno can answer this accuratly,but my past experiance and gut says stay with the 32's,or i think you'll drown it as it's virtually stock but with some stuff done to perk it up.

Amen to that, 38mm is pretty big and my gut says no good on a mild road car.

Oh sorry i forgot to mention that it has a cam I'm in Zimbabwe and the cam I have is what we call a stage 2 cam don't have the specs on it though.Oh one other thing is that we don't have anyone with a dyno here believe it or not.What else could I do to this motor to make it faster but still reasonably reliable.I don't want to bore it out as the bore is still in very good condition.

dont even think about using 38mm chokes, I would be very surprised to here you could even get them.

The recomendation for an A13 semi-race motor is for 30mm chokes, 115 mains, 160 air corectors and F16 emulsion tubes.

Going even bigger to a 1600cc engine in sports trim the recomendation is 33mm chokes, 135 mains, 160 airs and f15 emulsion tubes.

These two carby setting i have coppied from the "Four stroke performance tuning" book.

If you are getting close to 200hp you might use 38mm chokes but you would be using them in 45mm DCOE`s

In your case it would be closer to 90hp so the 32mm chokes might already cost you some midrange power, but they shouldnt be to bad.

38mm chokes = no bottom end. If you have to choose between chokes in Weber's the rule of thumb is always go for the smaller ones.

I run 36mm chokes on an A14 track engine and it doesn't come on until the high 4000 rpm range. It would probably run even better if I went down a size to take advantage of the low down pull away on the slower corners.

Great book of reference by the way Sikyne, I have a copy as well. great reading

okay I'm going to stick to the 32s but what else can I do to this motor to get more bang out of it but at the same time I wil be using it as a daily drive.

36mm chokes is as big as you can go in 40mm carbs anyway. You can machine chokes to slightly over this, but not to anywhere near 38mm.

okay fellers I am staying away from the 38mm chokes and thank you for all the help it is greatly appreciated.Now what else can I do to my A15 motor to get more bang out of it?????????

if your swapping parts around i would say the best thing for you to spend your money oin now is a good session on a cassis dyno.
but as you say you can't get acces to one i'd recomend you buy yourself a wide band o2 sensor. i personally use a innovate lc1 kit and can't recomend it highly enough and learn how to set up the fueling yourself. the ignition will be more trial and error, guesswork thou