Is it just me or does my car seem more aggressive when I first start it up and get going. It seems to me the motor sounds stronger when it's cold. I just tap the throttle and we're burning tire leaving the house and as it warms up to temp not as mean.

The motor is a new 383, keith blach hyperwhatevers, under 500 miles on it, 750 eddlebrock electric choke but not hooked to power just have it set , msd ignition and dizzy, 15 initial 34 total, 110 main jet and secondarys, runs at 160 cruising about 190 if you sit for quite awhile at a light.

I was wondering if it had anything to do with the heat from the manifolds and fuel line running just inches from them along the frame?

If the choke is set to start when cold and it's not opening all the way when warm, that's your problem. Make sure it is open completely when the engine is warm.

nope it is full open when it's warm...

Here in Minnesota, when it gets cold it leans out your fuel mixture. We used to really be able to tell with snowmobiles. When it got really cold out, friends of mine had to put in bigger jets ! I would guess that you might be running a little rich ! We used to say Lean is fast ! But when it is too lean, then you wreck stuff !

I agree! Too Rich.

colder outside air temps means denser air.
warm engine with open aircleaner means youll get hot less dense air.
cold air intake can help.

under hood air temp is at ambient temp on a cold start.That cooler denser air is what you are sensing in the butt o meter.Hp drops as underhood temps rise without a cool outside air source routed to the carb.

Hence the rational for the "fresh air hood". Allows cooler air to enter the carb from outside and not the heated air from the engine compartment.

So I am thinking I need a hole in the hood and bird catcher then.

You shouldn't be jumping on a cold motor, especially one with only 500 miles on it. 160 degrees is too cold, put a 180 t-stat in it. Running good when the motor is cold is a sign the carb is too rich. It should be lean enough to need the choke when cold. Cold air is good if the motor is warm, but a cold motor won't atomize the fuel properly so a richer mixture is needed from a choke. Also a thermally controlled clutch fan will freewheel when cold but may engage after the motor warms up, costing a few horses.

Simple science, cold air means more power.

Simple science, cold air means more power.

About 1% improvement per 10*F difference in incoming charge air temperature.

:beers: