Engine torque curve

[SimonP]

I have a Chevy 350 - it's the mid spec model from Repower.
For bonnet clearance reasons they are fitted with a TorkerII intake when used in the GD.

Has anyone had one of these on a dyno?
I'm not interested in specific torque figures, just the shape of the torque curve from 1000 to 6000 rpm, as I expect there to be some "knees" in the curve at low rpm due to the cam and intake combination. Many published torque/hp graphs only show data from 2500rpm upwards.

This info would be handy as an aid to placing the rpm set points in the fuelling table for my ECU where the curve changes slope or direction.

Thanks,
Simon.

[callum]

I think you'll find the manifold has less effect on your torque curve than the cam. My own 350 has the same manifold and an RPM Plus cam running about 9.5:1 compression. On the rolling road the curve seemed quite smooth but on the road there is a noticeable thump at about 2,500 to 3,000 rpm - possibly as much influenced by road speed and air flow over/into the bonnet as anything since it did not manifest itself on the rolling road. For sane road use you will have more than 'enough'. Less obviously the vacuum can was casuing a bog off idle as the manifold pressure was inducing way too much ignition advance. Plugging both the vacuum can and the carb produced a car that performed very much to the spec on the cam box.

[SimonP]

Getting closer now....

With the nose design of the GD (and other Cobras I suppose) there is a lot of air pressure under the bonnet at high speed - I saw manifold pressure of 105kPa when I stuck my toe down a bit on a datalog from the run home yesterday. Didn't keep it there long as the fuelling was too lean - my fuelling table only has MAP data points up to 100kPa.

Simon.