pushing beyond limits?

[DART340SC]

I am running a 1200 with a 7" crank pulley and a 2.79 charger pulley. I am running dual spearco stacked 800 hp incooler cores and feeding a smallblock magnum motor stroked to 406. The car is awesome till about 4500 rpm and then it just seems to flatten out. According to my boost guage I am at 10lbs at 6000 rpm. This would suggest to me that the supercharger is still within its limits as far as air flow is concerned. What do you guys think?

[james redman]

Welcome Dart340SC, I really like your engine bay. Stacked Spearco's ... cool.

I wonder if you have any instrumentation on your car? It would be interesting to know what the Air/Fuel Ratio is doing, the injector duty cycle and the fuel pressure.

If, as you say, the air is there, it must be the fuel.

James.

[DART340SC]

I am running a carb(750 quick fuel ban) I have a wideband o2 sensor and have had it on a dyno. At wot 6000 rpm its at 11.6 a/f

[james redman]

I assume flatten out means power/torque stay at a more or less constant value. If it's not fuel what about ignition timing?

[DART340SC]

I guess what I mean is it pulls like hell till about 45-4800 rpm then it just seems to stop pulling. My ignition is all msd, distributor, msd6btm, there top coil, wires and ngk plugs gapped at 35. I am not pulling any timing out and just disconnected the water/alky injection thinking maybe it was cylinder quench

[james redman]

Are you data logging so you can see what is occouring as it flattens off? If so what is being recorded?

[mrtbolt64]

How much air flow can your heads/intake support

[DART340SC]

No data log, its a 72 dart with carb. Heads are stock edelbrock magnum r/ts. 2.02/1.60. comp cams 1.6 roller rockers, the cam is 288/292 501/513 mopar performance