Aftercooler for Comptech SC's
11-12-2003, 03:08 PM
#11
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The interesting thing about pressure loss in an intercooler is whether or not you are actually losing air. The fact is, if you cool air it condenses, so it may exert less pressure whilst actually being the same volume of air. As the Comptech system uses a pressure dependant fuel regulator to maintain mixture you may find yourself running lean (same air, less pressure and hence less fuel). Simple matter of turning up the screw on the regulator. Dyno tuning would be a good thing of course. I wonder if the Comptech AC says you should adjust the FPR?
If you add a smaller pulley for more pressure and cool it with the AC you might be running the same pressure as before but will actually be putting in a lot more air with the same fuel (lean again) so I would recommend tuning.
Depending on the increased pressure (and hence heat) of the charge before the AC and the efficiency of the AC (cooling charge) you might end up with a lot more air, denser and slightly cooler than pre-AC. You woulddefintely need to up the FPR and the injectors will definitely be getting closer to maxed out.
This is the path I am currently pursuing. I have the SC w/o AC at the moment and I'm just using the FPR for tuning. I have just completed install of an E-manage but at the moment it is just passing through all signals (I have disabled injector and timing maps) except the MAP sensor signal which it is clamping at 2.9V (I removed the ESM). Basically it's just a very expensive boost cut defender at present.
I'm waiting on some 440cc injectors and when they are installed I will have it tuned.
Then I'll make one (or more) AC's and install it and my 9psi pulley and some more tuning.
If you add a smaller pulley for more pressure and cool it with the AC you might be running the same pressure as before but will actually be putting in a lot more air with the same fuel (lean again) so I would recommend tuning.
Depending on the increased pressure (and hence heat) of the charge before the AC and the efficiency of the AC (cooling charge) you might end up with a lot more air, denser and slightly cooler than pre-AC. You woulddefintely need to up the FPR and the injectors will definitely be getting closer to maxed out.
This is the path I am currently pursuing. I have the SC w/o AC at the moment and I'm just using the FPR for tuning. I have just completed install of an E-manage but at the moment it is just passing through all signals (I have disabled injector and timing maps) except the MAP sensor signal which it is clamping at 2.9V (I removed the ESM). Basically it's just a very expensive boost cut defender at present.
I'm waiting on some 440cc injectors and when they are installed I will have it tuned.
Then I'll make one (or more) AC's and install it and my 9psi pulley and some more tuning.
11-12-2003, 03:29 PM
#12
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Oh, and the problem with a front mount intercooler and the long plumbing required is the lag between the SC spinning up (as you rev) and pressure making it's way through all that plumbing to the intake manifold. This is a throttle response issue rather than tuning as the FPR makes sure that fuel increases proportionally with whatever pressure is in the manifold.
11-12-2003, 08:20 PM
#13
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Oh, and the problem with a front mount intercooler and the long plumbing required is the lag between the SC spinning up (as you rev) and pressure making it's way through all that plumbing to the intake manifold. This is a throttle response issue rather than tuning as the FPR makes sure that fuel increases proportionally with whatever pressure is in the manifold.
11-15-2003, 07:35 AM
#14
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I have a comptech AC sitting at my shop and it's going in on Monday. Without the AC the car made 308 hp to the wheels. I'm scheduled to Dyno again after the install. I'll let you guys know the results.
