Guys,
Can anyone tell me why a 2.7CIS engine would have a HP increase by going to early style SSI heat exchangers? Assuming it does, how much increase does it make? Also, does they CIS system have to be recalibrated?
Thanks
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Guys,
Can anyone tell me why a 2.7CIS engine would have a HP increase by going to early style SSI heat exchangers? Assuming it does, how much increase does it make? Also, does they CIS system have to be recalibrated?
Thanks
Keep in mind that I've never had a CIS car, but yes...there is a definite improvement if you go to EITHER factory (1973 & earlier) or SSI exchangers. I'd suggest having an exhaust analyzer used to test and reset the CIS after the swap. If memory serves, the horsepower gain because of the more efficient exhaust is in the 10-15 horsepower range. Pretty significant, considering the stock horsepower of the 2.7 CIS engines...
A guy on the Pelican board just did a before-and-after dyno run on his 3-liter SC motor, and got 10 hp out of the SSI's. The crossover and 2-into-1 design mandated by emissions equipment is less efficient than the near-equal-length header design of the early exhausts and SSI model.
My guess would be 8-10 hp on a 2.7, but I have no meaningful experience with those motors.