a cam is a huge change for the ECM, if you overcammed it then you couldnt drive it without a tune.
Question for the engine mod guys
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Question for the engine mod guys
I have a very stock (internally) 1986e engine with a Magnaflo cat and Borlas. The front pipe is replaced with the 85 (primary cat-less) pipe.
Engine mod is a custom tune from PCMforless. With 130K on the clock this gal runs 14.0's at 98-99 all day long and got 20-23 MPG.
I recently changed to a CompCam XE262 with the 1.6 roller tips. All is well and the tuning with PCMforless is still ongoing.
Cept the MPG is off by 5-6 MPG.
My question is did I overcam for a stock motor? Or should I expect the fuel mileage will be unable to return to the 20's?
Engine mod is a custom tune from PCMforless. With 130K on the clock this gal runs 14.0's at 98-99 all day long and got 20-23 MPG.
I recently changed to a CompCam XE262 with the 1.6 roller tips. All is well and the tuning with PCMforless is still ongoing.
Cept the MPG is off by 5-6 MPG.
My question is did I overcam for a stock motor? Or should I expect the fuel mileage will be unable to return to the 20's?
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From: Summerland B.C. Canada
I have the same cam with 1.6 rockers in my 355, my highway mileage didn't change much , if anything. I can still get 30 mpg if I drive like granny. I can't comment on average or city, I know my lead foot is affecting those. 
Hopefully your tuning will get them back.
Hopefully your tuning will get them back.
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I have a very stock (internally) 1986e engine with a Magnaflo cat and Borlas. The front pipe is replaced with the 85 (primary cat-less) pipe.
Engine mod is a custom tune from PCMforless. With 130K on the clock this gal runs 14.0's at 98-99 all day long and got 20-23 MPG.
I recently changed to a CompCam XE262 with the 1.6 roller tips. All is well and the tuning with PCMforless is still ongoing.
Cept the MPG is off by 5-6 MPG.
My question is did I overcam for a stock motor? Or should I expect the fuel mileage will be unable to return to the 20's?
Engine mod is a custom tune from PCMforless. With 130K on the clock this gal runs 14.0's at 98-99 all day long and got 20-23 MPG.
I recently changed to a CompCam XE262 with the 1.6 roller tips. All is well and the tuning with PCMforless is still ongoing.
Cept the MPG is off by 5-6 MPG.
My question is did I overcam for a stock motor? Or should I expect the fuel mileage will be unable to return to the 20's?
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From: sw Ohio
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
The current tune is the 3rd ver of an ongoing process. For those who haven't worked with the guys at PCMforless, there is a process of sending them datalog files and they return a bin file for me to upload to the ECM. (I modified my ECM with a Speedtronics chip that is programable) Currently the engine is completely different from the stock motor. It idles like a Corvette should idle, and has a "bark" when you open the throttle. My butt guage (SOTP) is telling me its pulling further up the power band yet still runs out of torque past 4800. I'm guessing the TPI is choking her down at the top end.
WHen selecting the cam, I missed the fact that CC's XE260 was CARB certified. Given the opportunity to turn back time I'd pick that one for just that reason alone. Yet for the effort to get this one in, it will be a long time (or another waterpump replacement) before I swap cams.
WHen selecting the cam, I missed the fact that CC's XE260 was CARB certified. Given the opportunity to turn back time I'd pick that one for just that reason alone. Yet for the effort to get this one in, it will be a long time (or another waterpump replacement) before I swap cams.
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From: Summerland B.C. Canada
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From: Summerland B.C. Canada
Thus, I was able to run a stock tune for almost 2 years.
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
I was running my stock custom tune when we fired the cammed engine for the first time. Although the open loop side of the program was very unforgiving, the closed loop side was way off on moderate to WO throttle power.
If I remember your yellow 86 was not an automatic. Maybe the stock tune was better than my auto trans.
If I remember your yellow 86 was not an automatic. Maybe the stock tune was better than my auto trans.
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24