hello.im looking into installing a new camshaft.i was just wondering if my ecm would read it or would a custom chip be required.i drive an 85 iroc 305tpi 700r4.i've heard that at times a new cam will not make the car run right or in my case more likely in the 85 year model.any advise is appreciated and thanks in advance.

 

read this to start with.

http://tpichips.com/?page_id=7

 

if you add all the high pro acceserys you better know some one to tune it. if you can find a good used cam .050 lift bigger than factory it wont miss it up. you go big cam you need big every thing. and thats a big money bag. i have a .410 roller cam

 

Even the factory calibration left quite a bit of power on the table simply by optimizing the factory setup. I have gained 15-20 ft/lbs of torque at the wheels on any year TPI by recurving the spark tables and leaning out the PE air/fuel ratio.

That being said I have personally run a 272/272 @ .004, 216/216 @ 0.050", .454/.454" lift (.484/.484 w/ 1.6:1 full roller rockers), on a 110* LSA cam (Crane 100052) with the stock chip on a 1986 mass air 305. To keep it from running lean up top I had to push the fuel pressure up to 50 PSI. It ran a little rich down low with the idle/low speed BLMs in the 115 range, but still well under ECM control. I had to adjust the minimum air screw so that I had an IAC count of about 5 at a hot idle in park/neutral. Doing this pushed the TPS voltage out of range, requiring readjustment of the TPS voltage. The engine also responded to an initial timing bump from 6*BTDC stock up to 10* BTDC (36* total advance above 4,800). The car had a set of ported/milled 601' heads with 1.94/1.60 vales, 10:1 static compression, SLP Tri-Y headers on it and matching Y-pipe. Had a set of ASM long tube runners, ported plenum, ported base, throttle body airfoil. Was putting down 240 RWHP/280 RWTQ through a locked 700r4.