I recently installed a comp cam xr259 hr cam on a 112 lobe sep with 206/212 duration & 515/522 valve lift.
vehicle runs okay on stock factory gm tune. ildes okay but does lobe up and start to stumble for a bit then clears up and is okay. worse under load like parking lots a/c on and so on. driving down the road is okay.
felt like a loss in power. currently do not have the hp tuners. a co worker has it for his turbo avalanche. he played with it for a bit and bumped the hot idle up to 700 from gm settings of 580 and seemed okay with the odd short stumble 90% better. I went to my appt to get the tune done on the dyno by a local shop. was able to gain 25hp and 30 tq across the board with a smooth strong torque curve. now up to 270 hp and 298 tq at the wheels. he set the idle to 650. it really seems to stumble now and has stalled once while switch from drive to reverse to back into the driveway. my airfuel ratio seems strange to me under wot the ratio drops to 12.3:1 wich to me would seem to lack in power.
I used to before the cam install be able to break the wheels loose on demand from a stop, now they wont even chirp. sure the dyno results show I made gains on paper but the truck does not better then it was.
not the truck does have the intake tube from airrade with the deck plate mod to the front of the air box. and has a cat back exhaust.
looking for anyone with the same cam or someone else with a suggestion or help.
I have read a lot of posts and searched the internet but no real info.
now I just use the truck for a daily driver and towing are 6300 lb travel trailer every second weekend, wich is the reason for the cam. looking for possibly saving a bit of fuel and more power up the hills.
I can get the file for the tune it is store on the laptop at work, can post in a few days if it would help.