killian96ss

I'm trying to help a friend that has a 2005 Silverado which originally had the 5.3, but now has a cammed 5.7 LS1 from a 2004 C5 and a TR6060 trans. The cam is a COMP 222/224, 566"/568" on 112. He is using the stock 5.3 truck intake, TB, MAF and fuel injectors. I mentioned the injectors might be undersized as well as the MAF, but his tuner says that isn't the problem which leads to my question. Is the stock 5.3 MAP sensor ok to use with this cam since it makes less vacuum and has more overlap? He has had engine tuned several times, but it has strange idle problems, more specifically it doesn't like to drop rpms between shifts, it gets hung up then slowly drops rpms and sometimes the idle seems a bit rough as welk. I've tried helping him as much as possible, but I'm no tuner and this is custom setup, so if anybody sees anything wrong with this setup please chime in. Any help would be appreciated since he's driving me crazy with all these questions, lol.

Steve

nickalltogether

The factory map sensor should have no problem with that setup. Factory MAF should be fine as well.

killian96ss

Thanks for the reply. I feel like it's a tuning issue, but just trying to eliminate anything obviously wrong with his setup.

Steve

tblu92

The only time you would want a 2 bar thru 4 var MAP sensor is if you are running any kind of BOOST--if you change the MAP sensor without boost you are simply asking for trouble-----Even sometimes with street boost of less than 6 PSI you can still use the STOCK MAP sensor----
Any engine that is N/A use the stock MAP sensor