Choosing a stall speed.
Choosing a stall speed. I have a 2012 camaro ss, lsx376, Tick stage 2 turbo cam, holley high ram, s480 96 turbine t4 1.25 ar, 3.54 rear gear, 28 inch tire. I swapped to a 4l80 cause the 6l80 was just stupid cause of the low gear. The trans came with a ptc 10 inch 3500 stall converter which I sent to ptc to get upgraded to triple discs and re stalled to 3800 cause the cam said 3600 and up. Drove it for the last six months and it works great if I'm racing or acting the fool but totally sucks just to cruise and yes this is a street car. Daily driver. 120 plus miles a day to workand back. Engine made 770 to the rear wheels on 9 pounds ran out of fuel. Got that fixed and now can run 14 no problem but never redynoed it. Converter is like a switch. It stalls to almost 3000 just to move. I tried hygard and it tightened like 150 rpm. It's so loose the converter locking feels like a huge gear change. My previous 3500 in the 6l80 didn't feel like that at all. Ptc says they can restall it but it will come in around 3000. Will that be to low to build boost off the line from this set up. Opinions would be appreciated.
This is where an egine dyno is way more useful than a chassis dyno. Let me start by saying your car makes really nice power. I learned a long time ago to completely disregard the rpm range that's listed on a cam card. Every engine is different and you might not have any idea what size engine the listed rpm range is referring to. As you know a 4.8 and a 6.0 are two different animals OEM let alone any additional modifications. On to the dyno, nice power, but I'm not seeing a chassis dyno being very helpful in regards to a torque converter stall speed selection. Too many variables. This is where an engine dyno shines, but that's probably not an option and that's understandable. I've hand luck with playin with the tune to build boost at lower rpms. I can footbrake to only about 3,000 rpms and can build around 7 psi so far, but that's with my combo. Each is different. Seems it shouldn't take that kind of rpm to get the car to move. Ive had 5200 rpm converters that were like that. Seems way loose. One thing I can say in regards to the converter is at least take it out and try it. If the rpm drop on the shifts isn't there and/or you're blowin through it, call PTC back and let em know what's up. Sent you a PM.
My main question is when can I expect to build boost with my combo. I'm not looking for an exact answer I'm looking for a 6.2 and s480 builds boost at 3400. I just don't know how low this will build boost the 3800 being so loose it will build boost almost instantly going wide open but it jumps to 4000 almost immediately too so when do less everyone think it will start building boost.
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Joined: May 2013
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From: ATL
My main question is when can I expect to build boost with my combo. I'm not looking for an exact answer I'm looking for a 6.2 and s480 builds boost at 3400. I just don't know how low this will build boost the 3800 being so loose it will build boost almost instantly going wide open but it jumps to 4000 almost immediately too so when do less everyone think it will start building boost.
