My TST isn't stacked with anything. It's a chip that plugs into sensor and injector connectors under the hood. I might try stacking with a smarty someday to see if I can get a little of the response back but without smoke. For now, I'm very happy cuz I bought a Jeep for running errands, etc. and the truck stays in the garage til I go camping. I have all the response I need for towing.
Every time I thought about buying a smarty I'd read about someone who had problems... I don't remember the specifics. I've bought a lot of things from TST and I've talked to Mark for many hours, about anything and everything, from his Purdue class projects to his dad inventing the PT fuel system. Mads used his shop/dyno to develop the smarty and the PMCR made more power. That could be old news from smarty early days, I don't know, but Mark also sells smarty and he has some customers that their ecms got trashed. So we talked more about response, smoke and touchy throttles and that's when he told me that the PMCR looks at boost to keep the bottom end clean. That was what swayed me his way.
We took a long trip with the 5er right after I got the PMCR and I got on a long stretch of flat road and set the cruise and started playing with the tuning. I found a combination that really dropped the egt and the overhead mpg went up immediately. I always hand calc every tank the real numbers proved the results. I gained a solid 2 mpg towing. I went from 12 to 14 towing my 15k lb 5er and I haven't seen 14 towing since I had a 10k lb 5er. I wont trade the change on the fly for anything, now, but I might supplement it with a smarty someday!
In case anyone needs more info on the Pred, I need to clarify some things. The 100/econ tune is very clean and it's a healthy power boost. It's also a PERFECT tow tune with a better turbo... good mpg, has some tq mng't down low for stock clutches/trans and max egt was 1225 with my truck. unfortunately the next steps are 170 and up and the throttle gets crazy touchy and it's HARD to keep clean in town. There's some really nice stacks with the puck and the canned tunes in the pred that do as well as the custom tunes that have to be down loaded from DS. Craig