PaulG

I'm trying to decide whether to get the regular PM3 or the PM3 Comp? I want to get really good low end power and grunt, but I don't want to make the truck unusable as an everyday driver and hauler. I've heard the Comp version has great low end. But I've also heard it has some draw backs like not really being usable on the upper levels, and that it shutters hard when you get out of the throttle. So what do most of you recommend or what has been your experiences with them? My truck is a '99 5spd with 13" OFE, DD3's, Scotty II, gauges, and exhaust.

Rod talked a while back about getting a special program with the low end of the Comp version and the upper end of the regular PM3. Anybody running that version? That sounded like the best solution to me, but I contacted TST about it and they indicated there wouldn't be much point in doing the programing like that. They said either go full Comp or stay with the regular PM3.

I guess I could start with the the regular PM3, and then upgrade to the Comp later if I want more. And I know I can stack the PM3, but I want to see how I like the box by itself first.

HOHN

The stock TST box will not produce very much smoke with stock injectors. The fueling curve is designed to follow the boost curve. With DD3s, you'll get smoke, but not as much as the comp version.

The comp version had a few primary differences. The fueling curve is shifted to the left a bit, so the fuel comes in sooner (relative to boost) and it WILL make some smoke. That's why they make you sign the waiver (because the regular TST is CARB certified). But the Comp version (with remote) is perfectly streetable on the lower levels.

The regular box maxes out at 63% on level 9. The Comp version hits this at only level 6! From 7-9, it inches up to about 72% fueling, and it will fuel the minute you lay the pedal-- it won't wait for boost to come in (which means mad smoke).

That's why the Comp box has a reputation for having the last 3 levels be useless. You won't want to keep it above 6 for any length of time, or your VP will be hating life for sure. Although I have to say, Steve St. Laurent had a custom PMAX comp that fuels to 80% and his pump is still alive, so maybe it's not the pump killer that people want to believe.

The shudder from the PMAX comp is the price you pay for the heavy fueling. The pump is pushing its limits, so smoothness tends to suffer, and you can't really expect any less. It's a bad idea to suddenly lift the pedal at high rpm anyway, because you can huff a turbo pretty badly. Just remember to ease of the pedal from WOT and the shudder goes away.

Most of the time, you don't need to have 9 levels of adjustability, so living with essentially 6 levels on the comp box isn't much of a sacrifice.

Then when you want wicked fueling, you always have the pump-grinder level 9.

Go for the comp.

Justin

Timinva

My pm3 is the oppisite of that. Levels 1-8 is a normal pm3 set like a stock one on levels 2-9. Then my level 9 is a full comp. Level 9 adds 19hp from level 8 on the dyno. I have a etc vs eth motor but my truck did not like the full comp on the street so Rod had mine custom programmed. The normal pm3 still fuels hard and it is only $50 to reprogram it. You will need more turbo with dd3s and a pm3. I made 425hp with dd3s, pm3 and hx40 but most make around 375 with the stock turbo and that set up. Tim

banshee

You get a little more down low with the comp, but IMO it really shines up top from 2700-3400 rpms. The regular PM3 will nose over the fueling curve at ~2800 to try to keep EGTs down, but the comp will just keep fueling and fueling to redline. For extra low end I would suggest stacking a timing box (EZ, TTPM, VA, etc).

For the levels, a comp level 5 is the same as a regular level 9 except for above 2800. That level is very smooth and puts out good power. With supermentals, HX-40, and EZ it made 455 on my truck and 473 on my dad's truck. It also pushed both trucks into the 12s at the quarter.

John

joefarmer

I'm not sure if anyone covered this, but I only see the defueling shutter on levels 6 to 9 with the comp version. Level 0-5 I don't see any trouble. I'm still a fairly stock truck (with max flow lines & scotty 2) for the next few days.

brandon.

DarrellB

The shutter that a PM3 Comp causes seems to differ greatly from truck to truck. At one dyno event last year I talked with a guy that said his shutter was so bad above level 5 that he couldn't use it except on a dyno. He also said it shutter under acceleration and deceleration. Mine on the other had is pretty civilized on any level except 9 which will only shutter on deceleration when slowly rolling out of the throttle. I took this guy for a hot lap in my truck and he was amazed at how smooth my PM3 Comp was over his, we then put his PM3 Comp in my truck and it was just as smooth as mine. His truck was an HO 6spd and mine is SO, not sure if that's the difference or not but I'm really happy with my PM3 Comp and would buy another in a second if I had it to do over again.

DB