I recently had my Tranny rebuilt with a NASTY shift kit. When it shifts it barks both rear tires and most times leave 2 little patches, but right after the shift the truck bogs down. I've heard this is GM's torque management/abuse mode. I want it gone . I know wait4me and pcmforless both can do this as i have already talked to them. anybody have any comments on either of them? im leaning toward Jesse at wait4me he was very helpful. That and his price for a new PCM is 160.00 (meaning i get to keep mine for warranrty), compared to pcmforless who wants 300.00 for the same thing.

My mods are; Magnaflow High flow cat, flowmaster 40, TB restrictor plate removed, MAF screen removed, FULLY built tranny, brand new rear end 3.42 with all new bearings and seals, Jasper perfprance (yea right) crate motor. I say "yea right" because with my BRAND NEW motor i have been beat my stocl blazers with ~150k on them. I know my truck is by no means a race truck but i want to easily beat stock blazer I NEVER tow or offroad, just a summer toy.

Both companies claim 30 HP increase with 40 to 50 Ft/lbs increase. Jesse did say that you get WAY more power out of the hole and i would be very pleased without TRQ management. So what do you guys think??


Thank you,
Mike

 

There is very little, if any, torque management in these trucks.

I would be interested in how much your MAF frequencies fluctuate. Between the throttle body deflector and MAF screen, both of which you have removed, I would bet that WOT has some pretty erratic behavior in terms of what the PCM is seeing and what the cylinders see for actual combustible material (oxygen & fuel).

When I removed the deflector, I saw no increase in WOT performance on back to back drives, same day, same stretch of road as recorded with my scan tool. What I did see was a miss-match in cylinder combustion from reading the plugs, with the front cylinders reading slightly rich while the back cylinders read slightly lean. I attributed this to EGR gasses being unevenly distributed in the intake due to the lack of the deflector. Excessive EGR gasses to the front cylinders will dissplace combustion supporting oxygen in those cylinders, causing a slightly rich condition. The rear cylinders not having that condition would run slightly lean as the O2 sensors average out the difference between the cylinders on that bank.

Removing the MAF screen also serves no purpose other than to cause the MAF reading (frequency) to be erratic due to inconsistent flow through the throttle body.

And I am sure that box in the back is not helping your 1/4 mile performance (hint hint - cause you are not talking about street racing, right).

 

X2 what Swart said I was thinking the same thing when I read the descreaned MAF and restrictor plate removed. Both of which are very bad for a stock and untuned/modiffied engine. Your bogging issue just might be in relation to the MAF. I would go to the junk yard and get a new one with the screen. If in doubt the search function will explain this. Jesse at Wait4Me is great, I had a spare PCM tuned for my Blazer and have been really happy with it. Truck has more power and idles a lot smoother. However, don't expect any huge mpg gains, as I have seen a 1+mpg gain max on 93octane. However I asked for different parameters to be set on my truck which is a 5Speed.

 

thanks for the input. The box is gone someone wanted it more than i did. I had another MAF housing laying around and swaped them with no change. so for the removed restrictor plate to be effective i would want to remove my EGR? i heard that can actually hurt you because it lowers cylinder temps. i can replace the TB plate, but before i pulled it my truck seemed to struggle to "brake torque". I also talked to my tranny shop who has a snap-on solus? and tech two. they said the PCM was pulling timing and it was indeed trqmanagement.

what were the pros and cons of the PCM tune?

 

did you disconnect the battery for 15 minutes when you swapped the MAF? I would listen to Swart about the restrictor plate and maybe check all your spark plugs and make sure they werent burning bad from the displacement of EGR gases. How many miles are on the truck? When was the last time it had a full tunep (plugs, wires, cap, rotor, fuel filter, air filter, etc. cleaned throttle body and MAF, flush the diffs, injector cleaner treatment)? new cat maybe?

The Wait4Me tune is definitely worth the money! no downsides so far in my opinions, I hear that the automatics benefit a lot more with shifting improvments from it.

 

it has a brand new motor with 5k on it tranny has less than 1k on it. all plugs are fine. if i remove my egr can i leave the TB modded?, or should just replace the difusser.?

 

The EGR system does not operate at WOT so I would not expect a change in your WOT performance at all. The EGR is always functioning while cruising down the road and this is where the deflector does its job of creating a more even distribution of exhaust gasses in the intake.

You have to have the PCM tuned to remove the EGR. And that does not just mean the removal of the OBD2 codes associated with the EGR system. The spark and fuel tables should be changed to correct for the lack of the benefits of a functioning EGR system. Typically you richen up the fuel mixture to reduce the cylinder temperatures that would result from the factory lean calibration.

 

so is it beneficial to have the PCM tuned to have EGR removed? it kinda scares me so i might just leave it alone lol. Thanks for all the input. I only wanna have to have my PCM tuned once and get the MOST out of my little V6. I love S seris but a little more power would have been great.