TM bad for good economy?

[N0DIH]

I am wondering if torque management is considered good or bad for economy.

Am I correct in assuming that TM simply jerks back timing to take power out?

Is so, wouldn't that be counter productive to good economy?

Yeah, I know, if TM is kicking in, you are probably stepping on it anyway, but considering when TM is engaged, you likely are stepping on it harder to overcome.

Like my 454, it really seems like it has a lot of TM especially off the line. I don't really complain between shifts, but off the line, it sure seems like it sure fights you early on....

Anyone do any testing with/without?

[cmitchell17]

Have you gotten rid of the pe delay on your 454?

I think a lot of people blame tm for all the lack of response and power.
With ETC stuff I think ETC does something. I think TM is more for if you rev it in park and put it in drive. I think people think tm makes there motors bog off the line, but I think it is the pe delay mode. Especially on heavy duty trucks. 6.0 454 8.1) Most of them don't even go into pe mode becuase they keep the timing so low.

For ecnomy I don't think it would make any or even slightly noticable diffrence. Torque reduction happends between the shifts when there is no power being applied to the wheels.

I disabled all my engine abuse mode but left the transmission abuse on becuase I did not see it pulling any timing anywhere (I dont think).

I still have torque reduction becuase I think the transmission needs it.

[N0DIH]

Yes, that is flat out awful. How on earth could GM do PE Delay? Seems foolish with a HD truck that tows and tows heavy.

Honestly I didn't complain about how TM felt (if it is still on, I didn't do this tune, Jesse@wait4me did it) when I towed 9K-10K lbs.

I will be picking up EFIL, HPT or RTOBD2 very soon here. Then I can tweak my own.

[cmitchell17]

It seems like they would need pe mode if they were really towing something heavy.

I guess they kind of did the opposite and just kept timing really low.

I know on the newer heavy duty trucks with the 6.0 have some special material exhaust valve with stainless steel headers.

[cmitchell17]

I know this dosent have anything to do with anything but

If gm thinks that these engines will be operating at high loads for long times, is exhaust gas temperature proportional to engine load?

So gm puts these parts in so something in the exhaust dosent melt?
Is this also the reason why gm puts big diameter exhaust on the heavy duty trucks? The big diameter exhaust on the HD trucks seems like it would hurt low end torque?

[N0DIH]

Well, the larger pipe does help keep exhaust temps lower.


I know this dosent have anything to do with anything but

If gm thinks that these engines will be operating at high loads for long times, is exhaust gas temperature proportional to engine load?

So gm puts these parts in so something in the exhaust dosent melt?
Is this also the reason why gm puts big diameter exhaust on the heavy duty trucks? The big diameter exhaust on the HD trucks seems like it would hurt low end torque?

[cmitchell17]

Yeah I could never figure out why the exhaust was so big on the 2500s.