I'm about to buy my first LS powered truck. I have always thought the 5.3 engines were unresponsive and mushy compared to 5.7 vortecs and especially the TBI motors I've owned.

How much does a tune and deleting 95% of the torque management make a 5.3 react? Looking at a factory dyno, they make comparable low end tq. Hell the TBI was only 300 ft/lbs peak.

 

The "mushiness" is the way the tune is written by GM. The throttle opening rate is very very conservative. This can be tuned out.

Compared to a 5.7 Vortec, a tuned 5.3 is stronger and more fun.

 

5.3 > 5.7 vortec.

More power and torque, better mpg and the tune makes all the difference.

 

Deleting 95% of torque management. LOL Like leaving 5% in is going to make some kind of difference. Turn it all off.

 

Turning up the throttle sensitivity will help I'm sure.

I'm mostly curious about the low end torque. I spend 90% of my time under 2k rpms. Just how I drive.

As far as the TM, I don't have alot of faith in the 4l60 (5?). Pre 07 truck. Some last 250k stock some burn em up in 75k. I don't tow heavy loads much with a light duty truck. That's another topic entirely but I'm mostly curious in the torque characteristics.

Thanks for replies.

 

There is no comparison... power, longevity, mileage.... Even on stock tune the 5.3 IMHO has more power than any of the vortec sbc engines ever did... a cam change and tune makes ridiculous power increases comparatively.....seems the average mileage on a bone stock 5.3 is around 250k and going.... Try that with an untouched 5.7

 

I'm not considering keeping a sbc. I have a built 383 in the basement but can't think of a good use for it.

Just to clarify what the purpose of my question is, I simply want to upgrade to a better truck (01-06). Looking for a super low mileage clean one. They're about $10-13k here. I would love it if the 5.3 can perform the same if not better under 2k rpms as a 5.7. I really want to avoid the rougher ride of a 2500 and the poor mileage. The hp of any truck engine is plenty for me.
I know there was the SS which I think was a 6.0 in a half ton. Hard to find those.
So I'd like to know how the 5.3 compares tq wise under 2k rpms to the 5.7. If I have to do a cam swap, I'll just swap in an LQ4. I have an LY6 but that's for a car project. I'd rather run a cathedral port head anyway. And advance the cam. Maybe more lift and tighter LSA, stock duration. There I go getting sidetracked again...

 

my o5 when it was in stock form was always very strong. i don't know about any mushy pedal issues. mine is so sensitive if i go over bumps or dips it will rev a little. its very responsive and any supporting mods will just add to that

 

Really not hard to find an SS if you want one. They're all over the place for sale, and some in your price range depending on condition, or spend a few more bucks for a nice one. Just ask yourself if you want AWD or RWD, if you want RWD then that wasn't available until '05 (optional, and not common) - then standard in '06 - no more AWD.

Richard

 

I need 4x4. I guess there was a model that did have a 6.0 1500 with 4x4. Like an SS but without exterior changes. Kinda rare. The SS is rare here in michigan. Not too many 2wd trucks.

I'll stick with a 5.3. If I don't like it, maybe I'll put a 4BT cummins in it or a JD 4045