Power cut back question

[bootlife]

I was watching a dyno on a stock C7 and GM set top speed to 200MPH, the car makes just over 400 at the wheels, on a top speed run on the dyno around 190 MPH at 4000Rpm in 7th gear the car dropped to just over 200Hp. They said this was in the tuning to cut power before 200 when the car shut off. So this brings me to my question. Is this a new thing or has GM allways done this? I have a mid grade Nelson tune and at 80 to 85 my truck looses most of its power, takes about 2 miles from 80 to 120. My truck shut of at 92 I think stock, but what would cause it to loose power at 80? I'm in 3rd gear at 4000 rpm that should be where my 5.3 is making power. Is this part of torque management?

[Botlfed]

Is it stock?

[bootlife]

Ya pretty much, cold air, exhaust, built trans, 4.10 gears. It gets to 80 in a hurry just looses power soon as it gets there, if your going 70 it doesn't matter if you WOT or ease in to it it climbs the same. I know the 5.3 has power to pull me threw a 100. Trucks with old 350, 351s can do it.

[bootlife]

It just feels like it stops making power.just seems odd to me lol

[Botlfed]

Thats because essentially 70% throttle is basically the same as wot .

[conekiller01]

My truck pulled almost as hard from 80-100 as it did from from 60-80 pulled the same till about 110 then the laws of physics started to fight me... I'd seriously doubt Allen put something in your tune to slow you down from 80-100 or gm for that matter but I've been wrong plenty of times before

[bootlife]

I don't think Allen did anything, just wandering if GM had something to do with it, I should have plenty of power at 80. I know it's a pretty big truck in terms of physics but wouldn't think it should stop pulling at 80 so fast

[Botlfed]

Once allen tunes it, gm's crap is gone.

[farmtruc]

Might be a lack of fuel. Fuel pressure. Wide band. Scanning would let you know.
Or could just be a big truck thing.

[RS/SS 4.8]

It could just be the way the trucks geared and lack of hp lol. My 4.8 felt the same way until I cammed and geared it. Now it runs up to 120+ all day on stock driveshaft lol.