How often do you go WOT aka "Italian tune up"?

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Sean Michael

Sean Michael

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multiple times every time I get behind the wheel
vehicle runs great, but extreme use requires a more severe maintenance schedule.
I also inspect it often and am therefore pretty sure when I do get on it that it's not going to pop a hose or break a belt or do something dramatic.
I should also note doing such a thing, tends to cause failures, primarily the transmission & rear end. until they are upgraded to absorb the abuse.
Do the stock transmission and rear end need upgraded to handle reasonable WOT use from an unmodified engine making stock power, or is that come more into play once people start tuning and adding power?

I understand that constantly wailing on any vehicle is going to wear things out faster, but I'm with @PG01, I'm going to enjoy it and fix it if it breaks.
There's a road speed under which, if you stomp it suddenly, it'll make a big to-do out of a multiple downshift,
followed by jumping over a couple thousand RpM.

The trick to an 'italian tune up' is to quickly roll into the throttle without stomping it from a low speed,
so that you don't unnecessarily shock anything with a multiple downshift.
(4L60E can do a 4Dn1 , think 6L80 / 8L90 / 10L80 multidownshift by going from a gear through neutral to a gear,
like 7-N-3 or 10-N-5.)
Then you gotta hold your foot down til you're threatening 85-90MpH.
The WOT pull has to be long enough to give the cylinder a good fuel soaking.
As enjoyable as it damn well should be, it's not about the fun!

1. Plan when and where to do this without concerns. I've a few favorite spots where, despite the illegality,
no one / nothing is in ANY danger, and after a quick reconnoiter of the spot, I know I won't get caught either.
2. Run a strong dose of Chevron with Techron Fuel System Cleaner, Marvel Mystery Oil, BG44K
or another very highly recommended fuel treatment.
(Many are benign but ineffectual, go read Bobistheoilguy for a week and then make your decision.)
Bonus points if you can do this using ethanol, which is a better fuel system cleaner than petrol.
3. It's not quite a drag race, don't worry about reaction time or 'hooking hard',
unless looking for the drivetrain's weak spots.
4. Once you hit 85-90MpH, don't stomp the brakes, but get back down to legal speeds quickly and safely.
Bonus points if you DON't have to stop! The engine will appreciate avoiding DFCO immediately after a WOT run.
There's a reason why Texas vehicles' engines tend to do better than NYC engines.
Good tips, and I am in Texas with plenty of long on-ramps and open highways where I can give it the beans in a relatively safe and legal manner. There's a county road near me that has a particularly long onramp with an uphill grade that opens onto a 75mph highway that everyone seems to do 80 on anyways, so I'm always stoked when I get to use it with nobody in front of me. Being an uphill grade makes the engine work harder and keeps me from reaching unethical speeds by the time I merge.

What is DFCO?
 

Doubeleive

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Do the stock transmission and rear end need upgraded to handle reasonable WOT use from an unmodified engine making stock power, or is that come more into play once people start tuning and adding power?

I understand that constantly wailing on any vehicle is going to wear things out faster, but I'm with @PG01, I'm going to enjoy it and fix it if it breaks.

Good tips, and I am in Texas with plenty of long on-ramps and open highways where I can give it the beans in a relatively safe and legal manner. There's a county road near me that has a particularly long onramp with an uphill grade that opens onto a 75mph highway that everyone seems to do 80 on anyways, so I'm always stoked when I get to use it with nobody in front of me. Being an uphill grade makes the engine work harder and keeps me from reaching unethical speeds by the time I merge.

What is DFCO?
Transmission is the weak spot, that's really all I can tell you. Most of the ones I broke were in the 1-2 shift, that might tell you a bit more
 

Marky Dissod

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What is DFCO?
Long story as short as possible:
Deceleration Fuel Cut Off

A bit longer:
Usually (when the TPS% is more than 0.0%) the engine turns the transmission which turns the R&P, which turns the tires, which push on the road.
Whenever the TPS% is 0.0% (for argument's sake, let's oversimplify), the road pushes the tires, which turns the R&P, which turns the trans which turns the engine.
Why use fuel to turn the engine, when the road is already turning the engine? (This assumes the TCC is LOCKED.)
No fueling, no combustion, engine slowly cools off though, so the ecm cannot allow the engine to go under 185F / 85C.

GM's Gen5 V8 can do DFCO one better; cylinders taking a break are not working sucking air past a closed throttle.

DFCO is NOT engine braking - which is technically powertrain braking, because downshifts are integral to the braking effect.
The higher the gear, the more it's DFCO, not powertrain braking.

(Decel Enleanment, when DFCO is NOT in effect even though the vehicle is decelerating, went out of fashion around the same time as Lean Cruise did.)
 

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