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Is WOT advised for non N* engines?

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JP500
7/19/2007 2:31:59 PM
Hey guys (and gals),

since I own two cars -- the DHS and an Infiniti Q45 -- I recently joined the Nico forum for the Q45. I was pretty surprised to read from that group that WOTs on that engine are ill-advised -- and lead to reduced engine and transmission life.

So, what gives? The Q45 has ~300 HP and a strong transmission, not unlike the N* equipped Cadillacs. I know from experience that the Q45 is designed to go very fast. The engine is not notorious for burning oil,however, so maybe that has something to do with it.

You can obviously infer my point. I would think that if a WOT keeps a N* clean it should keep any engine clean. Conversely, if it's bad for some engines, it wouldn't really make much sense if a WOT were good for the N*.

I've read the FAQs about this. Maybe I hit the nail on the head with the oil burning issue, but who knows. Any input would be appreciated.
G.A.R.Y.
7/19/2007 4:53:29 PM
What you have read in our faq was originated by a person who was directly involved with the developement of the N*, name withheld by request.  This little blurb from that may explain why it may be more important in the N* then other engines.  BTW the way I drive my vette I do lot's of WOTS.   LOL.
 
Occasional full throttle accelerations with a Northstar and any engine keeps the carbon cleaned out of the combustion chamber. This is maybe a little more important with the Northstar than some other engines due to the tight squish volumes between the piston and the cylinder head. It's designed this way to promote good in-cylinder mixture motion (good combustion) but it has the down side of providing a ready place for carbon build-up to touch the piston - causing noise. Ever heard of the Northstar "cold carbon rap" problem?? Simply put you'll hear a rythmic, piston slap-like noise when the engine is cold. Very prominent and very annoying.   etc. etc. etc.
 
I can't speak for your Q45, I would defer to the experts on that web site.  Perhaps we can find out some more info for you?  Anyone care to chime in?
 
G.A.R.Y.
Stealth
7/19/2007 9:37:36 PM

it depends on the WOT definition at the Infinity crowd.   did you read the WOT in our FAQ?
compare that with the WOT definition used by the Infinity folks.

the WOT we speak of is strickly defined as starting while in motion.
"Start at 55 MPH or so and go to WOT in 2nd gear and ............. Leave the transmission in
2nd  ...........  the engine brakes the car and creates some pretty heavy over-run conditions at
high vacuum levels.
  "    as long as you dont over-rev the engine past the "shift point, there is no
issue.   engines are rated to shift at a certain point being 5,000 rpm or 6,000 rpm  or whatever. 
i have yet to see an engine that cannot handle the rated max rpm.

i have seen some other interesting variations of the WOT, not all healthy IMO.
you get the point.  i dont want to repost the complete FAQ thread on the subject.
case in point:  0 to 60 in 4 seconds, WOT burning tires,  is NOT the WOT we quote in  our FAQ.

there are several complaints about how it is not a good idea and come to find out these folks
are doing WOT from a STOP sign ... NO NO NO .. not what we said. 
you do that enough times, you will break the trani or an axle or bend  a rod.
you gonna drag, be prepared to pay.

lets not confuse drag/jack rabbit starts  with WOT from 55mph !






JP500
7/20/2007 10:01:38 AM
When I WOT, it's always when the car is in motion on the highway. For the record, when should I ease up on the gas? Should I hold it to red line or 5000 rpm or 6000 or 'whatever.' When you manually drop into 2nd at about 55 mph you're already somewhere between 3000 and 4000 RPM.

Stealth
7/20/2007 11:28:14 AM
please read the FAQ.  here is the link to it:  WOT

starting at 3,000 rpm is fine,  4,000 rpm may be a bit too high.
i vote for the start at 3,000. 

when to stop and how to do it, is explained there.  
there is no "easy up" and no "hold it to red line"


so, for the RECORD, what is the definition of the WOT for the Infinity folks ?




quote:

ORIGINAL: JP500

When I WOT, it's always when the car is in motion on the highway. For the record, when should I ease up on the gas? Should I hold it to red line or 5000 rpm or 6000 or 'whatever.' When you manually drop into 2nd at about 55 mph you're already somewhere between 3000 and 4000 RPM.





JP500
7/21/2007 8:25:41 PM
I was doing WOTs by bringing it to redline then taking my foot off the gas as the engine brakes it back down to about 50 MPH, then repeating 2 or 3 times.

The infiniti forum is less specific on what a WOT is. I don't want to speak for them,, but I get the impression they feel WOTs lead to premature tranny failure.
Stealth
7/21/2007 8:40:37 PM
 
your trans shifting point is at the red line?

quote:

ORIGINAL: JP500

I was doing WOTs by bringing it to redline then taking my foot off the gas as the engine brakes it back down to about 50 MPH, then repeating 2 or 3 times.

The infiniti forum is less specific on what a WOT is. I don't want to speak for them,, but I get the impression they feel WOTs lead to premature tranny failure.







stomper
7/22/2007 12:27:27 AM
from our resident Cadillac Tech:

100,000+ miles,
100+ WOTs,
200,000 mile trani,
etc., etc.

http://www.cadillacforum.com/m_10123/tm.htm



quote:

ORIGINAL: FLCaddytech

I am really impressed with the wife's.
We have over 100k and never been into the motor or trans other than rocker arm upgrades and a shift kit.
We raced it 2 years at gainesville. Mostly test and tune but my wife ran a couple bracket races with it.
It's gotta have somewhere near 100 WOT runs to 100mph.
Very tough to get traction below 20 mph. 2.93 final gear and it gets 30mpg on the road and 24 around town.
My friends went 150k before it lost a rod bearing.
The tranny was still kickin at 200k when he sold it.


JP500
7/22/2007 8:18:33 AM
In 'typical' Cadillac owner fashion I never pushed the engine in the past, so I didn't know where the shiftpoint was. As I have a DHS I believe the shiftpoint is at 6000 rpm. That's where I'll let off the gas from here on.


FLCaddytech
7/22/2007 8:32:36 AM
quote:

ORIGINAL: stomper

from our resident Cadillac Tech:

100,000+ miles,
100+ WOT,
200,000 mile trani,
etc., etc.

http://www.cadillacforum.com/m_10123/tm.htm



quote:

ORIGINAL: FLCaddytech

I am really impressed with the wife's.
We have over 100k and never been into the motor or trans other than rocker arm upgrades and a shift kit.
We raced it 2 years at gainesville. Mostly test and tune but my wife ran a couple bracket races with it.
It's gotta have somewhere near 100 WOT runs to 100mph.
Very tough to get traction below 20 mph. 2.93 final gear and it gets 30mpg on the road and 24 around town.
My friends went 150k before it lost a rod bearing.
The tranny was still kickin at 200k when he sold it.




 
Please do not think i endorse this type of driving.
I can repair any failure that might result from that much abuse.
We have since retired that car from racing and it will spend the rest of it's days getting groceries and making trips to the airport.
Maybe embarrass an occasional mustang here and there 
GM does make strong drivetrains. But like any machine some are put together better than others.
 
I have yet to see a Northstar bottom end failure.
The 4t80 seems near bulitproof also, aside from the TCC issues.
 
Stealth
7/22/2007 8:48:26 AM
 having had opened a few non-N* engines driven by some  "little'o lady from Pasadena",  i seen
clean, i seen sludge, i seen coke build up.    often the ones with deposits were blamed on poor quality
oil or cheap gasoline - my teacher said it was mostly "driving style" or "lack of maintenance".

i been running the equivalent of the WOT long before i heard the term.  my "drives Vettes only" auto-shop
teacher strongly believed in "blowing out" the coke off the old cast iron engines.  i often did ask some of
what you have asked and the answer was "dont over-rev" and "dont pop the clutch at 6,000 rpm" and
she will be fine.

in my life time ( a short one, Gary) i have blown one transmission (towing) cuz of unk overheating, not WOT
and never have blown an engine including the old days (not that old, Gary) of dragsters at the track which
included engines and cars from GM, Chrysler, Ford and Honda. 

our "ID withheld by request" engineer has spent his entire life working the GM drivetrain dept.
he is heavily involved in the design of the N* as well as other engines before that - he often tours
the facilities of the company that receives the "dealer returns", tears them open and evaluates cause.
Should you doubt the existance (not that you have) of the gent, and you really wanted to find out who
the gent is, there are enough clues in this site to find him right down to his office phone.

however, at the end of the day, each of us own our cars and we make the final decission as to how we
drive them and take care of them.   if your car's shift point is 6,000 rpm and you are doing the total
WOT back down to the lower speed, i say you are doing right.  would i do that every week?  WHY?
i do it when it feels its right to do, and that is not every week.  But my cars do get heavy footed driving
often with rev's near the redlines and some of them are approaching 200,000 miles,  engines never opened.

IF you arent sure what the shift point is, it is easy enough to find out - take her out on a long straight
road and put the pedal down and watch the RPM's, or better yet, have someone watch and note
the rpms vs speed.   observe the speed limits ! ! !


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