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.

 

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.

 

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 !

 

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.

 

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 ?

 

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.

 

your trans shifting point is at the red line?

 

from our resident Cadillac Tech:

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

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

 

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.

 

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.