Stock Q45 hp

[az91q45]

I was just curious as to the HP on a stock 91 Q45.. I know its quoted at 278, but I heard that was the 90 model rating, due to the fact that they designed the ECU to run on non premium gas. Also does anyone know the accurate torque figures as well. Last but not least I posted a little while ago inquiring about a supercharger from BAD and I was given a phone number that was disconnected, has anyone been able to determine if they are still around and if so do you have a working phone number?Thanks

[Q45tech]

The Q was NEVER programmed for regular gasoline. There is a safety system if some person fills with regular or poorly maintains their engine ---the knock sensors.Some owners/techs turn down the initial advance from the specified 15 degrees to 10-12 and it tolerates regular at a 10% power loss sometimes in cool weather but no amount of retard will make up for the lack of cleaning additives in regular.Almost all early 90 engines regardless of manufacture had a 10% safety factor built in but 10% [cube root] yields only a 2.3% possible acceleration increase.....roughly the amount of the rear wheel torque increase [30lb/ft x 0.787= 23.6 lb/ft].

The new 2002/2003 Q engine does not have more PEAK Torque than the old 90-91 Q [with a JWT ECU] it just has more torque at a lower RPM and a higher rpm .......340HP@6200 rpm= [340 x 5252/6200= 288 lb/ft @6200 vs the old Q 307HP or 260 lb/[email protected] 28 lb/ft is significant but only in the 5500 and up range! So the new Q engine pulls a little better above 5500.

One would have to plot each 50 rpm increment a find the area under the torque curve ACCURATELY............10% is only <0.3 seconds in a quarter.

A 75 HP shot of Nitrous adds 98 lb/ft at 4,000 rpm declining to 63 lb/ft at 6200 rpm and allows a 14.0 second quarter time

[az91q45]

thanks for all the info... but i still dont know if 278 is accurate for the stock hp.

[Jberger]

Nope most 90 models had more the 278 HP. I'm not sure how much more, I've heard 290, I've heard 305, etc. But I can say that there is a difference in the 1990 units.

There was an agreement in japan, not to advertise more than I believe 280 HP in cars, thus 278 HP Rating. I believe it was a gentleman's agreement rather than a law.

It seems that the actual HP number shrank over the following years as emissions and NVH took precident over raw performance. If infiniti would just make the new Q handle and feel like the 1990 model I'd have one today. Maybe they will develop a real sports package for 2004.

[PalmerWMD]

thanks for all the info... but i still dont know if 278 is accurate for the stock hp.

The first 18 months of production were said to be significantly stronger than the stated hp, some have say by as much as 30hp, tho that seems excessive.Every model year since 92 dropped power a little bit until by 94/95 they had dropped to the stated hp.By 96 some even say a bit below the stated hp.

In 97 Of course they went to the 4.1L w/ 266hp (but somewhat better economy). and that number was accurate for the 4.1L

Fred...

[Ex-CA Driver]

I was told that same thing about the Japanese agreeing to state a lower HP rating due to the fact that the US had some kind of limits at that time. I was talkingto a Tech in Texas at Brubb's Infiniti and he told me that at tested the 90-91 Q's have a "tested" hp rating of 305 horses. NOw how accurate that is or not I am not sure. I can tell you though while cruising at 80mph, a slight tap of the gas or a swiift downshift to 3rd will leave a grin on your face and a frown on the Accord you left behind. (personal issue with them)

[Q45tech]

Since the Japanese don't use the term Horsepower [an English creation designed to confuse people] and derived much of their early technology from the Germans ..............how much horsepower is not germain!

Because whenever a Horsepower race gets going the marketers pressure the engineers to do things that enhance this peak number and you end up with cars [G35 and Q] with high numbers that are meaningless in the real world but the cache of having the most horsepower at a high rpm.

How do two different cars: the same weight, the same gear ratios, the same drivers, the same everything except one has 30 HP more accelerate the same............the shape of the torque curve and the self propensity of their engines to accelerate underload.

The early Q had more than the translated [from the Metric System] Torque!

The torque reached a peak of 307 lb/ft vs the 292 published rating at 4,000 rpm. The translated torque had two bumps at 5500 and 6,000 rpm in the downward slope from the peak [4,000]. They were 265 and 243 lb/ft respectively. Both of these translate to 278 HORSEPOWER at 5,500 and 6,000 rpm.Between these two peaks was [is] a tuning dip of 4% translating to 269 HP.

The english system of measurements makes it very difficult to translate power into acceleration EASILY.

The 307 lb/ft can be improved to almost the theortical limit by the JWT ecu [by 10%] to 337 [give or take a few] removing all the extra fuel richness [and overheat safety cooling] and advancing the timing at 4,000 rpm to the ragged edge of destructive knock with suitable fuel!As the rpms increase above 4,000 the VE falls and the engine needs [can use] more advance as the pressure drops. The factory was conservative to prolong engine life so fine tuning and optimization can increase the HP by 10% to 307 HP [269 lb/ft] at 6,000 rpm [the numbers just happen to be the same so many get confused with stock vs JWT enhanced programming].

What really counts is friction decreased rear wheel Torque and HP[ if you must use the term]. The highest rear wheel torque I have ever seen quoted or measured is a peak of 264 lb/ft at 4,000 rpm on premium non oxygenated gasoline after 6 dyno runs [the more runs you make the hotter, the thinner, all the fluids are so the numbers go up sequentially [255>256>260>263>264...264].

The stock Q peak rear torque is around 233-238 lb/ft at its peak roughly 30 more than that of the G35 AT car depending on the lubricating fluids and their temperature.

What each engine is ...is what each engine is.Pretty amazing we can still get a dialog going about a 15 year old design............maybe people realized this in 91 because this was the highest year of Q sales approaching 15,000! vs maybe 4,000 in each of the past few years.

278 HP sold more then than 340 does today? And $51k today is certainly less than $39k was in 1991!

[jimb]

Despite the fact the 90 Q is a 15 year old design, not a lot has happened to obsolete it. 8 cyl dbl overhead cam, 32 valves, vvt on the intake side, sodium filled valves, they dont' have a lot more today to work with.

My 89 Supra had the cams, valves and a turbo and intercooler, still not much more available in a production car. That paragon of engineering prowess, my 94 LT1 Corvette still manages a 13.7 quarter and 22 mpg around town with mid- 80's technology.

Most of the performance advances have been in marketing over the last 10 years.

The 90 Q stands as the high water mark due to the quality of the materials used in its construction and its performance. From the paint to the seats to the sheet metal, its a well constructed automobile with a few notable exceptions.

The well known valve guide issues, trans issues, underwheeled and tired, to name the major ones. Beyond these, however, the car holds up very well.

The shame is that what should have been a very capable and competitive car in its segment was hurt by a few very noticeable flaws that killed its resale value and cache.

Oh well, that's why we get to buy 'em cheap!

[Q45tech]

In 1990 all the others were worse from Lexus, MB, BMW, Audi, GM, Ford you name. Its just they took the wrong direction in 1994 and worse in 1997........to try and boost sales [broaden appeal].91 was the best selling year ever.

Nothing beats cubic inches [LITERS] except maybe a modern big supercharged V8 [AMG MB 55 series]. I expect everbody will take this path in the future.

[911/Q45]

Everytime I look at something new, Mercedes, BMW, Lexus or Infiniti, my 90 Q outclasses them. I think the build quality of cars is degrading due to price competition.

[Q45tech]

Totally agree! Inflation has been small but steady since 1994 and approximates 29-33%, so to keep current dollar prices the same, you must decontent [save costs somewhere by 33%]. a 94 Q should cost $66,500 today with the same equipment!Since 1990 we have had 48% inflation so a $38k 1990 Q should cost $56,500 similarly equiped.

When you examine the materials under the 94 skin you see some positives and some negatives but by 96-97 it was evident even to the buyer!

Looking back 1993-1994 was the best bang for the buck for all makes in build quality.....except the BMW 740 [a new design]

The Germans are in real trouble with their cost structures as are Americans Big 3 compared to Japan. They wouldn't be building factories here if they didn't have to ........saving that $1,000 per car for transport not to mention our lower labor rates in the South [no unions and minimal perks].

Why does GM whine about the Japanese .....they are more efficient...... heck no they have lower pension costs and retirement medical benefits....lower cost of prescriptions and lots fewer doctors and dentists.Its cheaper to work your employees to death than to pay retirement. The Gemans are lucky to get 40 weeks per year of real work and they can retire after 25 years!

When I strip a 90-94Q I see where another $1,000 worth of sound proofing, some thicker metal here and there, an extra brace and more welds, and a little of this and that would have made it spectactular.

Probably same with a 94 MB S500.

You can't get [and never will be able to get] more car for the money than a 1994-1995 Q even with its less expensive leather!

[greg_atlanta]

Just take the plastic cover off the front of the engine and you can claim anything you want!!

(I'm neurotic about fuel or coolant hoses leaking so I just leave them off so I can get a better view of the problem hoses).

[greg_atlanta]

Everytime I look at something new, Mercedes, BMW, Lexus or Infiniti, my 90 Q outclasses them. I think the build quality of cars is degrading due to price competition.

You've got to blame leasing as well. I'm sure the majority of luxoboats are leased. And most lease cars are turned in at low enough mileage so the dealers can "certify" them and make a big (or bigger) profit the second time around.

[911/Q45]

I wonder if it's too paranoid to think that leasing allows for a downgrade in quality as the "good" customer(lease guy) only keeps the car for 3 or 4 years?

[maxnix]

Quote »You can't get [and never will be able to get] more car for the money than a 1994-1995 Q even with its less expensive leather![/quote]And that is why I overpaid for my low mileage 1995 Q45s. I am sure I wll be tired of them in ten years, but I will be sorry I can't replace them, unless Nissan brings a redesigned President back to the USA.

I could have purchased the 740i, but I have had BMWs, and the 1994-1995 (and even 1996) Q45s are the best values out there if well maintained. The earlier ones are certainly as desirable or even more so for the extra performance (but lacking some of the extra amenities and refinements), but they are as costly or more so when updated to like-new stock condition.

Keep them all running! I still think it is one (if not the most) handsome cars on the road even today. Not the riceiest, not the most aerodynamic, not the most MB like, but handsome. Only BMW's 5s and 7s come close.

[greg_atlanta]

Quote »Keep them all running! I still think it is one (if not the most) handsome cars on the road even today.[/quote]

Agreed!

I'm tempted to buy another one (maybe 94 or 95) and fix it as budget permits... but kinda hard to have two cars living in a downtown apartment.

Anybody want to start a Q farm? I'll just put her out to pasture.....

[tkd_q45]

I have to agree here too - I love the profile of our 92 Q. Really elegant! I think it has aged well and will continue too - the mark of good design. I too wonder what I will replace our Q with. If I won the lotto today, I'd totally restore/refurbish our 92!

Oh forgot to ad that you don't see them everywhere like you do Lexus, Acura and Mercedes - even here on the West End of Los Angeles where you see EVERYTHING! I see more Porsche Boxters than 1st Gen Q45s (no exageration).

[maxnix]

I have thought about it, and one thing that very few other cars have is that fixed glass between the C and D pillar.

Most other cars include it in the rear door window frame, but it is just not as esthetic in my view. And also it is functional increasing the range of peripheral vision.

[PalmerWMD]

Has anyone ever thought about what a Coupe version with a 6 speed would have been like?

Fred....:drooling

[tkd_q45]

It was rumored back around 91 (I believe) to make a Q45 Coupe to compete with the SC 400 Lexus. I remember seeing a concept sketch in Road & Track towads the front of the publication where they'd often have sketches of rumored cars. I always thought that this would be a great car! Especially after I saw the SC400. I thought that Infiniti's version would be more like a 928 Porsche (in character) without all the mechanical head aches.

[longrunQ]

I still think it is one (if not the most) handsome cars on the road even today. Not the riceiest, not the most aerodynamic, not the most MB like, but handsome. Only BMW's 5s and 7s come close.

I totally agree. When I was looking for a luxury car from that era, the q45 was the finest and best fit for me. I even preferred it to the bmw 5series.

I think you used the perfect word. HANDSOME

[AZhitman]

I think you used the perfect word. HANDSOME

Quella says she takes offense at that word.... She prefers to be referred to as sexy.

Too bad all ladies don't age that gracefully....