Dyno runs
 

So, do you guys feel that we've been cheated by Nissan? I've dynoed my car this weekend and got no more than 230WHP from any of the runs I did.

It translates to about 270 at the crank - no way it's 287. I've seen other posts with similar results, and I know Nissan's done that before with the maximas which have 240 HP and not the advertised 255 and right now there is a lawsuit coming from the maxima owners.

What results did you guys get from your dynos (in 4th gear of course) and under what conditions? It was cold here in Massachusetts when I did mine, hood was open, fan was blowing right at the intake...

try 5th next time. 4th isnt 1:1, not that you gonne gain 15hp but just for futre reference.

it seems some people dyno low, some dont, I saw one guy that got 242 I thought...

is your car broken in? how many miles? which model? perhaps rim size could alter the drive train loss, but again, not by 15hp.

was it auto or manual, you could expect a higher loss from an automatic, but you said 4th, so unless you used tiptronic(in which case 4th is the correct gear) you were probably a manual.

anyway, just some ideas, I want to get mine on the dyno soon, just wanna finish the break in first.

Yeah I agree 30 hp is about normal to lose through the drive train but 57 is crazy I think they over rated the Z by alot! :confused:

Rare, but the drivetrain can have 20% power losses for your manuals. So 287 times 0.8 (80%) is 229.6hp...
Most of the time, people figure 15%, but it can be as much as 20%.

Rim size is stock, car is not broken in, transmission is manual, 4th gear is almost 1:1, 5th is not.

20% loss is not normal for manual transmission...

'

you need to get back to breaking in the car, and not spouting off your incorrect information...

what does this mean to you: ?

not normal maybe not, but possible, supposedly the carbon fiber shaft was going to help, but it didnt... nothing you can do about it. but yeah 5th is the 1:1 gear. :o

You're right I'm wrong... 5th is the 1:1...

Now I can't remember whether I dynoed in 4th or 5th.:confused:

If it's 5th then we're missing HP, if it's 4th then doesn't it mean we're missing even more HP?


Skidazzle, is there a post where you posted more information about your nav-tv mod and the rear view camera? I'm interested in something like that.

Let me know.

Michael

I wouldn't be surprised if the Z had 18-20% loss at the wheels, in fact I'd be VERY surprised if it only had 15%. Everyone seems to make a big deal of the carbon fiber driveshaft, but there are a lot of other factors that contribute to HP loss at the wheels. First, the Z is a rear wheel drive vehicle which inherently has more drivetrain loss. Second, it has a very stout transmission which I am sure contributes a bit to HP loss. Also, the Z has an independent rear which has more loss than a solid axle. The carbon fiber driveshaft will make some difference, but probably not more than 1%. Also, if you dynoed in 4th you will see some loss over dynoing in 5th. If you run your numbers using 18-20% loss, your car is making between 282 and 290 hp, which is pretty close to what Nissan says.

How do you figure 282 - 290 hp?! Even with 20% loss, it's still below 280. I guess in 5th gear you'd get more HP but no more than like 4-5 more at the wheels.

So if you take 235 which is not likely, and take 20% loss which really sucks if it's true, then you get 282. It's not 287 and certainly not 290.

Where did you get those numbers?

Also, 20% loss i'd expect from an automatic Ford Taurus, not from 6-speed Nissan. I know Nissan is no Bimmer but 20% is huge.

It'a all in the math. Let's work with 20% loss just to keep things simple. To figure wheel HP based on crand HP you might subtract 20%. That 20% figure is Crank HP - (Crank HP * .20) as opposed to Wheel HP + (Wheel HP *.20). The 20% figure is based on the crank HP, no the wheel HP. Make sense?

So:
287 Crank HP - (287 * .20) = 229.6 Wheel HP
287 Crank HP - (287 * .15) = 243.95 Wheel HP

Since I'm not 100% sure that the % loss should be calculated based on Crank HP, here is the numbers based on Wheel HP.

230 Wheel HP + (230 * .20) = 276 Crank HP
230 Wheel HP + (230 * .15) = 264.5 Crank HP

I think the first set of numbers (calculated from Crank HP) make much more sense. But, since the dyno run was made before the end of the breakin period the numbers are not a valid assesment of the true HP of the engine.

230/(100%-20%)=287.5hp

do a search for "nav-tv". i did not post much except pics... internetabyss, and one oter guy posted all the information.

m

My problem is 20% loss. That's unacceptable.

Manual should only loose 13-15% maybe a LITTLE more cuz of RWD

Right, but you're not broken in yet. Let the break in period pass and then go dyno again. Infact, it will be interesting to see just how much HP is gained at the end of the break in. In order to get to 287 Crank HP you'll need to dyno 243.95 at 15% driveline loss or 229.6 at 20% loss. Since you alread pulled 230 during the break in period it's probably safe to say that the loss is less than 20%. With enough cars and enough details we can probably pinpoint how much loss there is.

I'm thinking of starting a spreadsheet to keep track of all dyno runs. We can track the whole host of variables, temp, humidity, mileage, mods, type of dyno, etc. This could would be very usefull in determining which mods work, weather your car is tuned correctly, etc. If anyone is interested, send me you dyno info.

I believe I saw a dyno somewhere here of 240 or 241 at the wheels buy mostly everyone got the same as me.

Also, on the same topic, how long does it take the ECU to learn and adapt to a new mod such as an intake? I know some cars it's instantaneous and others it takes a few days.

Yes, do break in first!
 

My car is a totally diferent car at 2400 miles then it was at a few hundred miles. It feels plenty more powerful. I remember posting something that my 92 300ZX NA felt sronger (I had like 300 miles on my new baby) but now I take that back!

Drivetrain loss
 

nevermind.

That's a good question for the ECU tuners out there. Either that or someone is going to have to do a little trial and error.

I'd like to know what car loses only 13 or 14% power from their driveline. 15% is already being optimistic for a fwd car...

What car? Well we don't need to go far. Try Altima or Maxima - they should both loose about 15%. And like I said, a little more for the Z because it's RWD. 20% is too much loss.

15-20% is the norm amount of loss for just about any car.

the Z32 was 18-20% DL - 300hp - 240RWHP.
The 3000GT VR4 had 25% DL!!!! yowsa.
Integra GSR is roughly 17% (170hp and 137-140whp).
199X BMW M3 was 15-16% (240hp and 202-205rwhp).

It's not that hard to understand... each car type is different but they all fall into the same category.. 15-20%

myz350 is 100% correct on his formula for calculating crank horsepower from rear wheel horsepower. If it were a 15% loss, you would see 230/.85=270.58. Wait till you break in the engine, then you are sure to see a gain.

If you add any type of mod especially one altering the air/fuel mixture in the car you always want to reset the ecu after installation. It will produce much faster results then letting the cpu try and figure out why things are different. Heck in my Supra I reset it after every run at the track. Especially if I made tweaks. Another thing you want to check is if that's the corrected hp #'s or not. Your run may seem low but if it was hot outside or if you're at high altitudes it would have a big impact on the #'s. Usually they put a corrected # on the sheet somewhere. Like 1.3444 or something. I believe you take your #'s and multiply by that # to get corrected figures. Check your sheet again and see what the temp and altitude was.

What's the baseline whp of a stock Maxima or Altima on the dyno?

Umm thanks we all finished 3rd grade and know how to calculate %.

My problem is 20% loss which is too much for any car, especially manual.

Umm so looking at your figures, you should agree with me that 20% loss is too much for any car. You would think that there would be some improvement from the Z32 no? If 1996 M3 which is also RWD managed to loose 15%, why is 2003 Nissan loosing 20%?

MR B. - 2k2 Altima dynoes about 204 HP at the wheels which translates to exactly 240 at the crank with 15% loss.
Now here's something to think about, maxima dynoes exactly the same and is rated at 255.

So basically there are two options:
1)Altima is loosing 15% and maxima loosing 20%
2)They both loose 15% and maxima was overrated, just like the Z!!!

I'd go with the second option...

Come on, face it, Nissan is lying to us and that's why the maxima guys are taking Nissan to court with a class-action. go to http://forums.maxima.org and you'll see the lawsuit.

Michael

Any by the way...
the G35 (not coupe) is rated at 260HP... and my friend's theory is that is's rated so to compete with the TL type S.

I think I concur with that theory. Nissan kinda screwed up by using the same engine in all their cars so now they have to use some creative marketing to go around the problem

I agree. The 350Z's engine is overrated...and what is up with the massive torque drop after 5000 RPM's? I mean with DOHC and VVT as well as a oversquare bore and stroke, keeping high RPM power shouldnt be a problem. I mean if a less efficient old technology OHV V8 can make power until 6600 rpms, I think the 350Z should be able to also.

About the VR4 losing 25%, that is actually good because all wheel drive cars may lose up to 35%. Think about it, double the actual drivetrain loss then double the loss through the tires.
GS-R's only lose about 20-25 hp bud. Dont know where you got that dyno of them putting 137, cause most Civic Si's with the smaller B16's put down about 137. B18C1's in the GS-R's dyno around 145-150. It's actually my car that is overrated (97-98's at least, the 00-01 like mine dyno a bit higher)- The Integra type R. ITR's in 97-98 only put down 158ish, which isnt nearly the 25 hp advantage that it is supposed to have over the GS-R. The rumor is that it is a combination of detuning from Japan and the helical limited slip.

Anyway, point is I agree that 20% is a bit much, but i dont think it's really losing 20%, rather it's not making 287 to being with. Nissan really should have put more agressive cams in it to make it make power higher in the rev range if they wanted the hp rating to be high b/c hp= (torque x revs)/5252. I would be driving this car already if it revved to 7000 rpms and had a flat torque band that didnt fall off at higher RPM. The advantages of high revving could be discussed but we wont get into that right now.

1996-1999 M3's were underated from the factory. Actually made more than stated 240 HP from the engine. So that 15% is a little low. I used to have one.

That's exactly my point. I don't think it's loosing 20% because its cousin Nissans don't, and I think it's overrated to sell it... In theory I think it should be identical to the G35c.

Mike, care to explain this?

https://my350z.com/forum/showthread....threadid=10654

Explain what? If you look in there, you'll see that I was like the second person to reply because that was the first time I saw those numbers.

So I know about this post. The thing is that I saw many more dyno's with 230 and like one with 240 so that doesn't proove much...

But as I said earlier then I was in 4th gear too and car not broken in. You think that's 10 whp difference? Maybe... I'm not sure.

You should really read the whole thing before you ask me to explain it... You go dyno and let's see what you get. If you get 240 I'll be happy if you get 230 I'll be correct :D

Also, how Sport Compact Car got 244 from a stock Z using 91 octane. They even got 249 by using 100 octane.

Link

Yeah they also got 5.8 0-60 and 14.0 1/4 mile @99, which is freaking slow so? All I'm saying is I dynoed my car and wasn't happy...:rolleyes:

I think the reason the Maxima is getting the same numbers as the Altima is the helical limited slip combined with the 6 speed transmission. These could easily account for the missing HP.

Also, a factor everyone keeps forgetting to mention is what type of dyno you were running on. Some dynos are a lot more pessimistic than others and seeing a 15 rwhp difference between dynos is not un-realistic. I will try and dyno mine as soon as I can and see what I get.. I'm anxious to see what it will put down.

Yeah...I noticed you were one of the first replies. That would be why I chose that ~240 dyno in particular to post:rolleyes:

The reason why I asked you to explain it is because you didn't mention anything about there being other cases BESIDES your ~230 run. You keep saying that Nissan is lying, etc. Obviously this isn't the case if people are getting 240 runs, including SCC.

You made a big huff about this and now you're trying to downplay it as just being unhappy with your dyno run? Okay...:rolleyes:

OK when you dyno your car we'll talk. There's more 230's here than 240's that's for sure.

I still don't really know what you want me to explain to you though?:rolleyes:

Next thing you know you will see people here saying that 243 HP at the wheels combined with 20% loss that some people here believe is normal... then you get over 300HP.
So wait - my bad Nissan probably just underrated the Z so it doesn't sell too good :rolleyes:

Basically, don't live in a small world, open your eyes, look at the other side sometime, maybe, just maybe, Nissan is trying to sell more cars:rolleyes: like Ford did with mustangs before and ended up getting sued and lost... and I think Mazda did it with miata before...

Anyways, we're all entitled to opinions here, I did my own dyno so I have my numbers to show for it, someone else did theirs and got more - good, there just way too many factors though.

Michael

Actually, we just want you to stop being contentious and show us dyno runs when your car is broken in. Getting worked up over what is likely to be invalid data is...a waste of time.

Regarding the ~230s dyno runs- that just might have something to do with others' cars, like yours, not being broken in. The 350z is a new model, yes?

I think everyone's missing the point here. Bottom line is the #'s in performance. If the car can do 0-60 in 5.4 or somewhere under 6.0 secs it's doing it's job. There are so many factors in getting a proper dyno it's not worth banging your head over a few hp. Like I said in my earlier post those might not be corrected figures you have. On top of that to get the most power in your dyno you should be running a bag of ice on the motor with the fan blowing through the front. There's no way those dinky fans can simulate winds @ 100+mph of driving. If you think a 20% loss is bad try my Prowler for size. I lose over 30% to the wheels cuz of those bloody 20" rims on the back, rear tranny, auto-stick, POS. But the car looks PHAT as hell and it pushes 0-60 in 6.0 and it cost me way more than a Z. I'm almost willing to bet your numbers aren't corrected. If they are you're getting poor cool down while dynoeing.

These guys claim to have gotten 272 HP at the wheels, the article is in french but the dyno is clear enough:

Linky link

Based on 272HP they calculated 318 at the crank which means they used 14.5% as their drivetrain loss value.

Go to www.freetranslations.com if you want a rough idea of what they are talking about in english.

I dont know if it gives an accurate translation, but some of the sentences seem to make sense. :D

Yeah, I had actually already done it and posted it on 350zmotoring.com but I got lazy. Here's altavista's translation:

------------------------------------------------------------------------------------
Introduction:
Here an exceptional sports car, Nissan 350 Z This pure sporting represents the quintessence of the sports car Japanese woman. Superbly racée, the 350 Z shows with all the car industry that a sports car can be very advanced from the technological point of view while remaining accessible. Offered in the versions Performance, Tourism and Impulse, its price varies between 45 000 and 51 000 $. Our model of test are the 350 Z Impulse and its value is 46 500$.

Interior Installation:
The 350Z is pure sporting. Thus, to support road stability it is very low. Obviously, when we took seat in the car, we were not astonished owing to the fact that that is a little hard. With regard to the seats, they offer an excellent support for the people of small size. However, it is another history for the large people. These last will deplore the lack of support for the legs and the narrowness of the file. This defect makes obviously so that the seats become uncomfortable at the time of the long distances. Even in sporting control, the head offices of Z do not achieve the work which one awaits oneself from a car of this type.

As regards the dashboard, its presentation is neat. However, its stylism is too sober although it respects with the letter the characteristics which one must find in true sporting. The large dials (which are adjusted thanks to a clinometer, i.e. the dials follow the movement of the wheel when you adjust it) are very well thought. They are placed at the good places and are easy to consult. However, when we threw a glance with the central console, it is another history. The plastic panels are difficult to open and once opened, it is easy to note that their quality is doubtful. Another negative point, the quality of the stereo chain is very debatable. Moreover, its position is too low and it is difficult to handle.

Concerning the back trunk, the forage ladder of the 350Z is immense. However, it is where the vastness stops, because the trunk offers hardly enough space to put some bags of grocer at it.

Road Test:
Acceleration: Nissan 350Z is propelled by a superb V6 engine of 3,5 liters. Very powerful, it develops 287 horses with 6200 tours/minute. Accelerations of Z are formidable. Imagine, the zéro-100 km/h was realized in 5,77 seconds. It should be said that the engine of six cylinders is coupled with a transmission with six brought closer ratios which are of an exemplary precision. However, we would have appreciated a little more softness. But, in term of performance, the 350Z is a true bomb.

Slalom: Nissan 350Z is provided with a direction with pinion and toothed rack assisted according to the engine speed. During the test of the pylons realized with 50 km/h (to imitate a sequence of avoidance of obstacles in urban circulation), the 350Z literally swallowed the cones. We had the impression to walk us normally so much it was easy to avoid them. The 350Z answers the least requests of the driver. That proves obviously that Z does not have only the temperament of sporting, but also the behavior.

Avoidance of obstacles: During the test of avoidance of obstacles, Z truly made fun of these operations. Although these last are extremely demanding for the brake and the suspension, Z is drawn high the hand. The direction of Nissan is fast and answers quickly. The brakes also are very well gauged. They are precise and react spontaneously at the requests of the driver. Put aside light understeering (which is completely normal besides since Z is a propulsion), the 350Z behaves in an exemplary way operates some urgently.

Braking: Nissan 350Z is provided with Brembo brakes 12,76 inches in diameter, whose front clamps are with four pistons. All this power enabled us to obtain an exceptional braking distance, that is to say 36,70 meters. The response between the foot and braking is instantaneous. Nissan 350Z is thus a genuine car of performance! [ Visualtech Data ]

You forgot the bottom part:


Power with the engine announced by the manufacturer: 287
Real power with the engine according to our AUTOSTOP/Visualtech results: 318.2

Power with the wheels according to our résulats AUTOSTOP/Visualtech: 272

Nissan 350Z Pulsion is provided with an extremely effective engine. Its power with the engine, obtained thanks to the test bench Visualtech, is of 318,2 horses. They is thus 31 of more than that 287 horses announced by Nissan. With the wheels, that represents a power of 272 horses. Formidable!

If you're not happy with your car or it's performance, you could always sell it to someone who will appreciate it with a few less HP than spec'd.

??s on dynoing for those who know.
- How accurate are dyno's for this type of comparison?
- Don't the pulls have to be very controlled? (RPM range, etc...)
- Are there settings that have an impact that may not always be accurately set? (gear ratios)

I had my car dyno'd about two months ago. I had 7 pulls and had 7 results ranging from 231hp to 244hp.

The guy that was dynoing my car picked from a number of different gear ratios, did he pickthe right ones? He had never seen a 350z sow how would he know? Did he dyno in the correct gear?I noticed that the starting RPM seemed to have an impact on the results. If the throttle was mashed at 1800 rpm, the HP curve was lower than if mashed at 2000rpm or 2200rpm. Also I wonder how quickly "pressing" (maybe slightly gentler than mashing) the throttle would result opposed to "mashing"?

The point is...I'm not gonna complain about my car because it performs the way I want it to and I don't know thatit's putting out less hp than spec'd, especially after the dyno's.

You guys gotta be kidding me... 318 :icon18:


Anyways, this is retarted. So many closed-minded individuals in one forum... That's right, Z is the fastest, the most powerful, the best looking, the best car in the world... And whoever disagrees with that should go right ahead and sell his - is that right sdpearso ?:rolleyes:

By the way, I said at the very beginning that the car was not broken in and it was in 4th gear so why keep bringing it up? And we also know that dynos vary and other things vary as well so why bring that up too?

Stillen guys dynoed the Z and got 230 - I trust they know what they're doing. And to the guy with the prowler I'm sorry, no offese (really) but don't compare an american auto-tragic transmission on a 20" rims to a Japanese car designed to perform!:icon8:

Bottom line is I do like the car and I'm not planning on selling it soon, but I'm just sharing information and opinions. If you want to argue - fine but facts are facts. Oh, and those frenchmen I'm not sure what the hell they're doing with their "tours/minute" s:D What's a AUTOSTOP/Visualtech :confused:

Guys your forgetting a key factor. the LSD. you guys have the viscous slushbox lsd which is definatly robbing hp. The mechanicals are definately going to show higher power.

Im so glad i got my base, to build upon as I so please!

Mike, I hear what you are saying and I agree for the most part. It just seems from what I've read here (and I didn't read eveything in this thread) that you are dissatisfied with your Z because of the dyno results you've seen. This seems silly for the reasons you agreed with above. Dyno results can and do vary and other factors play in.

I do like the Z (I'm a little biased since I own one) but I don't think it's the best car. Maybe the best car in it's class and/or for this price range. But I do want all the facts stated.

I'm glad you're not dissatisfied with your car. ENJOY!

VQs use sensitive knock sensors that retard ignition timing when the engine is run hard... this causes hp to drop when the engine is not running on a high enough octane.

So if you run it hard to the dyno or dont let it cool off before dyno testing then you'll lose some hp. After you break in try octane booster.

Post up your dyno graph.

Mike 821,

Let's get something straight. I was replying with info trying to help you in an effort to figure out where the lost power might be coming from. Secondly, you start talking about closed minded people and then go bashing the Prowler in comparison. You're the one that needs to open your mind up you hypocritical bastard. Many have offered reasons for a possible loss in power in response to your thread. You have failed to see those. You are the one complaining about a 20% loss so I throw out the fact that I own a car which loses over 30%. You criticize it. Put your fugly ass Z next to my Prowler at the beach and see which draws more attention. That's what I thought. No the Prowler doesn't perform as well as the Z but then again with your lemon I would probably beat your Z. That's all beside the point. Point is you started a thread about how you were dissapointed with your dyno #'s. So many offered explanations as to why this may be and that it may not be as bad as you think (in my case I said you might not have corrected figures) but you ignore that only to bash others with what seems to be in your mind a flame against you from everyone else. It's NOT the case. Read the posts carefully. There's a lot of good info in there that YOU are failing to see.