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

 

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...

 

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

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...

 

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?

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

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 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.