While browsing the FAQ section in the stickies, I took a look at the stock whp numbers for the 5th gen, which indicated that whp is about 190 for 5 speeds. This is a 14.4% loss through the drivetrain. So seeing as how I own a 6 speed, I became curious about the power my car actually gets down to the wheels. Using the same efficiency for the 5th gen, I figured it should be around 218.28 whp.

So I started looking around the track & tune and dyno boards, but couldn't find anything for a stock 02-03 6 speed. After searching, I only found a few posts in the 6th gen forum regarding the subject, and the consensus there (of about 2 people) seems to be that the 5.5 gen 6 speed gets about 204 hp to the wheels. Unfortunately these are the only STOCK numbers I was able to find. This is a remarkable 20% drivetrain loss, which I thought was more synonomous to an auto tranny?

Does anyone have any real info on the stock whp for the 02-03 6 speeds? If this is true, why is there such a HUGE decrease in efficiency for the manual transmissions from the 5 speed to the 6?

Appreciate your thoughts.

 

Try checking the dyno forums for more information on other 6MT's.

You are not seeing the entire picture here. Peak numbers do not mean much. The A33B has much more area under the curve.

Also, 190 whp on DEK is unlikely stock, very unlikely.

 

I decided to take your advice Nmex, and came to find that you frequent the Dyno forums as well. I have to say, I'm really surprised at what I found. It seems to me that after reading quite a bit, the 5.5 gen dynos show surprisingly similar results between automatic and manual transmissions. What's more discerning, is this is not the result of newer and brighter technology making more efficient automatic trannies, but rather the result of a shockingly inefficient manual tranny.

If you look here:
http://forums.maxima.org/showthread.php?t=473771

You will find a dyno slip of a stock (the red line on the chart) 02 6-speed that reaches a peak of only196 whp. That implies a drivetrain loss of 23.14% . I find this number is outrageous and egrigious for a manual transmission, and it leaves me disappointed with Nissan. On the other hand, the consensus among the forum has said that 204-206 whp is more typical of a stock 6 spd, but that's still about 20% DT loss. Another thread discussing the similarities between the stock whp for the auto and 6 spd:
http://forums.maxima.org/showthread.php?t=357244

Bottom line, the 5.5 gen manual tranny does not necessarily put more power to the wheels than the autotragic. Leaves me disappointed, this is one of the reasons (thought there were many) I got a 6 spd .

All I can say to Nissan is
A MT that's as efficient as a AT is

Nmex, I am unable to find any dyno charts comparing the stock 5.5 gen 6 spd with the stock 5th gen 5 spd, any ideas where I can find them?

 

But the gearing is better. Closer gears, and better highway spirited driving (6MT vs 4AT)

I've got a decent size database of dynos, not at work with me a the moment. PM me with what type of set-ups you would like to see comparisons of.

Sadly enough, I do not have many stock runfiles, but I bet I can find something that will show you the defference under the curve.

 

you also have to realize that nissan over rated the 5.5 gen's HP figures and underrated the torque. They publicized 255 hp and 246 tq. yet we are making a little over 200 WHP and around 220 WTQ...

Also, you are going to see a bit more DT loss with the 6-speed than with the 5-speed because they are heavier.

 

You're assuming that the advertised 255 crank hp is correct, but that may not be the case.

We do however, have a 30+ lbs flywheel, so that explains some of your estimates.

 

Explain heavier.

Weight has nothing ot do with DynoJet readings.

 

Does the 5.0 have the same heavy dual mass flywheel the 5.5 comes with?

 

. . . . . . . . I thought you would know this.

 

maybe he means heavier gears? maybe thinks that because it has 1 more gear theres more rotating mass. i think thats not it though, only 1 gear is spinning when engaged, so unless the gears themselves are heavier its not about that.

 

I don't know LA02MAX personally, BUT, I have seen what facts (DATA) he has posted in the past...therefore, I know he knows he's posting about. So, essentially, he knows is up.... IMO, don't question him.


Ok....So...., back to your post, I know he(LA02) DID NOT mean heavier gears, but merely, heavier, in a sence, such as greater mechanical energy to move said tranny piece.

So, common sense would prove once again,......

 

This would be great if you could post this up. Unfortunately, though I browse these forums a lot, I'm not very confident with 5th gen mods and what they would equate to for 5.5 gens. I would say anything that has a similar setup, but I know there are little quarks here and there, like a y-pipe will give different gains for a 5th gen than a 5.5 gen. So if you could post up any two dynos where the modifications provide similar gains, that would be good too. Appreciate your insight into this.

I did read a few things about this point that you and LA02 brought up as well, but what confused me was that it had been said that the Auto 5.5 gen max was making around 195 whp, which given 255 bhp would by 23.5% DT loss, which seems right on par for an AT. I didn't, however, find any dynos to prove that this is true, however, in all the dynos I looked at yesterday, it did seem true that the 5.5 gens whether stock or modded were always putting down more wtq than whp, and by such an amount that it would seem the torque is understated AND the hp overstated to make up the gap. So all of this left me unsure of what to make of the underrated bhp idea.

 

I didn't think it did but I wanted to know for sure. I have a 5th gen also but it's my wifes car and an auto. I'm not allowed to play with that one.

The weight of that flywheel could account for some of the driveline loss. Also if the car tested has heavier stock 17" wheels that could affect it. The extra rotating mass of the wheels and flywheel could be enough to affect the numbers.

 

http://forums.maxima.org/showthread.php?threadid=166163
I'm sure everything you want to know is in that 20 page thread.

 

Let's sue them for the 15 hp, and pay them back with the extra torque they granted us.


Area udner the curve.

 

well I remember reading a long time ago that the maxima's 5-speed tranny has only 5 sets of meshing gears while the 6-speed has something like 8...that plus the nearly 10 lb. heavier flywheel would most likely account for more drivetrain loss for the 6-speed due to the weight I would think something that substatial would be reflected in DynoJet readings, right?

 

I knew I could get the explanation out of you.


My point was that your post was vague, and I took it the wrong way.(purposely) Such as thinking that the overall weight of the vehicle would not affect the readings, but you calrified.

 

no problem, I don't mind explaining my statements from time to time

 

well the specs i saw showed 235whp and my car runs like never had it a dyno test done it but from what yall saw i dont want to find out if it doesn't

 

 

only a blackbirdVQ type maxima SE-R

 

No run files no care.