370Z 7 Speed Auto Review
 

I promised a review of the 7 Speed Auto. Lets start with the bad news.

The Dyno.
I've attached an overlay of the Dyno pulls I did this weekend. The best number we could get was 269. That equates to about a 22% drive-train loss as compared to the 6spd manuals 15-16%. However, if you look closely you will see that the graph ends at about 6,500RPM. For some reason the engine was not allowed to rev over 6,500 (the ABLS?) and in some cases much lower RPM. I would like someone else with an auto to get on a dyno and see if they have the same result. This will make tuning almost impossible. This 6.5 limit DOES NOT occur when all 4 wheels are turning...on the street.

Now for the good news.

M-mode shifting.
M-mode shifting is everything it should be. The computer only takes shifting away from you at the very bottom of the RPM range; just enough to keep the engine from stalling.

On the way up the gears shifting with either the stick or the paddle works great. It WILL NOT MAKE A SHIFT FOR YOU. What else can I say about the shifting? For once the M-mode auto works the way it should.

I think I've noticed a difference between the paddles and the stick. It seems that paddles shift faster than stick. It's even more noticeable on the way down the gears.

The throttle blips for down shift rev-matching are AWESOME. It's like music.

When I first started driving I thought the 1-2 and 2-3 shifts where too soft. Since then it feels like they have tightened up considerably and now a max RPM shift can snap my head back. Overall I would say the shifting in M-mode is firm and sporty and the shifting in D-mode soft and predictable.

The power transmission feels great all the way to red line, in spite of what the dyno says. I don't feel like 332 is an underestimate of power. My guess is if the 370Z 7 Speed auto were allowed to rev to red-line it would make every bit as much power as the 6 Speed.

Back a little further though my lack of a Limited Slip is really showing. It's hard to get much traction at all coming out of turns at speed. Definitely need a limited slip.

Feel free to ask any questions about the auto if I missed anything.

According to that dyno, the AT is losing more power than I thought it would. Any thoughts on this?

didnt injected pull at 258 stock?

I think that was on a mustang dyno.

does the car rev beyond 6500 rpm on the street?

We saw 258-261whp stock. But that was on a Dyno Dynamics when the car had 499 miles on it. We typically see Dynojet numbers come out to be ~12% higher than our dyno.

But as I'm sure many other people will reiterate, there's no "good" way to compare two dyno charts on different days, different dynos, etc etc. Ideally, we need to see a 6MT and 7AT back to back at the same place.

I don't think you can make a determination at all until we understand why it can't rev over 6500 because it hasn't achieved max HP at that RPM yet. Do you see this limitation on the street as well?

It revs all the way to red-line on the street. There are only two possible reasons that it won't rev beyond 6,500. Either the ABLS is grabbing it or, the guy sitting in the car was afraid to push to 7,500. Either way on the street it drives perfect.

I think the power loss you are seeing is 100% the 6,500 rpm problem. I would guess that if I could have rev'd to 7.5 the result would of been about 280-285 but, that is just an interpolation of the graph we have.

Probably be a good idea to look at what similar dyno's on the manuals show at 6500.

edit: looking at some of the Dyno charts in the Forced Induction section, the base lines look around 8 to 10 HP down at 6500 rpm compared to 7500. That would suggest your's would be 275 to 280 HP if your dyno pull went out to 7500 rpm.

^I am sure you are correct...

Agreed, if you look at your chart at 6,000 and compare it to the baseline in this thread here: http://www.the370z.com/intake-exhaus...whp-18wtq.html you are within a few horsepower of the manual transmission car in the thread. That would lead me to believe the difference isnt that much. We really need a clean dyno pull to be sure though.

Thanks for doing this dyno—rep points dynoed your way!

Agreed to all. The 6500RPM would definitely be the problem, but of course, we'd STILL need the pulls to be done on the same dyno machine and on the same day as the the MT pulls to see for sure.

However, my guess was that the AT would only be about 7HP less than the MT (due to the new type of torque converter) and I'm still confident in that number. I look forward to the real results.

Great info thanks.

Would like to see how this power + 7AT translates to track times.

SO WOULD I :driving:

Hi JoeyD - any updates on your auto? e.g. track times, re-dyno? Thanks!!

I haven't had a chance to do much of anything with the car. There is an auto-x event close to me March 28-29. I'm going to try and get out to it. As for a dyno pull...I'm not getting another base-line pull done unless I have a 6spd to do it with me.

is this your first AT ever? how are you liking it? i remember when i bought my first AT and was so excited, by the time i got back from the dealer to my house i was like "**** i gotta get rid of this ****", then sold it in 3 months

^I'm heading down that road. It's great in traffic and the paddle shifters are a lot of fun. But, I plan on keeping this car forever. When I get it paid off I'll buy something new to drive every day and have this car as my tinkering toy. When I think of what I want in a toy I always return to a manual.

:werd:

Yep. I've already contacted a few dealers about trading. Problem is I kind of blew my wad on buying this car. The dealers want me to take a 8K loss on it already, and I just can't afford that.

The good news is that my concerns are totally based on me thinking I might change my mind in the future. Right now I love driving the auto. The reason enthusiasts prefer manuals is bescause it allows proper gear selection and predicatable shifting. This auto does the same thing when in M mode. You just have to convince your left foot that it likes doing nothing. Hopefully I will get to auto-x next month and have some more insights on the auto.

did u buy or lease? in either cases DO NOT go to dealer for that. they will rip you off. go to a private party. i lease my cars so when i wanted to get rid of my 335 (the auto one) i had a friend take over my lease.

whatever it is man, it is not the same. i dont care how fast i just cant enjoy it. even the sweet dual clutch transmission on the M3 isnt good enough, or F1 trannies on nicer cars... i also hate the idea that there's software that controls my shifting lol. disturbing!

try auto trader, or ur own community (friends, or even online forums)

good luck man

xoible - how are you likeing your M3 coupe? I am also considering a used 08 DCT in silverstone 2. I was lucky to test drive an 09. Felt good but didn't feel any power until you reved up high. Def less torquey feel than the 335 coupe.

Are you considering 370z?

Thanks

I am loving mine. I had a 335 before (and was chipped too) but i would never take the 335 over the M (steering, handling, throttle response, suspension, chassis, transmission, quality, etc.) Mine is a manual though.

In a 335 u get a lot of low end but once u hit 5k RPM the pull dies down for sure. in the M3 it's a slow car until u hit 4-5k RPM then it becomes very quick. It might not feel as fast as it is, the speedometer will keep jumping very quickly but u dont feel the pull u feel in turbo. unless ur like me u like to do 3rd gear pulls on the freeway from 80 to 110 mph.

the problem on test drives is they wont let u rev past 5k RPM. so hook up with ur local BMW group and have them show u around. the car feels amazing. The engine is a masterpiece for real. response is crazy on that thing! M3post.com is an awesome place for info and meets

I need a small quick car that's a bit fun. im putting too many miles on my car and i have to travel for work, so i thought of picking something up. I looked into Mini S, STi, S2000, 350Z, 370Z, Z4M and i have a few more on my list like Evo X. The 370Z is one of my top choices but the lease deals right now are looking too close to Z4M which is one of my favorites too (except it's very rare now). But then i have this inner-struggle coz i think the STi is the most practical and since i live out of my car i need a trunk + i snowboard a lot.

xoible - thansk for the info. I wish I could have felt that power after 5k rpm :)

I was very impressed with Evo X MR (dct as well) but just not sure about living with the styling. STi wasn't bad at all - was very close to picking one up when they were selling $10k below msrp over x-mas.

Good luck!

oh i can live with the styling, but cant live with DCT lol. thanks for your wishes.
yah some dealers still have the 10k off.

sorrh, but it is very informwtive
 

:) genuinely absorbed by this website

Im glad you think so too cuz I have thought the same thing, so when Im really racing someone I use the paddles and not the stick shift. Dont know if its suppose to be that way or Im just crazy but..

For track purposes, AND for young ones like youse guys, the bad news part may be disappointing; but this old man's in love with his Z's 5AT, 'cause I ain't crusin' for bruisin'; rather, I enjoy my old '04 Touring Coupe as a 60-year-old should. Cheers!

sorry, but it is very Important
 

Awesome! I think you should do an entirlly custom base, though. Like mine.(I havent acquaint it yet.) Not to be rude but I would like it absolutely custom. still great, aiir-conditiopned, good and, a lot of importantly, ALARMING!

Was the RPM limited due to the speed electronic limiter?

The ratios for the 7AT and the 6MT are a bit different enough where that could have happened.

Hell with track times...line up a MT and AT and have at it. Be safe though. 8-)

At the 1/4 mile drag the 7 AT will be faster, at least with my car.

I agree. I have an MT. My gym partner has the 7AT. I have driven both... and I feel like the 7AT is faster in a straight line easily.

Hopefully some time soon they will do a chip for the trans too and make the shifts faster and allow it to redline. On my other 6AT DSG car they came out with a chip that allowed M mode to stay the same but we also had a S mode and they made that faster and into redline. We also had the paddle shifting which was made faster too. Now we dont have the S mode but they can make the shifts faster and allow it to go into redline and we should see max HP and TQ then.

I am waiting for my roadster with 7 AT ;)

Is the ECU modified in this video ??

YouTube - ketosi.com nissan 370z test drive

I am not clear about when the car is not going all the way to redline. My 7AT redlines in any gear and is so much faster than my 2004 Base model 6MT 350Z ever was! Is it just on the dyno? Maybe a traction control issue?

Which vw did you have? I traded in my gli for the z.

I had the Audi 2.0T TT, very nice car but just not fast enough and I didnt have the $$$$ for the TTS so I got the Z which Ive always wanted and its a good bit faster even with the $3k in performance parts I had on the TT.