typeR

so...did you ride the limiter through the traps or did you shift into fourth

DomZ

I ride it thru, I still have ~2 mph left so I will continue to do that, but once I hit that point where I have to shift I'm going to need a decent amount of power to make up for the time the shift takes up....

95snoozer

or you can learn to powershift

95snoozer

you seriously need to chillout on the bench racing.

at least if you are going to try to compare, know the variables and how they relate to where a car accelerates. if you would look at them, there are BIG differences between your car and theres. you comparing me

Alberto

iTrader: (14)

Are you referring to Dom's last comment about the time it would take to shift from 3rd to 4th? Hes auto....

typeR

im not following you...im simply saying my car gained 24.5 from the 1/8th to the 1/4 and it used to pick up 21-22 ...im an auto and now i cross the 1/4 at the top of my rev band and am asking where does the Z cross...all im doing if prviding possibilities that the auto 350Z may also be capable of gaining 23-24 from the 1/8th to the 1/4

JonsilvZ

No wonder Ive been getting those slow times! I always go into 4th in the 1/4.

Dave B

iTrader: (2)

I don't know where to start. First off, I've read posts and your work done to your CL-S on the Grand Prix site. Hi!

You have a 3.2 CL-S with a 3.5 liter motor so clearly you did the 3.5 short block swap from the Odessey like you said your were going to do a while back. You state that your CL-S is a heavy 3,700lbs which I find hard to believe because the 2001 CL-S auto is listed at 3,500lbs in every publication I've found, including Acura sites. You've removed 150lbs in weight including 50lbs in rotational weight. On the scale, you're CL-S is pushing about 3,300-3350lbs. You're massive weight reduction in wheels leads me to believe you're possibly running drag tires/rims and most likely shorter ones at that to improve the Honda 5ATs horrendously tall 1st and 2nd gears. The fact that you're crossing the line 1000rpms higher in a tall gear also leads me to believe you've added shorter tires. You're CL-S is far from the norm compared to other CL-S and is sporting a power to weight ratio higher than the Z auto in question.

I must say though, you're power to weight in respect to your finishing MPH doesn't make much sense to me. That's an awefully high MPH for so little power. LS1 F-Body autos with 300whp/310wtq, 3,300lbs, and a crap load more power under the curve don't see that kind of MPH. Either there's more power in your car or it's way lighter than you're telling us or you've got a trapspeed friendly track.

I have a friend with a 01 CL-S with headers and an intake. His best is a 14.6@98mph with an upper 2.2 60'. I'll admit it, his car does have extra ordinary topend. He gains a crack over 23mph in the last 1/8. Why? That 1st and 2nd gear is so long that it makes his low torque CL-S a dog in the first 1/8. He can barely get 75mph in 1/8 and his 330' is really slow.

In the end, your CL-S is not representitive of a normal CL-S. Much like the 24mph this 350Z auto gained in the last 1/8. It's not the norm. There aren't factory freaks in this day and age of automated precision engineering. What is variable is track timing equipment and conditions, specifically density altitude. Good or bad air (regardless of elevation) can mean the difference between running .5 seconds and 4mph fast/slow in cars of this power.

Dave B

iTrader: (2)

Actually, the rev limiter is truely at 6600rpms, it's the tach that is off. My G35 tags the limiter at a crack over 6800rpms though every dyno I've seen for a G/Z clearly shows the limiter right at 6600rpms.

My G35 has the same gearing as the 350Z auto and the same tire height (26.3"). I tag the limiter in 3rd maybe 100 feet past the finish line. Calculating top speed in 3rd (3rd gear 1.471:1, 3.357:1 rearend), we're looking at about a 105mph. However, the gear isn't truely mated to the output shaft and doesn't account for torque converter slippage. Factor in about 4% for torque converter slippage and you're looking about 101-102mph in 3rd at 6600rpms.

typeR

hey yourself...first to clear one thing up weight:i m quoting weight with driver...im 210ish and yes my car starts out 3510 and yes ive removed about 150 lbs 50 in the wheels these are SSR competetion 17/8 at 14.3 lbs...i run on 235/45/17 toyo T1-S and this is ever so marginally shorter than stock at 25.3 from 25.5 215/50....if you ve seen my dyno ,realize as i mentioned thats old and ive dyno'd after my 13.30 run at 257.1/231.5 but the Cl has a very flat torque curve with probablly 200 available at 2500 rpms and 95% of the 232 from 3300-6500 with a 7100 fuel cut...i trap 81 concistantly at my local 1/8th mile and traped 81.43 during my 13.30 pass to a 105.83 and these were with a mix of 2.0 and 1.9 60's

typeR

its his 60 ' thats killing him...tell him to learn how to launch that thing and when he gets his first 2.0 60 hell be going 9.3 at 77 to a 14.3 at 98 on a good day(cold) could theoretically see a 14.1

95snoozer

what i am saying is your cars arent very alike to compare anything.

curves arent even close, the z is linear anbd yours flattens out. geraing is also very different. crossing at peak or redline changes the game.

you car is all topend btw.... thats horrible 1/8 mile mph... is probably due to a long 1st and or 2nd

back when i was running 12.9 at 105 i think i was trapping 83 in the 8th. my 60s were in the 1.78-1.8s on bald tires and i have a crazy short 1st gear of course. 3.73 rear gear with a 3.35 1st.

DavidM

Actually, the rev limiter is truely at 6600rpms, it's the tach that is off.

No, the tacho is not off ... it's the same tacho that is in a manual 350Z and in there 6,600rpm is the redline/cutout. In the auto cars 6,600rpm is only the redline, while the cut-out is at 7,000rpm. Speak to to your Nissan and they'll confirm it for you.

ps. There is no dyno that can read your engine revs. Whatever you see displayed on the screen/printout is extrapolated from the at-the-wheels figures and multimplied by number of constants that are entered on the dyno. So if you run a 350Z auto on a dyno that is using the variables for the 350Z manual, then the cutout will be shown at 6,600rpm even though it's really at 7,000rpm.

BriGuyMax

iTrader: (4)

That is COMPLETELY wrong. On a dynojet there is an RPM pickup that is clipped DIRECTLY to one of your coil packs. It's reads rpm straight from the coilpacks which is MUCH more accurate than a factory tach.

dcmaxclub

iTrader: (12)

well, since you guys are talking bout tachs and fuel cut off...

is the trip computer (where you set the shift indicator) more accurate than the tach?

DavidM

That is COMPLETELY wrong. On a dynojet there is an RPM pickup that is clipped DIRECTLY to one of your coil packs. It's reads rpm straight from the coilpacks which is MUCH more accurate than a factory tach.

I'll take your word for it as I have not heard of anything like that. I do know that some data-logging systems can record revs but it's a pretty complicated and complex method to wire it in.

How would a dyno pick the revs from a car? I'm not sure how it would read revs from 'coil packs'? Also would this work on every car? I'm interested to know as a few guys who have the 'data logging' equiplemnt I mentioned have a hard time getting a consistant revs reading from the engine.

Still, the all the dynos and dyno-sheets that I've seen come by default with a speed reading along the X-scale as the dyno reads speed from the wheel/tyre rotation. Then it can 'transtate' this speed into revs via the internal calculations/constants as I mentioned before. Have you got any links to information the dynos that you mentioned? I'd like to read up on and see what they do and how they work.

ps.
Even if there is a dyno that works as you mentioned that does ot make me 'completely wrong'. It would make me wrong for the dyno you mentioned, but it'll still make me right for all the others.

BriGuyMax

iTrader: (4)

The dyno reads pulses from your ignition (in the Z's case from the coils). Every 2 revolutions of a 4 cycle motor equal one spark per cylinder. Therefore it's a very simple math formula of multipling the spark pulse signal by 2 to get instant engine rev information.

I'd say the Dynojet brand dyno is the most widely used in the United States, and all their models come with an RPM pickup . I'll give you a link to one with the specs, you can clearly see the Ignition Wire Inductive Tachometer Pickup Leads listed as one of the features.
http://www.dynojet.com/automotive_dy...dyno/index.php

Another rather common dyno is the Mustang...and looking at their website, their dynos have the RPM pickup feature too.
http://www.mustangdyne.com/Options/Smartach.htm

The Dynojet and Mustang account for over 90% of the chassis dynos in the United States.

Nice try...but you're still wrong. Find me a dyno manufacturer that DOESN'T offer any RPM pickup feature and you may be able to salvage some of your pride. Maybe next time do some research before making a statement about something which you no nearly nothing about. That alone is my biggest pet peeve on internet forums. People spout off about a subject which they have nearly no knowledge of the subject matter.

Dave B

iTrader: (2)

Thank you, Brian.

As for on-board logging and not using rpm pickups off the ignition, I use my OBD-II scanner to datalog my runs. I can datalog my rpms during a 2nd gear run and if I run into the rev limiter, the log says the ending rpms were 6600-6650rpms though the tach clearly indicates 6800-6900rpms.

DavidM

The Dynojet and Mustang account for over 90% of the chassis dynos in the United States.

Thanks for the links I will read the, ASAP. Though, do any of the dyno operators use these RPM pick-ups?

Nice try...but you're still wrong. Find me a dyno manufacturer that DOESN'T offer any RPM pickup feature and you may be able to salvage some of your pride.

All the ones that I know here. Majority of them are "Dyno Dynamics". I didn't think that they cvould read RMP, but I know for sure that even if they do, then that is never used. A lot of the dyno-printouts/displays here show you speed along the X-axis, but they can 'convert' to RPM via the calculations/constants as mentioned before. here's an example (and just happens to be a 350Z):

DavidM

6600-6650rpms though the tach clearly indicates 6800-6900rpms.

All the automatics 350Zs rev (on the tacho) to 7,000rpm ... not a little bit under but spot on 7,000rpm. Also all the dealers here are aware of the auto cars reving to 7,000rpm instead of 6,600rpm.

I'll be surprised if your autos are different in this regard as I've seen a fair few people on here comment on the 7,000rpm cut-out for the autos.