So i logged my first few 1/4 mile runs and thought I was slower than I could be. I want to know how other 6th gen's launch/run the 1/4.

Here's my setup.

06 Maxima 5 spd auto
Fujita Intake
CE y-pipe
Conti Contisport 225/55/17's(stock tires)
44 Degrees
Damp ground/light on/off drizzle.

I tried just hitting the gas and also brake torquing @ 2500-2800

On the two runs I hooked up decently on I managed 14.3 back to back with a 0-60 of just under 6.

I figured I would be alittle quicker but admittedly have never tried timed 1/4 mile runs and I'm sure I can launch better. I would also think the tires are killing me a little but the low temps probably help.

So pretty much how do these runs stack up. How much quicker can I expect to be with better technique. These are average numbers for stock as far as I'm concerned.

Thanks!

 

Telling us a 14.3 doesn't help a whole lot. We need more than that. For example, 60' times and trap speed. Better yet, just give us everything on the slip.

 

Anyone who wants 1/4 mile help is required to post the entire timeslip. Without that no advice can be given whatsoever.

 

Yeah trap speed and 60-footers are especially important.

 

I think he is saying he used a G-tech timer (or something like it) since he only lists E.T. and 0-60 times.

 

Since he says 0-60, that leads me to believe this was Gtech run.

 

Sorry, I should have stated that I was using computer software and not at a strip. As soon as the tires start to move the timer starts. I've heard that you get slower times this way because you don't have a rollout. The program is very accurate in my opinion. I'll attach one of my graphs, it doesn't show a 1/4 mile on it but the blue run was a 14.3.

 

So how do you know it was 1320'?

I do similar analysis, but only use speed, since it's much too difficult to calculate distance with such factors as tire spin etc.

 

There is a access road behind the airport that has been used for years to drag. It is pretty well known how far the 1/4 mile is at this point. The timed runs match up with the markers. Also the good runs where done with little slippage anyways so even if the spinning did inflate the numbers it would be 5 feet max.

 

Distance vs speed with respect to time is what you're after.

I'm guessing the software is talking to the VSS, in which case, the 5' would not be pertinent and no inflation would be noticed. This is because you're only getting data from the VSS, and not say an actual distance readout. Distance can be figured from time & speed, but would be irrelevant due to any spinning and also be somewhat cumbersome due to the nature of the test performed.

Also, how do you know to 'stop logging' at said 1/4 mile distance


Not an irrelevant test by any means, but IMO, these types of tests are better for comparing your own mods/tune rather than comparing 1/4 mile times & traps to other A34's around the country.

Considering the calc you would need to go from in order to figure out 60', 330', 1/8 mile, E.T. and not have it 100% accurate (spin/ & other misc) I would just go to a track.

 

IMO, the track is the only legitimate way to conduct 1/4 mile testing.

 

this is a commandmant from .

 

What is VSS, in my experience it's Vehicle Security System. I assume you mean something different. The software connects to the ECM and gets all it's pertinent data from it. Once the system registers it's gone 1/4 mile then it stops logging. It gives time and speed at 1/4 mile plus 0-60 and some other crap I don't recall.

As far as going to the track that's not going to happen any time soon. Maybe Maxus if it actually happens. My new tires and rims will be on next week so I guess I can compare it to the runs I just did and what I'll do this weekend. I'm not saying these numbers are perfect/concrete but assuming they are correct aren't they alittle slow? I would think I could be 14 flat running the way I am.

 

Also, have you looked at the run files I sent you. I have a bunch more if you would like. I'm interested in a second opinion givin my amatuer expertise.

 

Nothing beats the actual track. Without knowing you 60 foot or 660 or actual trap speed and ET its pretty hard to get better.

 

VSS = Vehicle Speed Sensor.

Does this unit connect to the ECU or the OBDII slot?

 

It connects to the OBDII and reads the ECM, TCU, etc...

 

It's not accurate for 1/4 mile testing too because the sensor is giving you a time which excludes reaction time. The power of the car is a huge factor in 1/4 mile times, but RT and launch are just as important. Given your 14.3 with a monitor, I have a feeling if you go to the track, you're going to be dissapointed with first few passes until you get your launch and RT down to a science.

 

RT has nothing to do with 1/4 mile time.

 

like nmex said, your RT does not affect the 1/4 mile time in the essence of ET

 

Okay so aside from the it's not completely accurate, how can I improve my launch to lower my times. Is it best to rev it to 2500 and let of the brake or should I just hit the gas and go? Also how much wheel spin is okay. I realize to much and you just spin but also if you let of to much then you bog the engine and lose alot of momentum. So how do you know enough is enough?

So more than anything what are the keys to properly launching a 6th gen auto?

 

I don't 'powerbrake'. I let it sit just above idle (900-1100) then nearly feather it, then let it rip. My mod list is different from yours so results will vary. I tried this using my software and saw gains.

I first got the 'hair above idle' from Jime. This was prior to him getting his TQ converter.


Play with different set-ups and see what works with you & your car.

 

What track do you race? Maybe you can educate me and everyone else as to why RT does not affect 1/4 mile ET? My very rudamentary understanding and experience at the track is that the clock starts when the light on the tree turns green, not when you leave. Here's the perfect scenario - you leave exactly when the light turns green or an RT of 0.0 and you pass the timing beams at 13.0 seconds. Here's a more likely scenario...your eye-foot timing is normal and you have a RT of at or just under .5 seconds and you pass the timing bars at 13.5 seconds. And here's an example of what happens to most their first few passes at the track...you nap nap on the line for nearly a full second and you pass the timing beams at 14.0 seconds. How does that not affect ET???

 

The timing lights (E.T.) don't start until you cross line y.

Simple as I can put it... From x you go to y, this difference is RT, from Y to Z is your 1/4 mile ET.

You can have a 90second RT, and still run a mid 13.

 

But you'll lose .... that's what confuses people, I think... "If you snooze, you lose".

 

You are wrong.

You can sit at the line for 12 hours after the light turns green and then go down the track and still recieve a 14 second timeslip. The timing doesn't start until your front tires move out of the staging beams.

 

So you're still using the stock TC? Are you using sticky tires, and what are your 60' times?

I'm just curious, because I'm still having launch issues with 2800 stall, 23/8.5/15 M&H slicks, and smacking a 75-shot on launch just doesn't hook up right. Maybe these 12" Hoosier Ebay slicks will help...

Comparing 60' and 330' times might be helpful..... My PB slip is in my sig...

 

We'll I'm going back out tonight and hopefully I'll get another 6-10 runs in. I'll try a couple @ 1000 & 2500 and see what works out best. It's been 70 and dry for two days so hopefully I can hook up better. I want to get at least 30 more runs before the new tires go on next week. I think they will make a big difference.

 

I don't race, I do the logging like said poster. Come'on man, race @ mile high elevation

BUT...
I did notice a better 0-30 MPH using that method vs 'power' braking. 0-20 was inconclusive due to tire spinn'age' so 0-30 was more accurate. I don't have a way of calculating distance so speed is all I have, though it may be incredibly inaccurate.

 

What are you using to record your speed NmexMAX? I did 6 runs today with just hitting the gas and they where all consistent 14.6's. Next time out I'll try your suggestion of 1100 or so and see how that pans out.

 

Thanks for the education Neal. I stand humbly corrected. I guess it only matters if you are bracket racing.

 

Cipher & PLX R300.
PLX is mostly only for wb readings.

 

WTH is Cipher. I saw that mentioned on the 350z forum yesterday for the first time. I guess I could look it up but I've got to get back to work.

 

http://www.uprev.com/products/cipher_NI.html

 

It's an expensive Autoenginuity that samples faster since it uses the Consult interface.

 

What are your sample rates, ie.. if you where to log RPM, Throttle Position, AF1, AF2, and Ignition timing what is the rate of data. Does it hit every sensor once a second, twice a second, three times a second. Or what is the usable rpm resolution. If you do a 0-60 how many data points do you get before 60mph. Or maybe you could send me some 0-60 runs. I'm not happy with the resolution I get from AE as I'm sure you could tell from the files I sent you.

 

From memory the Consult port has horrible sample rates .. I think closer to once a second

 

The A32 ECU is what's slow.

 

From the logs I've seen with G35's and 350Z's you get about 8-10 readings a second (100ms) for every sensor. I assume there would be no difference between the sampling rate on a 350Z and a A34 Maxima.

 

my pocket logger does 4-5 times a second . thats pretty fast