I have access to a half-mile-long closed "course," so to speak, and my wife's new HTC Thunderbolt phone thing with the Car Performance Android app. It seems to be pretty darn accurate and the spot where I am able to safely tinker with how to launch a manual transmission FWD car has 12 satellites feeding my location to the program, so I trust its figures.

I messed around there this morning and was shocked to discover that, on street tires (Contintental Extreme Contact DWSs with ~9/32nds) on a purely stock Maxima SE 5.5 gen with no LSD, I am a terrible driver and my car is DE-K slow. The road is fairly old, not sticky, and has a fair amount of dirt/dust on it from construction.

I did three runs, one in the heat of the day, and two at night. (76 vs 68, approximate 1704 DA vs 1257 DA [from the dragTimes website]) The first run, I tried just dropping the clutch, super-fast like, from 3500 RPM. The wheel spin and hop was so crazy nuts that the tires didn't stop spinning until halfway up second. There was a gap in the tire marks on the ground from where I lifted off the throttle to depress the clutch to shift gears. Ha.

That night, I tried launching from 1500 RPM with the same clutch release speed. Pretty bad. The final try, I did it from around 3000 RPM, but slipped the clutch out to get no wheel spin until the torque rush hits around 3600 RPM.

The results were as follows:
*The 70 mph speeds are from braking down after I thought I heard the phone chime I completed the 1/4 mi, but it was actually the 1000 ft.

Yikes. 3.5 second sixty foot times!? 16.5 overall!? Can this be blamed on the street tires, AWESOME AWESOME BEST ALL SEASONS EVER that they are, and the aging, unclean road surface? Or is my car a big weakling in need of a serious tuneup? Calculating from those times, I've got an estimated 205 WHP. What's causing the huge gap between 1/8 and 1/4 mi times? Why are my speeds close to other stockers in the 1/8 mi, but my times so much slower?

After 128.5K miles, stuff's started to age. I get terrible fuel economy (trending downward from 21 to 20 these past few tank-fulls) and now this? Sad times.

The MAF is new-ish, the plugs are 10K mi NGKs, the suspension is pretty worn. The oil is clean Mobil1 0W-40, the air filter is fairly new. I know there was excessive squat on takeoff and the 9-year-old springs definitely took an eternity to deform, wasting time in the process. The cats haven't been touched, nor have the O2 sensors (but flooring the pedal ignores O2 inputs, anyway, of course).

What should I be investigating to blame the performance on? The cats don't really give any indication that they are clogged, but I'm not sure how one would be able to tell without gutting them. Are they the most likely culprit? My wife says I can't have a loud, ricey car, so I don't know if I'll ever be able to go the header route. =/

 

For a stock 6MT, you should have about 205 whp... but are you certain your thing is accurate.... I mean... for your first run if you look at the trap speed... you slowed your car down for the last half of the 1/4 mile by 5mph?

And then for the last run, you manage to accelerate from 74 to 92 mph but still get through the last 1/8 in 6 seconds, compared to slowing down in the first run from 76 to 71 but completing that last 1/8 mile in less than 6 seconds.

I'm pretty sure that app is a bit inaccurate...

I think you're about to get flamed.

 

Ouch! DE-K slow.

I wouldn't fully trust the app and hit a real track.

 

Either way you look at it, you're either a nub at driving or a nub for trusting an app to accurately quantify your whp. I had an entertaining time reading the post though.

 

I dont think the phone's gps is that accurate. I will test out my HTC desire on the track this year though. Your poor 60' could easily be attributed to a dusty road and poor take off technique. Go to a real track.

 

IIRC most of these types of apps don't actually use GPS data to find your times/speeds/power (earlier phones even used tower triangulation instead of actual communication with satellites). Instead, the phone uses its accelerometer to "calculate" these "data" - so the info you get is not an actual measurement. If there any errors in the values given to the formulas (acceleration, vehicle mass, etc.) it causes gross errors in the final results.

 

The app claims not to use the accelerometer, it lists how many GPS satellites it finds to track position, and the (separate) speedometer function is bang-on accurate, so the issue would arise from its inability to compensate for lag. There is a setting to mess with it, but I didn't feel the need. Some reviewers on the internet took it to a strip and the values the app gave were less than .1 second off from the track's ticket.

If all the values were wrong by, say, 1 second, then my car would be average, but who knows how to calculate a correction factor for any of a number of errors. I'm just giving it the benefit of the doubt, especially since my car has never felt as fast as others VQ35s are on paper. =/

I'd love to take my car to the only drag strip even remotely near, it's an 1/8th mi about 40 minutes away, but the past two years I've been working 2 - 10:30 PM, Tuesday - Saturday, so I could never go any of the nights they are doing test 'n tunes or other open events. I never felt it was worth it to take a vacation day to pay money to see how poor my shifting skills are.

 

What app was it the one that is advertised in the 4th gen section to enter...or a free app cause that one you still have to buy a piece to make it work correctly...I would say go to a track with that thing and compare it vs the track times you get and update....

 

if you ran 60 foots that atrocious at the track, you would run much slower than other stock times anyway. It generally takes a mid 2 second 60 foot to break 14s in a 6 speed, low 2 second 60 foots for mid/low 14s.

As for your trap speeds, 75-78 in the 1/8th and 93-97 in the 1/4 are pretty normal.

 

Nah, those just ain't dek times