What a lamer.

 

weird I just ran a 14.2@97 with y pipe and b pipe on street tires. heh also a JRSC ls vtec teg running 8 psi couldn't break 14.6 @ 95 and he dropped his exhaust at the track hahahahaha. Have a nice day Phat guy, BugNout, poppa z whatever you want to be

 

14.6 @ 95 ouch.

I raced a JRSC GSR at the track once a long time ago... he ran a 14.3 @ 98 to my 14.4 @ 96. I think I had just Y pipe then.

 

I can think of two things:

1) The cold plugs, of course...
2) Ignition coils...

If your ignition coils are faulty, you will lose a lot of power whether your engine is pinging or not. I'd swap the plugs first and then if it still doesn't make enough of a difference, try new coils. 5th gen ignition coils have been known to be bad...

 

Heres two things that I am going to check do right away....

A. Change my plugs to the normal heat range. They are dirt cheap and they take 30 mins to change, so no problem there.

B. Unbolt my cat from my y-pipe and inspect the flex section. I honestly think that his might be the problem. BTW....there seems to be some confusion about what I meant by a busted y-pipe. I am talking about when the flex section breaks internally and causes a restriction in flow. I had a hole in my y-pipe before and it gets pretty loud, so I would definetly notice that.

Also, my Variable Intake switched over on both dyno runs, so that is out of the picture. I just changed my oil (Mobil 1), pcv, cleaned my JWT, and replace the plugs recently. It could possibly be the coils though.....What are the symptoms of bad coils???? Hesitation?

 

There are so many resources on this forum I wish somebody would take 1 car and 4 sets of rims. 15-16-17-18 sorry to discriminate against 19's.

If smaller rims are so beneficial, why would a car as small as the Neon put a 17" on it yet blast through the 1/4 mile at 102 mph and do a 0-60 in 5.7? You mean if they did 15" they could possibly beat an E46 M3 in a straight line? That Neon stops 15' shorter than a 350Z with the 17's on the Neon. How much shorter if you reduce the unsprung weight even more?

Somebody, please, take your car and test it with all 4 wheel diameters so we can at least have hard numbers. Thx.

 

mine definitely had bad coils. In regular driving, there was no pinging or hesitation. But the car felt sluggish at times and when I first dyno'd, my numbers were way low and the dyno plot was very jagged. I swapped out all 6 coils at once and noticed a pretty significant difference.

 

NORMAL 4th gear dyno!

Is it?

Plus, your dyno shop needs to reformat that graph, so the X-axis isn't so streeeeeetched and the Y-axis doesn't go below zero.

Looks like that shop doesn't know what they are doing. I'd go to another shop and dyno in 3rd gear.

 

4th gear is the gear to dyno in....It is the closest to 1:1. 0.954(4th) vs. 1.272 (3rd)

 

I agree, but your HP numbers are going to be lower than your torque in 4th gear. Shouldn't that be the other way around? Hmmmn.

Most of the dyno's here are done in 3rd which seems to be more consistent, so if you are comparing yours in 4th gear to 3rd gear dynos, they aren't going to peak the same.

Again, try a different dyno IF there is one available, but that dyno is not really abnormal.

 

4th gear is the gear to dyno in not 3rd

 

MOST are done in 3rd, so it's not going to be the same.

Again, his dyno is VERY similar to other 5th gen 4th gear dynos and NOT with 3rd gear dynos. That's why I could tell it was a 4th gear dyno from the plot, however I think his dyno shop screwed up the graph.

So, I'd worry about finding a GOOD dyno shop vs. a witch hunt for nothing wrong.

 

BriGuyMax dynoed his Z right afterwards and got 244 RWHP. A couple of other members have dynoed at this same place and didnt have a problem, so I am pretty sure its not the dyno.

 

I dynod 182whp and 189wtq there last fall, in fact there were like 8 Max owners there then all dynoing where they should except Jason and BriGuyMax. Its the car, it's not his gear selection, nor the dyno.

 

Auto's dyno in 3rd Gear...
manual's dyno in 4th Gear...

 

MOST arent done in third. third gear dynos will give higher numbers. 4th gear is as close as you get to 1:1 ratio. if you dyno your car in third your fooling yourself with your numbers. feel free to compare 3rd gear runs to 3rd gear runs. %99.9 of dyno runs i have seen read or heard about are in 4th gear. all but one my dynos are in 4th.

 

this type of things doesnt help make him feel better if u are intending to cheer him up

 

even if most are done in 3rd gear, 4th gear is closest to 1:1, my auto 5th gen, with similar mods dynoed in 3rd gear 1:1 put very similar horsepower but only 180tq, exact numbers were 181/180, so his torque is fine, its hp thats missing, sounds almost exactly like flex section problems.

 

What kind of Integra do you have? Unless it's a GSR w.mods, Type R, or you have a ****load of mods (boost), your dad's family sedan will slap your *** around like a 5 yr old kid...

 

Check the Dyno Slip forum lately? Most don't list what gear, but I'm willing to bet that they are 3rd by glancing at them.

Of the ones listed, MORE of them are 3rd than 4th. So, where have you seen 99.9% in 4th? Not Maxima.orgY right?

I agree 4th gear is better, but MOST people don't care to take there car up that high, so they settle for third gear pulls.

 

think about it 4th gear is closer to 1:1 than 3rd ...


so tell me why wouldnt you just do 2nd gear? or 5th?

 

Are you sure computer is running right?
Was it hooked up to a OBD-II or other test/monitor equip. so you could see what was going on?

 

You want to dyno in whatever gear will give you nice smooth acceleration curve and won't have the engine on the dyno straining for too long getting heat soaked. You don't necessarily need to run in the gear closest to 1.00:1. In a BMW 330i, 5th gear is 1.00:1, so do they dyno in 5th? Nope, probably 3rd or 4th.

4th in a Maxima will go all the way up to 130 mph which may be a little too tall. I'd try dynoing in 3rd instead which will hit about 100 mph. Your horsepower numbers won't be affected because the dynamometer will still calculate that out properly. And since the engine is running a shorter gear, it'll complete the dyno run quicker and not get as heat soaked. This should give you a little more consistent results.

 

I AGREE 4th gear is closer to 1:1 than 3rd, but does it REALLY MATTER? No. Not unless you are trying to compare YOUR car to cars with different gearing.

As long as YOU always use the same gear you will see the pro/cons of each mod. Personally, I would rather see the difference in a 3rd gear dyno, since that's all I'll see in the 1/4-mile NA and most likely on the street. However, you must also only compare your dyno to other Maxima 3rd gear dynos.

So if all the 4th/5th gens use 3rd gear, we can all work/stress our cars less and still provide useful data on whether a mod helped/hurt performance. If you want to compare your car to other vehicles, then using a gear closest to 1:1 will help compare apples to apples.

 

What gear did he dyno in? 5th is 1:1 on the 350z? Also you should post his graph. 244 means very little since it could be a blip the curves are what need to be posted as well as exact mods and gear.

 

Really, I wasn't questioning the validity of the dyno, but the dyno operator. Anybody that has ever seen a dyno plot would have realized that NEGATIVE numbers on the Y-axis is worthless data and that it skews the data plot.

I would have asked for all the data points on disk instead, because I could make a better graph in Excel than that POS graph. You can't even see the details of the curve, because it's all squished into a vertical height of like 2-inches.

 

Here is Brian's stock Z dyno in 5th gear:

 

Try to find another 5spd 2k-2k1 to dyno there in 4th gear as well stock or close to your mods. Main thing is that it is done in the same gear. It would be interesting to see the curves.

 

Most manual transmission cars are dynoed in 4th. All my runs have been in 4th and my dyno shop insists on using 4th for most applications.

3rd gear dynos will typically show slightly less power than a 4th gear dyno. 5th will show more than 4th gear, etc. The Dynojet doesn't really care what gear you're in. All the Dynojet really does is measure how quickly your tires spin the 2000lb rollers over a span of time. Most Hondas are dynoed in 3rd because of their lack of torque. It simply takes a long time to accelerate 2000lbs rollers with a 1.6 motor with a relatively tall gear. Dynoing in 3rd just speeds up the process and keeps the engine from laboring on the dyno for too long.

You could use 1st or 2nd is you wanted, but the rollers would spin too fast too quickly that some of the data may become jumbled do to the quickness of the data coming in.

If you dyno your car in 3rd, then make sure to dyno it in 3rd everytime because if you don't the results will be skewed. The same goes for using the SAME MACHINE EVERY TIME!!!

Like I've said many time before, a Dynojet is a measuring tool. You CAN NOT compare your numbers to someone else's 8 states away. The Dynojet is there to measure YOUR CAR's gains and losses. It is not a comparison tool unless you're comparing Dynoplots from car's dynoed on the same machine and on the same day.


Dave

 

Hmmmm.. . . that looks familiar . . ..

Oh, it's mine (and a couple other guys)! The Cali had aftermarket wheels and that made the difference.

By the way - stock, done in 3rd. All 3 dyno'd around or a bit over 200 with intake and y pipe.

 

Thanks, I'll edit that part.

[edit]
Screw it, they don't show what he wanted anyways. Delete.
[/edit]

 

350z and g35 6spd should be done in 5th for accurate across the board 1:1 ratio numbers.

 

My understanding is the same as Dave B.

So, I've always dyno'd in 3rd. Plus, that speedo at 130 makes me nervous.

 

I finally had a chance to check my y-pipe and its fine internally and externally. I changed my plugs back to the right heat range and gapped them to stock about a month ago. My car ran a 14.91@94 in its current state at Byron on April 5th. Anyone have any clues to what could be the problem??? I am seriously thinking of returning the car back to stock and selling it, if I cannot resolve the low HP issue.

 

JP -

Not sure that the 14.91@94 tells you whether your power is off or not. I don't know what you ran before so maybe it is way below. But since there are so many variables at the track that could make the difference between say 14.7s and 14.9s, you probably ought to redyno.

What were your other runs? Did you have what you felt to be a perfect run? 60'? Track conditions? Previous runs? What do others run at that track with similar mods?

I mean if you had a 2.4 60' and ran that time, I'd say that you aren't missing any/much power.

 

Exactly. If he's getting slow 60 foots (high 2.3s/low 2.4s), it will kill his ET and even some of his MPH. Remember that the 00-01 5th gens do suffer in the 1st and 2nd because of thier extra weight and those heavy a$$ 17s don't help things at all. The 5th gens other problem is the low 6500 fuel cut. They need the 7000rpm fuel cut as bad as the 4th gen MEVI. I believe MadMax was the quickest 00-01 5th gen running 14.39@96mph. Remember he ran at sea level and he even admitted conditions were excellent that day. UNfortunately for the 00-01 5th gen, it's not going to be as strong as a fully modded 4th gen. If you can pull mid 14s in the NA modded 00-01, consider yourself in an elite crowd. There are just way too many factors holding the 5th gen back.

I think JP's problem is that he's too caught up in the "numbers". Maybe it's the machines they're using in Chicago because I think Neal's GXE dynos just around average, yet he's the quickest NA 4th gen out there. Like I said, it's just a tool.


Dave

 

Kind of like my dyno #'s not being the best but the track I run at is a pretty quick track although I found out its slightly uphill

 

My best run of the day is below:

60': 2.27
330': 6.315
1/8: 9.638@73.2
1000: 12.508
1/4: 14.915@94.72

The weather was in the high 30's IIRC and I removed the jack and spare. I had a 1/4 tank of 93 octane fuel.

I had ran a best of 15.0@95 previously at RT66 IN 90 degree weather and very high humidity last summer.

The car is clearly not making power up top....Take a look at my dyno. My VI is clearly working, thats the funny thing. I heard it switch over on the dyno and my friend watched it actuate.

FYI....My brother in his auto 99' ran nearly the exact time I did and I30MikeD ran a 14.6 that same day.

 

yes that does seem quite low for those temps. Bad flex section is the only thing I could think of if your VI is working. Just an observation but I believe you said you checked it and it was fine.