madmax2k

I just completed a few more dyno runs with the Cattman SS Y-pipe and the Place Racing intake. The test car was a 2000 Maxima SE 5 speed with 10,000 miles. All runs were in 3rd gear. I know some of you will disagree with this gear choice, but what we are looking for here is the change in output over a stock car. The actual peak numbers can be debated from here to eternity. I chose 3rd gear becuase the baseline runs resulted in what is normally considered a reasonable driveline loss. Specifically, the car baseline tested at 191 wheel hp. Since Nissan rates this car at 222 crank hp, 191 hp at the wheels correlates to an approximate 14% driveline loss (191/222 = 0.86) , which is just about what is normally assumed for a modern, manual transmission loss.

The dyno plot can be viewed here:

http://homestead.juno.com/madmax2k/files/567.bmp

Dynorun.005 is stock
Dynorun.006 is with the Y-Pipe and CAI
Dynorun.007 is backup run of Y-Pipe and CAI.

Basically, the Y-pipe and CAI added about 12 peak wheel hp and negligible (about 2 ft lb) peak wheel torque. All gains are at 3500 rpm and above. Below 3500 rpm, the setups are not really distinguishable. However, from 4500 on up, the gains are quite large. Just for reference, when tested in 3rd gear, the peak wheel hp jumped from 191 to 203, while torque at the wheels went from 189 to 191 ft lb.

The only parameter not considered in this test is how the CAI would react when the car is at speed. I would suggest that the gains would be slightly higher due to this effect. However, this is not readily verified on a dyno with only relatively small fans blowing air on the vehicle front.

Hopefully this info is helpful.

Larry

Y2KevSE

iTrader: (13)

Only 12 fwhp? Man...

Thanks for the info!

madmax2k

Yes, I agree about the lack of airflow and commented on it in my post. However, the numbers are still accurate as they will not change by a huge amount even with a massive fan. Ive "cheated" (just for fun) on dyno runs before when using a cone type intake and placed a large fan right over the underhood intake and blowing viciously on it during the run. It only makes a few HP difference. By a few, I mean less than 3-5 hp. So, I cant see more of a change than that with a CAI at speed. Yes, this change would be measureable, however.

Unfortunately, there are VERY few dynos that have the huge fans required to simulate the airflow at speed. I only know of one, and its in California. And Im in Florida

Mike S.

Kev...you sound a little dissapointed. I mean...12hp at the wheels is a SOLID improvement. Madmax2k now has basically a 235hp Maxima. Not bad at all. Don't forget...he still has the stock exhaust on it too.

madmax2k

Yeah...I think the improvement is worthwhile considering what has been done. The end result was about what I expected from such mods. A friend has the same set up, but with a Stillen intake which will be dynoed soon. Maybe we will blow a fan right on the filter during a dyno run to "cheat" and see how big a difference it makes.

Guest

A few quicks questions:

1) What type of Dyno were your dyno runs done on? (The charts don't look like they came from a DynoJet)

2) Is is possible to dyno an automatic transmission from a low rpm like 2,000 or 2,500? (All my dyno start at a little over 4,000 rpms which is where 3rd gears starts after upshifting from redline in 2nd)

Just wanted to make a quick comment, who cares about your peak torque not increasing much, when your high end torque (Important for the drag strip) has dramatically increased! That is the part of the power band you want to be in when you are at the track.

If you click on the links in my sig you can my dyno charts that I'm talking about.

sprung

can't really dyno an auto from a low RPM, b/c as soon as you mat the gas it's gonna downshift.

00 black max

not bad

madmax2k

The runs were done on a model 248C Dynojet. The charts were made with a new version of Dynojet software.

You are right about the peak torque. I really didnt care that peak torque (at around 4000 rpm) didnt increase much. Torque up top (and consequently power) was up drastically.

Also, its tough to dyno an automatic at low rpm for the reason that Sprung noted. The trans will always downshift. Thats why you have to start at a higher rpm where the trans wont drop down a gear when you go WOT.

Larry

Albert

Why did the graph dipped at 5k RPM?
12HP gain is not bad especially with
OBD-II these days.

madmax2k

All 2k+ Maximas have a tiny dip at 5000 rpm, then rise up again. This is the flap in the manifold switching over. This flap is designed to alter the length of the intake runners and give the best of both worlds; optimum low end (longer runners) and optimum top end (shorter runners). Notice how torque is dropping at a fairly fast rate before 500 rpm, then it rises up and falls more slowly? To me this is the major difference betwen a 4g and 5g Maxima. The flap effectively alters the runner lengths. Its pretty slick! This switchover can be heard clearly with the hood open on a dyno with an aftermarket intake. The engine takes on an entirely different tone after 5000 rpm.

Larry

Guest

That is not bad at all... considering that new cars come very well tuned from the factory, it's good to see that there is still room for improvement. I think that adding an exhaust like greddy or Hks will really show the benefits of the Y-pipe. I read an article in Turbo magazine where they test the 2k max and they pretty much got the same base line and after the exhaust install they got a good 4-5 Hp at the wheels... so if you got an intake, Y-pipe, and exhaust..you will get about 207 Hp at the wheels that's over 240 Horses.. man.. I am about to run to go get my filter since I already got my Y-pipe... peace...

Bryan91SE

Looks really good! Interesting analysis on the intake runner switchover at 5K. That's similar to the VE engine of the 3rd gen correct? You can see that the horsepower starts flatening out around 5000 and the boom, intake runner switch and up it goes! Same thing with torque, it starts to drop until those intake runner length's open up. What an engine Nissan has! It's great how that horsepower keeps getting higher as you get all the way to 6500. I don't understand why the autos switch early (at 6100 is it)? As for the manual tranny, which you have, what rpm will you hit the reve limiter at?

Another question since I don't know much about dynoing... You were saying how 3rd gear might not be the optimum choice. Why? Would another gear show more power? Which is the best gear to pick on a dyno machine and why?

Thanks for the info, I like that graph, it's easy to read.

RussMaxManiac

Hate to say it but your results are flawed. 4th gear is 1:1 ratio, and is a must for dynoing the maxima to get accurate readings. You did not gain what you should have seen on the dyno. When I dynoed the ypipe ss alone on my 2k se auto, it got 21 more hp

madmax2k

Well, most magazines out there test in 3rd gear with the 2k Max and get the same baselines as me. 4th gear is actually about 0.95:1, while 3rd is 1.2:1. So, yes you are right, 4th is closer to 1:1.

In reality, what matters is how much faster the car gets. The actual numbers can be debated forever.


Larry



[Edited by madmax2k on 10-27-2000 at 08:45 AM]

Max_Gator

MadMax will be helping me this weekend with the y-pipe install. After that I'll have the car dyno'd with the SI and y-pipe for comparison. We have as close to identical stock dyno plots as possible and about the same mileage. So, it will be interesting to see how the SI and the CAI compare. Should know sometime next week.

Dave B

Almost all the dynos I've ever seen done on manual cars (Mustangs, Camaros, Hondas, Talons, etc), 4th gear is used. In almost every single late model manual car, 4th gear is nearly a 1:1 ratio. Using 3rd is fine for tuning your particular car, but when comparing numbers to another car like a 4th gen Max or anthing, you'll need to run 4th gear. Using 3rd gear will show 2-3% more power thru the rpm range due to the multiplication of the gear.

It looks like the 95-96 Maxima with a y-pipe, exhaust, RT cat, and intake comes relatively close to the modded 5th gens power. It looks like the 4th gen is stouter down low and the 5th gen has got a bit more topend. Nice run.

Dave

Guest

wow... 21 HP now that is something I would have to see to believe....

Paul6speed

Actually 4th gear is not 1:1 Russ. It's .954:1 3rd gear is 1.2 to 1. So his results are biased towards slightly higher figures. Larry's results would be worse in 4th gear. On the auto you get a true 1:1 ratio in 3rd. So far most people get around 12-15 with CAI and Y pipe, which is pretty good if you ask me. Russ, even though you have dyno graphs to show your 21 HP, no one really believes it. (This is not meant to be critical of you.) I think some of us chalk it up to dyno variance. No one has ever produced dyno results higher than 15 for these mods, other than you. Larry did his dyno testing at the same place within the same week. Your dyno testing was done at 2 different places and not within a short time. Please correct me if I'm wrong.

madmax2k

Your assessment is probably correct! All I can say is I ran a 14.8@95 with the Y-pipe and CAI (all else stock) and a mid 2.3 sec 60 foot 17" wheels. Whatever power that equates to is probably still unknown! Im going again tomorrow night and expect 14.6's with a little better launch (maybe low 2.2) and slightly cooler temps than last time, hopefully around 70F at night. Keep in mind this is FLA.......We dont really get the good track temps here :-(



Larry

madmax2k

I would like to find some other modded 4gs down here (Tampa, FL area). Itd be cool to line up and see how things really stand on the street.

Larry

Paul6speed

Your dyno results are true and your timeslip backs it up. Fastest NA 5th gen to date.

Shingles

You do infact want to try and get a gear that's as close to 1:1 as possible. This way you won't get an advantage from gearing. however, in the 5th gen, 4th gear is NOT 1:1. I can't find the exact gear ratio but remember that is the overdrive gear. By definition overdrive gear is less than a 1:1 ratio. Now it is possible that 4th gear is closer to 1:1 than 3rd. At any rate, if you were to see a different b/c of the gearing, you would see a higher number in 3rd compared to 4th. My thinking is you have an advantage in gearing in 3rd as compared to 4th.

One last thing, just b/c one car gained 21 hp doesn't mean you too will gain 21 hp. Heck not every single stock call will dyno the same.

12hp is a good solid gain. From an automatic is's definately a good gain. The way to best see this gains would be 1/4 times. My stock 4th gen dyno'd 16.2 stock. when I was done, it was pulling 15.2s. This is with CAI, Y-pipe, RT cat, and a 60lb stereo box in the trunk. These are GTECH numbers. GTECH may not be accurate to the track, but it is accurate with itself. This means I realized a .8-1 second improvement in the 1/4 mile.

-Shing

[Edited by Shingles on 10-27-2000 at 01:08 PM]

madmax2k

Thanks Paul. I hope to run a bit quicker/faster tomorrow!

RussMaxManiac

Sure:

Stock
<IMG SRC="http://www.b15sentra.net/russ/2kdyno.jpg"

With YPIPE:

<img src="http://www.b15sentra.net/russ/D1199-1.jpg">

RussMaxManiac

Well thats there problem if they do not believe the real thing. The one closest to 1:1 ratio will be the most acurate readings.

RussMaxManiac

I also ran the car with a ypipe at the track. Stock it went 16.2 with tranny problems, after ypipe it went 15.8.

Dave B

MadMax-

It looks like we are running nearly identical times. I'm pulling off 2.4 60 foots and running 14.9@94+mph with one wild run a 15.0@96.51mph. You are lucky though, you're at sea level. I'm in the "high plains" of Kansas City (1200 feet).

Goodluck and post your results!!!!!

Dave

madmax2k

Yeah, sea level helps. But the temps down here sure dont! This morning is very cool here (about 60F!!!) ...I hope it stays that way tonight. But, I think its a fluke as it supposed to be 85 F today


Larry