Edit:

Things happened, which did not let me attack this as planned, so I only dyno'd with the setup in this post.

http://forums.maxima.org/7854364-post86.html

190whp/210wtq

 

Voted..

 

if youre gonna dyno, kill two birds with one stone and help yourself too!

with option 3, youre getting an after dyno wih the obx headers over your current setup, and a before and after for the 3'' catback. we'll finally find out what the difference is between a ypipe and equal length headers power wise.

 

Option 3, even if it does mean we have to wait.

 

http://forums.maxima.org/dyno-discus...n-headers.html

http://forums.maxima.org/dyno-discus...n-headers.html

I did the comparison almost 3 years ago.

To the OP go with option 3. I am looking to do the same with the 2.5" then install the 3" catback while at the shop.

 

I really don't care about the #'s I make right now w/ the VQ30, this is just pure scientific research for the good of the.org... The Dyno time I really care about comes hopefully in January w/ some Dyno tuning sessions w/ a VQ35

Not that long... The week of Nov. 15th, should be a decent paycheck, should have enough for headers and to finish the 6spd swap.

Just what I expected... Even though you're a DEK, I still expect similar results w/ my DE (Which is why I wanna do #3 personally, I dont think anyone has done this much for a USIM DE).

Well as of now, Option #3!! Expect a Dyno sometime within the next 30 days.

 

Why is this a poll and why the confusion??? Wouldn't you want to dyno the car with all the boltons you have and in good working condition??? What's the purpose of the dyno

 

Best suggestion here. Voted.

 

I have it in my head that most users on the forum here have a setup pretty much similar to mine (I/Y/Cat), so I was thinking that it would help most people on here to see results w/ this common setup.

My goal isn't to make most power right now, just trying to show the effectiveness of a 3" catback (this argument can go sooo many ways, I'm just trying to get the general feel of things with a poll).

 

I voted #3 but I think the most effective dyno time for the most .org users would be #2 since most 3.0 owners only have y-pipes and not headers as you said in post #9

 

Screw the benefit of everybody else... are they helping with the payments on the dyno, ppl on here need too much at times and to be honest, if you made the statement about the y-pipe about 3 yrs ago I would've agreed but most have recently changed to headers... go to the dyno to get your AFR's right vs some kinda show boat on one mod... either ppl buy it or they don't... you did........

 

3.5 Owners sure, but I still believe most 3.0de 4th genners use just the combo I have.

To clarify... You think even most 4th genners have went to the "long tube" OBX/Cattman/Hotshot design of headers? Or are still sticking to Y-pipes+Stock Manis?

I didn't mention anything about cost or money in this thread, so I would like it that you and others keep it out of their head (and thread) when making the decision, I chose to donate my resources to the org, not expecting much or any of a return on it besides having some good quality dyno comparisons.

 

Thats the reason I voted #2.

There are way more 4th gens with a y-pipe and catback than with longtubes.

Thanks for doing this comparison btw. I am thinking about doing the same type of comparisons soon at the track.

 

The argument can go sooo many ways, but as of right now I'm itching to pull the trigger on headers, until more 4th gen owners vote to change the results... I will let you guys know when I finally buy the headers, because once I buy them, thats it! It's over... In the meantime, the cattman is on my car, and I'm having a grand ol' time!

 

Not true, a few have done dynos comparison with the Y pipe and headers.


You already have a base dyno so Id say dyno with the Cattman 3" to confirm the actual gains made with a 3" setup on an NA car.
I dont believe Ive ever seen a dyno of a 3" setup on a NA setup before.

 

voted # 2 for a couple main reasons.

1. most are running y pipes, and it would be very interesting to see the gains just from the 3 inch catback as apposed to the 2.5

2. once you do the 3.5 headers and dyno you will see what gain you got from that mod and you can see if it was truly worth the money/mod to you

this way you will be able to say , 3.5 headers were worth x amount of ponys as well as the catback. install on the headers is a little bit of work, and im not sure people have tried, but a nice custom made equal lenth 3 inch y pipe using 2.25 runners joining into 3" is alot easier to install and i got a quote for 250 at a shop mandrel bent, which maybe worth as much as the 3.5 headers without the pain of install , just a thought,

edit: 250 was a miami shop price lol

 

I'm going to make one if I ever go n/a again

 

I'm pretty sure the VQ30DEK/VQ35DE 5th gens proved that there are gains already.

What I'm curious about is that I think I'm the first USIM VQ30DE w/ a 3" catback... This is one of the reasons I want to dyno for the hell of it this Saturday.

I thought about this, but I do not like the stock manifold design that much after researching quality header systems on other vehicles.

 

Iknow the 3.5's have, but thats not even a fair comparision for us.
I had seen some of the boosted guys gain around 10 more whp with a 3", im just curious to see what the gains are on an NA setup over a 2.5 system.

 

You need a MEVI for that 3.0. Did you see my old one in the garage?

 

In due time Flava.

Bahahaha, I'll stick w/ the USIM for a while longer... You guys may have caught wind of it earler in the 4thG section but there is a 00VI sitting in my room right now.

[edit #2] I'm dynoing on a stang dyno Saturday.

 

did you dyno today?

 

Not only did I dyno... I broke it....

Dyno'd @ 413whp and 58 ft/lbs.

I got my $30 back and backed up the line for an hour as they re-whatever'd the dyno.

 

F1 engine powerband FTW!

Damn I guess people were right about this 3" catback killing TQ and making more HP up top.

 

LOL. Awesome numbers....

 

As of now I'm collecting pennies and ordering headers next monday, 6spd project has been put off indefinitely until I decided wtf I'm going to do about my motor swap... Another topic for another day.

In the mean time... I plan on Dynoing sometime soon....

OBX 3.5 Headers+Custom Test Pipe+Stock Catback vs. OBX 3.5 Headers+Custom Test Pipe+Cattman 3"

The only point of this dyno was to show the benefits of going 3" or not, right? If I should reach numbers higher than 2.5" catback guys then it's worth it, correct?

The dynos will be done on the same day using the same dynojet I used back in march (I'm thinking nov. 22nd or 29th).

Custom test pipe you say? Yes custom... As soon as I get the headers on my car I'm having a shop mock up a 12.5" pipe that will start out with a 2.5" flange 2.75 diameter and exit flange to greet my catback.

And that will be the last of any planned exhaust work this car will have seen hopefully.

 

So once you have the headers,your gonna put your old cat back on for the Dyno and then remove it and put the 3" back on to dyno again?

 

Correct.

 

Eeek, gonna be hot. Are you paying per pull or by the hour?

 

If you haven't moved already, do yourself a favor and save up a few more pennies for a Cattman header set. Obviously I'm not impartial, but you can be absolutely certain that you won't regret it.

Brian


.

 

3 pulls (maybe 4).

The plan:

Quickie Maintenance:
-Oil Change
-Lucas through the fuel tank
-Spark Plugs
-Clean Air Filter
-Clean MAF.

Dyno Plan:
-Drive about 100 miles with the stock catback on before I dyno
-Dyno with the stock catback that morning (1-2pulls)
-Drive about 100 miles with the 3" on before I dyno
-Dyno with the 3" on (2 pulls)
-Post results on the .org.

My stock catback has always been cold to the touch, maybe slightly warm the closer I get to the cat (my cat gets pretty damn hot, I feel it on the shifter some times), but the only waiting I did before I dropped it the first time was the time it took the jack the car up and put it on stands.

The cattman is a different story, I can actually feel exhaust coming from the muffler and it gets pretty warm (not hot though).

Why drive so much? Why not just switch it in-between dynos and why not just do it at the shop? I didn't say this in the main thread but my car had a god awful first 20 miles with the cattman on, (I had to goto class so I shut the car off around 22 miles) it was misfiring and I couldn't go anywhere near 1/2 throttle, around 40 miles the misfiring dissapeared, then litterally, the 51st mile... It was a different car (I drove miles 23-51 without turning off the car) all of suddenly it woke up and started kicking @$$, and things really got going good around 90-100 miles.

Maybe it was a freak occurence? I thought so until I had to replace my starter (which involves unplugging the battery!). The car went through the same exact syndrome... I call it the 3" syndrome, and here I am again around 60 miles since I replaced my starter, different car again.

Now is this a problem? Or normal... Did any other owners go through this? Does anyone else own a 99 and have this catback?

And gains? Well I'll say this, the car has never done 135 and still climbing under it's own power before (It used to hit a wall around 125-130). This was all done on a test track of course .

And 35 mph in 5th, is nooo problem.

I plan on writing a full review after the dyno, with videos pics, and such, I'll have it on my blog.

I know, I know, but the money saved will pay for this experiment and ceramic coating.

 

IDK, your car is very weird I guess. I know personally my car never operated any differently in regards to having to adjust to any of my exhaust setups.
I went from OEM to the Apexi WS, then to the Greddy SP1, and then with the full 3" system Im currently using. Never had to deal with any ECU relearn times. Even when eliminating the cat, my car didnt have those issues.
By your explanation, running a cutout would be horrible on your car. Which Ive also run and my car never hiccuped with it open, even at low idle and just crusing. It was just hella loud.
On the dyno, with it open I did see some power gains, nothing amazing but the tq it made was much better.
Larger piping usually results in exhaust gases cooling down, which makes it denser and requiring more force to push it out, This is why Im curious to see how the gains are on an NA motor using a 3" setup.
With an FI'ed car, there is plenty of force to keep those denser gases moving. Its wierd how your setup is acutally running hotter then the 2.5

 

I think it's because most of my exhaust escaped before the catback.

But I can't wait to ditch this ECU by getting an 02 or a JWT 95.

 

02 ecu???

 

Teehee, now why would I be using an 02/03 ECU w/ a VQ35 , one of the reasons I'm not 6spd'd yet.

 

 

Headers purchased , Depends on how fast they get here, I doubt they'll be here in time for me to have em on to dyno thursday, so we'll say I'm dynoing Monday.

I'm taking predictions

 

kinda hard to make predictions without knowing the setup but my mind wants me to say 223whp 211TQ remember i dont know what motor you have or either if the catback will be on

 

190whp 205tq

 

I'm guessing final numbers with....

190k Mile VQ30DE
UR UDP
Bomz SRI
OBX 3.5 Headers
2.75" Test Pipe
Cattman 3"

God if I break 200ft lbs I will cry tears of joy, and champagne will fall from the sky (I still do not have a way of tuning the car, it's well known VQ30DE's break 200Ft/lbs w/ ECUs).

In all honesty, I'm thinking more like 180/195 with a much better looking redline.