The ECU doesn't adjust to mods. MAF voltage is MAF voltage, period.

 

Good question and i am not sure how long the ECU takes to adjust and time was somewhat limited so it hadn't crossed my mind. I figured Back to back runs would have been best because their would be very little diffrences in temp of the engine and the environment. Also it should be noted when i reinstalled the stock midpipe the numbers increased again as far as Tq was concerned.
Here is a graph of that
the order is Stock Midpipe then Frankencar midpipe then Stock Midpipe.
This time the Franken car midpipe is Green Line
http://memimage.cardomain.net/member...6_108_full.jpg

 

I don't think by using the track is the best way to determine which intake is the best because there is too much human error in order to produce true data. One run you can run 14.5 and the other you can run 14.6. That wouldn't say much for the intakes being used per say. There are to many variables that could make the data false and that's why I'd rather see dynos.

Take my ride for instance, 15.6 in the 1/4 all stock auto. There people that can't break 16 stock. Is it really because the car wouldn't produce the HP to take them faster? Is it the driver? Is it the weather or altitude? Lot's a variables there.

 

Whether or not the ECU had time to relearn anything doesnt seem relevant. It's the fact that the shape of the torque curve is so dramatically different that matters. If given time to learn, the curve may shift one way or another, but its shape (which is the problem) would be the same.

 

I like many of you guys have tried differrnet intake set ups. 2 weeks ago I went stock and I enjoyed the balanced low end pull and silence. But I read this and old threads no one has mentioned (or did I over look) Midpipe and stock intake box. (no cone) MAF Midpipe Stockbox K&N FIlter. I will leave the snorkel installed as well. I will throw this together and see how it feels.

 

There are definitely variables but DaveB did the test on the same day and did 3 runs (I believe) for each intake and took the average from those 3.

The Dyno plot does show some variances...no doubt...but 2-5 hp differences don't add up to huge losses/gains when racing. Not like a KS being out or a front o2 sensor anyway.

It is enough difference for me to go back though...lol

 

How big is the resonator in the 4-gen?

 

The Noise is what made me happy that the stock Resonator Retained more TQ. While the car sounded agressive and had a nice tone with the Frankencar midpipe it would be too much for daily driving. The stock resonator is so much more tolerable for daily driving. Hence why i kept my stock resonator in the first place.
You are right 2-5 hp isn't alot but i need all i can get.
I only wish i didn't have a calispec car with the extra Precat maybe i would have the same power your putting down MrEous. you have far more HP but i have almost as much TQ

 

Here is the size of the snorkel in question






The intake resonator is located before the air is sucked into the airbox, IIRC its a white box that is connected near the airdam after it curves down behind the radiator on the 5th gen and I believe its similar in a 4th gen.

 

I believe the resonator is the large box inbetween the maf and TB.

 

It is.

 

I switched back to stock a while ago as well from frankencar w/apexi filter. I noticed an immediate jump in lowend even with the crappy/restrictive OEM filter in there. Once I got my K&N panel everything just seemed really smooth; throttle response, etc. It's good to see some numbers that prove this though.

The next thing to do is somebody needs to test with and without the OSCAI. I have the black abs shopvac tube coming off of the first hole in the stock snorkel going down under the car with the shopvac sucker end on it. I want to say I felt something, but we all know butt dynos never really mean anything.

drew

 

My theory is Nissan got it right the first time, "if it ain't broke why fix it"...There's a reason why our cars do 0-60 in 6.6 secs.

 

I was under the impression that it was called the accordian section But thats the size..

Off the top of my head

about 12-14" side to side
7-8" top to bottom

 

My auto takes 6.7

 

I have tested with and without the resonator at the track and I saw no discernable difference in ET or MPH. I kept the resonator on because it makes daily driving much more enjoyable and I don't have to listen to wail of the intake as much.

 

The 1995 section has one more small plastic box added to that.

 

There is no learning curve for the ECU in WOT applications

 

i really wounder if this would hold true for a 5th gen (berk mid pipe). ive been hearing the stock is better but just dont see the actual physics...if the aftermarket pipe is less restrictive, straight and "seems" to flow better why would the stock produce more TQ? on the other hand im sure nissan engeniers are not retarted and that midpipe is the way it is for a reason. now im thinking should i go back to the stock set up, or the stock midpipe at least?? any opinions?

 

All this crap about resetting the ECU after mods is BS. The only improvements you feel is the ECU relearning the info it already had. Net gain is ZERO. Besides, anytime the ECU adjusts it's in closed-loop mode. WOT fuel/ignition maps are preset based on sensor signals. But that isn't the point of this thread, so i digress...

 

There's more to power than outright flow capacity. Resonance is used to create a ram effect and increase volumetric efficiency (VE).

Increased VE = more air in cylinders = more torque

Read up on the use of helmholtz resonators in automotive intake systems.

 

I think you guys are putting too much tought behind all of this. For what?....2-3 horsepower?? Whatever, I mean you guys aren't going to feel it when you drive so who cares. My 2cents.

-Paul

 

Well, some people do care and that's why it's here.

 

I thought I read in that article that the resonator also works like a capacitor by storing air as opposed to electrical power. When the cylinders need more, the volume is there instead of having to be pulled from the filter.

 

Well, the resonation of the air column in the intake can be modeled as a spring, mass, damper system which has an equivalent equation as an electrical circuit containing resistors, capacitors and inductors.

So yeah, sort of.

 

i want my torque back....i hate the sound of my weapon r cause when i am not really racing it sounds like i am and i dont mean to

 

Wow your the smart one. Good for you man I'm proud of you!

-Paul

 

Actually he is. People pay over $100 for 3-5 hp. ie... UDP. If you can get this back for free, what's the problem?

 

Has anyone ever noticed the '95 has an extra plastic box that sits on top of the port which goes to the valve cover?

 

No problem...I was just stating MY opinion. That's why I said "my 2cents". lol

Anyway...when I first bought my car I was into modding it and gaining hp but now I've come to realize...it's a 4door sedan. I'd rather mod another car for speed so I chose to just keep the Max how it is with very basic modifications like a ypipe. Currently I have a k&n filter but stock midpipe section because I don't like the loud sound of after market ones. I'm about to put the stock airbox back on too becuase it's still too loud. I honestly don't care about 5 horsepower. It will do nothing for me.

My brother has a 93 Lexus SC300 with a supra tt motor in it. It's only bpu and he ran a 12.1 @ 118 mph. Now thats a nice car to go all-out speed imho.

-Paul

 

yep....that's why '95's are faster. Joking of course,there was a discussion about that piece a long time ago, but no one knew why it was there.

 

Your 2 cents was BS and that's why I made my comment.

Good for you.

Good for your brother. There's still a Maxima on this board that's faster. So the reality is what your saying means nothing. Do what you want with your car and let people talk about what they want to talk about. That's what the forum is for.

 

Deezo - Do you have a problem with people giving their honest opinion? Holy crap what is this world coming to? Everytime I check back here, you have something to say about what I said. I'll just stop now because this is getting us nowhere. Have a nice day!

I'm truely sorry for interrupting your ingenious intake discussion fellas...continue...

-Paul

 

 

You jumped on him being sarcastic with your statement/opinion and expect him to not reply?

 

You should've stopped before you started. You obviously don't know who the powers are around here are so you have a nice week off for trying to be the bada$$.

 

what someone needs to do is take the rough integral contained between the stock midpipe and aftermarket/frankencar midpipe curves where there is a discernable difference...that way we would know how many hp or tq we are losing across the entire powerband...cause as seen in the dyno graphs, there is no difference in peak #'s...

 

It's pretty clear that the FC graph has less area under the curve. It has a couple of noticeable dips in tq where the OEM intake is relatively smooth.

 

well i finally decided to put my stock mid pipe back in...(by the way i have a K&N pop charger, 5th gen)

im no but-dyno expert but i expected to notice some difference. if there was any change with the stock vs my berk mid pipe was that the stock actually reved up slower, the car seemed to have a bit more lag, of course this is just a but-dyno. so i donno, go back to berk mid pipe od stay with stock now??? any suggestions?

 

I just tried the swap as well...only took it around the block....(I have the frankencar with apexi filter)....sound is competely gone now...so I can listen to the exhaust more...didn't notice till now how wierd the WSP mandrel y pipe sounds...and I have a resonated b pipe from them too....still sounds kinda raspy or buzzy in a way....but it's suddle....of course to me suddlety is always magnified!!! low end seems remarkably better....didn't get a chance to really open it up to see the top end...maybe I should compare maf data...of before and after using my auterra...