quick question-i was looking in my haynes and saw there was a difference in the 4th gen resonator and my 2k1. i figured i would give putting my resonator back on a chance but i was curious if yours had multiple chambers inside(like mine) or if it was wide open on the inside. any input on its design would be greatly appreciated. edit-also those who say they switched back to stock resonator and picked up low end; did you also switch back to the stock air box or hack the stock box? im just trying to figure out if putting the resonator would benefit any if one kept the cone on? thanks again.

 

As the saying goes:

"Power that you can FEEL is power that is REAL". About a couple weeks now and my car is definitely faster at all rpms with the stock resonator box. It hot weather, the low end improvement a little and the top end improved a lot. In cool weather, both the bottom and top end improve a lot.

 

Before everyone jumps ship with their midpipes someone needs to prove that it hurts track times. And keep in mind that it will be on a car by car basis as well as the specific midpipe setup you use. I adapted the FCP midpipe to work with my stock airbox and I am happy with it. Putting a midpipe on your car can make it slower because of bad MAF placement (distance and/or angle). I have seen extreme lean conditions at 5200 rpm with certain setups but the setup I have now seems to be about perfect.

And you're only going to see the results with a A/F gauge. I know most of you don't trust those things but I know they work and I know how to read mine.

 

I'm wondering if something like this will work with the Place Racing CAI... that may help me in the long run as well...

Anyone with the PR CAI try this yet? Let me know what you did, and if there were any differences...

 

Good info. Did you start off with the resinator then move to the midpipe? After seeing that the resinator was better did you move back to the midpipe and still witness the improved track times? Great post!

My question about Franken cars add that their intakes provide a couple of horsepower over stillen has been answered, apparently emax has those dyno graphs, it would be great if someone could get him in on the conversation (I asked DMBMax about it (owner of franken car) and he said that e-max was the one with the graphs.

I have always had my questions about this mod, hopefully it will be answered soon, but for now I will probably move back to the resinator as per slammed95's post. I can't wait to see the dyno graphs from emax

 

I switched out my midpipe for the resonator and took it out for a run and it may have been all in my head but i couldve sworn that it didnt push me back in my seat as much when it hits 3-4000k RPM. It felt slower to me in the higher RPM's 3000+. I switched back to the midpipe and it pulled better again. As for the lower RPM's below 3K, it might have felt more responsive but it was negligable to me.
I just dont see how a straight thru design would be worse than the big resonator box with that accordian flex section. Maybe the plastic resonator keeps the air cooler as opposed to the metal midpipe..i dont know? Maybe one way might be better for automatics or 5spd's?

Just my thoughts and observations

 

Yeah, my track is open at night from 6-10pm, but the problem is that it's still deep in the 90s at 6pm and only cools to the lower 80s by 10pm. The biggest problem in the Midwest (Kansas City) is that humidity which skyrockets at night therefore making things much worse, racing wise. Like I said, when the temps drop into the lower 80s then I'll go to the track because the temps should be in the lower 70s in the later evening.


Dave

 

Yeah, my track is open at night from 6-10pm, but the problem is that it's still deep in the 90s at 6pm and only cools to the lower 80s by 10pm. The biggest problem in the Midwest (Kansas City) is that humidity which skyrockets at night therefore making things much worse, racing wise. It's 11:20pm right now and it's 80 degrees and 65% humidity. Not good for racing.

Like I said, when the temps drop into the lower 80s then I'll go to the track because the temps should be in the lower 70s in the later evening.


Dave

 

I'm running the hacked airbox with a K&N filter panel and a 2.5" piece of shopvac hose running from the driver's side of the airbox to behind the headlight.


Dave

 

I don't think using ET's is the best way to know if you running faster or slower. You would have to have the exact same launch in order to compare. The best way is to make multiple runs with each set up then average out the trap speeds.

 

next thing will be atleast dozen of midpipes and HAI intakes in the for sale forum !!!!
Before people start jumping horses, we need solid proff !!!!
I still stand behind theory : in order to gain something you have to lose something -
HAI and midpipes - nice growl but bottom end slacks
any suspension setup - better handling and looks but rougher ride
any wheel combo 17"-20" range - great looks but ride quality sucks
MEVI - nice top end , but few members here blew theirs VQ
and the list goes on and on !!!!!

Nick.

 

I completely agree with you that we need numbers. I just wanted people to compare between the two to verify if I was the only one feeling the difference. To me, the difference is pretty noticable, but I don't have any track times to verify and track time probably won't happen for a month. All I know is that driveability has improved and the power in 3rd gear is eye opening.

Like you say, everything usually has a trade-off, but I really can't feel it. Topend power (5500-7000rpms) feels no different and possibly better. Power from 4000-6000rpm is even with the hot temps. I really want the cooler weather back so I can get a real taste of the power. From what I can tell, the only trade-off is that I can't hear my VI open anymore :balling:

Like Mike said, when I go to the track, I will be more focused on trapspeed instead of ET. ET is far more dependant on traction, MPH is power.


Dave

 

Yes. People around here are unbelievably quick to change based on a$$ dyno results which is absoloutly ridiculous. People on this site over react to poor quality info. This could definitely be true, but let's definitely figure out some hard numbers before everyone gets crazy and sells their intake.

The other benefit to the con/midpipe that I noticed is improved throttle response. Rev matching, especially into the higher RPM ranges is easier now...I don't tend to under-rev like I did with the stock intake.

I have thought in the past about doing something like whoever said about running the additional tube to behind the headlight...i.e. adding a tube or replacing the stock tube with a less restrictive one. The midpipe makes a difference in throttle response, but I tend to doubt that the stock intake from the filter back is making you looks much in the way of horsepower. Eliminating the insanity of the cuves in the stock intake pipe befor the filter is probably the only place I would think there would be real soliud gains to make...

 

What where the trap speeds? The ET's mean nothing too me b/c they are mainly based on the launch.

 

Agreed. That's why I'm asking people to go out and make the simple 10 minute swap and tell me what they think. Unfortunately most people think that extra "sound" means better performance.

Quote:

The other benefit to the con/midpipe that I noticed is improved throttle response. Rev matching, especially into the higher RPM ranges is easier now...I don't tend to under-rev like I did with the stock intake.

I do notice a little more engine braking and the throttle doesn't feel as soft. But to me that's a good thing because acceleration feels more linear in relation to throttle input.

Quote:

I have thought in the past about doing something like whoever said about running the additional tube to behind the headlight...i.e. adding a tube or replacing the stock tube with a less restrictive one. The midpipe makes a difference in throttle response, but I tend to doubt that the stock intake from the filter back is making you looks much in the way of horsepower. Eliminating the insanity of the cuves in the stock intake pipe befor the filter is probably the only place I would think there would be real soliud gains to make...

The more I thinker around with my Maxima (going on 5 years now), the more I'm starting to realize that the stock intake is actually of a very good design. It might look ugly, but it seems to perform quite well. With a K&N filter panel, some opening cut in the lower stock airbox, mid-pipe, and secondary hose running behind the headlight and I ran a 14.4@99.5mph with a 2.3 60'. My ET/MPH pretty much matches what Requim6 and Nealoc (on street tires) have gotten with they're hybrid/JWT ECU/MEVI setups.


Dave

 

By Mike Kojima, from Nissan Perforamance Mag...

"Unlike the G35 Infiniti and the new 350Z, The new Altima, Sentra SE-R and Maxima have very poorly designed stock air intake systems, almost as if Nissan was trying to reduce the power on these engines from the factory on purpose. These cars respond very well to air intakes, especially cold air intake systems."

Umm, lets see. I think I might have a theory on this whole resonator vs. midpipe thing.

I think that the resonator's job is to quiet down the intake, but also provide optimal power and smoothness in the LOW powerband. This yeilds a good butt dyno in the low end as well as in city driving. As the revs get higher, I don't feel there is much of an advantage of the stock resonator. It just doesn't make sense to me, thinking about rapid airflow (even if the accordian type devide + the box provides an "air buffer" or whatever that is).

On the other hand, I feel that the midpipe is more optimal towards the higher RPM range. And contrary to popular believe last summer when the midpipes first came out, there IS a small loss in the lower RPMs (torque-wise anyway, since it's a butt dyno). This comes down to the theory of sacrificing low end for high end output. Once the RPMs get above 4000, I think this is where the midpipe shines and shows its strength. UNFORTUNATELY, our VQ engines aren't high revving motors, so we can't take advantage of the increased flow of the midpipe and we can't feel it so much either since we have a big torque dropoff up top.

So...in conclusion, stock resonator box will yield better results overall since our engine is "tuned" to that type of power and torque, mid to low end. That's why lots of people are noticing a nicer performance feel since the resonator box is tuned to the VQ's strengths.

A midpipe design itself is obviously a higher flowing air passage, but the VQ engine can't take much advantage of it unless our engines were optimized to provide peak HP at higher RPMs.

Well, that's just a theory of mine...but I feel that it is a good argument and makes sense.

 

Dave: You need to dyno so we can see where the differences are.

Everyone else: You have to be kidding me to say that your cars are slower with lesser restriction of the midpipe. I have one and my car is definitely more explosive on the low end and don't even have any other mods installed yet. The midpipe is proven to give close to 10 HP (give or take) on a VQ 3.5 and I'm pretty sure its close to the same numbers with the VQ 3.0

 

Midpipe is making 10hp on the 3.5VQ An intake system on the 3.0/3.5 VQ will get you maybe 5fwhp on a good day.

Why not install your resonator and see what happens. You opinion would be more valid if you tried it. Simply remove the midpipe (leaving the intake portion on) and install the factory resonator and drive around for a day.

I dynoed my HKS hybrid intake (with a midpipe) vs my stock intake (with just a K&N filter, not the "hacked" setup) and my VQ made the same exact power at every point along the curve, even at peak power (5400rpms). Not until 5500-6500rpms did the HKS hybrid setup make any more power over the basically stock setup. As we all know, power on the US-spec VQ drops like an anvil after 5400rpms. The hybird intake was only able to hold on to the power a little better as it dropped off (5fwhp at some points from 5500-6500rpms).

This is why I think the stock/mostly stock setup is probably most ideal on the NA VQ.


Dave

 

5fwhp???? What did Steve's dyno runs show? It wasn't 5 HP.

I'm not saying it doesn't work Dave. Everyone just jumps on a bandwagon istead of trying it and seeing the results first.

 

Can anyone get the dyno's from emax comparing the franken to the stillen (which is basically a difference of a midpipe)?

Also, does anyone know anyone at stillen. Maybe you could ask them to ask one of their techs why they didn't use a midpipe with the design of their intake.

 

Dave B,
I have A/T. I have used the resonator with a cone. It has no power on highway at the speed around 55mph. Since you have learned that the resonator sucks in small amount of air with a stock hacked air box works better compare to a midpipe with a cone, what do you think if I build a box around the cone filter and have a tube pointed downward for cold air and still use the resonator? It would still sucks in small amount air compare a hacked air box and I can still use a cone filter. What do you think?

 

Seeing that I still have my HKS hybrid intake, I've done a ton of experimenting and I've actually done exactly what you said above. I took (don't laugh) a bowl-shaped Tupperware container with a lid and used it as a "cold air" box for the cone filter. I routed the stock intake snorkel plumbing and the 2.5" shopvac hose into the container thru holes I cut in it. Essentially the filter was sealed off from any engine compartment hot air. I ran around with that setup for about a week and sadly, the hacked airbox still felt stronger at all rpms.


Dave

 

Your lack of power at 55mph won't be helped by a mid-pipe or a colder air breathing intake. If I understand the automatics gear ratios correctly, 55mph at full throttle is just towards the beginning of 2nd. Due to the long gear ratio of 2nd, strong acceleration doesn't start until about 60-65mph. In the autos I've ridden in, 1st winds out to about 45mph and then it shifts to 2nd which is followed a boggy sensation because the rpms land outside of the optimal powerband.

Seeing that I still have my HKS hybrid intake, I've done a ton of experimenting and I've actually done exactly what you said above. I took (don't laugh) a bowl-shaped Tupperware container with a lid and used it as a "cold air" box for the cone filter. I routed the stock intake snorkel plumbing and the 2.5" shopvac hose into the container thru holes I cut in it. Essentially the filter was sealed off from any engine compartment hot air. I ran around with that setup for about a week and sadly, the hacked airbox still felt stronger at all rpms.


Dave

 

What would do more good would be CFM measurements on both intake setups. As far as I know, getting as much air to the manifold in as little time as possible is the design goal of any intake, and for good reason. Smooth air flow simply allows the intake to do just that: increase the amount of air sent by reducing turbulence.

As for the "storing" of air in the plumbing to increase low end: I don't think that theory holds too well. Air can only leave the plumbing as fast as it's coming in (unless you actually think the elasticity of the plumbing will help you here), so it's all bottlenecked by the opening at the end of the tube.

I submit that a 3" intake track with a sufficient opening will yield better air flow than our VQ could ever use.

 

What about heat shields? I have seen some of the heat shields that almost entirely block the sides of the cone and leaving flat tip of the cone expose. It takes in the cooler air and less amount of air like your hacked box. I know you experience the hacked box with the stock resonator. Have you experience some of the solid looking heat shields with your mid-pipe?

 

Hey Dave if you get a chance try measuring the peak MAF voltage with and without the resonator. Or what you could do is time a couple of 3rd gear pulls from 1500-4500rpm or 4500-6900rpm. Figure around 2-3 run for each setup and then average them. I've been thinking of adding my resonator back to my se-r, based on the results you have. If I can gain alittle more lowend response it will be well worth it.

 

There's more to engine intake design than CFM. Velocity and resonance tuning have just a big a role as total flow.

 

How would I go about doing that? Don't I need an OBD-II reader what can store data? My volt-meter cords don't reach long enough.

As for you SE-R, we need to talk. My buddy just picked up a project 91 SE-R. Last week, bonestock, it ran a 16.1@87mph in 90+ degree heat and a crap 2.4 60'. I think it could go 15.6s with some better driving and cooler weather. I need to get your opinion on the best and most worth while mods.


Dave

 

I ran a custom heatshield setup for about 1.5 years and the metal framing around the cone still got very hot once the temps went over 75 degrees. IMO, heatshields don't do much because once the intake manifold heat soaks, the air coming in is going to heated.


Dave

 

Yep. I still don't quite understand how this resonator works because it looks like a straight-thru design and is nearly 3" in diameter.

The next time I go to the track I'll make a few passes with and without the resonator. As for right now, it's staying because my car feels much better with it on. 1st seems to be noticably stronger which is important because our cars need all the low-end grunt they can get.


Dave

 

My $0.02 for what it is worth:

If you want to routinely drive around 4000-6500 rpm then mod the car with all the goodies (MEVI, y-pipe, intake, cam, ECU, cat-back, suspension, brakes, etc).

If you want to drive it around 2000-4000 rpm then keep it stock cause it is already a good performer around all US speed limits!

If you want to have your cake and eat it too then remember any mod you do is a compromise to the original engineered design of the car. Only God knows what will happen to your particular car with one mod over another. Certainly, the reliability and longevity of your car is in question. I have a hard time believing that any one person or company can be more knowledgeable than the entire Nissan engineering department.

Granted the Max is a sedan with great performance. If you really want a performance car that is a sedan then maybe you should consider a 528 M5!

 

what is a 528 M5? i know M5 is bmw but a 528i is a significantly slower model.

 

i agree to this 100%. Are any of us smarter then car engineers?

 

According to your logic, there is no point to modding cars. Do you think the Nissan engineers had all out performance in mind when the designed the Maxima? C'mon, let's be serious. Aftermarket parts short of F/I or nitrous help the engine operate more efficiently by removing restrictions. And seegarman, in your infinite wisdom, can you please explain to ALL of us how an intake is compromising the design, granted a good filter is used? Or a y-pipe, or MEVI for that matter? The only reason the longevity of a car would be compromised wouldn't be because of the parts themselves necessarily, but because the car might be driven harder. But then again, you can beat the hell out of a car even if it is stock so once again your argument sounds even more foolish. And a 528 M5?

 

Yeah, what is a 528 M5? Is that a 2 on 1 Bimmer or something?

 

I'm surprised that the guy from Nissan performance didn't see that all the "badly designed" intake systems were on FWD sedans, and all the good ones were on RWD cars. It could be a simple case of not having enough room in the engine bay in a FWD vehicle to fit the correct system. I always found it very interesting that the throttlebody is sitting right there, pretty much in front of the driver. What an odd place to be. That, to me, is an example of the lengths that the engineers had to go to to make the intake system fit inside the FWD engine bay. In RWD format, the VQ35 has more room for a proper intake system, and, even more so, room for a much better exhaust system with a much less restrictive exhaust manifold.

DW

 

IMO I think the Nissan engineers did an awesome job with the DE-K. It makes power all the way to redline and has a much broader torque curve than the DE. Too bad it was transplanted into a much heavier chassis.

 

thats what mevi is for

 

Dav B I know its hot there...but since u have both a mid pipe and a stock intake...why dont u just do both in the same night even tho its hot...?

 

Because I've given up racing in hot weather. There's no point in beating on my car when I know I won't run a best. Plus it's expensive ($20).

Obviously, anyone else is free to try this though. The results should be there whether it's hot or cold assuming that the 60' and shift points are the same and nothing else changed between the run (tire pressure, icing the intake, long cool down, etc.)


Dave