Ok heres what i am running.. intake speaking
z-tune
jwt popcharger
heat shield

my ques... hp/tq difference with modified vs stock

1. from doing readings im getting the impression that running the stock box is better (sustaning hp with other mods)
2. do you use a k&n drop in filter with stock air box or leave oem filter with airbox
3. can i use z tube with stock air box
4. whats the gains with current set up vs. stock air box/filter
5. what year if any year makes a difference on stock air box
6. will a tune help with current set up (intake wise or w/e )
7. what incorporates this stock air box set-up

 

1. from doing readings im getting the impression that running the stock box is better (sustaning hp with other mods)
Yes.

2. do you use a k&n drop in filter with stock air box or leave oem filter with airbox
Not necessarily.
I've found from opening up many, many plenums that the dirty plenums always had some kind of aftermarket filter associated with it.
The clean plenums always had a stock paper air filter.

And from dyno testing, I've found that "clean" paper filters dyno no differently than after market filters as long as the paper filter was clean.

When a paper filter gets dirty it loses HP. When an aftermarket filter gets dirty it doesn't lose power.

But the difference is in the filtration capasity. The paper filters never let dirt into the engine. Never.
The aftermarket filters never lose power, but once they get dirty, they lose their ability to clean and start letting dirt into your engine.

So if you want the best of both cleanliness and performance, use stock paper filters and change them out often.

3. can i use z tube with stock air box
Yes. For sound enhancement only.

4. whats the gains with current set up vs. stock air box/filter
Negligible assuming everything is clean.

5. what year if any year makes a difference on stock air box
Negligible.

6. will a tune help with current set up (intake wise or w/e )
Some. But better if you have a lot of mods.

7. what incorporates this stock air box set-up

 

I couldn't have answered better than Hydrazine. Thanks Tony.

I would like to stress though that I do not think an aftermarket intake will cost you power. DaveB will argue me on that point. I have proven via dynos that the stillen airbox definitely cost me power(quite a bit, averaged). But I'm not willing to extrapolate that to "an aftermarket intake will cost every one power".

Let me put it this way: if you don't race, then keep the popcharger. I love the sound of those things. But if you're racing, then go back to a stock airbox.

You might see some gains if you picked up an 05+ stock airbox, but they would be minimal at best.

 

so would you say I would be wasting my time this labor day weekend by trying to build a larger airbox to house a large paper filter or drop-in style aftermarket filter.

To me it seems like a larger higher-flowing filter in a higher capacity OE-style box may be benefitial especially when mated to a better than OEM tube (overall improvements in breathing and sound).

I think OEM intakes are designed fairly well nowadays as you see a lot of factory supported race cars running OEM boxes with either drop in K&N units or no filter at all and then usually I see a modified smoother flow pipe depending on the car manufacturer.

I think I may still pursue my box design, but I will probably never dyno it versus stock unless i take advantage of a dyno day locally. it will at least be cool to say I built it and it hasnt hurt my performance.

 

so your telling me that since i race drag n roll highway race that i should use my stock airbox???i would notice a lil difference from me swapping out my jwt intake lol ???? thats nuts how???

 

1+ for Tony's post.

And let's not forget heat soak. The pop charger itself is very vulnerable to this. It might not affect you as you are driving since the flow of air is cooling the engine bay a bit. But with stop & go traffic [city driving], all that heat soak will have an affect with intakes such as the pop charger.

As for my personal experience with an aftermarket intake, I myself have the Stillen intake. I didn't notice any decrease or increase in performance.

 

Da_ReD_G in races like that intake or not will not decide the race. Reaction and who goes first during a roll honk will decide the race outcome much more than having an intake or not. If u go to 5th gear(above 100-110 mph) where RPMS start climbing slowly, then u might notice the difference between 3-6 hp across the power band. Again there are too many variables when it comes to 3-6 hp and one of them is that people do not pay that much attention is their shift points especially on a non-revup car like mine and urs. On tuned non-revup we have about 600 rpm to decide where to shift. I personally don't know the exact shift points but i will find those out very soon when i go to a private drag racing at the track and hopefuly get over 10 runs.

 

Based on my spreadsheet analysis of dynos on different cars with all the different mods.

Always shift at exactly redline.

And when racing from a roll, with a revup engine, start the race with your gearing such that the RPMs are starting at ~5250 RPM.

That will give you the best jump.

 

03-04s stock redline @ 6600 rpm (6900 on the tach). Rev limiter bumped up to 7100 (7400 on the tach). This is what i ment saying us non-revups have 500-600 to play around with.

When u say: always shift at redline? Does that mean 6900 on the tach or 7400 on the tach? This is what i will try to figure out in couple of months at the track when i get over 10 runs.

 

Tony summed everything up perfectly and Trey brings up a good point about the using the Revup airbox which uses a much larger velocity stack. I will be testing that setup as soon as I get my hands on one.

Another advantage to using the stock airbox is that it becomes slightly presurized at speeds over 60mph. The pressurization helps improve throttle response and in some cars like the 2nd gen G35s, it actually makes a few extra HP. Removing the stock airbox removes the pressurization effect.

 

For whatever the redline may be for the different generation engines, shift right before it bumps the rev-limiter.

And always avoid actually bumping the rev-limiter. The bump slows you down.

 

i think he means that if you have a non revup with the limiter bumped up to 7100 should you shift when you hit 7100rpm or shift at 6600 (factory limiter) all this of course with out bumping the limiter. I have wondered this question too before but i always shift at about 7000-7300 on the tach which is about 7000rpm. Another question what is the best rpm to take off from on a roll race if you have a non revup? I usually take off at about 4500rpm

 

I changed to a revup intake box with the larger velocity stack, however, the larger veloctiy stack seems to yield equal maf readings. Maybe the non-revup just doesn't rev high enough to take advantage of the larger velocity stack.

That being said, I am sure that you can take advantage of the larger velocity stack once you start to work on the intake side, i.e. boring the TB, swapping in a larger MAF, spacer, etc.

 

I think Vlad (klubbheads) concern is shifting in the meat of the power band… with a bumped rev limiter many (maybe most) cars aren’t making power all the way to new rev limit – in some cases it may actually diminish… So he is on a quest to find the perfect shift points to target keeping the rmp is the meat of peak power.

Unfortunately, I must max out revs (even with bumper limiter) in order to finish ¼ mile in 3rd (due to shorter FD)… with OEM 3.3 FD I found that shifting around 6700 yielded better results (even though my rev limiter was 7200).

Two things to consider though… 1) the OEM tach isn’t exactly accurate and 2) the engine will rev another 200-300 even after shifting (at least for AT)

 

Hey klubb, have you ever dyno'd your car on a dynojet?