Hey fellas,
I recently purchased a 3" BPi stack and put it on a 3" pipe I got for free from a local business as a promotion. I previously and still do own the Yowaii SS intake (J's copy) and run it on my Poorman's R in a DD application. If you are familiar with my earlier threads I was pondering the ideas of putting the BPi stack on the "whale *****" to see what it would do, if anything. So after about a week of owning the stack, and about 500+ miles logged on the clock testing out each setup separately in a DD application I wanted to share my findings as well as give my opinions on all the differences I encountered. My car is tuned w/ the Yowaii SS on it, and NONE of this was done on a dyno, just DDing and going by feel. I did include input from my dad, long time dragger and builder, and my good friend who is a honda enthusist as well. So all statements are based off of a "butt dyno", but all 3 of us came to the same conclusions.

**This is strictly an opinion-based post as I have no dyno numbers to back anything up. I feel it is VERY unbiased and spending 5+ hours driving the car under different setups gave me a great chance to compare and contrast. If anyone has further questions or comments ask or post away. Ill do my best to answer them. HOPEFULLY this summer Ill get a dyno comparison on the 2 setups I tested above for proof or disproof of my claims.


Ill list the weather here in seattle over the past week I have encountered while driving.
Daytime Highs around 50*, scattered rain showers, 60-70% humidity
Nightime lows around 38*, rain...once again, and humidity near 75%

Here is a list of my build for a reference:
82mm GSR (GSR crank, rods, PR3 pistons-11.4:1 CR)
Stock port B16A head w/ 3 angle valve job, ITR cams, P30 IM/TB, Yowaii SS Intake
RMF narrow header
S4C tranny w/ qualife LSD
ACT 10lb flywheel, exedy stage 2 Clutch/PP
Apexi WS2 catback
Dyno'd @ 175whp/130tq

Setup#1- Yowaii SS w/ BPi stack "retrofitted"
I was very anxious to run a test with this setup. I had both high and low hopes for it. I installed the stack on the CF tube and went for a spin. I noticed a slightly better throttle responce, could be from having no filter, as well as a SLIGHTLY better topend while doing a pull onto the freeway. The powerband seemed to drop off 2-300 rpm later then it did with just the filter on it. The mid-range cruising around the town stayed about the same, just louder intake "whistle" under partial throttle acceleration. Overall not a bad compliment to the whale *****, but nothing that will blow your socks off. If I had to put a number on it I would say 3whp gain.

Setup#2- 3" pipe w/ BPi stack
So this was "the hype" I have been reading about, and I will admit I was very impressed with the performance of this simple swap and change. The pipe I have is about 20" long, just for reference. I put the pipe/stack on and immediately headed towards the freeway to get a top-end pull in because I knew this is where it would really shine. While pulling onto the freeway I pulled off to the shoulder to get a full 1st gear run. The car picked up about the same as it does with the whale *****, but once in vtec it was a totally different motor. I was fighting to keep traction, on dry pavement, and it pulled up to 8500 with no feel of leveling off like it does with the whale *****. Top-end performace, this thing was unbelievable. Next I went around town Christmas shopping with this on for a more DD feel. It did have a different feel. The whale ***** really shines between 2-4k rpm while accelerating and constantly shifting compared to this setup. I felt like it fell on its face a bit when I shifted and the RPM's were below 4k. This could be due to not being tuned with this intake, I cannot be certain. Overall best "race" mod for top-end performance, but not used for DDing. If I had to put a number on the performance gains I would say 7-10whp untuned. Definately pulled much harder after vtec engaged. My dad said "wow, that vtec is 2 times the pull"

Overall thoughts and opinions:
Adding the BPi stack undoubtedly increased performance and made better power, but only really noticed post vtec engagement. The Yowaii SS as I use it for a DD is still my favorite. I baby my car around on the streets, so throttle responce, low/mid-range and overall drivability are my main concern. The whale ***** gave me the best DD experience when staying out of vtec. It is no shock to me that these 2 intakes perform completely different, and both have their pro's and con's. For me running the whale ***** daily has more pro's, but at the track more con's. So as I sit I will continue to run my Yowaii SS intake daily, and for track use removing the passenger headlight and installing my 3" pipe and BPi V-Stack will be reserved for there.

Thanks for your time

 

According to my dyno test experience, the Stack will not help your setup

the exhaust is too retrictive

 

Please don't take this the wrong way when I say this, but posting an opinion thread in a technical forum is like accepting a medical opinion from someone other than a doctor. It's incredibly subjective and not conducive to what this forum is supposed to be about.

I would have waited until you got some actual numbers from a dyno or track testing before posting something like this here. For example, 3 whp is not something anyone is going to feel or notice.

Another member here, when switching intake manifolds swore that he gained power everywhere, according to his butt dyno. When he actually tested it, the results were a lot different than he thought. He didn't post anything until he had actual data to share though.

Your initial interpretations may be correct, but in this forum, we typically require hard data before we accept subjective reviews on anything.

 

true research and development from your butt wow...

however, i have used the 4 inch aluminum blox one welded on a 4 inch intake off my turbo setup and at over 600whp it was like 1 or 2 horsepower difference which means nothing... the only benifit of this part is that it looks incredibly awesome and allows you to put a big non restrictive air filter on your setup lol

 

I had a gian of almost 10whp in some spots in the powerband... But there is something wrong with my intake system

 

i did a dyno test with aem 3" cold air(front bumper) and a short ram 3". i noticed no power gain, only lost the cold air hump before vtec..

 

i bought the 3" bpi also. it def made more power than the 2.75 pipe i had. And u got 11.4 compressison and only ws2 exhaust gotta be restrictive as ****

 

Yes my exhaust is VERY restrictive. I have been told by MANY people that open header w/ the 3" and BPi stock would give me anywhere from 15-20whp easily. Unfortunately the cops in my area pull hondas over that make any sound noticible over stock, therefore I will continue to run what I have. At the track its a different story, I can open it up. If I had the money I would get a 3" Kteller system but being in college and working partime 3 months a year makes it difficult. I thought for $35 I might as well test this part out and give a unbiased opinion and what I thought of it. Without dyno posts and numbers HT members find it pointless to do, which I understand, but I have been building and tuning hondas for 7+ years now as well as building small blocks for over 10 years with my dad so I wont get on here making false "ricer" claims about what I noticed. I did this so people could take it for what it is worth, instead smartass comments followed. Oh well, I'm not perfect, nor do I own a dyno or have the money/time to get on one everytime I do something with my car. Just trying to put a usable "average guy" opinion out to the HT community. But "opinions are like ********, everyone has one" so really this post means nothing.

 

Check out vrsexhaust.com. They have mandrel bent tubing kits for good prices.
I thought your opinion was interesting. It backs up the dyno graphs Ive seen of the product. Big increases up top. Im probably gonna be purchasing one myself soon...

At least your post was written well and wasn't like " Yo I maKe MAD p0wa wit dis nu chipt ECU".

 

LOL thanks bud. I knew I had to write this out well so I took my time to include good word choices. I guess 4 years of college and a CJ degree on the way is worth something.

Im glad someone likes an opinion on the part and can get over the fact I dont have 30 dyno runs to go with it. I wanted to do it from the perspective of anyone who gets it in the mail, throws it on the car and goes back to their daily life w/o having to dyno tune do to the new mod tomorrow. Get one, I bet youll love it. I do.

Ill check out the exhaust website you mentioned.

 

Everyone likes opinions including me, however this is a technical section and while I appreciate what you've attemted to do here, it's not something that should be encouraged. If you had of posted this in the 92-00 Civic and respective Integra forums, it would have been a big hit with lots of "positive" comments from everyone and that's because you would be in the opinion forums. As long as you can understand that, you should be able to understand the nature of the comments you got here and why.

 

I felt nothing when I bolted it to my CAI on my H22.

 

I know exactly what your saying and I knew I would get negative feedback with having used no dyno tests or tuning. I would be the same way. Sometimes we all get so caught up in the numbers and technicals we forget about the small things like a review or overall drivability. I figured since my car is a DD and I do have 2 totally different intakes, most popular/controvercial at that, it would include insight from more then just a dyno/numbers perspective. Trust me I am in no way butthurt over the comments, like I said it was expected and I appreciate all opinions.

 

To add to what you said, getting caught up in numbers and technicals is what sorts out fact from fiction, or a hundred different opinions, which is why the technical forums exist seperately from the general forums. Small things like a review are generally delt with in this section as to if the part works or not. Overall driveability is a tuning issue more than anything else. This is why we thrive on hard numbers and facts, it's the only thing that differentiates us from the non technical forums.

 

Well put 00Red SiR...
Merry Christmas guys! I can really feel the love in here!!!

 

sounds interesting ... will try with my coupe at the dyno its important to see where is the gain n lost taking place

 

It's an air intake. Theres nothing technical about them. Thankyou for your time I guess?

 

Without back to back dyno runs your comparison has no hard evidence. Basically its all your opinion and what you felt. Overlay graphs for a real test.

 

i know that a dyno graph would've been beneficial cuz of the "tech" and viewing pleasure involved, but..wow..i dont see why peeps would go over-board..have u guys ever seen daves chapalle: when keepin it real goes wrong..lol..chill out a bit..i didnt get heated when i read this..let some post slide 00redsir..we've all seen how v-stacks compare on the graph already..and yes..every setup is different..and i know you guys wouldve pointed out what he needed to do to optimize his setup and or gains from the v-stack if he had a graph..this whole site "is" honda-TECH..and yes..that doesnt mean we go postin everywhere but ive seen to many bashing to care for one reasonable thread..just my .02..good or bad comments welcomed..

 

I can appreciate a well written thread. You obviously took your time and wanted to share your personal opinions, which I can respect. Not many people would take the time to write a thread like this that didnt have malicious intent behind it.

One of the problems with a "butt dyno" is that it is based a lot on audible tones. Your brain interprets the change in tone the motor makes and can conceive it to be more power just because the new intake resonates louder. Which in turn can be false.
I have to say I dont think you would be able to feel the powerband going 2-300rpm higher. At that speeds 2-300rpm goes by very quickly. I am not trying to discredit you, I just think this goes back to the change in tone of the motor.

However I have dyno'd my race only set up with and without a v-stack and there is a horsepower change. It is very negligable, but the point of a velocity stack is to straighten the incoming air. There are few fans that can mimic that incoming air going 70mph on a freeway or 130 on the track. Which is why I stick with my vstack and many other racers do the same.

Either way, Nice read and thanks for sharing

 

I am not sure straightening the flow is the best choice of words. The benefit is from the reduced flow loss by preventing or reducing turbulence at the inlet. The turbulence that is created is a restriction, just like bend or a ID reduction. By reducing the magnitude of that inlet turbulence or preventing it, you can improve the volumetric effeciency of your engine. As discussed though, it is unlike the butt-o-meter will accurately discern the small percentages of change, ranging from as small as 1% to the most we have seen is around 5%.

 

I switched out my K&N FIPK pipe for an ebay 3" pipe and the BPi stack I had off my Prelude. My butt dyno like it. But was it the pipe(slightly bigger piping) or the stack. I'll probably do some testing once I get my AEM EMS put on and street tuned.