F22A Bisimoto Header: How well is yours working?

[illinois_erik]

I feel like this comment is pointed towards me?



I am very familiar with Bernoullis law, scavenging vs over scavenging and how velocity can dictate pressure (or a lack there of) how all of these affect flow.



Exhaust gas temps have a tremendous amount to do with exhaust gas speed, so, if this comment is pointed at me, I am curious why?

what do theories have to do with half assed fabrication skills and inflated prices.
if the things actually sealed up then you could employ those theories. Wheres the whitesheet on these headers? I think the R&D was poppin the hood and seeing how many homies gasped at the dopeness.. on an off topic rant, I thought vibrant performance was quality till I saw MADE IN TAIWAN on my collector's box...
1200 bucks ought to buy you stateside quality..ahh well. Guess the crow complex seduces many (shiny things get your attention) The hammered dog turd welds shouldve clued in potential buyers that the quality was lacking and all the other issues shouldve been the last nail.

[gloryaccordy]

I would imagine the hooks and bends in the runners are for opimizing heat scavenging. Or thats atleast the idea anyways. Since the runners bend like that right out of the port, the exhaust has some velocity build up when it hits that corner.

When managed correctly, heat scavenging can actually suck air out of the cylinder and that is probably what this design is shooting for.


My opinion anyways. I feel this way because of the extreme variables in performance people report. My opinion; EGT's dictate just how well this header works so different tunes with different EGT's equate to very drastically different gains.

I dont know if I buy this. Exhaust gas moves pretty quickly, I really doubt the radiation losses on those pipes are making a huge difference. Especially given how turbulent and weird airflow in the engine compartment is. I think the design was done just for brand recognition. He made it so when people bought his headers, the people buying them would pop the hood and everyone would recognize them right away. Theres no real functional reason for such a design, I dont even think actual race cars utilize such designs.

[GhostAccord]

I dont know if I buy this. Exhaust gas moves pretty quickly, I really doubt the radiation losses on those pipes are making a huge difference. Especially given how turbulent and weird airflow in the engine compartment is. I think the design was done just for brand recognition. He made it so when people bought his headers, the people buying them would pop the hood and everyone would recognize them right away. Theres no real functional reason for such a design, I dont even think actual race cars utilize such designs.

The curves and bends are in place to add length to the primaries in a restricted area. To put it basically these are equal to a 24" straight primary 4-1 header that you see SMSP use in a race setup where you have tons of room to run them.

Look at an F1 engine and exhaust setup.... they have xxx amount of room to fit an XXXX length of exhaust into. This XXXX length has been researched and developed to make the best peak Hp & Tq based on given engine parameters. Yes it is a neat looking design but in this particular case. It has more to do with function than form. That is more than likely what Bis was looking to achieve.

You can see that the bends are a larger diameter than the straight pipe.... that has the distinct look of a purposely designed header. With flow in bends taken into consideration. Fluid dynamics is used to calculate the diameter change required to maintain and or increase the flow of gases/fluids around corners with the least amount of restriction/turbulence. I have never disagreed with the design or the sciences behind it as they are fact and there are formulas to follow.... It was more the finished products QA and the lack of proper customer service.

[steelbluesleepR]

I dont know if I buy this. Exhaust gas moves pretty quickly, I really doubt the radiation losses on those pipes are making a huge difference. Especially given how turbulent and weird airflow in the engine compartment is. I think the design was done just for brand recognition. He made it so when people bought his headers, the people buying them would pop the hood and everyone would recognize them right away. Theres no real functional reason for such a design, I dont even think actual race cars utilize such designs.

uh, yeah, like formula 1 headers are designed like that for "brand recognition"

[jhoff]

AE86.

[deevergote]

I don't see why you people are backing up a product by saying it is a race header. I have been around race pipes and slip on exhausts that don't fit as poorly as these do. And they are mass produced not custom.

This isn't even a race header. This is intended to be a "street version" if I recall correctly.

[19dabeast85]

I have no problem with the design of the runners or quality of welds. I could care less what the welds look like. All I know is I examined the welds inside the runners prior to install to verify they were smooth AND they have held up fine for 2 years dd including hitting my dp on a curb and running over a tire......quality is fine.

The bends are there so the runners are equal length AND the firing sequence of the engine 1-3-4-2 enters the collector in circular sequence causing the exhaust in the dp to swirl increasing scavenging.

Untuned this header gave me more low end torque and more high-end power. IT WORKS. Dyno proven.

The ONLY gripe I have with Bisi is he lied about them being custom tailored to each engine and refuses to fess up to the obvious. That's it.

Why did Bisi use slip joints? No clue. Here's what I know, slip joints leak no matter how good the fabricator is. It's just a fact so face it and deal with it. I wouldn't go back to any other f22 header for anything. I have my fingers crossed that 5-6 years of soot will clog the leaks, lol.

[CyborgGT]

^ But what if you were running a more popular engine like the H22 that had actual options? Would you look into something else then?

I'm not trying to support the argument either way in saying this, but Bisi's site has a general 'Conditions of Use' page saying all their products are for off-road use only/not for use in pollution controlled vehicles (i.e. highway vehicles). Nothing is said about the header specifically being for race or street.

[19dabeast85]

^ But what if you were running a more popular engine like the H22 that had actual options? Would you look into something else then?

I'm not trying to support the argument either way in saying this, but Bisi's site has a general 'Conditions of Use' page saying all their products are for off-road use only/not for use in pollution controlled vehicles (i.e. highway vehicles). Nothing is said about the header specifically being for race or street.

If I had an h22 I would not choose Bisi, same as if I had a j32.

[deevergote]

Bisi knows the F22, and he provides the only noteworthy option for it. Until someone else improves upon it, it's the only option there is.

[93AccordLXwhite]

Bisi knows the F22, and he provides the only noteworthy option for it. Until someone else improves upon it, it's the only option there is.

I would suggest that there are numerous quality independent shops/builders/fabricators spread across the country. Yes it can be an issue finding one, but I think there is far from being just one option available.

"Noteworthy" of course is personal opinion.

I was not included in the original group buy. From the transcriptions I've read since then (emails through the Bisimoto shop) I consider myself lucky.

Personally, I don't mind spending more if it means receiving a quality product, or quality labor/service. I haven't found anything to prove that my money would have gone to such.

In conclusion, I hope no one lowers their expectations. There's nothing wrong with paying high prices for high quality. There are numerous things wrong with paying high prices for misrepresented goods/services, and I hope the people who feel that way stand firm. If you don't feel comfortable, don't be pressured into buying something because you "have" to. Don't be pressured into accepting less than what you paid for. Other options always exist, you'll have to do the work to find them. Personally I'd rather put 10 hours of research into a purchase than a cent into padding the wrong company's pocket.

There are always other options, and other knowledgeable builders (albeit not as popular or easily accessed); your time & energy shouldn't be wasted with unscrupulous companies.

[toycar]

I dont know if I buy this. Exhaust gas moves pretty quickly, I really doubt the radiation losses on those pipes are making a huge difference. Especially given how turbulent and weird airflow in the engine compartment is. I think the design was done just for brand recognition. He made it so when people bought his headers, the people buying them would pop the hood and everyone would recognize them right away. Theres no real functional reason for such a design, I dont even think actual race cars utilize such designs.

Nah man, he needs the appropriate runner volume to allow for proper scavenging. He's bending and twisting the pipes to stuff so much runner length into such a small space. I'm not claiming to be an expert on the topic, but if I remember right we are talking about wave tuning.

The bends in the runners offer restriction, and may be specifically placed to help maintain flow in between pulses. Maybe he did it to look cool, but I doubt it.


There's a science to the design and I am positive there is a benchmark egt, compression ratio and valve overlap to get this header flowing to its fullest potential. Bisi isn't selling those secrets, he's selling a race header.


It's not like he cut those n/a times on hopes and dreams.


And don't just take my word for it. Read up on header design, scavenging vs over scavenging and the relationship exhaust flow has with intake pressure and you'll quickly see what I am talking about. Not claiming to be an expert, but I have been in the car game-actively racing-for two decades. Just read up on it. Don't take my word for it, go form your own opinion.

[deevergote]

I would suggest that there are numerous quality independent shops/builders/fabricators spread across the country. Yes it can be an issue finding one, but I think there is far from being just one option available.

"Noteworthy" of course is personal opinion.

I was not included in the original group buy. From the transcriptions I've read since then (emails through the Bisimoto shop) I consider myself lucky.

Personally, I don't mind spending more if it means receiving a quality product, or quality labor/service. I haven't found anything to prove that my money would have gone to such.

In conclusion, I hope no one lowers their expectations. There's nothing wrong with paying high prices for high quality. There are numerous things wrong with paying high prices for misrepresented goods/services, and I hope the people who feel that way stand firm. If you don't feel comfortable, don't be pressured into buying something because you "have" to. Don't be pressured into accepting less than what you paid for. Other options always exist, you'll have to do the work to find them. Personally I'd rather put 10 hours of research into a purchase than a cent into padding the wrong company's pocket.

There are always other options, and other knowledgeable builders (albeit not as popular or easily accessed); your time & energy shouldn't be wasted with unscrupulous companies.

The only difference between a header produced by a different builder (perhaps with higher quality workmanship) and a Bisimoto header (with what seems to now be regarded as inferior workmanship) is the engineering. Regardless of Bisi's posturing, his results DO speak for themselves. The Bisimoto header design is far more than just a few pipes slapped together.
Maybe if Bisi would allow his design to be purchased so that the final product could be made by a fabricator of the customer's choosing...

Since, to my knowledge, Bisimoto headers are not made in-house, the biggest flaws are mainly Bisi's choice of fabricator, and his sustained defense of the shoddy work of said fabricator. Granted, I'm certain that the fabrication cost is what has allowed Bisi to provide his headers at a relatively low price in the group buys (which seems to be where the majority of the problems lie.)

[toycar]

There is no denying that there is some quality lacking in the workmanship of the piece. I also think that some user error is to blame(not in oyajicools scenario) that bisi gets a bad wrap for.


I mean, in this thread we have people suggesting and thinking that the header is designed the way it is to look cool with no other reasoning aside from looks.


Some of the same people that complain about the gains not being what was advertised, would argue that EGT's have nothing to do with the headers performance.



Total facepalm scenario.


I would like to think that if you are selling a RACE HEADER that it is a safe assumption that TUNING EDUCATION is not included.


Maybe its just me, I dunno. I would be pissed about the craftmanship of some of these issues if I were you guys. I would also be pissed if people wanted to ridicule me as a person when THEIR lack of knowledge/ability is more to blame than a lack of performance on parts I sold/designed. The flaws are the flaws, no denying that. The header performs though, and there is ALSO NO DENYING THAT.


People will argue until they are blue in the face that exhaust temps have nothing to do with exhaust flow just like they will argue that scavenging and valve overlap have nothing to do with eachothers performance.





Im just gonna drop this little tid bit on the conversation and walk away;



Did you know, that if you have a header designed for scavenging an engine but you do not adjust valve timing or piston compression you may actually DECREASE performance?


Why? The vac created in the cylinder from scavenging will draw unburnt fuel out of the cylinder before the ignition cycle happens.

So you can both have a bad ass header that is wave tuned and dialed in for optimal scavenging-but if you don't have the compression or overlap to pair with it-you are shooting yourself in the foot and you will most likely LOSE performance in the process.


You could easily argue that this header has no business on an OEM engine in the first place. It's basically like getting a custom cam and then not adjusting the tune.


And in the REAL performance car scene, people believe that the scavenging affects of a header can outperform forced induction when wave tuning is handled appropriately.

F1 engines prove that day in and day out.


The thing is, backyard guys like us don't have access to the bazillion dollar shops that can monitor pulse in a wave length and identify room for improvment. We just don't have that kind of money to throw at the problem.


F1 teams, they have plenty of money and they make GOBS of power N/A. Manifold design is probably 75% of the reason they make that power. This is an outstanding design, and POOR quality fabrication. Nothing more, nothing less.




***Edit***


This is a pretty easy to understand, paraphrased rundown on scavenging.

Check it out.

http://www.x-pipe.com/Scavenge.html

[deevergote]

In the defense of the customers... Bisi's near-27whp gains were produced on an untuned, bone-stock F22A1. That was a major selling point, especially for those that jumped on the group buy. Significant gains were promised WITHOUT the need for tuning.

Also, this product is the street version of Bisimoto's header, not the race version. Therefore, it is intended for street use (though not legal on in areas with emissions control.)
Any header designed for use on a car that is occupied for more than a few minutes in a race scenario, especially in stop and go traffic, should NOT leak exhaust fumes directly under the cabin. That is dangerous to all occupants of a vehicle, and it is very irresponsible product design for anything intended to be used for more than a few seconds/minutes at a time on a track.