Boom! Just got this from Bisi

[deevergote]

Seems to me all he does is pump out beautiful show cars to boost his image and then taking shortcuts on the products for you and me. bad business if you ask me.

It'll be interesting if he tries the same business practices he pulled on us with the Porsche guys he's catering to now. Dr Carrera and Boxter S Cayman Esquire aren't just going to bitch about him on the internet.

[98vtec]

If he would go back to his roots, his audience would regrow

[thatoneuser]

Just to clarify this is the f22 header as I'm building my a6 up a bit for fun. Im planning on getting the bisi level two camshaft and the valve springs though I don't particularly want to be buying from bisi again because their customer service sucks. but as he's moving into Porsche these f series parts are going on sale and I imagine will soon be a distant memory in bisiporcho..

Any suggested alternative camshafts and valve springs would be appreciated.

[CyborgGT]

Isn't he still doing what he's been doing since his first D-series? Taking engines that are rarely built to high levels and squeezing stupid horsepower out of them? Look likes it with his classic 911s.

*ED. - F22A cam options. Aside from Delta, I don't know if any of these are actually still manufactured.

[thatoneuser]

Dcb7 my build is going to be very similar to jdm92 accorns na build though I'm not as hungry for horses as he is.

[thatoneuser]

Also I almost forgot here's the headers after a flat black ceramic coat.

[DCB7]

Dcb7 my build is going to be very similar to jdm92 accorns na build though I'm not as hungry for horses as he is.

Cool. I was studying out some of his earlier stuff for ideas at one point. I don't think this header can hurt you in any way, over the dented DC's especially. I like that thread as like a log of what the F can do, from a spectator stand point anyway. If I could get 160 from the stock engine in a reliable way, that would be cool for me. I'm not drag racing or anything, but want to be respectable at the light (at least like a civic, and those come with like 180 now, but probably heavier)

anyway since I done stuck my mouf in this convo, let me give you my advice. Gather as much info as possible before diving into it. Like an aggressive cam might require some head work, porting or suppm. May be you can link with somebody who has one and get some measurements for the Y collectors, stuff like that.

just my 2cents.



edit: some interesting reading
http://whythisride.com/hyundai/bisim...ema-sensation/

[F22Chris]

I wonder what the math is behind those runner lengths.. If somebody could shine some light on that for me that'd be awesome.

And that flat black looks good, but you should have waited to paint it! They're going to have to sand it off when they weld the downpipe.

[deevergote]

If he would go back to his roots, his audience would regrow

No doubt. As an engineer and racer, Bisi is world-class. I don't doubt for a second that he has the knowhow to wow the Porsche crowd, and I'm sure he's doing exactly what CyborgGT said, and focusing on less-popular engines.
Still, once he gets his foot in the door and tries to market Bisiomoto as a legitimate high-end tuning house and producer of parts, he's going to be in some deep trouble if he treats his new customers as he did his old ones!

Bisi is not a stupid man. He's just a poor businessman.

Just to clarify this is the f22 header as I'm building my a6 up a bit for fun. Im planning on getting the bisi level two camshaft and the valve springs though I don't particularly want to be buying from bisi again because their customer service sucks. but as he's moving into Porsche these f series parts are going on sale and I imagine will soon be a distant memory in bisiporcho..

Any suggested alternative camshafts and valve springs would be appreciated.

Delta still makes decent regrinds. They're not fantastic, but they've been consistent. Their products have never declined in quality, nor has their service, for as long as I've known of them. Prices are fair, too.

The last guy I knew to order a Bisimoto Level 2 camshaft was sent a bone-stock camshaft. I believe I mentioned it before. Dude is out like $1000 or something (because Denmark.)

As for upgraded springs, I'm not sure. I did a quick search, and found nothing. None of the brands I know offhand have F22A springs, and nothing came up on Google. You might have to do some digging to learn exactly what specs you need... then either have some custom-made, or use some from another engine that meet those specs.
If I can come up with something, I'll be sure to post back here. If you find another solution, please share!

I wonder what the math is behind those runner lengths.. If somebody could shine some light on that for me that'd be awesome.

And that flat black looks good, but you should have waited to paint it! They're going to have to sand it off when they weld the downpipe.

The math behind the runner length is probably a closely kept secret. That's kinda what makes it what it is. If Bisi let that secret out, his header wouldn't be worth purchasing anymore. Anyone with a mind for math and the ability to acquire and weld pipe would be able to replicate it!

[Accrdwgnguy]

why did you coat it before welding it?

[CyborgGT]

The math behind the runner length is probably a closely kept secret. That's kinda what makes it what it is. If Bisi let that secret out, his header wouldn't be worth purchasing anymore. Anyone with a mind for math and the ability to acquire and weld pipe would be able to replicate it!

I'm surprised I haven't seen replicas yet. It's not hard for anyone with custom exhaust experience to cut the header apart at the welds, then measure diameters and lengths, and copy the bends. Math doesn't matter when the shape is in your hands.

I think Supertech once made springs for the F22A as well as Bisi, but both options appear to be discontinued. It's looking like your only real option for your power goals is to swap in a H22, lol. Head over to HMO for a reliable low-miler and keep it stock, sorry.

[F22Chris]

I think it would be the same for all vehicles using the calculators online. Bisi used 24" equal length runners if I remember. But runner size is seriously based on RPM ranges of power production. The calculators that I found use bore, stroke, RPM range, displacement, and max HP/TQ rpm. Calculators are great, but I want to see the actual math behind it, not just the outcome of the set equation.

It just looks like he took the longest length runners while still being able to utilize accessories like AC and power steering components. And then just put it at 1342 to increase velocity and scavenging.

[CyborgGT]

Notice the diameters are stepped a little ways off the flange, too. Aside from simple tube lengths, are the bends before the merge going to do anything? I would think they might slow down the flow a bit, but again the diameters are stepped up before the major bends. Between the smaller diameter before the bends and a true merge collector after, maybe these things aid velocity enough that the bends don't matter so much?

[deevergote]

I'm surprised I haven't seen replicas yet. It's not hard for anyone with custom exhaust experience to cut the header apart at the welds, then measure diameters and lengths, and copy the bends. Math doesn't matter when the shape is in your hands.

I think Supertech once made springs for the F22A as well as Bisi, but both options appear to be discontinued. It's looking like your only real option for your power goals is to swap in a H22, lol. Head over to HMO for a reliable low-miler and keep it stock, sorry.

Bisi claimed that people were copying his design, but I've never seen any copies floating around the internet. Either he was full of shit, the copycats didn't generate enough notice to matter, or Bisi did a good job at snuffing them out before they got anywhere.

Supertech was the first place I looked today for valves. I think they did once make F22A springs. I wonder if they could still make them if someone asked.

I'm a big supporter of a near-stock H22A in a CB7. IMO, it makes the car what it SHOULD be. It'll never be a sports car. But the H22A brings it to life, while retaining near-stock reliability and fuel economy. A few simple mods that don't compromise those thing can be done for a modest investment... and the car will be respectably quick. Not "fast" by today's standards (especially when a $32,000 Mustang GT will hit sub-13 second quarter mile times with a potato driving it...)

I think it would be the same for all vehicles using the calculators online. Bisi used 24" equal length runners if I remember. But runner size is seriously based on RPM ranges of power production. The calculators that I found use bore, stroke, RPM range, displacement, and max HP/TQ rpm. Calculators are great, but I want to see the actual math behind it, not just the outcome of the set equation.

It just looks like he took the longest length runners while still being able to utilize accessories like AC and power steering components. And then just put it at 1342 to increase velocity and scavenging.

There's more math to really doing it right, but that's the bones of it. When it comes to designing a header like Bisi's, the minute details matter (and I DO believe that at least the initial design was fantastic... not sure how well it was reproduced, though.)

Notice the diameters are stepped a little ways off the flange, too. Aside from simple tube lengths, are the bends before the merge going to do anything? I would think they might slow down the flow a bit, but again the diameters are stepped up before the major bends. Between the smaller diameter before the bends and a true merge collector after, maybe these things aid velocity enough that the bends don't matter so much?

The subtle designs are what aid most in scavenging at the prime RPM range, I'd assume.

[f22ax_Rocks]

looks nice. maybe operates best at 9k rpms. I wonder how much of low end torque is sacrificed with these headers. Wish i had the money to spend on N/A but spooling, bov, and wastegate got me by the neck.