Fujitsubo 2018 new header system

[JDM4E]

The frontpipe looks good, but the header looks like almost every other JDM header on sale. The best headers are much longer tube, like ACE, JDL, PL and others, I dunno why any of JDM manufacturers don't do that. Plus it will cost a fortune for sure.

[bfrank1972]

Originally Posted by JDM4E

The frontpipe looks good, but the header looks like almost every other JDM header on sale. The best headers are much longer tube, like ACE, JDL, PL and others, I dunno why any of JDM manufacturers don't do that. Plus it will cost a fortune for sure.

But it's so shiny!!

[churchx]

JDM4E: long tube headers are less universal fit / more often with clearance issues. Take for example Ace - extra runner length is gained using overpipe portion. = not clearing RHD (which btw JDM is ), or rubbing if on worn engine mounts, and may need some hammering for engine protection pan. Nameless (& it's copy of P&L) - extra runner length tucked in front of engine with extra upwards bends. Also clearance issues with some other aftermarket parts/kits, and something that hot running near parts too close for me to feel comfortable about it. I guess, it's about manufacturer choosing other compromise. Yes, gains will be less, but they will be nevertheless. But no issues with clearing other parts under bonnet/universality.

[bfrank1972]

Originally Posted by churchx

JDM4E: long tube headers are less universal fit / more often with clearance issues. Take for example Ace - extra runner length is gained using overpipe portion. = not clearing RHD (which btw JDM is ), or rubbing if on worn engine mounts, and may need some hammering for engine protection pan. Nameless (& it's copy of P&L) - extra runner length tucked in front of engine with extra upwards bends. Also clearance issues with some other aftermarket parts/kits, and something that hot running near parts too close for me to feel comfortable about it. I guess, it's about manufacturer choosing other compromise. Yes, gains will be less, but they will be nevertheless. But no issues with clearing other parts under bonnet/universality.

Slight correction:

Nameless copy = PLM = 4-2-1 long tube, a lesser quality but sufficiently decent copy of Nameless

P&L = 4-1 long tube, 2 piece with v-band, routing is in front of the motor similar to Nameless, don't think there's another design like it (yet)

You're correct about clearance though - routing in front of the motor can sometimes interfere. Also there's the thing about heat, but so far I haven't had any issues with things melting


Regarding tuning, without tweaking fuel/ignition/cam timing, results from a header switch aren't really indicative of full potential (not even close).

Any time you modify an engine system significantly, you need to re-tune to optimize. Things like cat back exhausts are not as critical to re-tune as they really don't make that much of a flow difference on a stock car compared to a header.

ACE as you mentioned is a great example of this - while a good design, a big advantage is DT's experience with this specific header, I imagine they've spent so much time with this piece they know how to squeeze every ounce of power out of it. Compare that to some average Joe, buys a JDL, Nameless, Tomei, PTuning, P&L, Gruppe-S, etc. and has someone e-tune it (or uses an OFT canned tune). It's like Apple vs Android - iOS typically performs more efficiently because it's tied to a specific set of hardware, Android (I'm an Android user) is less optimized for hardware and is not quite as integrated and fluid.

Yes, I said it - ACE is the iPhone of headers, it's good, costs a lot, and has a borderline fanatical following

[churchx]

Ouch. Stupid mistake of P&L with PLM. I should really reread prior clicking post button .
Imho 4-1 design of proper runner length with best scavenging is near to impossible in cramped underbonnet space of twins though. No wonder that many 4-1 EL headers looks like targeting only high-rpm track use (Anaconda, PTuning..). 4-2-1 has way less overall tubing width to cramp there and even them needed to use tricks like Ace & Nameless did for just two parallel tubes. Majority of EL headers seem design wise copy of stock, just w/o cat and of bigger diameter tubes.

[bfrank1972]

Originally Posted by churchx

Ouch. Stupid mistake of P&L with PLM. I should really reread prior clicking post button .
Imho 4-1 design of proper runner length with best scavenging is near to impossible in cramped underbonnet space of twins though. No wonder that many 4-1 EL headers looks like targeting only high-rpm track use (Anaconda, PTuning..). 4-2-1 has way less overall tubing width to cramp there and even them needed to use tricks like Ace & Nameless did for just two parallel tubes. Majority of EL headers seem design wise copy of stock, just w/o cat and of bigger diameter tubes.

Yeah I run the P&L, somehow they make it work pretty darned well, it has a nice top end but also has a big bump that starts picking up after 3500 rpm and really gets going from 4000-5000. Big difference from stock. Read somewhere that long tube 4-1 vs long tube 4-2-1, the 4-2-1 gets a more consistent/flatter curve as it gets two smaller 'bumps' that can be tuned, where a 4-1 get's one bigger 'bump' to tune where you need it. The real downside of this header is it's not a mainstream design and I feel like I'm going to eventually have to switch to Ecutek and resort to spending for some dyno time to really get it optimized.

Anyway sorry to tangent from the main thread - having another option on the header market is always good, will be interesting to see this thing does tuned.

[mav1178]

Originally Posted by JDM4E

The best headers are much longer tube, like ACE, JDL, PL and others, I dunno why any of JDM manufacturers don't do that.

Because most of these companies design without any constraints.

To understand design philosophy you have to understand constraints. Japan does not take vehicle inspection as a joke, it's a very serious matter and costs a lot of money for the car owner.

Thus, all their products are produced with this in mind. To simply register a car as "off road" is not an option, because of lack of space and other things preventing one from simply storing a car in their home.

At the end of the day, a long tube design is great for everyone outside of Japan.

Edit: a great read for an overview of shaken. Generally speaking, anything that fails this test would make your car not road worthy and make it exponentially more expensive to just get your car back to roadworthy status.
http://aretcars.com/shaken-guide/

[mav1178]

Originally Posted by nikitopo

What are the total gains on the new cars? I mean with or w/o the header. I am asking because a couple of new Fujitsubo catbacks give very minimum gains.

Fujitsubo does not give out power figures with tunes, this is mostly because of the shaken (vehicle inspection) stuff.

The numbers are entirely bolt-on without tune.

[nikitopo]

Originally Posted by mav1178

Fujitsubo does not give out power figures with tunes, this is mostly because of the shaken (vehicle inspection) stuff.

The numbers are entirely bolt-on without tune.

A header specific tune wouldn't make much difference anyway. They don't have much longer tubes and besides most of the improvements should come from the mehanical advantage (less backpressure -> less resistance in the combustion chamber). Unless someone tries to mix up the gains of a general tune with the gains of a header, but then you are not really "selling" the header.

[bfrank1972]

Originally Posted by nikitopo

A header specific tune wouldn't make much difference anyway. They don't have much longer tubes and besides most of the improvements should come from the mehanical advantage (less backpressure -> less resistance in the combustion chamber). Unless someone tries to mix up the gains of a general tune with the gains of a header, but then you are not really "selling" the header.

Well, back pressure is just one aspect, and tuning is necessary for this as well. The less back pressure, the more air you can move through the engine system. The more air you can move for a set amount of fuel, the leaner your mixture gets, and this requires re-tuning. On top of this, one of the bigger benefits of a custom header (without packaging constraints as mav1178 pointed out) is the ability to resonance tune the power curve. Whenever you do this, you may need to change the intake & exhaust cam timing, and whenever you do that, you'll most likely need to increase/decrease ignition timing accordingly (i.e. changes in effective compression ratio at a given rpm).

Really the way I see it, the engine components are pieces of an orchestra, and the ECU is the maestro. Change around the instruments in the orchestra, and the maestro will have to change his arrangement to make sure they sound good as a whole.

Again - it's a gray area depending on the degree of impact. Headers make a big impact, and should warrant appropriate ECU tuning. Changing an axle-back or cat-back exhaust on an otherwise stock car wouldn't necessarily warrant a re-tune, because the impact of that kind of change is really minimal.

[nikitopo]

Originally Posted by bfrank1972

Well, back pressure is just one aspect, and tuning is necessary for this as well. The less back pressure, the more air you can move through the engine system. The more air you can move for a set amount of fuel, the leaner your mixture gets, and this requires re-tuning.

Why do you think this requires re-tuning? You engine has been designed to breath in different conditions like different temperatures, different altitudes with changed air pressures and in general to compensate on changes. Of course, this can be done up to a point and if you pass a line then yes you need a re-tune.

Another argument which I don't see to be mentioned often is that a less restrictive header will be more safe on spark timing. Why not keeping a bit more safety for you engine? It is not always about power!

Originally Posted by bfrank1972

Again - it's a gray area depending on the degree of impact. Headers make a big impact, and should warrant appropriate ECU tuning. Changing an axle-back or cat-back exhaust on an otherwise stock car wouldn't necessarily warrant a re-tune, because the impact of that kind of change is really minimal.

You can monitor how much off your fuel mixtures are and how much the engine tries to correct them. If you see the percentage correction to be too high, then yes it is better to have a re-tune. This is the answer I would expect from a really professional tuning shop.

[bfrank1972]

Originally Posted by nikitopo

Why do you think this requires re-tuning? You engine has been designed to breath in different conditions like different temperatures, different altitudes with changed air pressures and in general to compensate on changes. Of course, this can be done up to a point and if you pass a line then yes you need a re-tune.

Another argument which I don't see to be mentioned often is that a less restrictive header will be more safe on spark timing. Why not keeping a bit more safety for you engine? It is not always about power!



You can monitor how much off your fuel mixtures are and how much the engine tries to correct them. If you see the percentage correction to be too high, then yes it is better to have a re-tune. This is the answer I would expect from a really professional tuning shop.

And you will see your mixtures change. Will it blow up your motor? Probably not. Will it perform sub-optimally? Probably so, and how much it needs a re-tune depends on how different the header design is from the stock header. Do you understand the difference between ECU open loop and closed loop modes? Don't take my word for it, talk to any reputable tuner and see what they say. Also it's not just about relieving backpressure - a header with tubes tuned to increase power in the lower mid-range will also increase effective cylinder pressures in that range. So a stock header may have a lot of timing advance in that range, and you may have to actually pull timing in that rpm band. Even that is oversimplifying, not even touching on the effects cam timing can make - again don't take my word for it. Talk to a professional about it and report back

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[Kodename47]

Originally Posted by nikitopo

A header specific tune wouldn't make much difference anyway. They don't have much longer tubes and besides most of the improvements should come from the mehanical advantage (less backpressure -> less resistance in the combustion chamber). Unless someone tries to mix up the gains of a general tune with the gains of a header, but then you are not really "selling" the header.

Any change in primary/secondary lengths will have different cam timing for optimal performance. Even the OEM manifold performance can be improved by some changes.

Yes a manifold can make improvements without a retune however the resonance changes on OEM cam timing may not necessarily show gains where correctly tuned gains are relatively good.

It's unlikely that a manifold will massively change the fuel trims, as it's a MAF fueled the changes in VE are picked up by the change in airflow so the fueling adapts. It's not like changing an intake