Twin Scroll Turbo Manifold question

[Ghetto_CB7]

wrong?

I think there is some confusion from reading that. When referring to firing order I think he is saying the first to fire goes on bank one, the second to fire goes on bank two, the third to fire goes bank one, and the fourth to fire goes bank two again. This would be the order of 1342 on ours making the pairing of 14, 23 the right order. This even makes sense with his description of pressure. If 13, 24 was run each side would see a period of two pulses making high pressure follow by two periods of no pulses, this would make the pressure in the banks uneven all the time. Doing it the otherway the two banks would always be close to the same pressure and the changing affect is improved greatly by giving an empty pulse where the turbine is pulling creating a lower pressure in that bank while the pulse from the other bank is spinning the turbine.

[toycar]

Though the difference would be 10x greater if you were N/A, yeah equal length is the whole point of going tubular. With a turbo its not going to make a huge difference, but it will make a difference.

As far as the manifold, I hate to break it to you but I agree with others. The weld's look nice-and thats the problem. The sections should be altered(Not going to go into specs over whats best) prior to welding.

Welding butt end to butt end = cracked manifold, especially if your going to run an hx35-nice choice BTW.

[Ghetto_CB7]

equal length

I am not concerned about equal length on the runners, many professional builders have done tests on turbo manifold showing that equal lengths on a turbo manifold don't really help.

As for the wells, it isn't mine, but a friends, when it is completely done I will post pictures and see what you guys think, if cracking is still a worry, and I expect it will, we will fabricate a bracket to take some force off of the manifold.

[toycar]

I am not concerned about equal length on the runners, many professional builders have done tests on turbo manifold showing that equal lengths on a turbo manifold don't really help.

As for the wells, it isn't mine, but a friends, when it is completely done I will post pictures and see what you guys think, if cracking is still a worry, and I expect it will, we will fabricate a bracket to take some force off of the manifold.

Thoughts on parts I made bold/bigger;

a.) I am not sure who you talked to about the runners not needing to be equal, but they are completely wrong. Runners have everything to do with flow. Since the exhaust is under higher pressure then it would be naturally aspirated, the range of variables is HUGE. Dont get me wrong, you can make due with different lengths, but to say it doesnt matter or that its ok is just a complete lack of knowledge and a bunch of BS. How do you suppsoe BISI makes so much NA power with his header, if the length of the runners has nothing to do with it? Its all about pressure, and volumetric efficiency buddy, and Im betting the "Pros" you talked to are also the people you trusted to build this manifold. Did the "PROS" you talked to explain how pressure in the manifold will change with the length of the runner? Dont you understand that each runner, should have the same pressure, so they actually collect at the collector, rather then create turmoil/resistance?


b.) Seems like you already figured out the manifold wouldn't hold up, and have accepted the idea that you are going to modify it to support the weight better anyways. So, if you already ruled out the length of the runners problem(ahahahahahaha, your so wrong), and you decided to upgrade the POS manifold, because you already assumed it needed it-AS WE POINTED OUT IT WASNT WELDED CORRECTLY.

THEN WHY DID YOU ASK ANYONE FOR HELP IF YOU WEREN'T GOING TO LISTEN?

[Ghetto_CB7]

wow

Man you need to take a chill pill!

If you read the posts I have made, then you would reiize that it isn't even my manifold. I advised the person who is paying for it not to go local, but he didn't listen.

Furthermore comparing a na header to a turbo one ddoesn't work. The na one is equal length primarily for scavenging affects, which is how visit's manifold works. With a turbo manifold avenging is a bit more difficult because you have a huge freaking restriction in your exhaust, The turbo.

The equal lengths of a turbo manifold only work for scavenging if some how you could get all of the first exhaust pulse into the collector before the next one comes. There is however another problem with this in turbo manifold. That problem is reflection, when the first exhaust pulse gets to the turbo it rodents magically go on through, it hits the turbo like a wall. This causes a reflected pulse back up the runners. This is not what we want at all.

With an equal length manifold the reflected pulse theoretically travels up both runners at equal speed and if you did a length match like you would for an na header then guess what. As the exhaust valve opens and that next pulse is heading down the runner it runs straight into the reflected pulse.

With unequal length runners you have a reflected wave that will hopefully not be completely opposing the next pulse.

I believe that the most optimum turbo manifold would be of equal length runners, but with a longer collector design and longer runners, much like the top mount manifold available.

However if you read my posts I was trying to say that for this manifold runner length is by no means what I am most concerned with. Please stop being a dick!

No one enjoys reading shit like what you just posted.

Do not assume that just because I posted a question that I am an idiot. There are many people on this site of whom's opinions I value greatly which is why I posted the question here. This also seems to be an area of misconception and lack of information in most automotive communities, so I think it is good to least talk about it.

I am not a welded and did not know about the problem with the lack of beveled ends, I do now and have informed the person buying the manifold.

I am not ignoring your or anyone else's comments, but if I think you are wrong then I will say so, up until your last post politely. I expect the same from you and everyone else.

[Ghetto_CB7]

words

Sorry for the replaced words, I am doing this on my phone and auto interpret has a mind of its own.

[toycar]

Sorry for the replaced words, I am doing this on my phone and auto interpret has a mind of its own.

Look, you've got the concept right, but now your trying to act like you knew this from square one and obviously you didnt or this thread wouldnt even exist. Your trying to argue facts with someone who at a glance knew your shit was fucked up, and you needed to start this thread to confirm your instincts-whats that tell you?

The "reflection" of the exhaust is the issue, which, is 10x worse with a turbo car. I hate that people think PSI measures flow, which is prolly why you are thinking what you are. However, your car is only as fast as your slowest, least breathing part. You can jam as much air in the car, with as much PSI as you want-THAT WILL NEVER DO SHIT FOR YOU POWER NEEDS, OR INCREASE FLOW LIKE YOU ARE WANTING TOO.

Do what ever you want, but you still didnt answer the giant ass lettered question.

WHY ASK IF YOUR NOT GOING TO LISTEN?

At this point, you've acknowledged the runners do matter, and that the welds were spotty, and that your going to have to modify the manifold to support the weight-SO WHATS THE DEAL?

Your getting your panties in a bunch right now, acting like I was some giant DICK or something. The runners should be the same length. The "Reflection" that you are talking about, is a real problem-THAT I POINTED OUT.

The length in runners will create a varying degree of pressure-IN BETWEEN THE TURBO AND THE CYLINDER.

Dont you see how that will effect the way the exhaust leaves the cylinder? Or for that matter, how the back pressure from the crap ass manifold, resisting the new gases from the next stroke.

You see, if the runners are not the same length, then you will have one cylinder pusing air into the other. You already said that.

So, WTF?

1. Runners should be same length, and will have poor flow if not.

2. The fact that you are not argueing anything about this manifold being a twin scroll manifold means you have NO CLUE. In a twin scroll configuration the pressure in the manifold is EVEN MORE IMPORTANT THEN A REGULAR TURBO SETUP. Only 2 of the runners will go to one side of the collector(twin scroll), so obviously you would pair 1&3 and 2&4.

So, it functions like a 4-2-1 header- You follow? 4 cylinders, 4 runners, 2 sides of one collector. So the length being off in one runner, is actually 50% of the flow to that side of the collector. Do you see where Im going with this? Its not like 1 long runner vs 3 of the same size. Its one that is one length, paired with one of another. Different length=different volumetric pressure. Now that we are talking about twin scroll, not just equal length tubular manifolds does my point make a little more sense?


Jesus fuck-Ive been more of a dick in this post then the last one. The point of all this was to show you that YES, THE RUNNERS ARE FUCKED UP-YES THE WELDS ARE SHITTY-YES, THE STUFF YOU ORIGINALLY THOUGHT WAS WRONG, IS IN FACT WRONG.

Is that nice enough for you?

Please, just dont go on arguing that your going to "Fix" the obvious flaws. If you want to live with them, go for it. Adding a brace is a good idea, and getting the entire thing welded correctly is a GREAT idea. Should the runners be the same length-for sure, no two ways about it I would not pay someone who gave me a manifold that was built like this,-If you guys want to go for it. Will it run-sure. Just not as well as it should, and until you wrap your head around the restriction that is created by this particular issue, your going to wonder WTF is going on.

You asked if the manifold is right-NO IT IS NOT.

Sorry for being too straight-forward, if you think im a dick though you need some thicker skin..

[Ghetto_CB7]

twin scroll

I honestly have not seen you put any information into these last two posts, the physics here are different than an na setup, which is what you based your hole initial post about. You also state that the pairing of 13: 24 is what it should be.

Now if the idea is equal pressure in the collector, which is separated on the divided flannel manifold how is it that the correct pairing is 13, 24. Don't that create the most uneven pressure you could possibly get?

I called you a Dick before but maybe I was wrong from reading your posts over you seem more pompous than a Dick. Assuming that I didn't know anything before I posted and that you are somehow better than me by coming into a thread and posting the exact same thing about the wells that has been posted before, then using an na argument for a completly different physics situation, and now saying a runner pairing of 13,24 is the way it should be.

Please honestly explain why 13,24 is right, and use actual arguments comparing 13,24 to14,23.

I have also heard you mention volumetric efficiency a few times, but have not mentioned anything about the differences between constant pressure spoiling and pulse spoiling. Please also include that in your explination, not forgetting of course that this is not a true twin scroll because of the single waste gate.

I am honestly looking for your thoughts onthis manifold, but to me so far you have not made a valid argument on anything you have stated.

From what I have read and read multiple places is that equal length runners do not have.much of an effect on the turbo manifold, the same people have stated over and over that waste gate placement and collector design are so much more important that worrying about equal lengths is not worth any sacrifice you would have to make to either of those.

Please don't think I am trying to prove I am right, state your case, preferably without the attitude, and we can discuss it.

If you were wondering why I posted this knowing it was wrong, which you should have gathered from the very first post... it was because I was hoping someone would shed more light on the physics, because there is a lot going on, and in all honesty it appears as though very few people have done enough research to determine what really matters in a turbo manifold.

Your thoughts?

[toycar]

Long story short, I ran an hx35, twin scroll setup on my DSM from 1998-2003.

1&3 and 2&4 is so that no single bank fires twice in sequence. Im talking about firing order, not cylinders from left to right. You need to give a constant pressure to really give the best results, from my experiences. Altering the cylcle as I stated, gives you the best consistant flow as well as the best response, which is the whole point of running a twin scroll manifold.
Twin scroll tubular should flow as well (Usually waaaay better) then a cast, but the split collector allows for higher pressure to be created with less exhaust=faster spooling.


If half the bank takes 2&3, then 4&1 have to fire before that side gets pressure again, and likewise on the other side. 2&3 fire, which is a longer delay, thus reducing the pressure in the bank.

The length of the runner issue really plays a role in a TRUE twin scroll manifold, I understand that you are not going for a TRUE setup now and remove the value of the runner length from my arguement. I would say that this is a TUBULAR manifold, with a twin scroll collector. But meh, its all technical mumbo jumbo right.

The runner being the same length is important, as far as Im concerned really important. BUT, its not going to fail if its not exactly perfect, your just going to have to go down this road to better understand what Im implying. As you prolly have noticed, more power =more money=more shit breaking for stupid reasons. With a runner thats particularly long, it may cause wastegate issues as it will take longer for the exhaust to leave the runner. Then it takes forever to build boost for some unknown, or not thought of yet reason. Who knows, until you are running/tuning the car its hard to tell exactly whats going to come up, but shit always happens.

I really dont want to sound pompus either, I have great experience(40k miles) running the hx35, realibly, and I believe that just like anything else in the powertrain-its either perfect or its not. Any imbalance to the system will eventually fail, even an unequal length runner.

If its not perfect it breaks under this kind of power, and causes all sorts of weird shit to come up. BTW, what kind of power goals are you shooting for? The Hx35 is a monster.

Everything from pressure to temps will be different on the longer runner, and it will throw other variables at you(maybe you'll lose compression on that cylinder faster, maybe it will runner richer, maybe the valve seals will burn up quicker etc)

Stupid shit will come up is all im saying. You will deal with stupid, stupid shit with a poor(r) flowing runner.

As far as the physics that confirm/deny anything Im saying, what is it exactly your looking for? I think i answered the pulse question, or statement by clarifying that Im talking about the firing order not the cylinder number from left to right.

Serious conversation at this point, lemme know and Ill try to give my best advice possible.

I first owned a turbo car in 1993, and Ive been building/racing cars for 20'ish years. I am not a guru, but I know my shit

[Ghetto_CB7]

firing order

firing order on honda is 1342, so that means that your augment for the physics behind that is correct, but that you thought the firing order was different on a honda, probably thought it was 1324.

As for the manifold, to be freaking honest, I hate it.

I have hated it since the second I saw it. It is in no way the way I would have designed the thing.

The main reason why I posted was about the runner pairing, and even that was because the guy building it claims to have built it with that runner pairing because of some article or post he read somewhere. Now I couldn't find it, but I though that someone else may have read it, or something similar to it and enlighten me on why this counterintuitive pairing was somehow correct.

I believe the text quoted by a member on the previous page is what the guy read, and interpreted the runner pairing incorrectly, as it is misleading in that article.

As for the setup....

Well it is really sort of amazing that the thing is still running.

The story goes....

1 and a half years ago I met the guy who currently owns the car at the track, at that time he was running an h22 swapped dc3 and when in the pits asked if I wanted to race(it was open test and tune), I said sure, I expected a pretty good race, and to loose since I was stock at the time and he was in a lighter car.

Well I won, car had lots of stuff wrong with it startig with the fact it was running a stock p75 ecu.

Anyway that same day we met a guy with a white h22 swapped teg with an hx35 and a build that was litteraly thrown together.

That year that engine put down 350hp on the dyno and ran a 12.1 quarter at about 115.

Later that year he blew the motor.

now this is where it gets scetch

he bought a $500 block that was "built" by a shop locally and had a lot of money put into it. It was 500 because the guy who had it built never paid for it.

the guy gets the block puts on a stock head and throws back together the setup with the hx35.

He has it tuned, or tunes it and my friend buys it a few weeks later.

Over the last year and a half we have upgraded a lot of shit.

As it sits now we are on

stock head internals
arp head studs
golden eagle intake manifold
Polar bear tuning 74-68mm tb
nice catch can
bosch 1000 fuel pump in line
walbero 255lph in tank
bosch 1800 cc injectors
unknown brand of press in sleeves
JE 9.0:1 comp pistons
I think crower I beam rods
tial 40mm wategate
greddy BOV
I haven't measured the size of the front mount, but its pretty large

the hx35 is unfortunately an 8 blade

Now tuned on neptune rtp

the motor made 350 hp, but from looking at the dyno and the tune much more could have been made, the previous setup had an ebay tubular manifold, and it is being replaced, primarily because last summer while tuning it literally exploded.

The torque peaked at like 5K and didn't level off and slowly drop it dropped like a rock and then leveled out telling me the tune sucked ass.

We will be running e85 this year and are hoping for 500 hp at around 22 psi.

I rebuilt the hx35 a week of or so ago and was very happy with how easy they are to work on. I love the thing, especially for the price!

I have expected to spin a rod bearing for over a year now LOL

[toycar]

The torque peaked at like 5K and didn't level off and slowly drop it dropped like a rock and then leveled out telling me the tune sucked ass.

YUP!

Tuning is interesting, but that is what happened for sure. I would consider running a twin walbro setup and ditch that inline pump if it were me.

You can easily push 30psi on that turbo. People have hit upper 30's on DSM's with that turbo. If you google search the twin walbro setup Im sure you will find something on it, if not pm me and ill give you the skinny on how it works. Its a cheap way to get alot of fuel delivery, and though those inline pumps sound like an awesome feature, they still restrict the flow to some degree or another and every time I've used one I had fuel pressure issues around 5000-5500 RPM's with high boost.

What sort of MAP are you running? That may be an issue to. That turbo will let you rev to all sorts of RPM's that you dont want to rev to, that drop off is in the tune. Do you have an A/F log for the same run?

[Ghetto_CB7]

tune

At that time, I was not involved in the tuning of the vehicle, since then two people are tuning it, me and a guy who is really good. When we get it up and running we will post datalogs to look at, I don't think the dyno we have from the previous setup/tune shows the afr, so they must not have had the sniffer in when dynoing

The reason for the bosch was because we are running e85, and the owner felt more comfortable with a pump that explicitly stated it was e85 safe. For the e85 we are also going to run a new fuel tank, or get the old one hot tanked to avoid any clogging in the lines.

With the e85 and a retarded timing curve we are looking at running mid 20's for psi, again that is the owners decision, and one I support considering I know nothing of how well the block was put together.

If we have fuel pressure issues we will deal with that as much as possible with tuning, and we are tying to sell the bosch 1800cc injectors and pick up a set of ID2000's.

we are currently on a gm 3 bar map sensor.

[toycar]

Good luck on the build/tune

[Ghetto_CB7]

She lives

I have pictures of the stuff that has been welded, but I have not organized them enough to find and post them.

The manifold is on the car and the little bugger turned on tonight. Its not much of an exciting video, but it does live.



Not a bad idle for 1 year old 93 octane and bosch 1600cc injectors.

[blazenem]

nice keep up the good work cant wait to see some numbers...