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Got my 1 ½" header laid out and tacked together. I wanted to try and make an unequal length header, to try and give the exhaust a "Subaru" rumble. The night before starting, I stumbled upon the fact that a few companies are making UEL headers for Hondas and Miatas! So, hopefully this will sound cool!
The usual way to do this is to make a 4-2-1 but match the wrong cylinders up if you just want the sound.
The UEL are supposed to be for turbos so the shorter length ones get it to spool up faster and then the long ones take over
I see theres a bunch of camshafts on the market now called rumble cams. THey give that big cam idle but actually decrease performance everywhere over stock lol
u must be bored
why on earth would anything want to sound like a subaru ?
Subarus probably don't even want that shitty sound..... but realized they're stuck with it from birth
Always sound like they're broken, and not firing on all cylinders. Are you ? Nah, jus kiddin
interesting stuff seem to be going on underhood
I've never heard of 'rumble' cams but there are some pretty weird auto trends out there (look no further than Japans' car culture :)) You would only need to shorten one runner to get the effect but it will screw with your tune badly especially in one or 2 specific rpm ranges. It'll be an interesting experiment but I think you'll get annoyed with it, sort of like having a straight through or rally spec exhaust. It's novel for the first week until the neighbours come after your ass and the cops keep doing laps of your car.
No, not bored, just wanted to do something different. It's not like these things sound great, anyway. Plus, I just wanted to build a swoopy header.
Besides, I see a bunch of people bemoan the fact that they can't buy a header and act like they're going to do something about it, so I will.
I don't see many other people making it happen.
you mean you are going to go into production?
Not doing production off this header. This is for a bodydropped truck with a Z'd frame.
I can build a header for anything, if it's brought to me, though.
Which are the "wrong" cylinders? Which are the "right" cylinders?
I was going to make 1 and 3 the long runners like a Subaru but Subaru firing order (1-3-2-4) is different than inline four cylinders. I matched the design of the Honda and Miata headers because the firing order is the same, 1-3-4-2.
As far as the spinning the turbo theory, Subaru turbo exhausts were designed that way because turbos don't care. Subaru only went to equal length manifolds because they wanted to run twin-scroll turbos on the newer WRXs. Twin-scroll turbos need equal length runners.
Quote:
Besides, I see a bunch of people bemoan the fact that they can't buy a header and act like they're going to do something about it, so I will.... I don't see many other people making it happen.
prolly still decent demand around here. Might be enough to keep you busy..... if worth your whileQuote:
I can build a header for anything, if it's brought to me, though
U got the skilz. Truck is your 'jig'
sounds like a cool build. Did u post it up anywhere ?Quote:
This is for a bodydropped truck with a Z'd frame
on a 1432 firing engine you would typically have 1-4 and 2-3 paired. you get a different sound (among other things) by paring them differently, there was an old site that had a good example of this that i will link to if i can remember it.
https://www.maperformance.com/pages/...aru%20Headers.
If someone wants a header for a stock truck, they can bring it to me.
This is where all the people with big header dreams seem to go quiet. Two headers isn't enough to get the price below $500 a piece.
The build is on Instagram @boogiechassis and Facebook at Boogie Chassis and Fabrication. Attachment 26209Attachment 26210
False. The link you quote shows an EL and an UEL that are 4-1. There ARE 4-2-1 headers but it doesn't create the sound.Quote:
Originally Posted by tortron
Here are links to the Miata header I'm referring to.
I may be wrong but I doubt it.
https://www.youtube.com/watch?v=O5PDL2NVYTM
https://www.youtube.com/watch?v=f32ZwCUzY88&t=338s
The link is one I found about ulh and mentions what it does to turbos.
Cylinder matching headers is pretty well known header stuff, and misatching them gives you a "WRX" (farty be beetle sound" and poorer performance due to how the exhaust pulses match up
Watched the video. It's got the 'brap' of a flat four but I'd like to have seen a dyno chart on what it was doing after the install. I think putting something like this on an engine that doesn't have great efficiency from the start is going to knee cap it. This is the kind of header you'd install for a custom show or a meet'n'greet for enthusiasts. It would definitely get attention.
UEL Headers make power on BRZs/86s.
Not to forget, this is a 90hp truck motor designed in the 70s. Don't try and get all sciencey about it.
I can't stand it when people want to get dicky and act like this is F1, asking about scavenging, pulse timing, and EGTs, as if they can do anything with that knowledge.
Like I said, I wanted to build a header, I decided to do something cool. This is what builders do.
What have you done?
u posted an unusual topic.... folks debate. U never been on a forum? Its what people do
No need to get all up in ya feelings, guy
So what if it's a 90hp 70s 4cyl. Non u.s. 2.0/2.4 sohc starions gone past 400hp. How? By "gettin all sciencey"
One poster in the thread owns a 3800 V6 powered mitsu pickup
I, myself am long time mitsu SOHC turbo guy
Guy X, and so on..... etc. You are not the only one doing stuff. Stop trippin
Your project IS hella cool(to me at least)...... We gearheads like that sorta stuff
Keep us updated..... and relax - lol
just do this if you want loud. But put it in the bed
https://m.youtube.com/watch?v=ai6Xo0...ature=youtu.be
From this thread I've found out about 2 things I didn't even know existed - rumble cams and UEL's. You're right, these aren't hi-po exotic engines and I had to go check this stuff out online to get informed. And as I said, this will get attention so nobody is actually canning you for jumping first. We have a handful of guys who have skills above those of normal mortals that have made some pretty amazing and unique mods. Making headers is no mean feat and we're all interested or we wouldn't be following this thread and commenting. How far in are you on making a prototype?
we're good :)
Yeah, we good, just venting.
I'm not building any prototypes. Like I said, this is pretty a specific fit.
In order for any headers to be built, someone will have to bring a stock truck to me.
I really don't see this being loud, either. I'm running a cat and haven't decided on a muffler, yet. The only G63b I've heard was from a YT video and it had an unnamed Magnaflow muffler. I'm planning to pick a middle of the road muffler noise-wise and adding a resonator, if I have to. Exhaust is 2 ½", exiting out through the roll pan.
Not to mention, this could all backfire and sound horrible.
Video's up at boogchassis on Instagram and Boogie Chassis and Fabrication on Facebook. It works a treat, just like I said.
2.5" is pretty ideal size for NA, not much gains going bigger (and the usual space issues that come with it)
How much exhaust is there in the video? headers and cat then open?
what was the problem getting it to run/idle?.
i dont think you are the original 02 sensor feedback carb?, but when you have an exhaust setup with a bunch of solid reversion waves going back and forth it messes with the sensor, expecially when its a short exhaust because it sucks fresh air quite a way back up inside. can be a problem when tuning big single motorcycles.
Though a shorter free'er exhaust usually alters the afr anyways. or at least thats what they say on COD
The running and idling problem was just setting idle and timing. It happily starts and runs now. The exhaust is done now, too.
I am having trouble finding tuning information. It seems to run rich and is smoking. I have a Redline Weber 32/36 and didn’t get installation instructions, natch. I think I was supposed to tap and plug the coolant port under the carb but I’m having trouble verifying that.
You 'can' tap and plug it but it's more of a safeguard to prevent coolant from backlogging under the carb base. The vast majority of the time nobody seals the coolant port up. Try adjusting the mixture screw first, then adjusting the idle speed screw.
Thanks, Geezer.Quote:
Originally Posted by geezer101
I got a 701-DGV4 jet kit from Carbs Unlimited and have been working through it. I blocked off the PCV and I think that's causing me Lean Best Idle tuning issues.
It was running great at 4-4.5 turns OUT from seated on the mixture screw. If I understand the LBI tuning directions, that would have me put larger jets in. When I was working on the jetting, I plugged the PCV, I think I messed myself up.
1. Am I understanding the LBI tuning right, where too many turns out means my idle jets are to small?
2. The carb came with 55 primary/50 secondary. Do I need to up both idle jet sizes?
Thanks, Geezer.Quote:
Originally Posted by geezer101
I have it running well at 1 ½ turns out from seated on the mixture screw. Timing is 8 degrees, set with the advance disconnected from the distributor and plugged.
It's blowing smoke from the exhaust and the plugs are caked and sooty.
Should I look at jets or maybe float level? I haven't driven it yet.
I initially went with the jetting recommended here on my '87 2.6L:
http://www.mightyram50.net/vbulletin...ber-32-36-DFEV
That said, it flunked emissions with high HC and CO indicating a rich condition, so over a few more rounds of that I would up bumping the primary air corrector up to a 195, which passed handily but with numbers suggesting I could prolly go a wee bit leaner yet, either with an even-larger air jet or a smaller main jet (w/ smaller air to match), so will try that out with next year's smog test. I also moved the 165 air to the secondary, figuring that richer mixture would go well with the larger secondary barrel.
Also note this is at 2400' elevation, so lower elevations would prolly need to jet richer than I did, thanks to higher oxygen content in the ambient air.
Thanks, Geezer.Quote:
Originally Posted by geezer101
I have it running pretty well at 1 1/2 turns out on the mixture screw and about 1 1/2 turns in on the idle speed screw.
The carb came with 55 primary/ 50 secondary idle jets. Timing is at 8 degrees.
I'm getting smoking from the exhaust and sooty black plugs from stationary idling and revving.
1. Should I be looking at idle jets? I have a Redline jet kit with 55s, 60s and 65s.
2. Should I be looking at float height?
Any suggestions would be appreciated.
With the idle speed screw 1-1/2 turns in or less, a mixture screw anywhere from 1-1/2 to 2-1/2 turns out indicates your idle jets are correct. If it runs better with the mixture any less than 1-1/2 turns out, the primary idle jet is too rich, or more than 2-1/2 turns out, it's too lean.
That said, sooty plugs suggests a rich condition, so you'll prolly need to tune your primary main and/or air jets. Main jets are big steps in tuning the mixture, and air jets are for fine tuning within those big steps; larger mains are richer, while larger airs are leaner -- i.e., when swapping to a smaller (leaner) main jet, also swap to the smallest (richest) air jet you've got and increment up from there to fine-tune it leaner, or going to a larger (richer) main jet should also start with the largest (leanest) air jet you've got and increment down to fine-tune it richer. From the sound of things, you might just try swapping your primary and secondary main jets, and put your smallest air on the primary and largest air on the secondary.
BTW, did you plug the PCV barb(s) on the valve cover? Or the EGR on the intake manifold? If it's the PCV, you should at least have the PCV valve at the front of the cover connected to the hose barb in the manifold right at the carb mounting flange. The rear barb on the valve cover can be plugged or capped with a breather filter; I like the Spectre 3995 for its durable low-maintenance stainless-mesh filter media, which is fine for this vent that really only ever purges vapor from the crankcase and doesn't intake anything.
I do have the pcv hooked up now, I had it plugged earlier.Quote:
Originally Posted by SubGothius
I appreciate the in depth explanation.
For reference, I'm in Pennsylvania, at an altitude of about 400'.
I'm only starting on lean best idle tuning and haven't driven the truck yet. Do the main and air jets matter this early in tuning the carb? Basically, should I wait until the truck is driving to get into the main and air jets?
Link to the (mostly) finished truck
https://youtu.be/FQrYYG2XxNY
your projects, your skilz..... WOW!