Exhaust megaphone angle - Dyno tested

[@Garage4age]

Anyone keen to send me some 3d printed or any form or low cost velocity stacks/trumpets for that matter. So we can do another round of this: kzbin.info/www/bejne/fWmvapKOhJicedk Will throw up a post with details if there is enough interest. Maybe someone can beat my normal intake setup?!

[@crd-nz_001]

I do... But can only make them out of steel. And need to find the time to do so... Almost got my Levin ready to go back on the road, so has sucked up a fair chunk of change and time.

[@tiitsaul9036]

I'm keen to make some. Mine won't be 3d printed but hand made.

[@Garage4age]

not worried about what they are made out of. long as they wont fall apart and end up in the engine. will also leave plenty of time for people to send stuff in

[@sachadohc2912]

What about a variable lenght intake with yamaha R1 stack ?

[@Garage4age]

@@sachadohc2912 would be a bit small for my setup

[@jharris280zx]

Would be interesting to see the difference between 4-1 header and 4-2-1 header.

[@bennyz1971]

I wish the same test

[@cafemotorsports]

And a tri-y header

[@skiptastic1000]

@@cafemotorsports tri - y is a 4 2 1 header

[@gorkzop]

4-2-1 should give more low/mid and 4-1 would give more top. That's what they learned me haha

[@hiramwillis]

Tri y or 4-2-1 can get close to the same top end power as a monster 4-1, but the mid range is significantly better. Scavenging and trumpeting the merges correctly can be time consuming, but worth it if done correctly

[@sigmamale4147]

I love this channel. A bunch of tuning stuff thats actually dyno tested and not butt dyno tested

[@andretorben9995]

Engine intake test suggestion. Some 4 stroke bike engines use a 2 stroke type reed valve in their intake in conjunction with a large duration intake camshaft. They claim the reed valve gives a good mid range improvement in power by reducing the reversion of the long duration. Each cylinder would need its own set of reeds. Not an easy test though.......

[@HouseholdDog]

This is the best engine channel on youtube. No bs, jut tested facts.

[@cbdrift]

Holy shitballz - i checked the link you put in the comments for the slip on collectors and then checked the main site - you've got a history of beasty old toyota stuff - its an awesome read through to see the other projects and fun you've had! I also love the repeatability of the dyno your using - your the only other youtuber i click like on before i watch the vids, the other one is a DJ so not even car related lol - pity you stopped updating the blog site - but im hella thankful your doing youtube stuff :) I didnt realise just how modified the whole starlet was until i went through the website you had been using :)

[@Garage4age]

if you google kpr's kp60 there is a big thread on oldshool forum on the starlet. same deal for hilux and my ae85.

[@mikemikeyee]

Garage4ag has been a legend from the old forum days. So glad his stuff does well in the newer eras.

[@aksfactory]

it would be super interesting to see comparison between 3 inch exhaust, double 1.5 inch and double 2 inch. oval exhaust would be interesting to throw in there

[@otomotiftrend]

Wow @5 degrees, the power goes smoothly. Just 1 deg, made a huge diff. You are 4A GE mage.. 👌👍

[@Pynoxim1]

4 mA-GE?

[@otomotiftrend]

@@Pynoxim1 definitely 👌

[@rolandotillit2867]

3 inch straight pipe is basically a termination box for up to a 2.4 liter 4 cylinder. You'll be hard pressed to find anything substantially better than that.

[@jabberwockytdi8901]

Interestingly when I measured the factory secondaries on my BMW 3.0 ( N52) they had a very slight increasing taper from the cats all the way back to the merge point at the 1st silencer, a couple of mm over 1m length , ( the rear bank secondary was also very slightly smaller than the front bank , presumably to compensate for the shorter length from the manifold to the merge point) Was planning on fitting N55 with larger secondaries cat back, but dropped that plan when I found out the lengths BMW had gone to when tuning the secondaries on the non turbo car, and only fitted the larger N55 exhaust from the centre box back - which still made a big difference...

[@spreadhysteria3650]

This is one of the best, car tuner channel in youtube.

[@TheBlibo]

Hi from the uk I remember megaphones being used on single cylinder race bikes or 1 per cylinder. from what I have seen and used a 4 into 1 for peek power or a 4 - 2 - 1 for system with a bit more mid range, not forgetting that the length and diameter of the primaries is the first step Great vid car sounds awesome

[@diesel-technology5507]

Diverge and don't reconverge, and adjust the distance of the divergence from the header collector

[@timothythompson3029]

You should try a NASCAR style "boom tube".

[@wiltse0]

The only real big difference will be if you do total exhaust length tests. Like start with a total exhaust length of 5 meter's or something and just cut off half a meter over and over.

[@rickybobby7660]

Good test! On 2 strokes the expansion pipe cone geometry dependent on port timing. Be interesting to see a vvti swing with a range of megaphone set ups or a set of cams with massive overlap

[@Garage4age]

The vvti seems to like to be in the same place with all the exhaust changes ive done so far. There is possibly a tiny bit the exhaust cam timing. i haven't tried it yet, but is only a small window of adjustment for various reasons. It's running pretty big overlap, with vvti fully advanced (is throughout midrange) its around 5.5mm lift at tdc. cant remember the numbers on exhaust side but is in the 3-4mm range

[@MrAcepilot72]

Love these videos so much

[@CraigOverend]

Interesting that 5 degree divergence filled in down low and up high. All the venturi papers I've read suggest around 7-8° is ideal for air @ 20°C. If exhaust gas density accounts for the difference then 5° makes sense.

[@Ottobon]

It sounds great eitherway but have to admit the megaphones sound nice, i'd be tempted to use best result from that just for the slight change in noise it makes.

[@MrAcepilot72]

Would love to see a pov drive of the car especially going into rpms

[@samfreshly5331]

Sounds mental

[@jacksonbermingham2168]

can u make a motorized runner manifold so it adjust through the rpm range .. see if u can smooth the bottom end better

[@sergio_prz]

It would be cool to compare a 3" single pipe to a double 2" pipe or a 2,5" oval full exhaust

[@brandonrohrer7914]

The longer pipes merge the better the flow. We'll with water. I've always wanted to test a longer merge on the collector

[@Garage4age]

The headers on the car have slip on collector. was zero difference between a steep merge and shallow merge. the part after the merge always makes some difference though. garage4ag.files.wordpress.com/2023/09/20230714_131545.jpg they both had a straight section after the merge like on the right when tested.

[@sachadohc2912]

Wow always good contain you are a god of knowledge buddy ! I wish i would have been in your country to let you my zzt231 celica and let you test anything you would have like to !

[@anidiotinaracingcar]

This is *fascinating.* That 5° cone has literrally no drawback

[@calabar92]

Nice that 4age sounds awesome

[@hydrocarbon82]

Given the range you tested and the full exh vs 3" muffler, it doesn't look like you're getting anything meaningful out of the megaphone. 6hp at the last 400rpm doesn't seem like it's going to help anyone. Great test none the less.

[@Garage4age]

that bump at the end isnt a thing, just dyno having a bit of a mare. you can assume the power just tapers down to 160kw from 9500 - 10000 rpm on all runs. yes most of what needs to happen is already happening in the part built into headers. the 5 deg would make for a nicer street car though

[@MaggieCat83]

That motor is just terrifying! One day…

[@eddieconvey9223]

Love from Ireland❤

[@garage4k989]

Nice welding on em cones

[@Garage4age]

pretty good aye, hazzz taught me

[@HouseholdDog]

Been watching since it pulled 110 BHP.

[@woodzy575]

787B ran a variable trumpet intake. I guess maybe controlled by vacuum or lack of vacuum. I was hoping for a better result with the expansion exhaust, and then the 3" full exhaust came along and ruined everything😭

[@Garage4age]

the full exhaust has a megaphone setup on it too. but isn't quite right. hence why i was testing these pipes before make another one.

[@liubutu16vt]

it actually runs on servo power the 787B setup - it's a damn complicated setup, but it works a charm :)

[@cam3002]

Interesting results, thanks for sharing. I'm now subscribed. Have you considered doing "cookie cutter" style exhaust tips. I've seen them used primarily on Porsches from the last 60's. to mid 70's.

[@Alastair_cox]

Have you ever played with a Venturi in the exhaust where it initially goes down in diameter before going back up, or an anti reversion chamber?

[@Garage4age]

Yeah basically what the header have on them. this video shows what it does better kzbin.info/www/bejne/i3LcgWqPf7Zrgck From the limited things ive tired that resemble anti reversion chambers, is the dont work

[@Alastair_cox]

If you add 2” of pipe into the Meg then that will make it an AR chamber which will stop reversion but make the wave, also placing the Meg in different areas of the exhaust gives different characteristics. Tuned length and all that, a bit like 2 stroke applications.

[@Garage4age]

@@Alastair_cox Have tried a setup like that. diverging cone by itself was better

[@stevesimpson5994]

When you change the angles it looks like the overall length of the megaphone is changing?? Is it possible to keep the length constant with a custom made tube between? I can donate some Watties golden peach tins -- with or without contents -- if that helps.

[@Garage4age]

Yeah its hard to test, bad science. as isn't really possible to keep the length the same, without changing something else. if change the straight section before or after, its going to do stuff. possibly running it open after the megaphone would be a better test. but the length still changes. plus i have zero interest in running without a muffler.

[@jareknowak8712]

Imagine making a V8 out of this engine :)

[@samuelforsyth6374]

that bonnet stay gets some abuse haha, mean vids man

[@ilham7345]

ok this is now 2 stroke territory

[@deanharris9662]

Have you changed the different lengths of intake tubs?? Yet

[@Garage4age]

Is a lot of intake length content on here. setup on the car atm is dialed in

[@makantahi3731]

what theory is behind megaphone, it has some benefit for 2 stroke but for 4s?

[@nzuncovered1845]

Do you run the MRP N2 cam belt stabiliser idler? Would be interesting to see if there's any difference with one fitted on the dyno.. I've noticed Honda B series have an extra pulley on the right side because I think the water pump is driven by the cam belt, also noticed RBs have an extra cam belt idler and 4AGE doesn't

[@Garage4age]

I had one on there for awhile some time ago, not anymore. I dont see how would be any difference in power, unless was some kind of weird harmonic going on. Remember B series spin the other way, the tensioners are on the unloaded side of the belt on both engines. So is a straight pull on the cam gears.

[@nzuncovered1845]

@@Garage4age Apparently the belt wobbles around quite a bit at high RPM on 4AGE and it can mess with the exhaust cam timing and ignition timing. RBs have this setup and the Hasselgren FA engine runs it. I dunno, I just think it would be interesting to see if power is affected

[@Garage4age]

@@nzuncovered1845 I'll put the camera on it next time i run it up. see how wiggly it is. it runs a crank trigger so ign timing wont be affected.

[@nzuncovered1845]

@@Garage4age Ok sweet

[@nomadworld6192]

Have you tried that anti reversion cone? I am not sure that thing really works.

[@andydarbo7450]

you tried the cone wide to narrow to wide again

[@tlovsoe4211]

test stepped exhaust headers and give bsfc data

[@DatBlueHusky]

you should try unequal length headers

[@ThePaulv12]

You've been watching DV - I can tell LOL. What my takeaway from that episode was it works on V8s that are cross plane (so most V8s) but not on flat plane crank V8s. Essentially a 4 cylinder is a flat plane crank engine so they'd be unlikely to work but hey citizen science could prove otherwise.

[@CL9k24a3]

​@@ThePaulv12it worked on that v8 because of engine design /firing order. That header was not done at some rantod uel shit but it is done at calculated lengths for specific engine. He also stated in that video that difference of 2 inch on 4 cyl engin will cost you a race. For this type of engines header has to be equal. On the other hand I have seen el and uel header test on subaru brz and it makes nod difference.

[@dominicanwar363]

What you are doing is Fricking awsome! If you could change the length of the pipe to the expansion chamber, I suspect you could change the effect. In theory by dynamically changing the length (dependent on load = flow), you could optimize the supercharging / scavenging effect over a wide rev range. BTW, valve timing overlap will really start to matter now.

[@Garage4age]

yeah exhaust stuff is hard to test, especially when end goal is making it work on a full system. even here with the megaphones, the length is changing with different angles. If i get motivated will make a setup that i can change things directly after the merge.

[@Danleyson1]

Resonance tuning seems like it can quickly become a rabbit hole but it might be worth exploring with the 3" exhaust. Could be wrong

[@dfuent1988]

can you try adding a pipe inside the megaphone? like 2-3 inches inside the megaphone@@Garage4age

[@mattk9438]

can you do a test on that ep3 you had in?

[@Garage4age]

Its long gone sorry

[@ryandull6581]

Oi m8 what front lip do you got on there?

[@vytautastumasas]

Stepped Primary Exhaust Extractors ?

[@Garage4age]

The ones im using in this video have a step in them

[@vytautastumasas]

@@Garage4age it produced more power due to pipe diameter or stepped ?

[@Garage4age]

@@vytautastumasas My "big" headers were originally 44.5mm all the way, they made the same top end as the small headers and big loss down low. adding a smaller stepped section to the headers from the head. they made more top end. but still had the big loss in bottom end. this was tested a long time ago on a lower power engine setup and before i owned the dyno. they have more of a cone out rather than a step also. would need to do more testing to confirm anything

[@vytautastumasas]

I installed an exhaust manifold with a larger diameter than the exhaust port, I got 2 ag more, here is the same as stepped, or is a longer small diameter channel required for a better result

[@ItsDaJax]

I don't understand the point of an expansion chamber on a 4t.

[@jiceli5713]

any plans to ever consider a 2zz material?? please...

[@Garage4age]

Happy to do other engines If someone pays me to do it. these vids usually don't even cover the fuel bill unfortunately

[@jiceli5713]

@@Garage4age money it is always a factor damn it would be so nice for us and for you

[@TheSol115]

🚀🚀🚀

[@uwu3130]

interesting :3

[@tiitsaul9036]

Why is 10krp so sensitive to changes?

[@Garage4age]

do you mean the bump at end of the run? if so ignore. just dyno doing weird stuff. when car starts to go into limiter. i

[@tiitsaul9036]

@@Garage4age ah I see. Cheers.

[@crd-nz_001]

I thought that it might be valve train distress, eg valve bouncing off the seat. However, two runs at opposite times (not back to back) prove this to be incorrect as they continue to maintain power above 9500.

[@Garage4age]

yeah its just the dyno. gets a bit wiggly rolling over peak power on everything. kinda a combo of things why it does it worse on this car. its a bit over max speed. But also remember the real time graph has zero smoothing. If engine floats the valves its game over on this one. lets just say there wont be any carbon build up in the valve pockets

[@tiitsaul9036]

@@Garage4age I'm amazed with American racing V8 running 10+krpm with pushrods and humongous valves.