All numbers in KW at wheels. Engine setup: 16v 4age 300deg cams Supertech valvetrain 47mm itb's on garage4age manifold & trumpets 13:1 compression garage4age head work
I've run a shit-ton of headers on a 4A-GE. What you really want is a tri-Y setup with about 18" primaries and 12" secondaries. We would also tune the intake trumpet lengths to shift the powerband. The 1 & 4 on short (50mm on the TRD intake manifold w/ individual blades) and 2 & 3 on long trumpets (90mm). It would rip to 10,000 rpm for 500 miles at a shot on a road course and 350 miles on an oval. We'd blow them up all the time, too. It was all part of it. They can make a little north of 250 HP if done right.
So to explain to people what they are seeing. The small header has much higher air velocity. Then the air pulse gets to the collector there is a wave of negative pressure behind the exhaust pulse with higher velocity it helps with scavenging. Bigger is not always better, larger runners slow down air velocity making the scavenging weaker. It moves the band of peek performance for the header, up the rev-range. Also a year late lol
Ever thought about exhaust venturi at the end of the headers(extractors).I made my own exhaust venturi on my 2zz engine. Pulls hard all the way from 3200rpm to 8500rpm. The effect was quite noticeable. Excellent coverage. I agreeded with another viewer about 40 ml intakes instead of 51 purely to increase air speed which increases torque.
For this set up the smaller header better suited,of course you can try the steddep section for small header,or make the 4:2:1 header for more mid range power.
Great short test video! Basically the smaller one would be better because it has much more power in the 4500 and 5500 RPM range. While peak horse is only a few horses difference. I think if you add a big turbo you'd better off with the big headers.
First, thanks for the short and informative video. This kind of stuff is usually at least 20min long. Is the big header cheaper or easier to fabricate?
Thanks. I built the big header to see if there was any power to be gained with bigger diameter. the small gains from the big header at high rpm actually came from the stepped section. when i get time i will make some small headers with some kind of stepped or anti revision section. they both too about same amount of time to fabricate
Those are well thought out fabrication pieces... do you have a video on those builds.. are those equipment-length header pipes..? Keep up the great R/D that you dare to do..👏🏽👏🏽👏🏽🙏🏾👍🏽👍🏽👍🏽🇿🇦🇿🇦🇿🇦🇿🇦
I'd go big header with a lot of tuning around the big dip power drop mid rpm. But more importantly is gearing. If next gear change drops rpm above or below small header efficient area.
Go further on this kind of dyno test! If you want some suggestions you can try: a home built helmholtz resonator air box, different header lengths (from valves to the 4-1), different intake temps, 4 straight pipes with no 4-1 cut at different lengths, ecc
Hey buddy, I came across your videos and they are very entertaining and helpful. I subscribed and I'm fascinated by that little toyota of yours. I don't have an 4age but I have a Toyota Tacoma with a 2rz-fe l4 that has some mods here in the usa. Are you from Australia? Also does this 4age come stock with 13:1 compression or did you alter that? Thanks for your dedication and continue the good work.
Thanks. nice the rz's are solid engines. There is a few variations, this one comes standard at 10.3:1 compression . the highest they come factory is 11:1 on the blacktop 20v 4age. Im in new zealand
@@Garage4age Hey thanks that's awsome. Love the aeg4. Let me tell you that you might be giving up even some low to mid torque and response with having a 3" exhaust. Have you tried running a 2.5" all the way? You saw how much better the smaller header made power than the big one. The same is true with pipe diameter on these l4 engines.. I also have longtube header and exhaust but mine is 2.25" all the way with no step up anywhere. My 2rz has better response and torque because a 2.5" step up did not work, it only had a little better top end. The 3" might just give you a little more up top but you might get better response even though your engine is built and revs very high. You might be surprised how much the pipe diameter affects the engine response. Also I was hoping you could tell me how you ported your cylinder head. Did you enlarge the intake runners or you just did some bowl work? Are the valves bigger etc. Thanks you..
My findings are the opposite. after the headers and collector, bigger the better. it doesn't really do anything on a stock cam engine. but when there is a decent amount of cam overlap, need to reduce exhaust pressure as much as possible. at low airspeeds this reduces reversion. most of the gains are in the same place you see the gains in this video. with a small exhaust on the small headers the power curve looks more like the one of the big headers. if all goes to plan will have a vid showing this in a few weeks. this engine has the whole port modified along with bigger valves and chamber work.
@@Garage4age Cool, thanks for the explanation. It seems since your moving alot more air with your aeg4, the higher compresion and high rpm you have different results. I hope to learn more from your testing and you have really done amazing with the car.
excellent video proving diameters and velocity. From your experience, what would be your recomendation in primaries diameter for a mild 135hp@wheel 4age with cams? 35 OD? 38 OD? cheers!
So how small can you make them? I've been reading from a well known pro-stock guy and he usually makes the initial pipe off the head anywhere between 10 and 25% smaller than the port while getting low down gains without hurting top end. (They are stepped headers, up to 3 steps, so they end up at normal diameters) Some of his stuff is also 4v and he got really excited when someone gave him a new coyote motor with a 1.5" ID round exhaust port at the flange. He put 95hp/cyl through a few inches of 1.625" pipe before stepping up. It's entirely possible that remaking the big headers that you've abandon because of this test into a set that *smoothly* shrank to below port size for 6-10" before stepping up a couple of times will yield killer low down gains while keeping the 3kw up top
Wow the 4hp peak gain is just not worth losing upto 25hp in the 4000-5000rpm region . That's a pretty built engine, you'd think the big header will really perform at the top, it must be chocked from the header back exh system or is it open?
Being that Dyno results are always from full thottle runs, what is real world drive ability like between the two where you're not always giving the berries? I'd imagine the mid range torque increase would be much more noticeable under medium throttle conditions?
On the street the big headers are fine at light throttle, not much difference. The further down the throttle it starts felling quite flat going through the dip at 4000 -5000rpm. which is where its driven a lot on the street. with the small ones its like driving a different car, so much better.
Hello, what fuel do you use? Because I see that you turn at 13:1 of volumetric ratio, I’m also at that level of volumetric ratio in my car but I can’t pass 6500rpm it saturates....😆
very minor peak horsepower difference, but look at how much better the torque delivers with the smaller header, you gotta consider the tprque curve on this one id leave on the small and tune with them
Around 10mm and same number of bends on the big ones. Small i had a few things to work around at the time, so one of the runners has an extra bend. Still pretty close to equal length on all 4
Thats NA tuning for ya. Its not easy making this kind of power on a na 4age. Also thats around a 25% gain at 4500rpm, which most people would think, "comes on cam at 5000rpm" and not an issue with exhaust.
I wish someone could dyno a standard 16v two vids one with cheap coby extractors for 280 an another dyno with some them big banana ones that like 1000 bucks or something I wanna know is there really much difference an is it really worth spending an extra 600-800-1000 more. It just seems silly.
its already at best timing. can go a few degrees either way on this engine and zero change in power. have played with timing on both headers in the past. but not on this back to back test
Good luck. the corolla FWD OBXR E-bay headers are paired to the wrong cylinders. (2+4) + (1+3) SV3power headers are the design you want but the original builder quit making them. (1+4)+(2+3)
The torque scale is way off. I calculated that at about 4750 rpm the smaller headers are picking up 35Nm. That's truly insane because the car is developing a peak torque of 185Nm @ 5000rpm. Almost 20% torque gain =/
Also, the collector of small header could be more advanced. I say this because it looks more like modern f1 collector and big header look like 1970s American v8 collector.
@@Garage4age 1-375" OD that's actually relatively small for a 4 pot at this power thought nthe bends are fairly generous unlike some you see. is that the same size as ex port exit?
@@findtherightbeat another one again. but more similar to the "small" ones. this is actually the same "good" engine btw. just has had a few changes since this video
