ITBs are generally known more for their throttle response and sound instead of big power. That being said, the “wall” at 8000 could be due to a multitude of things, from the head package (cams, ports, chambers), to exhaust pairings or primary sizes. My guess is you guys need a biger cam with more duration for the flow requirements of the ITBs. EDIT: Going back to the engine build video, the cams used are the Drag Cartel 003.2 cams, and the dyno chart on their website shows peak at 8000 RPM. The Hoonigan Skunk2 K24 10K RPM build used Skunk2 Ultra 2 camshafts. (EDIT2) The drag 003.2 specs: Intake: 13.8 mm Lift / 254 Duration @ .050 Exhaust: 13.2 mm Lift / 250 Duration @ .050 The S2 Ultra 2 specs: Intake - Lift: .560"/ Duration 270° @ 1mm Exhaust - Lift: .535"/ Duration 270° @ 1mm Thats a big difference in duration 254/250 vs 270/270… (EDIT3) Corrected the Skunk2 duration @ 1mm lift (EDIT 4) Converted cam specs for @dooby1445 to show I’m not a caveman: The drag 003.2 specs: Intake: 13.8 mm Lift / 254 Duration @ 1.27mm Exhaust: 13.2 mm Lift / 250 Duration @ 1.27mm The S2 Ultra 2 specs: Intake - Lift: 14.224mm / Duration 270° @ 1mm Exhaust - Lift: 13.589mm / Duration 270° @ 1mm
Just to restate what was already said in the video: we're not super impressed with the power the car made, but making horsepower on small, NA engines is all about finding the perfect recipe for flow. Nothing on the exhaust side has been optimized yet, and we have a lot of brains to pick in the all-motor ITB community about what the best combo is for power. Here, we just wanted to get the car running and driving. Can't wait to revisit the dyno with more of a game plan to make power.
with the ITB's you need to look at pulse timing between the exhaust and intake, you may find playing with trumpet lengths as well as ex primary lengths may where your extra power will be hidden, it might be worth putting a single throttle manifold with longer runners to see what it does to the power.... these are things i have played with when converting to ITB's because they generally dont make the power initially you think they will....you have to find it
And if Andy is going to build headers for it bigger isn't always better, keep your primary tubes down in diameter to keep the exhaust velocity up.... 1 3/4" stepped up to 1 7/8" and I would think about 24" long to the collector 4-1
@@I_know_what_im_talking_about And that's how someone should state their opinion, some people say everyone else is wrong and dumb whereas what they think is just the best/only answer. Mad respect to you 👍
@@I_know_what_im_talking_about I think longer stacks sound better there is a different in sound depending on length and such plus its in a metal garage so yeah its gonna be some earrape
I like how this video shows that not all Dyno runs or engine swaps are a success like RU-vid conveys. It’s way more interesting seeing you guys trying to troubleshoot why the engine isn’t making as much power compared to watching another 1000hp dyno run video on RU-vid
That’s it right there. I’m so much less interested in the next ultra fast RU-vid build. That’s cool too don’t get me wrong. But as a dude who drives a 350Z, I’m much less interested in annihilating the 1/4 mile or high speed highway runs as I am a well developed dynamic streetcar build. There’s just more character there lol.
the resonance length of the ITBs needs to be tuned in sync with the cam duration at a certain RPM where you want to peak; you want the pulse generated by the valves shutting to bounce back and fourth in the ITBs and return just before the next close of the valve. Ideally less bounces (longest possible pipes) gives you more of the effect.
Its worth adjusting the intake runner length for sure- But hed be chasing a single digit for HP here. He more than likely is just being limited by his cams. Theyre drag cartels "street" cams with only 254/250 duration. Theyre mild aimed at meaking peak power by 8k rpms.
Longer pipes are better for low end torque. The longer the pipe the longer the travel time. If anything they would need to be shorter, but most likely a cam duration issue.
@chippyjohn1 Most ITB kits far cars are limited by packaging, and so are shorter than they should be. In order to not hit the shock tower or require a hole in the hood, ITBs for the K usually have super short runners like a sport bike. Most tests I've seen of trumpet length favor the longest ones you can possibly fit. The ITB kit for NC Miatas uses curved trumpets facing forward, something like 2 feet of length from.the valve to the trumpet end, and that kit makes 225bhp at 7,500 with pretty minimal non-VTEC cams. Ben's ITBs are less than half that length, which says to me that they want like 14,000rpm. Obviously the cams and the exhaust will have gone to sleep long before that ever happens. But the point is, all this stuff is dependent on resonance and timing. An engine like this has to be treated like a 2-stroke. Bulk flow is secondary to resonance timing. The exhaust and the intake must match the RPM target, and the cams must not get in their way. Most importantly, you have to at least know what you're working with in terms of length and resonance timing. Simplistic ideas like "good" or "big" have little value at 10k rpm.
The ITBs are rad as hell but please try running it with a single throttle manifold and intake tube at some stage, if nothing else it'll at least tell you if the ITB config/setup is the reason for the power issues. This series has been really interesting so far and I'm super keen to see you get to the bottom of what's going on here and finally perfect that engine setup.
I agree. Maybe I’m wrong, but I’ve only seen ITBs outperform across the power range with higher (13.5 and up) compression and some sort of race fuel like m1. They sound cool though…
Yeah that’s what I was thinking, take off the itb and do what they have been troubleshooting with and stick some of the OEM stock variables back on like they did with the exhaust header. Run it with the OEM spec then one by one swap bolt on mods and see what’s improving the numbers
Hmm, I think they need to do some basic engine maths (inlet velocity, exhaust velocity and the way that's matched to the cam profiles etc) before just trying random parts! The maths (or math in American English) will show guidelines of the cam profile required, inlet runner diameter and length, exhaust runner diameter and length etc required, before then dialling it more precisely with trial and error on the dyno. No race team would try to design an engine without doing the maths on it. 🙂
@@ziglol "Maybe I’m wrong, but I’ve only seen ITBs outperform across the power range with higher (13.5 and up) compression and some sort of race fuel like m1" Obviously this is a 4age- but ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-lnGvIfwjYis.html This is a great video, and great channel to watch. guy has been "Testing" different things on the dyno for ages, some of them are funny things, but many are serious as he looks to improve his engine. This video is a good "milestone" video, showing how the engine responds to various popular changes, and then his extreme ones as hes pushed the limits. of note in this video: He goes from various stock manifolds, to an ITB set up, and shows the power change. Its not insignificant, and hes not running crazy compression- 10.3:1. The itbs arent the problem with this guys set up. Though the trumpet length may be worth checking into (Fun plug in again: that guy i linked has one with him testing numerous length runners for the ITBs to find the ideal length for his engine), the biggest restriction is more than likely, his cams. Hes running 003.2 "Street" cams from drag cartel. Like the name implies- theyre street cams, and rated to make peak power by 8k rpms. This is undoubtedly the biggest restriction for making more power. He needs more cam- plain and simple.
Double check valve lash, after getting my head redone with DC 2.2’s we were struggling to make power every hit it started making less power(got all the way down to 185 at one point), so i left it at my tuners shop and he re set valve lash and ended up making 226whp on a mustang dyno which are the lower reading dynos. Previous to the cam install it made 212whp My setup: K20a2 -54mm ITB’s -Skunk2 megapowerRR header and 3” exhaust -DC 2.2 cams -E85 -Supertech dual valve springs w/ titanium retainers -Stock bottom end -Still running power steering and a/c
The most important thing when building a naturally aspirated engine is pulses and harmonics. There are calculators online that show you the ballpark of intake and exhaust lengths for your cam setup.
There are plenty of ways to build just for insane power numbers. When I had my B18C1 swapped Civic, I obviously wanted power but the joy I found was in light weight and lots of revs. I didn’t get into seriously wild setups, but I rebuilt the block with higher compression and she revved to 9000, made peak somewhere around 8300. That car wasn’t about making 400 HP, but she weighed less than she did stock (even with several hundred extra pounds with the swap), and she revved and made amazing noises. If I ever did it again, I’d go for that kind of setup over tons of power. And I really respect what Ben is doing here for the same reasons.
It was my understanding, I may be wrong, but 4-1 headers work better for higher rpm power, while tri-y headers are better for midrange power with a sacrifice of high rpm power? Maybe try a 4-1 header.
I can’t believe they didn’t AUTOMATICALLY opt for a 4-1 header with the initial plans to rev that high. That’s like basic high revving Honda engine 101. 🤦🏻♂️
Tbh I thought waaay more power. I know Cosworth made some Duratec motors with ITB go up to 250-300 depending on the capacity. But I’m sure you’ll get it where you want it to be and you got a great team to help you! Awesome work guys! 👍🏻
The K20A never raced in an ITB class of touring cars IIRC (i.e., super touring), but even with a single throttle body under Super 2000 rules, Neal Brown Engineering K20A engines make 280bhp (at the engine) on a 8500rpm rev limit. Tegiwa have a video on their ex-BTCC Integra Type R race car. 🙂 Sadly the lack of basic engine maths and engineering calculation before building this engine seems to have bit Ben!
Esslinger makes a bunch of the racing duratec motors now. 260whp/220tq would be easily accomplished in a 2.5 for less than 8k if you go 13:1 compression
Ignition, cam timing, inlet and exhaust port flow, exhaust flow and fuel and air mixture is all about n/a engines. I'm all n/a myself, never really been into boost as I love ITB bark lol. I love the Vtec crossover btw, insane bark 😍😍
I love how you guys eclipse the truth behind building awesome cars. Not everything works out how you plan but it’s the journey and knowledge gained from it the makes it worth while. Great video
@@chrisvera841 ya, e85 has an insane octane rating, so for FI builds ot makes it so you don't have to worry about knock as much, meaning you can run more aggressive settings
E85 doesn't do much on an NA motor. And ITB's aren't meant for huge gains in power. They are meant for better throttle response which is why he stated ITB's are heavily used for racing applications.
In the process of chasing this same goal with my S2000. I've got the ITB's on an essentially stock F20. I hit 217 to the wheel. Cams are in my future. My goal is also 250 to the wheels. Excellent series of videos. Sounds AMAZING over 9k!
Man...I chose the wrong career. This seems so fun. I'm sure there's a lot of frustrating moments we don't see but it's just so cool to build stuff that like.
Really loved the series. I feel like I'm living vicariously through the builds since I would do similar things; especially wanting a 10k rpm screamer driver and not caring about the power. Meanwhile, I'm just starting on my TRD front strut brace for my GR86 and hoping that adds the rigidity up front that I'm looking for since So Cal roads aren't getting any better, and I swear roads are wearing out faster because EVs are already heavy and SUVs/trucks dominate the market. This S2000 build is something I would do with lottery money.
Motorcycle Tech here, What you got is what i call a "BIG GULP" build, wack open the butterfies and it takes in a huge gulp of air. great for bottom end numers but you lose needed velocity at higer RPM's. You need the "BIG SUCK" to get the better flow at topend. velocity is everything. Looks like you would benift from secondary ecu controlled butterfiles and secondary fuel injectors. TL:DR Big suck vs the big gulp. BIgblock enduro single: Big gulp Highreving superbike twin: Big suck Play around with the exhaust all you want, that intake is gonna make this car a pain to drive on the street
I have a k24 bottom end with 12:5.1 pistons. Stock rsx type s head, rbc intake. Running on e made 235 to the wheels. Definitely think you could squeeze some more power out of that setup. Something isn’t right.
i have read before that going with the biggest itbs you can find isn't the way to go, and for each head and runner size there is always the "right" size itb that you should go with for the most power
I own a 00 s2000, Look into ballade sport's header. I have seen and talked to a couple people and they seem to make the most power N/A if you can run it on the K20. I would also look into maybe even a more aggressive cam setup then what you currently have If you're looking to make power past 8k rpm(which is crazy, I know). There's definitely more power on the table with this setup.
European and Japanese K20A from the EP3 Type R made 200hp originally and you could bump up the HP even more just by changing cams, valve springs and a tune for example. Check out for a European K20A head from the Type R as it has better flow. 👍
instead of headers try longer intake tubes for itb. and i noticed the muffler has wrong diameter. tubing for n/a k engines is ideal 2,5" we have simmilar setup on our racing engine 300hp k20 and can rev 9900rpm after a lot of dyno runs we switched back into skunk 2 intake manifold and its more usable this way. engine is in Noma M20 SC racecar and it won a lot of national hillclimb events
I know your pain and i understand the optimisation needed for high revving engine. Had done the same thing in my honda but its only a D15. Its revving to almost 9k and a lot of carful thinking and workarounds had to be done to make power that high. I would suggest maybe a different cam. One that has a bit bigger lift and a lot longer duration because at that high rpm engine needs to breathe as best as it can and cam will do just that.
I was wondering whether a stock port head would hold them back with cams and ITBs when they first put it on. I'm not an expert or anything, but the only advantage ITBs have is massive flow. If you're running them on a stock head, it doesn't seem worth it.
@@samnolte749 Unfortunately with all motor you have to do alot of work to the head and have non restrictive valves, and you need alot of compression. I wouldnt have even used Itbs, they just suck for street use. I would have went with minimum 13:5 compression. Most likely if I was going all in it would be 14.5:1 to 15:1. above that its very nock sensetive even on ethanol.
Honestly I wonder why he committed to ITB's. Like if he knew he was going to be throwing in a K20 and that the lack of torque would be less than ideal then why not supercharge it?
@@seagullsays5831 he's building a high rpm NA 4cyl with a usable amount of power on the street for the character and sound of it, listen to what he says in the videos
@@seagullsays5831 Oh 100% it should. It appears they didn't pay much attention to the cams they chose (the description says peak at 8000) or the ITB runners they chose, which are too big to generate the velocity they need at those rpms. They also didn't do any head massaging. So from what I can tell, there wasn't enough homework done on the build choices, and this is the result
reminds me of a teaser for a Sport Compact Car feature car: “we can’t tell you what we’re doing to it next month, but it rhymes with ‘splindividual flottle toddies’” RIP SCC
Both this and Civic have power on the table in the Valve Job. Specifically the seat angles. I was not surprised when the civic was down on power last year after seeing how the valve job was done. The K is an amazing flowing head stock and that equates to some very high efficiency of flow past the valve and seat requirements. I've been part of back to back flow bench tests where a gain of 10+ cfm was had with just using a different valve seat multi angle cutter. Have also seen losses just as big when it's wrong.
@@RollingRoadEFI rule of thumb is 1 hp per CFM. So a sub par valve job will absolutely hurt power and an excellent one will increase it. Especially at high rpm when the most amount of air is trying to move through the engine
Pro Tip: 40% ethanol provides a VE bump above all other concentrations of ethanol. So if you don't need more octane, e40 is the best ratio for an NA build.
A friend of mine faced something like this power restriction and it turned out that he needs an airbox for the ITBs to have a better airflow. After that he gained some power. Great content!
I have the same build, similar starting point, and similar goals. Thanks for the inspiration- mine has been 3 years going and yours is getting done way faster 😢
Don't worry, taking your time often results in more detail work being done. Also, I assume you do most of the work yourself which in and of itself it admirable to say the least. (Obviously, no offence to Ben and the boys!!) So take pride, and when the time comes to roll around like a 'baller', the enjoyment will be even greater!! ;) I recently started a new build and I recon it will take close to 4 or 5 years to finish. Most of the work will be done by me and my father. Whereas paint, cage and ECU tune will be outsourced when the time and money is there. (The build is complete with engine swap, bigger brakes and the such...) Close to Pro-Touring to say the least. Then I look around and see whole teams do a similar build in just a few months :O .....
I agree, I’ve raced motorcycles and what I’ve realized is that even though HP is great to have. I’d rather have lower HP for better power delivery and handling. I’ve got my 350z tuned and specifically talked with my tuner with the understanding that I want usable power and torque to balance out my handling. No I race at VIR and some other tracks and the plan works well.
ITB's really benefit from resonance tuning, particularly Heimholtz resonance. -Caveman explanation time (TL;DR): Intake valve closes, air still have momentum. Air slam against intake valve backside, it pressurize. pressure shoot back out trumpet. Once pressure wave exit trumpet, ITB at partial vacuum. Nature no likey vacuum; air (positive pressure) rush back down ITB. If timed right, positive pressure wave reach backside of intake valve as it open. Extra air enter engine while valve is not full open, then engine give atmosphere the good suck. This cause increase in Volumetric Efficiency, and more powah. -Non-cavemman explanation: ITB's work best when they're treated more like a 2 stroke expansion chamber/exhaust pipe than a standard intake manifold. Just like an expansion chamber in a 2-stroke, there's a certain RPM range where the dynamics of the pulsing pressure waves (explained above) are timed correctly in relation to engine speed, and cause a natural supercharging effect. This phenomenon is directly influenced by 2 things: real-time air momentum/density (measured in real time seconds and not in relation to crankshaft degrees), and physical runner length. This is one of the reasons why the LaFerrari has infinitely variable length intake runners (which are ITB's). Those runners utilize stepper motors and a linkage to extend or retract the trumpets closer to and further away from the intake port, and have the adjustable portion of the trumpet moving inside the port-side portion of the ITB as 2 sleeves; the upper/adjustable portion slides in and out of the lower portion, allowing for very finite control of overall/effective runner length. -The general rule of thumb is that the higher the RPM, the shorter runner length you want; and that's true for both intake and exhaust runners because of the real-world amount of time the air charge has to enter and exit the engine. With that being said, on multiple cylinder engines, that's not always the case due to pressure wave spillover from one trumpet to the ones adjacent to it. -Which is why it bugs me that no one has ever considered attempting a motor-actuated exhaust header (at least in an experimental setup) that adjusts the lengths of the header primaries throughout the RPM range and makes them shorter as the RPM climbs.
Time to call Spoon good video hope you guys get it sorted out. I'd venture to say its a combo of the ITB with other parts as others have already stated.
Try playing with the ITB trumpet length and cam timing. I know shorter trumpets typically resonate better at higher RPM, but you gotta just play with everything, everything you change changes the resonant frequency of everything. NA is a trial and error tuning process, i mean Garage-4AGE can attest to that. Check out his adventures in NA power if you want, he's getting 220hp out of a 1.6. Try shorter trumpets, longer trumpets, advancing the cam timing, and pulling it back, and every compbination of those you can. Try changing when VTEC comes in to help tune out that dip.
Tuning ITBs on F20s and K20s has always been a pain in the ass with low returns. Almost every build has been track only for that reason. Hit up Js racing if you have questions.
You need to restore the body and do rust prevention to match that engine. For exhaust, use Hemholtz pipe to eliminate drone boomy noise while keeping tones.
So funny story, I just had my car on an all-wheel drive Mustang dyno, with linked rollers, front wheel drive car, on the draggy it did a 7.81 second 60-130, and 129 mph trap speed. Dyno was 280 WHP and 300WTQ at 32.8 psi on an HX35. I think dynoing a two-wheel drive car on an all-wheel drive dyno with the rollers linked is going to cause a huge drivetrain loss.
