K-Series Throttle Body Comparison Dyno Testing - 8Th Gen Civic Si 

I have a 70mm on my 260 hp na .. love it

Did you watch the rest of the video? People also say that a 3” exhaust is too big for an NA 2.0, 3.5” intake is too big for a 2.0, etc… point is you gotta test and see, theory takes a back seat to actual test results.

@boblast5582 Exactly! And sooo many independent 3rd party tests have been done in the past to back up that with a stock block and with the best boltons, making 245whp on a Z3/A2... a 64mm TL throttlebody makes all the power and any larger and there is no gains. If you watch tests from non independent 3rd parties, aka they have personal-stake/vested-interested in claiming higher because they sell them, then they play plenty of tricks/scams to get you to believe their hype.

engine masters did a test like that, but on a v8

the spacer actually helps a lot - LHT did a spacer comparison with a Mugen FA5 and it gained about 6hp on a stock throttle body

For sure

I live in Florida, deleted mine. If there is a difference, it's marginal. Have yet to hit a dyno so no hard numbers, but it's nothing noticeable..... During warm weather lol When temps hit the 50-60s down here, the car pulls noticeably harder more consistently than before the delete.

really u loose cruise control

facts

Check description

Like Nick said it’s something you won’t notice on dyno but it does definitely makes power response much more greater on your car.

Me too

While NA the throttle body becomes a restriction of the engine sucking in air, In a boosted application, the air is forced through so I doubt there would be any different

Heard it has issues

If the USB cable reaches, you could definitely use a windows based PC

I am also wondering 😂

Run it at 3k rpm for 5-6 minutes to do an idle relearn

I personally had that so I could comment something useful :D stock RBC and 72mm TB = Felt barely anything, but heard a lot more air suckle noises inside the engine bay Inlet ported RBC and 72mm TB = Instantly improved throttle response, and felt much peppier then I got tuned by nick shortly after, felt incredible until my clutch ended itself. Just couple weeks ago installed stage 2 clutch, lightweight flywheel, and fully ported RBC (same mods everywhere else) Fully ported with 72mm TB = holy f**k what a lively difference. Granted, old clutch was destroooyeeeddd, so may have some power loss from the get go. The drivability improvement is worth it 100% though, just slight revs are so responsive, you can tell the car is tasteful and not some half-effort modded.

@@mykov3677 thanks for all the info good to know

@@Onelovej absolutely, I haven't uploaded in a while but check out my build as of last summer, not the best video and not much changed I dont think, but I'm hyped to do a vlog update by next spring. Only thing I really added in this year is a 0km OEM FD2 Type-R cluster, and the fd2 type-r steering wheel. & lastly touchscreen dual din deck. Otherwise been slowly recovering from a fat fall in life lol

@@mykov3677 right on I’ll check it out🔥💯

He is not doing charity work brother

@@ModernWarfare924 I’m not asking it for free bro not that kind of person

@@MrCrowley925 mmmmm don't try to mod your parent's car...Stick to Cod for now with that sentence structure. I like that you're repping Honda though, so you're on the right path #hondagang

the manifold was already port matched to the biggest TB

@@jesselee4405 Then, get another manifold, and port match it to the next throttlebody, so on, and so forth. It's not a good comparison unless it's apples to apples comparison. Port matching to the one you secretly are wanting to praise, is cheating.

yep thats what it is, u paid u expect pschological gains 😅

no traction so try second lol

yes port matching is a must! but for budget newbies who cares about bolt ons - it is informative :)

@@salteveline It's misleading is what it is. It must be an apples to apples comparison. Hondata has done a ton of tests... and it was over 10years ago... and they found that going from 61mm to 64mm was "About 2hp from 6000 rpm up and pretty close to the margin for error of the dyno. A bored throttle body will probably show better gains if tested with the Toda N2 Cams, but it is pretty low on the bang for the buck list at this point." The fact is, as you go smaller on your throttlebody, there will be a point where the engine will be able to out flow throttlebody, and the throttlebody will begin to become a bottleneck. For a stock motor, with full bolt-ons that size is about 64mm, as the results of Hondata's test. The other side of the sizing also causes an issue. As you go larger on your throttlebody, there is a point where the engine will be flowing to its max potential and then eventually the throttlebody will become so large that it becomes a large resonator/chamber where the air is not able to flow properly and becomes a hindrance. For a stock motor with full bolt-ons that size is about 70mm, as the results of Hondata's and many others test. As you can see there is a window where the sizing does not hurt you, outside of that window you will lose power... and therefore, any throttlebody that is 64mm up to 70mm, on a stock motor, you are plenty large enough. If you have no bolt-ons, then your window may be 60mm to 64mm. If you do all the bolt-ons possible (intake, header, exhaust, intake manifold, cams), then your window increases to 64mm to 70mm, where there is no loss of power. If the stock throttelbody on an RSX-S/EP3 was 60mm, then any bolt-ons would immediately throw you outside of that window... but it's not 60mm, it's 62.5mm (TSX & 8th gen Si is 61mm), which is why a throttlebody is way down on the list for bang for the buck list. Once you are full bolt-ons, then 62.5mm becomes too small, and you can have the factory throttlebody bored to 64mm and you will be at optimal size for all bolt-ons. This is what I recommend, that you port the factory throttlebody on the RSX/EP3/k-swaps if all you are going to run is stock block. There are a few companies that remove the stock butterfly, bore the throttlebody, and put in a larger butterfly... and keeping all the sensors, cruise control, reliability, etc that comes with the factory throttlebody. I recommend King Motorsports (they are the US Mugen distributor). Maxbore is another company, but I have seen very poor results from them, in my experience. Now, if you go boost on the stock block, or go with a high compression all-motor built block, then that's a whole different story, and you should get the aftermarket throttlebody. 70mm would be minimum on that window. Be prepared to silicone the heck out of it, as it has really poor mating surfaces that are not true.

@@copperkeyracing6167 thx for that post it is a good read 🙏🙏