Significant Gains from Manifold Porting

[Hondanickx]

Yes you could enlarge it by 1 or Maybe 2mm but that's about it .The Intake manifold needs to match the bore of the TB and the plastic wall is getting very thin.
I found out a long time ago when i was still working on my D-series engine that honda marks the TB plate with the bore size .
Every TB has a number stamped in the TB plate on the back usually 650 or 655 or something else.The last 2 digits is the TB size .
Here's some pictures of the Stock 1.5T TB and one of a 2.0L LX .
The LX tb has 655 stamped in it and the 1.5T TB has 650 stamped in it which means the LX TB is 55mm and the Stock 1.5T is 50mm.
Would be great if the Type-r manifold and TB would fit the 1.5T ,but i don't think the ports line up.

 

[turbociv910]

a ctr tb is 60 mm for anyone wondering

 

[Hollywoo0220]

Not having done this kind of modification, I would lean toward an increase in "head wind" and differing "fuel vaporization" accross the cylinders. Whether "fealt" to be beneficial or not, the smoothing of the air flow is reduced for both spatial and time symmetry.
All good ideas though....

 

[mtking479]

Only reason I asked is it showed an improvement on the 2.0 removing the fin in the manifold - i have experience removing it and having good results as well. If I can source a cheap stock intake manifold I will modify it and put it on - probably so some low level porting as well on the entrance paths if necessary. That's ONE part of the equation - and yes it's on the back side of the engine In all honesty there are newer civics in my local pick and pull and they have 25 dollar all you can carry days - i can get the manifold and other items for 25 bucks then take the time to port and it would cost my 25 bucks plus new gaskets an time only. I WILL do this.

For the front side - the pancake of the stock plastic pipe bothers me, this is a bottleneck once power starts to go up and it creates a bit of turbulence and disruption of flow, not a big deal on stock intake setup and power, but when you add more power, more boost, better intercooler and intake it will allow for more air. If cheap I would try this as a separate item and of course there are tons of ways to reduce the heat soak on the metal as opposed to composite going across the top of the turbo. These are all ideas for little tweaks and improvements only till I'm over 100-120k miles and when i throw a larger aftermarket turbo setup I looked back in Nov/Dec an noone offered an aftermarket solution, so revisiting a bit due to this thread discovery

Anyone can throw random parts at a car, but maximizing what you have and complimenting mods with other mods is how i roll

Did you end up doing this and what were your results/findings/gains from doing it??

 

[Myx]

Lately, I ditched my K24 manifold in favor of the stock unit, albeit modified.

What I did was remove the cutout that is located directly behind the throttle plate. I also radiused the outlets of the individual runners (not pictured).

This is designed to reduce turbulence caused by the throttle plate at part throttle, which increases fuel economy and smoothness under normal driving conditions. However, it does pose a restriction at wide open throttle, and removing it resulted in sizeable gains across the rev range, but most noticeably beyond 5.5K RPM's.

My injector duty cycle increased by 6% (from 74 to over 80% at peak) over the non-ported setup. My short term fuel trims increased as well.

In addition, I have also had MAP readings, particularly low in the rev range, where pressure was beyond atmospheric, suggesting that intake efficiency beyond 100% was achieved at certain engine speeds.

All in all, the car feels stronger everywhere, but especially at the top end. Noticeable power was also gained below 2.5K RPM's.

@DarkLight
It looks like you haven't posted on the forums for a few months. I just wanted to let you know that your information is being used. I had this done on my engine as it is being re-installed back into my car. This data you provided is very convincing. Every little bit of extra air counts. I appreciate it man.

 

[salik990]

@DarkLight
It looks like you haven't posted on the forums for a few months. I just wanted to let you know that your information is being used. I had this done on my engine as it is being re-installed back into my car. This data you provided is very convincing. Every little bit of extra air counts. I appreciate it man.

Do you felt any better response/gain/better timing after this?

 

[Myx]

Do you felt any better response/gain/better timing after this?

Car still in the shop. Honestly though, I never report what I feel since it's subjective. I always try to provide before and after data if I can. I don't expect to feel much of anything though.

 

[WhosClunk]

Any update on this? Would like to hear if anyone felt gains from this

 

[Myx]

Any update on this? Would like to hear if anyone felt gains from this

I can't say I felt anything from the mod I done above. I'm the worst person to ask though. I can't feel a difference if a car accelerated 1.5-2 seconds slower/quicker sometimes. I'd drive a car with a louder exhaust and it seemed faster but be slower. Then another one that may have been tuned with a stock exhaust that I thought was slow but it was hauling arse.

I always go to a track to confirm. Hate to give anyone bad info.

Sponsored