B18C: T/B and air intake question...
 

I am almost ready to get a full tune on my Civic finally. Motor is a B18C (GSR) with ITR cams, ITR pistons and a Skunk 2 intake manifold. The downside of my motor is I am still running a oem B16 throttle body and a Password JDM carbon air intake/filter combo (aka whale penis). I know my throttle body is too small, and I have heard the air intake I'm using is crap. Before tuning I am going to upgrade these parts. I need help on which size throttle body to buy and also which intake is "the best" or at least better then what I have. I will be buying a BPI velocity stack/filter combo to go with my set up. I will probably go with AEM short ram, but a local performance shop also makes custom fit short rams that I can pair with my BPI stack. Does it really matter which brand short ram I use? I will be port matching everything before the tune also. Any advice will be appreciated. Thanks.

Re: B18C: T/B and air intake question...
 

What header are you using?

What kind of power are you expecting?

Honestly, I would tune with what you got and then start throwing parts at it to see what kinds of gains you get.

I'm using the Password JDM intake as well, it works okay. My motor (stock usdm b18c1, s2s1 cams, s2 intake manifold, itr tb, spoon header) did make decent power, 187/130. I'm using this as a baseline.

Re: B18C: T/B and air intake question...
 

For now I have a JDM 4-1 header, OEM. I was expecting with a tune and the parts I listed above installed around 185-200 whp. If I topped that I would be very happy.

I have had several people tell me that AEM short ram makes more power than a PWJDM Carbon intake. I have not seen dyno graph to prove or disprove this. What seems to be the best combo is a AEM "style" short ram with the BPI velocity stack/filter combo.

I really need some advice on what size T/B to use with my combo. It will be port matched to intake manifold and I'm going to throw a Hondata gasket in the mix too.

If it were really beneficial I would upgrade my header also.

Re: B18C: T/B and air intake question...
 

I'm already running test pipe and full 2.5" exhaust.

Re: B18C: T/B and air intake question...
 

I would send the TB to Maxbore.com. They can make the TB 64mm and still maintain OEM reliability, all for $100. It would be a good idea to upgrade you header as well. Any name brand header is going to be super expensive, so you might have to settle for one of the cheap knock-off headers. If you choose to get an aftermarket IM then get a Edelbrock Performer X, if that is out of your price range then a Skunk2 is a close second in performance. Neither have to be modified to accept a 64mm TB. A 3" cold air intake will produce more power than either of the intakes you have listed above. good luck.

Re: B18C: T/B and air intake question...
 

The PWJDM is worst, AEM shortram is better, same intake with a Bpi stack is even better, 3" AEM CAI is better still, same intake with a BPI stack is even better, custom tuned to length intake (always longer than a short ram) is awesome, same intake with a BPI stack is best intake you can get...all in that order.

The stock TB isn't as bad as you think mainly because you are still only running stock cams and replica of a stock intake manifold and Gsr block. Upgrading it to something like a 68mm will do little for power and probably cost you some throttle response. It is the LAST part I would consider swapping out until you have bigger cams and/or larger bore or more compression. Once you consider upgrading it, I would also sent it out to MAXBORE.

Re: B18C: T/B and air intake question...
 

Here is a link to my Intake System Upgrade. Might give you some ideas.
https://honda-tech.com/forums/all-motor-naturally-aspirated-44/gsr-intake-system-upgrade-2671606/

I have a very similar build to you, ITR cams and ITR pistons.
My throttle body was sent out to RC engineering and bored out 64mm.

Re: B18C: T/B and air intake question...
 

After a little more research and consideration for my driving conditions, I think I should go with a short ram intake with a BPI velocity stack. Possibly a AEM, but if the shop in H-town can custom fab one for me that can perform as good or better then I'll go with them. Still probably going to upgrade the T/B, I want one that will leave me room to upgrade motor in the future but how big of a throttle body is just too big. Most power I will ever make all motor will be in the 220hp range, that is the long term goal. I'll probably stick with my Skunk 2 intake manifold as well, it's the old school one. I thought of upgrading header, but don't have funds to go all out. Would a Hytech knock-off out perform a JDM ITR header? I hate to buy a knock off part, for now it would just have to do.

Re: B18C: T/B and air intake question...
 

I don't know how much a difference it makes, but I said earlier I was running ITR cams. They are CTR cams, not ITR.

Re: B18C: T/B and air intake question...
 

congratulations on taking good advice....