I have a B18C1 in my 1995 Civic. I am looking to retain my stock GSR throttle body and stock GSR manifold. But I want to bore the throttle body and port match the manifold to the new size of the throttle body.

I'm looking for all available shops in SoCal that can do this CORRECTLY.

I know I can go aftermarket, but I want to keep a perfectly stock appearance for stealth, smog, and legal reasons.

 

http://www.maxbore.com

you can do the portmatching of the im with a dremel

 

http://www.team-integra.net/fo...age=1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Originally posted by Jacksont001 on Feb/01/06

Today we talk about matching ports for flow, including The Throttle body, the Plenum, Runners and intake head-ports. So Strap on your pro-tec helmets and buckle up your seat belts because the Short bus is on it’s way!!!

In previous installments I went buck-wild on the combustion chamber, and that portion is very near completion. What remains to be done on the head is the make the ports align with the runners, open them up slightly, and do a mild porting job. When that is finished, it is going to get NEW valves (high compression ones) and a valve job done by a pro.

Remember, frugality is good, but reality is better. There are some things even “I” wouldn’t do with a Dremel, and a 3 angle valve job is at the top of the list.

So we start with the Throttle body.
Currently I will be re-using the original TB. The Intake Manifold is from a Type-R so the opening is larger. The problem is the transition from one to the other will create a separation bubble and restrict flow. Later on (when I get big & nasty cams) I will need a larger TB (read – bored out), but until then I will use what works.

Tools will be a scribe and a Sharpie © brand marker


Slather up a nice coating of marker juice on both the Plenum and TB surfaces




Next use the gasket as your reference. The plenum is the same size as the gasket, so the best bet would be matching the TB to the gasket. if you want to use this method and you are using a different manifold, use the scribe to scratch a line as an outline of the gasket opening.







Line up the gasket on the TB, and scratch an outline. This is your reference for comparison. Ideally you want to match the Plenum and TB openings together, but you don’t have to OPEN up the plenum and TB to match the gasket.







For MY situation, I plan on running a larger TB in the future, but I want to aid the airflow on the Current TB. The risks are if I remove TOOO much material the seal would be compromised near the sensor opening. My goal is to bevel the edge like a valve seat, to make the turn more gradual and eliminate the separation bubble.




Remember the MOST you should bore out a B18 A/B TB is 2mm over.

Not too shabby?


Now Time to turn around the TB and look at matching the inlet side.

I will be using a 3inch OD intake pipe fed from a custom air box. The problem lies in finding a piece that will transition down from 3 inches to the OD of the Throttle body.

Michael Delaney has often posted this picture of a “mega tube” connector. Well MD, I have figured out Where that is from, and for $2 buck and two cuts I can get you one…. Stay tuned!


If you have been around a while you might have heard the term anti-reversion thrown out there. Basically it is a sound-wave trap, it allows air to flow well one direction, but it also helps limit flow and pressure waves from going the opposite direction as well.

Here is an example of an anti-reversion chamber that Hytech uses on their headers.




I will create one using a rubber spacer between the 3-2 ½ adapter and the intake pipe.
My Idea on the intake side


1- Intake tube with laminar air flow
2- Rubber spacer on the outside of the intake tube to match the “3inch” (really like 3.5 inch) reducer
3- Pocket created creates an Anti-reversion trap, while beveled intake tube reduces separation bubble
4- Tapering the TB opening will aid airflow into and through the TB

Here it is….. The Thompson Mega-tube intake reducer is simply a Rubber 3-2 ½ pvc pipe reducer, with the lip on the end cut off on both sides. I will trim down the side that connects to the throttle body when I am done, so the transition meets up with the throttle body opening, but for the purpose of this write up, It will be pictures un-modified. Which means the TB will seem to be a ¼ inch short than it should be.


*(TB is a non-working model for demonstration purposes only)









As you can see the stock TB opening looks like it’s surrounded by a wall, this definitely will inhibit air flow.


WIZZZZ-BRRRRRRRR

I blended and tapered the entrance down to better meet up to the transition. Ultimately I will trim the rubber reduce so the edge of the TB meets the transition better.






Of course after all the metal whittling, I thoroughly cleaned it and painted it with metal cast paint. So it looks Sexzay!




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Nice, low budget DIY mods

 

How far down do you shaved the 2mm off the stock b18b1 TB?

 

And where did you get the 2 1/2 to 3in adaptor at?

 

^^^ It's from lowes/home depot ect ect. It's in the plumbing section.

 

Thats awesome. ima do that 2 my throttle body. Thanks for the tips on the DIY im a freak with a dremmel in hand