K series Throttle Body Install Guide

K Series Big Bore Throttle Body Install Tips:

Features:

Knife-edged 76mm inlet

Anodized 6061-T6 Aluminum

Bolts to RBC, RBB, and PRB Plenums

Dual Concentric torsion springs

Dual ball bearings

Dual needle bearings

Integral o-ring seals

Allows multiple IACV configurations

Allows use of cruise control

Staked Butterfly Bolts

Package Contents:

(1) Big Bore Throttle Body

(1) Thermal Gasket

(1) 1/8 NPT Nipple

(2) Vacuum Plugs

(4) 1/8 NPT Plugs

(4) 25mm M8x1.25 Bolts

(1) 10mm M6x1.0 Bolt





Below you will find tips on how to install your new Hybrid Racing K Series Big Bore Throttle Body into a Honda K series

equipped vehicle. *This product may not be legal for highway use. Hybrid Racing is not

responsible for any direct or indirect, actual or incidental expense attributed to the use of any performance parts sold by

Hybrid Racing LLC. Purchasers agree to all of the terms of this agreement upon the purchase of parts. More information

can be found at www.hybrid-racing.com.

Install Guide: This install guide does not show all steps for installing this throttle

body into a vehicle as it is compatible with many applications. Howev-

er, this guide addresses many of the key steps you will encounter

when installing your new throttle body.

Shown to the left is an illustration of most hardware included with the

throttle body. For your convenience, most of the bolts for the throttle

body have been supplied already threaded into their proper positions.

Refer to this guide if you remove the bolts and need to determine

where they were intended to go.

DO NOT REMOVE the graphite colored paint on the

rim of the butterfly. This paint is used to seal the throttle body from a

vacuum leak. If there is a small amount of flaking, still do not remove

it. If it comes off and goes into the engine it will not hurt the engine

since the paint is carbon based.

Step 1:

Before installing your throttle body, you will need to remove the two M8 studs that are installed from

the factory on your intake manifold. This is because the throttle body will need to be mounted to the

flange using the supplied M8 socket cap screws.

A big bore throttle body should not be used on a manifold that has not been bored to match

or exceed the diameter of the throttle body (ie, a 70mm throttle body can be used on a manifold

that’s bored to 74mm, but not on a manifold that’s bored to 65mm). If you intend to bore the mani-

fold yourself, use the supplied plastic gasket to trace out the bore before removing the studs, as

shown in Figure 1b. Once traced, remove the gasket and check to see that the traced circle is well

defined as in Figure 1c. Next, the studs can be removed. The studs should be removed by threading

two nuts onto the stud and binding them together as shown in Figure 1d . Note that a Honda M8

nut uses a 12mm wrench.

Step 1 (Continued):

Next, loosen the stud by using a wrench to rotate the inner nut counter clockwise as

shown in Figure 1e. Once the studs have been remove, use a razor to clean any gas-

ket material off of the flange as shown in Figure 1g. Removing gasket material will

ensure a better seal after installing the throttle body.

Step 2:

If you’re boring your own manifold, a die

grinder or high-speed drill can be used

with a grinding stone or sanding drum to

bore the manifold from its 63mm stock

size up to the outside edge of the circle

you traced in step 1. Figure 2a shows a

manifold being bored; Figure 2b shows

a manifold after boring. Once finished,

check the port against the gasket to en-

sure it’s opened enough. Remember that

it’s better to open the hole up too big

than too small. It’s very important to

thoroughly clean your manifold after

boring it as any aluminum dust left in the

manifold could cause damage to your

motor. For best results, first blow out as

much dust as possible with compressed

air. Next, use a waterhose to thoroughly

flood the manifold. Allowing water to flow

through the manifold for a while will help

to carry out debris that may not have

been removed earlier. Make sure the

manifold has thoroughly dried before in-

stalling it back on your motor.

A Note about boring manifolds:

It should be noted that a big bore throttle

body should never be used on an intake

manifold that has not had the inlet bored

out to match the bore of the throttle

body. A setup using a big bore throttle body mated to an OEM sized inlet port will yield lower perfor-

mance than the OEM throttle body. That said, when boring the inlet on an intake manifold, it’s best to

overbore slightly (about .25-.5mm is sufficient), to prevent the chance of a lip that could create turbu-

lence. While many people will prefer to have a machine shop bore their manifold, if you are familiar

with forming metal using a die grinder and sanding drum, you can bore your manifold yourself. If you

are hesitant to bore your own manifold, you should consult a machine shop first. Hybrid Racing is

able to supply prebored K-Series intake manifolds for an additional charge. Also, note that the use of

a 74mm throttle body on a K-series intake manifold dictates that the boring process be a bit more

involved. Because of IACV port geometry, boring a PRB, RBC, or RBB manifold to 74mm requires bor-

ing a 74mm hole, then welding the IACV passageway shut, and finally reboring the welded area back

to 74mm. A 70mm throttle body requires a single boring operation only.

IACV Install:

This throttle body is designed to allow for 3 different IACV mounting options. The IACV mostly serves

to stabilize idle after startup and when the AC compressor is engaged. However, its general function is

to provide a stable idle at all times.

The IACV can be installed in the same orientation as its supplied on an OEM throttle body. In this con-

figuration, you can use the supplied 1/8 NPT nipple to hook up the OEM coolant supply. You may also

loop the coolant supply on the block, and not install the nipple. This latter option is normally preferred

in performance applications as it allows for lower intake air temperatures. See Step 3 for information

regarding installing the IACV in its OEM orientation.

On some k-swaps where the intake manifold is very close to the radiator, there may be clearance issues

that make mounting the IACV in its OEM orientation difficult. The most common problem is that the

plug on the harness for the IACV does not have enough room to plug into the IACV. If you wish to re-

tain your IACV functionality but are having these clearance issues, you may wish to rotate the IACV 180

degrees. The IACV can still function properly like this, but you will need to install the supplied 1/8 NPT

nipple and run a hose between it and the nipple on the IACV. This setup may produce a slightly rough-

er idle than the OEM setup, but variation is typically minimal. See Step 4 for information regarding in-

stalling your IACV to provide best radiator clearance.

Finally, some users may prefer to remove the IACV unit entirely. Note that doing so will result in an un-

stable idle on startup and a generally less constant idle speed than if the IACV was used. Deleting the

IACV without use of an aftermarket ECU like the K-Pro is not possible as the stock ECU cannot run the

motor properly without the IACV. On any other throttle body, an aftermarket plate would be needed to

delete the IACV. The Hybrid Racing throttle body, however, has 4 built-in 1/8 NPT ports that allow the

Step 3:

If installing your IACV in the stock orientation, you

may opt to run coolant through the IACV (as is

done on the OEM throttle body). Alternatively, you

can loop the hoses that go from the motor to the

throttle body. If you wish to run coolant to the

throttle body, you will need to install the supplied

1/8 NPT nipple as shown in figure 3a. You should

wrap the threads in Teflon tape or apply a pipe

sealant before installing the nipple.

Step 3 (continued):

Thread the nipple in by hand, then firmly

tighten it using a 9/16” (or 15mm) deep sock-

et, as shown in Figure 3b.

To install the IACV, simply place the OEM rub-

ber gasket in the groove on the throttle body,

then bolt the IACV to the throttle body using

the (2) supplied 20mm long M5x0.8 bolts and

(2) M5 flat washers. The bolts can be tight-

ened using a 4mm allen wrench. When in-

stalled, the nipple on the IACV should point

away from the intake manifold, as shown in

Figure 3c.

Step 4:

Installing the IACV flipped 180 degrees is very

similar to how it was installed in Step 3. The

key difference is that you cannot run coolant

to the throttle body, and you must install the

supplied 1/8 NPT nipple. The IACV should be

installed with its nipple facing towards the in-

take manifold. Once bolted to the IACV, the

nipple on the IACV should be connected to

Step 5:

If you intend to delete the IACV on your throttle

body, you will need to install the (4) supplied 1/8

NPT plugs. (2) plugs should be installed on the back-

side of the throttle body as shown in Figure 5a. The

other (2) plugs should be installed on the underside

of the throttle body as shown in Figure 5b. The 1/8

NPT plugs can be tightened with a 3/16” (or 4.5mm)

allen wrench. The plugs should be wrapped with Tef-

lon tape or have a pipe sealant applied before instal-

lation.

If you are not using an IACV on your setup, it will

likely be necessary to adjust the idle adjustment

screw to allow more air to pass by the butterfly in its

“closed” position. To adjust the idle screw, first you’ll

need to loosen the idle screw jam nut with a 10mm

deep socket as shown in Figure 5c and Figure 5d.

Note that the yellow Torque Seal that’s applied to

the idle screw may have adhered the screw and nut

together. You may need to use a wire brush or razor

to clean the yellow paint off. Once the nut has been

loosened, use a 3mm allen wrench to screw the idle

screw in as shown in Figure 5e. Once the idle screw

has been adjusted to the desired position, retighten

the jam nut.

Step 5 (continued):

Note:

Do not loosen the idle screw beyond its supplied position in an attempt to lower the motor’s idle.

During assembly, the idle screw is installed and the butterfly is sealed with a graphite-based sealant.

Attempting to close the butterfly beyond its supplied position may increase the risk of the throttle

body “sticking” in the closed position. If you adjust the throttle body and notice “sticking” in the

closed position, open the throttle body fully, gently close it, then tighten the idle screw at least half

a turn. Open the throttle plate fully and allow it to slam shut. If it sticks, open it fully, close it gently,

Step 6:

If installing this throttle body on an Acura RSX,

the supplied 10mm M6x1.0 bolt can be used to

attach the cable guide bracket as shown in Fig-

ure 6. Use a 4mm allen wrench to tighten this

bolt.

Step 7:

If you don’t intend to install the Emissions Sole-

noid or MAP sensor, you can use the supplied

plugs to block off one or both of these ports. If

you are using the throttle body on a naturally

aspirated setup, simply push the plug into the

port you want to block, as shown in Figure 7b.

Install the supplied retaining ring (as shown in

Figure 7c) if you are using the throttle body on a

turbocharged setup. The retaining rings can be

installed and removed with a flat head screw-

driver or similar tool. Simply press the teeth into

the machined groove to install, and pry on the

Step 8:

On the Hybrid Racing K Series throttle bodies, the throttle cable and cruise control cable are

flipped when compared to an OEM throttle body. To install the throttle cable, first insert the barrel

between through the bracket as shown in Figure 8a. You’ll need to open the throttle plate slightly

to get the cable into the proper position. The barrel

should be inserted into the hole on the throttle ca-

ble cam, as shown in Figure 8b. Next, thread the

jam nuts on the cable collar as far apart as possible,

as shown in Figure 8c. Fit the cable collar into the

bracket as shown in Figure 8d. Pull the cable back

gently until you feel the throttle cable cam begin to

open the throttle plate, but do not adjust it so the

throttle plate is opened when the throttle pedal is

not depressed. Adjust the first nut so it rests against

the bracket, as shown in Figure 8d. Next, tighten

the other nut against the bracket as shown in Fig-

ure 8e. Use a 12mm open ended wrench to tighten

the nut firmly. Install the cruise control cable (if ap-

Step 9:

If you do not intend to use the cruise con-

trol feature, you can remove the cruise con-

trol cable bracket as shown in Figure 9a.

The bracket is held on with two bolts and

can be loosened using a 2.5mm allen

wrench.

Step 10:

The (4) supplied 25mm M8x1.25 bolts

should be used to mount the throttle body

to the inake manifold. The supplied ther-

mal gasket should be installed between the

intake manifold and the throttle body. The

gasket is designed with an outline similar to

the throttle body to aid in alignment during

installation.

Figure 10a shows the throttle body as in-

stalled on a PRB (RSX) intake manifold. For

best results, install the throttle body and

gasket by first loosely installing the two

bolts indicated by arrows in Figure 10a.

Next, loosely install the other 2 bolts. Tight-

en in a criss-cross pattern. You may need to

retighten the bolts several times as the

plastic gasket will compress as it’s tight-

ened.

Figure 10b shows the throttle body as in-

stalled on an RBC or RBB manifold.

If you have any questions or comments, please email [email protected]

or call us at 225-932-9588

Legal Disclaimer

Users assume all cost and risk associated with these or any other items purchased from Hybrid Racing

LLC.

Parts sold or manufactured by Hybrid Racing LLC may not meet legal requirements for use on public

roads. People thinking about purchasing product(s) from Hybrid Racing LLC should check with their local

and state authorities for legality. It is the user’s responsibility to know and comply with all local and fed-

eral laws and regulations. Use or installation of Hybrid Racing LLC products may affect user insurance

and/or vehicle warranty coverage. It is the user’s sole responsibility for consequences that may occur due

to having the product installed in his/her vehicle.

Hybrid Racing LLC assumes no legal responsibilities and/or liabilities, whether to user’s vehicle, engine,

person(s), and/or property(s), that result from the use of, or servicing of a vehicle of which a Hybrid Rac-

ing LLC product has been installed/attempted to be installed, or to any other vehicle(s) and/or person(s),

regardless of whether or not this product has any involvement

directly or indirectly and/or liability, and/or whether or not proper installation has been carried forth.

All engines, engine parts and electrical components are for OFF ROAD USE ONLY/RACING

VEHICLES ONLY. They are not for or to be used on public roads in the USA.

Acquisition of a Hybrid Racing LLC product will act as an acknowledgement of the legal disclaimer stated

herein.

Hybrid Racing LLC reserves the right to change this disclaimer at any time without any prior

consent or notification.

Should you need to contact us our details are as follows:

Hybrid Racing LLC, 3348 Drusilla Lane, Suite 2C, Baton Rouge, LA 70809

www.hybrid-racing.com

K series Throttle Body Install Guide

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