If you want a no-cost mod. to lower the temperature of the intake charge, the following DIY shows you how to by-pass the hot coolant that is normally circulated around the Throttle Body. Keep in mind that if you live in the northern U.S. or Canada where winter temperatures drop well below freezing, this mod. may not be for you. Only attempt this mod. if you feel that there would be no potential for icing up of the throttle plate inside your throttle body.
First step is to prepare about 18" of 5/16" I.D. fuel hose to be used as the new by-pass hose.
Then remove your intake to be able to get to the two 5/16" I.D. coolant hoses that run from the engine to the TB. Remove the two hoses shown
Next, remove the coolant line that runs to the top side of the engine as shown
Take your new hose and clamp and secure it in place there.
Next, remove the lower hose that connects to a nipple on a black coolant pipe and clamp the new hose in place.
Wash away any spilled coolant at this point, taking care not to get any water into the TB or the manual transmission vent (small right-angle rubber tip facing forward sticking out of the tranny). I also flushed out the Throttle Body after removing the lines and capped the nipples.
Optional:
Take some 1/2" I.D. plastic corragated cable covering and place over the new by-pass hose to protect the near-by fuel line from heat.
Reinstall your intake, making sure you reconnect the MAF sensor harness and vent lines and start 'r up and check for leaks.
This mod. really drops the temperature of the throttle body which in conjunction with an intake manifold insulating gasket (Hondata style) should really help drop the intake air temperature making for a denser and more powerfull charge.
Enjoy... Bill.
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