VQ37VHR-K28

Disclaimer:

The DYI (Do it yourself ) below is only to share what I have been doing for the 370Z and Infiniti G37 cars. If you are lacked of automotive knowledge or experience, please DO NOT perform this task yourself.
I shall assume NO responsibilities, whatsoever, for any consequential damage to you and/or your vehicle in this case.
The 370Z in general, depending on what you do to it, is NOT a simple vehicle to work on. If one thing goes wrong, many more can follow since the car has very tight tolerance and very low margin for error. So, take care and be very careful.

This is a DYI for eliminating the throttles heater hoses for the VQ37VHR motor for your 370Z and Infiniti G37. I recommend removing these hoses ONLY for the folks that are living in the geographical region where the ambient temperature does not come below 30F (-2C). Otherwise, leave them on in order to prevent
possible throttles icing during freezing temperatures.
For the enthusiasts that live in the tropical regions, this heated throttle motors and chambers design not only clogs the engine compartment with hoses, but will DEFINITELY reduce engine performance dues to hot air temperature, especially for supercharged and turbocharged folks. By eliminating these hoses,
the system will NOT activate a CEL because this heat elimination occurs after the air temp sensors, and nothing is being monitor after that. Cooler air will DEFINITELY helps engine performance and prevents knocking.

So here are the basic steps:

First : Disconnect your battery before starting anything. One mistake could cost you the IPDM controller, which can be throat cutting expensive

Please refer to the factory cooling hoses diagram below and study this picture very carefully. I will be referring the 4 throttle coolant hoses by their respective numbers.

LEFT SIDE = DRIVER
RIGHT SIDE = PASSENGER


Pictures below show the original factory set up for the left and right throttles. Here you have burning hot coolant running through both the throttles and heating up the intake air considerably. The hood temp of the VQ37VHR is very high to begin
with due to the wonderful VVEL design and unfortunately, a very flimsy thin cooling radiator.

For the LEFT throttle, the hoses are #15 and #16. For the RIGHT throttle, the hoses are #6 and #7.



For both the LEFT and RIGHT side throttles:

Remove hoses #15 and #16, #6 and #7 from the both throttles' end.



For the LEFT side throttle:

1) COMPLETELY remove hose #15 out of the car. Discard this hose.
2) Connect hose #16 to the metal coolant pipe shown below.
3)) Plug both the throttle nipple openings with high quality rubber plugs.
4) BE SURE that hose #16 does not rub against anything. If it does, you have to put rubber sleeve on the hose.
5) Done for this side.


For the RIGHT side throttle:

1) COMPLETELY remove hose #7 out of the car. Discard this hose.
2) Now you only have hose #6 as shown below.



3) Cut this hose #6 around the place shown below, just between the 2 sleeves



4) After the cut, this is how hose #6 looks like



5) Custom fabricate a preformed hose, around 4 inch long as shown below. Also, custom make a sleeve around 2 inch long to go over the hose . Use a barb fitting and install on one side of the hose as shown:



6) Connect the other side of the barb fitting of this hose to the cut end of hose #6 shown above



7) Connect the the loose end of the custom hose ( Marked X ) to the metal pipe ( Marked X ) as shown in the photo below.



8) Finally, the hose #6 should look like this. BE SURE to adjust the sleeve to where the hose rubs against the harness below.
9) Put high quality rubber plugs on the throttle nipple openings.



9) You are TOTALLY done.

10) Start up the car and check for leak.
11) Drive the car, hard and fast..... and check for leak again.
12) Periodically inspect to be sure that there is absolutely no leak !!!
13) Have fun with cooler air intake....

You engine compartment will be less clogged from now on. It will be easier to get to your spark plugs and coils. Most importantly, you shall have colder intake air for sure.