As PrjctMax stated, on some VQ35s, the intake noise will change for the better. Some cars have a hiss or whistle while accelerating. This is not due to an intake leak, it's just due to the change in airflow since the spacers are port matched and the stock intake gaskets are removed.

But other than that, your car should drive and idle perfectly normal. You'll just have more low end and midrange power along with a much cooler intake manifold resulting in less heat soak!

 

I have the spacers and I also used the coolant bypass connector. No cold weather issue to report down to 25F here in Virginia. No negative issue or adverse behaviour. It just pulls more. 10hp here, 10 hp there, and soon you are talking serious power.

 

I'm still on the bypass valve and it's purpose. Aaron, remember how I kept PMing you on the point of it because my tech didn't install it? lol

 

lol Yeah.

The purpose of the coolant bypass fitting is to prevent coolant from flowing through the Elbow. Having coolant flow through your intake manifold is just one more thing that will heat it up. If you live in an area that sees subzero temps and you drive your Maxima in those temps, I would advise against doing the throttle body coolant bypass.

 

What is the purpose of coolant in a manifold anyway? My other vehicles have a composite intake and no oil or coolant lines go into them. Just vacuum and PCV stuff. Is it due to thermal expansion differences? Such as a hot block and heads but cold manifold causing sealing and gasket problems? One shifts before the other causing issues etc.

 

Its to keep the throttle body butterfly from freezing closed I believe. Ive done it and live in kind of cold weather. Havent had problems yet, knock on wood.

 

Wait...so for those that live in "tropical" climates, it's not "needed?"

I still have the valve and may consider doing the work myself if I REALLY need it.

 

Less heat the throttle body has , cooler air going in is better.

 

The theory is to prevent freezing and sticking of the throttle plate in extremely cold weather. You have to remember that Maximas are designed to run in all types of climates, including northern Canada.

The throttle body bypass has been tested in temps as cold as low single digits without any problems. But I recommend if you ever drive your car in temps that regularly get in the single digits while you are driving the car, then do not bypass the coolant.

Definitely not! You do not need coolant flowing through the manifold if you live in warmer climates.

I would recommend that you install the NWP bypass fitting yourself. You should easily be able to handle it. Try your best not to remove the elbow or TB. You will need to remove the MAF and intake tubing though. It will be a little cramped. But just remove the in and out coolant lines in the Elbow and connect them to the bypass fitting and secure the clamps.

This is shown in the installation instructions. If you lost them, you can download the pdf file on the website.

www.NWPEngineering.com

 

time to grave dig....

so no news must be good news right? will be installing these soon when spark plugs get replaced.
any stock intakes with the whistle?
any issues with the elbow coolant bypass? i guess i could bypass it when i put my summer wheels on and replace it when stockies go on for the winter...

 

I woudl not do the coolant TB bypass if you have 32F or less for longish periods like here in Iowa. You will have issues with ice in the TB if so. We regularly have -15F air -35F wind chill let alone moving at 60mph into a wind...... So the spacers = awesome, TB bypass if it stays above freezing where you live for most the time.

 

No issue other than the whistle. I suspect is need to readjust the 4x4 TB spacer. Its the only spacer that had some play. Because I enlarged the lower intake ports, I had to match the port spacers so I doubt those are the source of the whistle. I actually like the turboish sound.

I did coolant bypass. I live in VA. If car is parked outside in winter, and temp is less than 20 F, I must let it warm up a bit first, or I get a code about engine taking too long to warm up. I must say that I run a 165F thermostat and EGR is 50% blocked. I pass emission tests without problem.

 

why is your egr 50% blocked? it's not bc of the spacer i assume, just curious.

 

definitely not. if anything, it's because of our egr's being ****ty...as well as our cats in our manifolds.

these spacers are a great buy. i highly recommend em

 

The Throttle Body Spacer should match up perfectly without any play. If the bolt holes and TB port don't line up absolutely perfect, then you probably have the TB Spacer upside down. It's an easy mistake to make if you rush through the install and didn't read the instructions line by line.

Please do not hesitate to contact me if you ever notice anything other than perfection from NWP. I'm serious.