2010 July

Go with the flow : The VQ35 Cooling System

On July 13, 2010, in Engine, by B.Hobbs

Heat

You may consider it your enemy, it has definitely been responsible for more than a few oddly shaped pistons and blown head gaskets. The fact of the matter is that heat is simply energy, it works both for us and against us. A tremendous amount of heat is generated from the combustion process and put to work, the more we can harness the more efficient our engine becomes.

Approximately 1/3 of that heat is wasted through exhaust gas ( which can be utilized by turbochargers, but that is another story ) approximately another 1/3 is actually used to drive the piston downward and get the job done. The remainder of this heat energy is radiated outward from the cylinder and your cooling system is designed to transfer that heat to your coolant and pass it through a heat exchanger to keep engine temperatures in check.

Z33 cooling circuit

This is the cooling circuit diagram for the VQ35 straight from the 03 350Z factory service manual. One look at this diagram will tell you that this aint your granpappy’s ol’ small block. Shortly after the 350z was released, aftermarket performance parts came pouring out of the woodwork to support enthusiasts.

Before you knew it there were big time turbo kits and high powered engine builds to the tune of 600whp. It was then that these tuners began to see the apparent downfall of the cooling system for the VQ35 used in the Z33. In this diagram you will see the rear cylinders ( #5 and #6 ) circled in red. If you follow the flow chart from the water pump you will see that coolant flows into the engine from that point, up through the heads and into the engine block. Coolant flows from the front of the head to the rear and exits through the water pipe connected to both sides.

The block on the other hand is another story, the coolant flows from the front of the engine to the rear cylinders and has nowhere else to go. I’m not about to call out Nissan engineers (although I’ve had cause to curse them in the past) because under normal and even spirited driving conditions the factory cooling system will keep engine temps manageable. However, under heavy load conditions such as a long highway pull on a high powered engine or pulling lots of weight uphill, coolant flow to the rear cylinders is insufficient and can lead to troublesome or even catastrophic engine failure in the form of blown head gaskets or over expanded pistons that will have a once smooth cylinder looking more like a funnel.

Pathfinder cooling circuit

Enter the Pathfinder. The VQ35 found in the Pathfinder is only slightly different than the Z33 VQ35, but the one major difference worthy of discussion in this particular post is pointed out in red on this cooling circuit diagram.

If you follow the same flow, from the water pump and into the engine block, you’ll find that the coolant now has a “back door” out of the block where it will meet the other superheated coolant from the heads and return to the radiator. A thermostat is in place between the block and water pipe (shown on the diagram as an X) simply to let the engine reach operating temperature more quickly and reduce emissions.

Nissan engineers saw this one coming during their road tests for the Pathfinder, though they didn’t tune those VQ35′s to unscrupulous amounts of power, they more likely just ran them really hard off road and hauled lots of weight uphill. There’s no telling how many engines they scrapped before they decided on this system, but their loss is our gain.

Many fine retailers have put together “Pathfinder cooling mod” kits that will supply you with the rear coolant pipe, thermostat, hose and plate that you can swap right into your Z33 to greatly improve your coolant flow and safeguard your rear cylinders.

Is it something that your momma needs on her sedan to run to the grocery store? No, but you should give the Pathfinder system as well as other “reliability mods” some consideration if you plan to really put your VQ35 through a beating with lots of boost or serious track time.

O HELLA OEM’s Porsche G35

On July 10, 2010, in G35, G35, by O HELLA OEM

This is my Porsche powered by a VQ35 engine…Oh wait back to reality, my G35 just got a fresh Porsche 911 GT3 paint job called Atlas Grey Metallic that is. Anyways My G is my daily driver so I tried to keep the look as OEM as possible. So I put a Full Nismo body kit because this kit just looks like it came out of the factory, don’t you agree?

O HELLA OEM’s VQ35 Powered Porsche G35

To think a couple months ago my G35 was pretty much stock. 2010 was the year for my G35′s transformation east jump and i went all out as you can see but i still have much more to do.

O HELLA OEM’s VQ35 Powered Porsche G35

Your probably wondering what’s with the Blue wheels? Those aren’t just any ordinary blue wheels. The color is called Fzero Blue from Volk Racing and I believe there’s only 2 sets in 19″ with +12 offsets ever made. So trust me when I say that you probably wont see any G or Z with these set of wheels at a car shows you attend to. That may sound a bit cocky but take it how you want it. HA!

O HELLA OEM’s VQ35 Powered Porsche G35

I think the G35 has one of the most sexiest stock rear ends period!. Everything about a G35 is just perfect in my eyes. Any angle , every corner you look at the G35 lines wont disappoint.

Leojang’s Turbo G35 Anime Beast

On July 10, 2010, in Engine, G35, Widebody, by admin

When I first saw this car I was browsing the forums over @ G35NYC.com and I was flat out amazed that someone took the time to be creative and put some ill graphics on their show G. Little did I know then, that it was a DAILY DRIVEN G. Now this VQ35 powered turbo G, has got all the trimmings, including a built engine courtesy of VinnyTenRacing.com. I believe it pushes over 500whp, and I forgot what he ran at the track, but I know it was some impressive numbers, with full interior, system and all. I’m sure a lot of you enthusiasts have seen this vehicle already, but we here @ VQ35.com wanted to make sure it got a spot on our featured cars line up. Alright, enough of the small talk, on with the goods!