Radiator Cooling suggestions
 

I looking for ideas for more cooling for my car, I ran Homestead a couple weeks ago and had it hot (light before hot or first light in hot) most of every session and it was only in the 70s. I have a CSF triple pass radiator in it, the hood is vented, running water and Water Wetter and have the fan going to 100% as low as I want to go. Next week we are installing a Stillen bumper, removing the washer fluid tank, venting both fenders to move some of the coolers to the side with fans to try to get them away from the radiator. I thought moving the heat away from the radiator would help but I am also adding a Frozen Boost cooler that will be in the way. What else can I do to cool it down?

Better fans & fan shroud, you just need to pull more through and out faster to help.
Having the vented hood will help this as all that hot air can get pushed out of the engine bay quicker.

Never mind

Do you have a fan/shroud to recommend?

Fans I would go with SPAL, shroud I don't think anyone has one specific for the 370z ever.
I will say this only because I know a member has one, but GTM had a fan/shroud combo built and for sale. This leads me to believe either the SPAL fans fit our shroud or can be modified to do so.

um... not sure but do you also have coolant and running distilled water?

that could be why your not cooling as much as you'd like....

Only other thing not mentioned already that I can think of is switching to the "pressurized" system/reservoir from the 12+? models. Wont help temps but will increase boiling point a bit.

It's distilled water and Water Wetter. From everything I have seen it cools faster than antifreeze and all the tracks around here do not want antifreeze on the track.


Sent from my iPhone using Tapatalk

Definitely true

Oil cooler????

An oil cooler to help keep his water temps down?

It has one and oddly the CSF radiator helped my oil temps, guessing it allowed more air flow.


Sent from my iPhone using Tapatalk

Yep. Might not make a big difference but anything you can do to remove heat from the engine will help coolant temp.

At OP: Are you sure the vents in the hood are doing any good? If placed in a high pressure area, they could be counterproductive.

I'm 100% sure, it the best cooling I have done. Every drop of water or supercharger oil that comes out gets blasted all over the windshield like it came out of a cannon, they are flowing lots of air.

The top vents (closest to the windshield) that are questionably in high pressure areas are covered in plexiglass.

Unless you can come up with a better coolant, your choices are limited to more surface area and more air flow.

It's probably going to take more than one mod to cool you down but I think theDreamer has the best single fix - bigger, more efficient fans. The shroud is a critical component and need to be carefully matched to the fan. Placement of the fan in the shroud is also critical.

Can the undertray be modified to allow more air to escape from the engine compartment?

Edit: Have you checked flow through the cooling system? It can cause overheating if the flow is too high (not enough time in the radiator) or low (too much time in the engine).

The cooling system works very well, in the Florida heat and humidity it never gets to half way on the coolant light and haven't seen oil much over 170 on summer days on the street. I know that not high enough but it's measured after the cooler. homestead is basically 4 long straights that start off a slow turn so it a lot of WOT.


Sent from my iPhone using Tapatalk

http://tapatalk.imageshack.com/v2/15...42394fc4e0.jpghttp://tapatalk.imageshack.com/v2/15...7cb770930d.jpg

I hope this works because I don't know where to go next. The oil cooler is now in front of the passenger wheel, the trans coolers is in front of the driver side wheel and both have their own fan and the liners behind them are vented. We removed the Aquamist ( wouldn't stay working) and added the thicker Frozen Boost cooler. If anyone has any other ideas to help cool the car I would love to hear them!


Sent from my iPhone using Tapatalk

I remember reading a long time ago, but will take a bit to find, a couple track guys found a product that was temp stickers or something. Basically you can apply them and they change color to when they get to certain temps. This might be helpful to find out if you are having pockets of hot air stuck in the engine bay somewhere.

Another quick idea might be the moment you are done with a run, jump out and have an IR heat gun that just do a few key spots and capture the temps. See how hot the pipes, coolers, etc are really getting. I see Amazon having one on sale once a month for under $20 which is a good deal. Plus the gadget comes in handy at home if needed.

I have a IR gun and thats a good idea. The last time out everything was fine but the supercharger cooling and the radiator, hopefully this will solve that.

Tempilabel works well.

Distilled water and wetter is the way to go. best heat transfer. raising the system pressure helps also helps to some degree. You biggest problem looks to be air flow management to the radiator, you have a lot going on there, and that seems to be your problem. you might want to add some openings in the front bumper cover above the bumper.

I actually have these and they work very well, we have been using them on the brake calipers to see how they were doing. I will stick them all over the place at the end of February when we go to Homestead and see what getting hot.

Lightly hit the radiator fins with compressed air and purchase fans that move more cfm would be a good guess at you running cooler. Also, humidity plays a big factor on your engine temps. I occasionally race at the drag strip and I have to shut my Z down after about 3 passes even in 70 degree night weather here in Texas. Good luck if you find the perfect formula and let us southern high heat brothers know too!

If you are not running an aftermarket radiator, can I suggest that with a S/C kit, you might just be taking the demands on the cooling system outside the OEM design capability.

Running around town/down the highway could be fine because you only need cooling for <100hp - that's all the demand on the engine (and cooling system) needed for that sort of speed.

Running WOT for 10-15 seconds is a whole different ball-game., because you need to cool 500hp or more (I'm guessing you are at least 400+rwhp so that is close to 500 at the crank and that is what needs to be cooled).

The OEM radiator is a thin little sucker and an extra row will increase heat absorption by a minimum of 35%, but you will also need to look at air-flow thru the rad.

I have to cool 540hp in my race car (not a Z34, but comparable) with a radiator that is 19" across and 21" deep (because that is the only space I have to fit a radiator in). I had PWR design a radiator and specify a water pump specifically for the application - it is not a simple set of calculations to do, because you do not want to over-cool the engine and nor do you want it to overheat. PWR do sell a Z34 radiator, but it is specific to the Fairlady Z race car and can only be ordered thru Nissan Motorsport in the US. There are other uprated after-market rad's but I have no experience of them.

The 3 middle dots in the temperature gauge cover the best part of 40 degrees F - you really need to log exact temps and you can get that from the OBD II port and an app if your are not already doing this.

It is also worth monitoring your peak temps where the water exits the radiator as well as where is enters the radiator, to see how efficient the rad actually is.

If your track does not have a lot of part or off throttle time in a lap, that is certainly going to cause heat to build up when you are running boost.

You should not under estimate the impact of oil cooling on engine heat as well. The biggest oil cooler you can find is probably a good idea.

With the intercooler in front, it is also reasonable to fabricate some ducting to make sure that air heated by the inter-cooler is not going thru the radiator - especially as at WOT, the cooling demand from the inter-cooler circuit is also significant and that hot air can only go straight thru the radiator.

It has a CSF Triple pass radiator in it now. The oil cooler,supercharger cooler and trans cooler used to sit right in front of the radiator. In the picture above we have moved the oil and trans coolers to in front of the wheels and replaced the supercharger cooler with a larger one and left a much larger space between it and the radiator. I like your ducting idea but I don't think it's possible. The supercharger cooler covers almost all of the opening in the Stillen bumper not taken by the oil cooler, trans cooler or brake ducting. I don't want to do it but if this doesn't work cutting holes in the upper part of the bumper to get more in the top of the radiator is probably my next step.

Attachment 99764

This was how it was set up when it was over heating at the last track day.

Don't know why that pic is upside down!

So when you moved the oil coolers, you added fans, did you also vent the back end of them out the fender well? If you didn't you just going to push the hot air around. If you need a inner fender vent, look at the Audi SUV's front inner fenders. They have a nice size plastic vent that looks like it snaps into the inner fender and the area about the size of 24 row cooler. This is similar to the Nismo vented fenders I seen when they mount the coolers in this area. I have also thought about moving my oil cooler from the radiator area and venting the heat out it in this manor.

I got the idea off my Audi TT and GTM. http://tapatalk.imageshack.com/v2/15...873c99daa8.jpg



Sent from my iPhone using Tapatalk

Great minds think alike!

Attachment 99773

I really like the new bumper so I hope I don't have to cut holes in it!

It's done, I hope this solved it!http://tapatalk.imageshack.com/v2/15...2120a30673.jpg


Sent from my iPhone using Tapatalk

If nothing else, it sure looks good.

Looks Great!:tup:

You're making a lot of the right moves - distilled water + water wetter, and relocation of the auxillary coolers to the sides.

Fans are needed for the street and low speeds but on track they are restricting airflow/cooling. This is one area where the compromise of a street/track car comes into play.

If you still have an AC condensor in there, removing it (or getting a radiator without one integrated) will help.

You want the hood vent to open in the lowest pressure areas over the hood - and you also want a nice easy/smooth path for the air on the back side of the radiator to make it out that vent. Seems like from the factory the back of the radiator/fans are right up against the front of the motor. If you can lean the top of the radiator forward, and duct the backside up to the vent(s), should help. This is how it's done from the factory on Corvettes and Vipers. Another hood vent laterally in the middle, roughly aligned longitudinally with your forward-most existing vents, should give the hot post-radiator air the easiest path out.

Your boost cooler thing is pretty big and eating up all the prime airflow surface area. Some of the balancing act here may be giving up a little bit of that optimization (smaller size, or a more out-of the-way placement) for better coolant cooling. Since those are liquid lines and more line volume doesn't affect boost response (the way an air-air IC does) you might consider trying to place that whole thing somewhere way out back under the car.

Last thought would be increasing area inbound to the coolers with some holes in the yellow portion of the nose above the bumper beam (along with maybe trimming/removing the bumper beam) to allow for direct flow to the upper half of the radiator.

The factory has a lot of shrouding to direct all incoming air through the coolers - through your extent of mods, ensure you are taking steps to ensure you continue this practice. Air will take the easiest path to lower pressure, which will only be through a stack of coolers if you force it to be.

Thanks or the ideas, if this doesn't fix it we will move on to some of these ideas. I'm taking it to Homestead again in 4 weeks so I will know then if it needs more work. The car does have A/C but I drive the car to the track and live in south Florida so thats not coming out.

Looks great Sir! :tup::tup:

Car looks nice. I think some NISMO side skirts and it will be done!

YzGyz

Something I just thought of looking through your photos.
Heat wrapping your pipes & thermal coating for your intercooler & radiator, small change but can help keep heat out of the pipes and keep temps down.