Hi

Sorry if this has been covered but using search option lead me nowhere.

I have a 350z Vq35de with Greddy Twin Turbo kit 20g.

Problem I came across is that, on race track car is overheating after 3 or 4 fast laps. I have OEM radiator and Nismo thermostat.

I did try Mishimoto high performance radiator and fan shroud it was a big failure. Car was overheating in normal traffic and amount of time it was taken for draining system was abnormal. Obviously something was wrong with that rad. Returned OEM rad all is OK except track issue.

So main question is can I fit Koyo 53mm rad with Greddy twin turbo inside engine bay and OEM fans.

Second thing is are there any upgrades for OEM fan shroud did anyone try upgrading them with Spal fans or similar.

 

Correct me if in wrong... but the rad should be in the front behind the bumper cover not in the engine bay itself...

 

Yes thus my question due to it's thickness how far back is pushing fans and will there be space for OEM fans.

E.G with Mishimoto rad you need to go with their slimmer fan shroud to make it fit

 

ill have to recheck my measurements, but im pretty sure my engine bay has 6-8 inch of clearance from the fan to the belt assembly, and the rad for my turbo sits right where the crash bar is and i have plenty of room for improvement if i needed a bigger one.

 

Are you as well running Greddy TT?
Cause Greddy intercooler is removing front crash bar.

 

If you're having clearance issues, the Pwr steering pump pulley will hit first, AC pulley second with spal fans unless you get the slimline fan motor which reduces fan output..ask me how I know.

Try the maradyne dual fan kit/shroud.....on ebay....some swear by them

 

Hard to source Maradyne products over in Europe. Will try sending e mail to Spal if they have any double fan shroud in slim edition. As well hard to find any CFM rate of OEM fans online.

I reckon that by description Koyo should fit in as it is stated it accommodates OEM fan shroud

 

I put two 14" spal fans on the mishimoto shroud (like several others on here). Ogie is right, the HO spal fans are too deep. I used a SSR and PWM them from the Haltech.

Car is in storage so I'd need to dig up invoices for details. May have some pic's around.

 

Sure any help would be appreciated.

I'm on Haltech as well

 

Here's the shroud as it came. The fans they supply suck. They are single speed and the way it comes wired means full power on both if either stock level is on and they don't feel like they move any more than the stock setup on LOW:


!4" Spal's installed. It's a tight fit, you have to orient the fans with the flattend sides vertical:


The fans are VA08-AP71/LL-53A (30102042_2056), high performance 14". Why these ones? Simple, the 12" extreme's don't fit (too deep), the straight blade 14" version pulls less CFM then a 12" high performance (30102038). So it came down to two. The 12" moves more cfm if the resistance is greater than about 10 mmH2O pressure differential through the rad. The 14" moves more less than that.

So I setup a quick and dirty manometer by drilling a fitting into the stock shroud and measured it at idle on full fans (used the haltech to force them on). Result was 5.5 mmH20, so the 14s win.




In the car:


I made all new wiring using heavy gauge wire from a sub install kit. New fan connectors, fuse from battery, SSR to duty cycle installed by the ECU on a heat sink.


Here's my fan map on the generic duty cycle output:


Frequency is around 85 Hz, with this current level (~40 Amps) the SSR is limited to around 250 Hz, and the sound is audible in the garage without the engine running, so I played around to find the least resonant one.

The quick 0 to 50% transitions are because low duty cycles under 10% ish don't start the fans, so I've set it well below normal temps so the fans go from 0 to 50 as fast as possible. It then smoothly scales to 100 at the temperature I'd like to hold. I may change the 50% to 40% in the spring.

I've got a gauge on my display for the fan duty cycle along with the coolant and oil temps so I can see whats going on.

 

I did something similar .....but used an amazon shroud with two 14" spals on my G35. since you throw the fans away anyway saves a bit of money.

 

Yup. I was hoping the setup would open some space and move more air than stock. It only did one. So as I had it, I modded it.

If you're starting at step 1, see if you can get the shroud part cheap.

 

I had the same problem with my car on the track. I also have a DE with greddy twin 20gs. I have the mishimoto rad, fan shroud, and silicone hoses. After about 3-6 laps depending on the outside temp the car would get hot. This a very common problem with our cars and it is pretty difficult to manage. Along with the upgraded fans i would install the largest oil cooler you can find or do a dual stage oil cooler this will help some. But i think the single most important thing is to have a coolant expansion tank that is large enough to allow for the heat compensation these cars make. Is the car pushing coolant out of the overflow? Mine was but only on track. I could make several pulls on the street with 0 problems.

 

Thanks for such a thorough reply. I did make a small change in cooling plans. Since Koyo is bit hard to source over the lake plus import and taxation I went with Skunk2 Alpha radiator. Which is as well larger aluminum dual core rad.
I have sent enquiry to Spal EU for price on this 14 mentioned above.
As for Mishimoto shroud I think this can be easily fabricated from aluminum to accommodate Spal fans.

 

That's just how these cars are to a point. They run hot especially with FI.

I know a lot of guys who have full cooling upgrades and still run hot. Most street cars can't do more than 5-6 hot laps anyways.

Also what bumper? All that cooling does no good if air isn't going in. Fans aren't supposed to cool, just maintain and be a last resort, mostly for traffic or street normal driving use. Look into a new higher flowing bumper or making bumper mods.

I know my buddy on his turbo G made some massive bumper cuts and cooling mods to his bumper and it helped him on track a LOT.

Also look into oil coolers, but again same thing no use if you don't get air flow to let them do their job.

 

Also make sure your system is FULLY burped and your fluid is fresh.

I also prefer a 70/30 mix of anti freeze. Over the standard 50/50 mix, helps keep boiling down.

 

I have 24 row oil cooler if I'm not mistaken. In track water was not going out of the expansion tank but Haltech was kicking in as soon as temp would reach 110/115 °C. At that time I would just easy the gas and drove a cooling lap and than again 2 laps and cool down.

I did manage to find some bumper with big opening at front still awaiting on delivery plus I was thinking to input a bumper intakes like R33 has.

 

Hopefully that bumper should help some.

At least it looks like it should breathe well.

 

aarrgghh, nicely done. I've not seen anyone use a solid state relay and the Haltech before this on our platform. The only recommendation I would make to your set up is to make the fans easily removable without having to remove the shroud because the fans will fail and it's messy to remove the coolant tubing to get the shroud off just to get a failed fan off. After I had to do it the first time, I used rivet nuts so next time around will be easier. My first set of 14" SPALs lasted about 4 years (both failed about 1 yr apart). Now on 2nd set. They move a lot of air.

EDIT: The crydom SSR is pricey - and I see you put a heat sink on it. job done right!

 

Looks bit bigger opening plus with 2 nostrils like on R33 should have enough air flowing there