Ok I'm going to be doing a few "mods" in an attempt to reduce engine temp a bit. Not comfortable with running straight water, mabye 70 / 30 water but I want the corrosion control. A lower temp T-stat is also comming. My question involves the fans themselves. I was at PEP Boys today in a futile search for a locking gascap when I wandered on the Hayden cooling fan display. On the boxes they list the CFM of OEM replacement fans. Well I noticed there are a couple of fans the same physical size with higher CFM.
I guess my real question is a 2 parter. One, does anyone know the CFM of the stock fans? Part deux.. think there would be any appreciable lowering of coolant temp by replacing both fans with higher CFM fans???

 

dude, stock cooling is more than sufficient on these cars. anything below 150-160ish and you'll just be causing excess engine wear.

 

I think the stock fans are more than you'll need. But if you race your car a lot in warm weather, then a nice expensive radiator might help ya. But I kinda doubt you'll need that.

If you do the things I did to control coolant temps, then you'll be fine unless you road race in 100 degree weather.

First, I would wire a switch so that you can turn on your high speed cooling fans manually. This will allow you to kick them on at any time and not at the stock times, usually above 200 degrees. 212 is when your fans turn on when your AC is off. As a matter of fact, the high speed fans don't kick on until MUCH later... something over 220 degrees.

Check out the wiring diagram I put together:



All you need to do is tap into the correct ECU signal wire and ground it with a SPST switch. Personally, I just tapped into the high speed fans ONLY and didn't bother with the low and high speed fans function. I figured if I was going to kick my fans on, I might as well kick them on high.

If you already don't have an aftermarket coolant gauge, then GET ONE! You can find a mechanical one pretty cheap at Auto Zone. Even though it's very cheap, I don't have many complaints about my Sunpro gauge. It gives me accurate readings. I tested it in boiling water with a candy thermometer before I installed it. Spot on.

With your fans running on high and you driving normal around town, you can usually lower your coolant temps all the way down to your thermostat rating. Without having your fans running, it's impossible to operate your motor at the same temp as your Tstat rating unless it's cold. Something like below 45 degrees F.

The ONLY reason I installed a Nismo 150*F Tstat is b/c when I bracket race, I launch at 160 degrees. That's the temp that I found to be most consistant. If I had a Tstat that was rated at 170 or 180, then when I launch at 160 degrees, the Tstat would open during my 1/4 mile pass and that sudden flow of coolant can only make a car more inconsistant. It's an old bracket racer trick. It's just one less thing to worry about.

With my fans on high, Nismo Tstat and driving slowly around town, I can easily operate my car at 160*. But since there's no reason to drive around that cold, I only do that at the track. I usually kick my fans on when my temp reaches 190 degrees. Which I found to be a good operating temp and completely gets rid of heat soak.

I have found that my car doesn't get sluggish due to heat soak until it's over 200 degrees coolant temp. Anything over 215 or 220, then the car REALLLY gets slow. All this time, your stock temp gauge will be sitting in the middle acting completely useless. My temp gauge doesn't start to creep towards the H until after 230 degrees.

Also, very imporant! ... The normal OEM Tstat is 180 degrees. You can buy a 170 also. But make sure you test the 170 Tstat. I went through 3 different 170* Stant Tstats and tested them all and they all opened at 180. I tested several 180 Stant tstats and they all opened at 180. My Nismo tstat opens at 150. So, if your really picky like me, make sure you test it in a pot of water before installing it in your car.

Check out my website for more information.

 

Wholly $hit!!!! Yes Sir!! I read a bunch of your posts but damn man thank you for the single page bible on "how to " cooling. I guess I'm installing a Coolant temp gauge on the morrow. Really thank you, awesome response!

P.S. I brought up Pheno spacers awhilr back and got poo poo'd over all. Mostly about the coolant running through the IM and TB. I was on your website , but didn't find anything on where you found the spacers or how to by-pass the coolant passages and imstall the spacers. I know, I'm needy, just humor me and take it all as a compliment.

 

Yes it was.

You got that b/c pheno is poopoo:
-->In daily drive, no meaning.
-->In racing, airspeed surpasses all possible cooling effect: one 'spoonful' of air spends maybe (?) one μs around TB. Just do homework and install temp sensors all along the air intake...
-->On the contrary, if feelings get better after poopoo, BUY IT!

 

dude, there is no coolant running between the lower intake manifold and upper intake manifold and between the upper and the throttle body.

 

wtf are you talking about? seriously

the entire purpose of the spacers is to minimize heat transfer. If you match them properly you should not effect airflow or create any turbulance.

Now since you are lengthening the runner path you are going to shift the powerband downward. If anything thats better for daily driving (hence your no meaning is completely false)

Racing, well I dont know about you but I am rarely below 3500rpm so you the shortest runner length and largest plenum possible will net you the most gains.

 

About measured, actual air temps...as usual. 'Ten' spots between MAF, injectors. Then, install whatever, measure again. (dont use finger as a measurement tool.)

The first thing is to calculate the affected area, its radiation energy. Then calculate how long one measure of air spends being heated. Then calculate air temp change. Then calculate the theoretical power loss due to oxygen content. That number is gonna be awfull small. Then do the measurement to compare to the calculations...

All measurements done in various rpm, driving situations. Plot diagrams. Seriously, nobody can diffrerentiate if given two similar cars, one with plastic bits, another without. But then what do I know when I have not done such research - in this particular issue. On the other hand, if smbdy sells & claims smting, he is the one that should have the research facts available...

Seriously: if smbdy likes plastic bits or propeller turbos, feelins are better, I have nothin to say but be happy with him/her.

Yes, any time intake is modded, some change will happen.

 

That sounds like a whole lot of trouble to find out if you gained 2 hp.....

 

Trouble rests on the salesmen. But DIY; no need to prove anyone anythin, just show ya rearlights... And of course cooler air is better, me wannabe beleive in intercooler with a turbo; then towtruck bill.

 

On the VE30DE motor, there is no coolant running through the upper intake manifold. It only runs through the lower intake manifold. My spacers are between the upper and lower IM and between the TB and upper IM. They GREATLY reduce heat transfer from one manifold to another. While the lower IM is way too hot to touch, the upper IM will be COLD.

Anytime you decrease temps, you will only produce more HP. Why do you think it's beneficial to put ice on your IM at the track? A lot of domestic guys swear by it. I haven't personally found it beneficial in my track times, but you know good and well, it can't hurt track times. Every little bit helps.

The gain that I felt wasn't due to lowering the IM temps, it was b/c I lengthen the intake path. I noticed an immediate increase in low end power. Since it's harder to tell if I lost top end (since it's so smooth) I can't comment on whether I lost top end power.

My website doesn't show anything about how I made them. It doesn't even show pics b/c I didn't have time to stop and take pics while I was creating them. The only pic that I have is this one before I started cutting the sheet. BTW, it's a sheet of teflon plastic. It had a greater heat range resistance than phenolic and delrin, so I felt this was a good choice. In fact, MadMax024 researched it first and made the decision to use this sheet. Then since he had an extra sheet, I just bought it off of him for about $30-40. I forget.



I wish I had more pics. Wait, I think I do have a couple tiny ones here:

http://www.iwdwebdesign.com/maxima/TBSeat.html

Look closely at the upper intake manifold and near the TB. You'll see a white 1/4" spacer. It's pretty much the same stuff as the cutting board material you've seen.

 

Again Aaron excellant info. One quick question on the fan switch tho. The lead to wire 6 off the ECU goes to the switch, got that, then the switch goes to ground or to 12v power??

 

Look VERY closely at the diagram I created. That little symbol with the 3 little lines means "ground". So you will go out and buy a SPST switch from radio shack. I got the switch to the right on the switch panel I made out of my ashtray.



Next, you need to get some inline wire splices. They are able to tap into a wire without having to completely cut the wire in two pieces. Just carefully use a sharp razor blade to help cut back some of the insulation, do NOT cut the wire. Sometimes, the wire splices do not cut the insulation properly on such a small wire. I am guessing the ECU wires are 22-24ga. So buy the splices that I use in this picture:



Next, tap into #6 ECU wire if you have a VE30DE Maxima. If you don't, then I can't speak about the harness connector layout being correct on other Maximas. Run a wire to your SPST switch. Then run a wire from the other terminal on your switch to GROUND. If you put 12 volts to it, say bye bye to your ECU!

Get an ohmmeter and make sure your connections are good before trying the switch. It's just good practice while wiring something up. Good luck!

 

Dude, you bracket race a Maxima?

 

CyMax: Get a proper temp gauge, that should help clue you in as to how the cooling system is performing. Like they said pretty robust studff here. You probably won't want to run any less than 30% coolant in your mixture. Try 35-45%. The back of the antifreeze bottle should have some info about that.

 

Yes. What are you confused about?

 

just never thought of a maxima as a braket racer, maybe more of a street cruiser, highway blaster kind of car. didn't mean to sound condesending.
Yeah, so just went to your page, nice. you're doin' pretty good at the strip i see. car looks choice as well. what's up with runs in cali, then runs here in the caka-lac? you move?

 

You might find a Maxima to be one of the best bracket racers in the street class. It all depends on the driver and how the car is setup.

Yeah, I use to live in Las Vegas. So I had to drive to Cali, which was the closest track somewhat near sea level. I then moved to FL, where I got some more 1/4 mile runs in insanely hot weather. Now I live in Eastern NC, where I expect to see some REALLY nice tempuratures at my local track.... Kinston Drag Strip and Fayetteville.

Thanks for the comment.

 

Where is Snow Hill anyway? I'd love to checkout your Max in person.

 

It's a VERY small town about 25 minutes from Greenville. It's only about an hour east of Raleigh.

 

One procedural comment: Skip tHat piggyback robber connector -IF- u dont want intermittent faults, fire. Every one of those will fail, q is only when...

The only long-life connection is to solder, wrap on self vulcanizing tape & tape. No need to cut the wire. Second best is screw terminal, there u need to cut the wire.

 

You have no idea what you're talking about. These are just signal wires. These wire splices are the best and easiest way to get this to work. They will never fail if installed properly and they will never cause a fire.

 

When I was young, I used to think as u say. While the moisture behind ears dried, experience taught the hard way. Yes, every one will fail. Just be patient...

I did not say signal wires typically cause fire. U said. I said those type connectors are a hazard. Intermittent problems always follow the lazy mans connectors which cut, open the wires for oxidation. Surely u will use them anywhere as they are so good... Quite a dangerous joke to say that bad connections dont matter. In this particular application, nobody cares if u fans dont work...

Pls try to learn from others experiences. Can u? I can see no wrong in warning ppl off from trouble.

Tell me ONE global company using those suckers in their electronics products. No. Nissan? HeHe. Hey, You cannot, and the reason is hereby told: every one is already out of business.

 

Crap dude. Everything you are saying is verbal crap.

You said they would cause a fire. I said they wouldn't.

On more important connections, I wouldn't recommend these type of cheap connectors. But for this application, they will be perfectly fine. I've been using them for years without a single one failing on me. It's just a fan.

 

Years. lol. even three? Single failing: how many connections have u made during u long life? Four? lol. Long way to go to learn facts, behaviour. My electronics job experience is longer than u life.

However, THE issue which u warped to persons as facts failed, was a problem causing connector type. Lets return to it: these connectors are a cause for fire, intermittent problems.

This time I'll not go into the science of the connector: lack of contact point pressure, blade warp, broken wires, materiel, non existent sealing causing unacceptable transition resistance etcetc. I will just note that anybody with any knowledge or sanity, will not praise or use them anywHere.

End of Issue

PS. To those readers who just want information, here's some issues about not making verbal crap, but making contacts work:
http://www.cardomain.com/ride/748507/14

 

There is NO WAY a fire can happen b/c of the write up I showed above. I don't care how long you talk about it, it doesn't make a fire.

I can't believe this. Every single word you are saying is not true! It's possible that this connection can fail in 10-15 years! But we aren't resigning the Nissan from scratch. If we were, then we wouldn't cheap out and buy these inline wire splices. But, blade warp, broken wires, non existent sealing causing unacceptable resistance... that's all total garbage. Non of that will happen. If you know how to install these correctly, they will hold up for a very long time. Much longer than anybody will own a 3rd gen.

The bottom line is, these connectors are PLENTY good enough to get this job done easily and for a VERY long time. They will hold up just fine.