I went though all of these guy's posts. Dave described what his 3-4 final options were but I couldn't find what they finally ended up with or what the results were after it was done. ie.. performance, opinion etc....

 

BUMP to the top, I'm curious as well.

 

One of the G35Drivers.com members, Andycon, tells me he has been in contact with DaveO about doing this conversion himself. Since I know Andy, I told him I wanted in on his conversion. i.e. I want to watch, drink beer and take notes while he works. I have yet to hear back from Andy. I will give him a nudge.

 

I wanted to do it and spoke at length with DaveO about it and decided against it. One good thing is that DaveO has done it and that means a helpful guy with meticulous skill can help you. But with the fan being off most of the time...it seems like a lot for 8 hours or more of labor. For that time what else could you do to make that power. Maybe port and polish your plenum and intake runners???

 

I know DaveO says the conversion is good for 8-10whp, but when I've asked him to post the data, it seems to fall on deaf ears. I know he doesn't care for me one bit, but at least he could help out others that are also curious.

Jeff, like SixFive said, it's a lot of work. I also think the gains are questionable. I could definitely see the electric fans gaining some power over the fan-clutch setup when the clutch is engaged, but at all other times, I don't think there's going to be that much difference at all. The fan does spin a bit even when not engaged and the accessories do have to spin the clutch assembly; however, even with the electric fan setup, there is a pulley that has to be driven (in place of the clutch-fan). Also remember that when the electric fans are on, they are putting load on the alternator and sucking out power.

I never quite understood the rational for the fan-clutch setup on the 03 sedans, when the Z/Coupe cam with electric fans. It seems like having two different setups would increase costs. I guess Nissan originailly thought the sedan maybe needed a more effective cooling system since it could be hauling around a lot more weight when fully loaded. I guess they changed their mind a year later.

Seeing that my G auto has consistently seen 97-98mph traps with a Z-pipe leads me to believe that the fan-clutch isn't sucking out much HP.

 

I've been planning on doing this as soon as my warranty is up (12k miles from now). I've exchanged quite a few emails with DaveO and spoken to him on the phone. I think the process is quite well defined, though it'll be a tricky task, for me anyway. He's given me a list of all the parts required and even some photographs of a finished install.

Like DaveB, I wish there were some numbers to back this up, but I do believe that the clutch fan will pull more power from the engine than the electric fan. But this is only based on 1) anecdotal evidence from DaveO and 2) the fact that the coupe, 350Z and future models of sedan all switched to elec fan - it must be an advantage somehow. There are also plenty of elec fan conversion kits out there for various cars: all with the purpose of increase horsepower.

 

Is it not odd that those who do have the clutch fan set up (ala high towing capacity trucks) go to the trouble to install better cooling systems and radiators?? There is one thing that car does not need is a better cooler system, tranny cooler notwithstanding.

I like how BMW uses an electric water pump to save weight and ponies. If there was a sophistication to power ratio war- BMW would win. They have all that cool stuff in their motor designs, and then they are still barely pumping out any more HP than a mediocre for class rating. New BMW 335i is what they save all the power for and then they can charge 50k for a small car! Sorry I degressed.

 

As of last Tuesday I've now personally done 10 G35S electric fan conversions and helped a few others do it themselves. (Last Saturday I did my first Type 2 Sedan conversion. The wiring is totally different than the Type 1 Sedans. VIN numbers not trunk design determine a Type 1 or Type 2 Sedan.)

There are several ways to get the job done. Yes, the factory dual electric fan set up will work if you're willing to replace the IPDM E/R (or it's fan wiring), the engine room wiring harness, and the radiator. I wasn't. And yes there are other ways to do this with other components that I haven't tried.

Fans:
1) Single shroud mounted 14" fan in combination with the stock auxiliary fan.
2) Dual 12" fans which replaces both factory fans

Note: For those concerned about either fans cooling capacity, both the 14"/aux fan and dual 12" fan setups have been tested over Barstow, California type summers without a problem.

Fan Control:
1) VSC/Thermister (variable speed controller/temp probe)
2) VSC/Thermister and ECM
3) VSC/ECM
4) Direct wire ECM sequentual fan (fan 1 A/C low temp - fans 1 & 2 hi)
5) Direct wire ECM dual fan - currently testing. Have concerns regarding factory wire size vs. dual fan amp draw.

As for "proving" the power gains associated with this conversion... I have feedback from those who have done the conversion along with my dyno, G-tech and dyno-butt results. I'm pleased with this information and don't feel the need to justify this conversion to anyone... especially those who have never dynoed their sedan. If you doubt the advantages, my suggestion is real simple, don't do it.

 

I just wanted to have the information available to those that wanted to try it. I'll post this link in the my sticky post above.

Dave O. Just to clarify, which of the above options have you installed in the past 10 projects?

Fans: Dual or single? Looks like you went dual?

Fan control. Looks like you opted for option 5?

Thanks for the info

 

Jeff,

I've installed and tested all of the options listed on my Sedan. I've done 4 single fan and 6 dual fan conversions on other's cars to date. All used the VSC with the owner's choice of control.

I've only recently done the direct wire ECM control on my Sedan. Option 4 looks real good for "staged" control of the dual fan setup. Simplicity, factory wire size/amp draw, etc. is good to go.

I'm currently testing "option 5" but have the noted reservations. Right now I need the ampere rating for 14 gauge twisted copper wire at 12.5 Volts DC. Can anyone help out? I believe I'm right on the edge as the dual fans are drawing more than 15 amps but less than 20.


DaveO

 

14 gauge THHN is good for 20A. What is the type of sheath/insulation of the wire since that determines the heat rating based on the Amps/draw.

 

Same answer, different day

May I ask what is so hard about posting the true dyno results?

 

Jeff,

Make sure you find out whether you have a Type I or II motor. Mine is the Type II and was built the month before the 03.5 non-Doggie door G appeared.

 

Thanks a bunch for the info. The sheath/insulation is made of the "harder" plastic material. Would it be fair to say that since most G35/350Z running voltage is around 14VDC this should be a safe setup?


DaveO

 

Thanks DaveO for pioneering this mod. My take on the mod is this - the price is minor, and a day spent under the hood is a day well spent, IMHO. This is definitely in my plans for future mods once my warranty is up. Thanks for all your patient help with this.