Why would Nissan incur the added expense of e-fans on the 6MT cars instead of a $39 clutch fan? Certainly not due to cooling capacity since the 5AT has much higher thermal load from the tranny cooler. Why didn't they just leave the belt-driven fan on the 6MT cars? There must have been an advantage other than cooling.

 

^^ Ding Ding. This person hit the target.

 

I think the advantage was overall cost and parts bin sharing. I believe the orginal reason Nissan used the mechancial fan on the sedan was because they thought the car needed it since it would haul more overall weight therefore a superior cooling mechancial fan was used. Then Nissan's bean counters got involved and decided that there should be more parts pin sharing so they gave the sedan the coupe/Z e-fans. I believe the reason the coupe and Z didn't use mechanical fans is because there was a clearance issue. Interestingly though, the 2002/2003 VQ pictures in the 350Z advertizements showed the VQ35 with the mechanical fan on the front

Just like the routing of PCV blow-off into the intake manifold, we'll never know the real reason why Nissan did what they did.

 

Thoughts:

1) It's odd that Nissan decided to do this. Even the 3.5 maximas/altimas aren't clutch fan driven.
2) Russ and Earl. Are you two just arguing with Dave just for the fact that you don't like him or something? How about addressing the dyno sheet presented. It's the ONLY thing Dave is questioning. Try to keep the flaming to a min and keep the discussion on topic. It's just like the 10 other threads that have 2-3 posts of great info and 19 gazillion of idiot flaming.

IMHO, this mod involves a few hundred dollars and a few hours of labor. It would be nice if there was more solid info also. I'm still on the fence but find the ADULT discussions interesting.

 

It would be kind of hard to have a mechanical fan on a FWD engine layout

 

True but even so, why have it on this one model and then switch not even 1 in the future? Seems like alot of trouble to engineer something like this for 0.5 years of service. Unless some of the VQ35 trucks/suvs had this?

 

I'm sure all the trucks and SUVs have mechanical fans. They offer superior cooling capabilities.

FYI, most BMWs still use or did use mechanical fans. Maybe Nissan wanted the 03 G35 sedan to be as close to a BMW 3-series as possible

 

To me, this is one of the most logical reasons to lead you to believe that they screwed it up the first time. Let's never assume that the manufacturer has done it the best way. They do it the best way they can within the money specs that they intend to use. There are many times where those two things do NOT always go together.

 

If we were to follow that train of thought, one would think that dyno results would be more conclusive.
But I'd be a bit more willing to try this if the cost of admission wasn't so high. ie.. if a set of later model fans could be swapped in easier.

 

That's why I'm leaning towards the parts bin sharing idea.

Really not about the VQ, but here is something interesting thing I found out in one of my Motor Trends. The Trailblazer SS with the 6.0 Liter LS2 makes 395hp. The C6 with the same motor makes 400hp. The General says the differences in power is related to the more restrictive single pipe exhaust and the mechanical fan.

 

I think it "might" bring down the price of admission to something reasonable. I don't know why one couldn't power the oem fans with aftermarket solutions like they have already done. There is one question on fitment though. So it might be a e-fan AND radiator conversion?

 

I don't think that is always a 1:1 correlation but I see your point.

As I said earlier I was not aware what amount of cost involved in this mod. What are we talking here? Where is the cost coming into play? Is this a parts issue? I may be asking questions already answered and I'm sorry if I am. Just trying to get some more info here. I haven't followed this extremely closely as it didn't really apply to me.

 

I think it's around $180-250 for parts and about 2-4 hours in the garage.

 

OK $180-$250 is a big range. I'll try to get with DaveO this evening and find out what the exact parts are. I'm very curious where the cost lies. The time isn't too bad though.

 

I've stayed out of this thread long enough

Um, how can the first dyno indicate the power is starting to rise at 6400 if it ends at 6300?

Regardless, the dynos do confuse me. It appears that there was no correction factor applied. I'm assuming that the TCF entry indicates some sort of correction factor? I'm not an expert on dynapack's by any means. How hot was it the first time the dyno was performed? I'm asking because it appears to me that he in fact lost considerable power at certain points, which is certainly contrary to his impressions.

For example, in the original plot, there's a dip/valley that occurs around 5600rpms. That appears to be roughly 205ish torque. At that same point on the new plot, he's only making 195ish. Is this an environmental/conditions/factor issue? Is it a scale issue? The two plots have a strong resemblance to one another...

I'm in agreement with DaveB on this one, but for different reasons. I'm afraid that these two dynos are too vague to draw any empirical conclusions from the dynos themselves.

Unfortunately, like a few other types of mod, the fan conversion may not be readily observable on a dyno. Flywheels are an example. The fan conversion is specifically for Type I sedans, correct? Aren't the Type I sedans notorious for being difficult to load properly below 4k rpms or so?