Intercooler Upgrade - adding a fan

[DocK Member Find all posts View Profile Close DocK]

I know this is not a new idea and has been done before on other vehicles but it seemed like a good idea to increase the airflow at low speed - eg crawling up rocky slopes. It is also a cheap upgrade about $100. I went for an 8 inch fan and offset this to avoid a bonnet rib. The fan does not weigh very much and I felt that the mounting points on the intercooler for the cover would be OK with it sitting there. I also put some rubber boots under the fan mounts to absorb some vibration. Overall, there was no problem with clearances. It seems that the original boot still seals around it when the bonnet closes so that would increase the efficiency. So how did it go - for all you sceptics here is the answer. Dyno tested with fan off and on,( yes, of course it was stationary with the bonnet closed) also bear in mind that the dyno was done on a 35 degree day so on a cooler day expect more - 5kw at the wheels Well, I hope that stimulates some minds out there. Now I guess someone will say - yeah but what about at high speed wont it reduce airflow and obstruct the intercooler? We need one of the more technical guys to answer that but my guess is that there would be so much air flow at 110kph it wont matter that much. Over to you PPs what do you think?

[stewy Advanced Member Find all posts View Profile Close stewy]

Re: Intercooler Upgrade D4D

Dock,

Looks like an interesting mod. 5kw at the wheels you reckon. I'd luv to see the look on the fellas face next time it's in for a service.
It's interesting an innovative ideas like this that keep me coming back time and time again to this forum.

Regards

[DocK Member Find all posts View Profile Close DocK]

Re: Intercooler Upgrade D4D

Thanks Stewy
Just a small point - designed the support brackets to take the weight off the intercooler. So, it is actually suspended just above the engine cover with 3mm thick silicon spacers underneath the fan shroud in case it does vibrate a bit. Did not want it to rub on the intercooler and poke a hole in it. Other good thing is it is really easy to remove - 4 nuts, quick release electric plug, 3 minutes and its gone. So if I don't like it or think its causing a problem it can be removed without any fuss.

[DocK Member Find all posts View Profile Close DocK]

Re: Intercooler Upgrade D4D

Just for those interested I figured out a way to get the dyno for you. What you will find interesting is the shape of the curves. With the intercooler fan on there is signficantly more power /torque at low rpm. The top curve is with the fan on and the lower with the fan off. At low rpm the gain at the wheels is nearly 20KW. (AWKW = at the wheels Kilowatts) When doing low rpm work that is going to make a difference. Means that I should not have to push it so hard - take things more gently, which is better for everything. Hope that helps.

[photoprado Avid PP Poster! Find all posts View Profile Close photoprado]

Re: Intercooler Upgrade D4D

Ok, I'm confused now. (maybe I always was)

Is this the same car with the Toyota Diesel performance kit?

What are the whited out lines about?

Was the fan 'on' for the whole of the top dyno line?

Looks like a neat low budget power boost!

Michael

[MickL Addicted PP Member Find all posts View Profile Close MickL]

Re: Intercooler Upgrade D4D

At low rpm the gain at the wheels is nearly 20KW

Low rpm = low boost= low engine flows=low intake temps=intercooler at its most efficient.... and you say 20kw at the wheels (The drive train loss in a Prado is up near 35-40% so your saying 27-30kw at the fly wheel) from the fan? please explain.....

The top curve on you graph looks suspiciously like a nice flat torque curve, not a power curve.

Mick

[DocK Member Find all posts View Profile Close DocK]

Re: Intercooler Upgrade D4D

Sorry guys - I tried to white out the other curves to make it less confusing and just show the dyno for the intercooler fan. As some of you know mine is also LPG/Diesel. So on that dyno was a gas/diesel curve as well. As the dyno guys explained to me they could not do the torque curves because it was an auto, so these are definitely the power only curves. There are no curves of gas/diesel/intercooler fan all on. Are we still confused :?:

[DocK Member Find all posts View Profile Close DocK]

Re: Intercooler Upgrade D4D

Yes, it is the same car as the DPK - I think it may be time I stopped fiddling with the engine bits and go onto the drivetrain now.

[VL400 Member Find all posts View Profile Close VL400]

Re: Intercooler Upgrade D4D

The low RPM response difference looks very much like the difference between loading the vehicle up against the dyno and getting the turbo on boost before the power pull and just mashing the go pedal and waiting for boost to build during the power pull :?: Can make the low RPM response look very different, a plot with boost would show whats going on.

Either way, cant argue the 5kw peak power increase Good cheap mod!

[DocK Member Find all posts View Profile Close DocK]

Re: Intercooler Upgrade D4D

Geez, I glad some people out there know more about these dyno charts than I do. I really dont understand the ins and outs of the turbo too much and how that shows on the dyno chart - low boost/high boost and so on. Thanks for the feedback.

[DocK Member Find all posts View Profile Close DocK]

Re: Intercooler Upgrade D4D

I have been taking a closer look at the dyno chart and the results. As you know by now this car has LPG/Diesel and the DPK. The DPK kit is always on so that baseline wont change. What is interesting is the comparison of performance on LPG/Diesel and the intercooler fan. The only difference at the time of the test was fan on or off, gas on or off. The test on the dyno is based on kph not rpm because of the torque converter.

The results are: fan on gave an increase of 24Kw AWKW at 31kph, 24Kw AWKW at 41 kph and 8Kw AWKW at 51 kph. Gas on/fan off and at identical speeds and conditions; 22KW AWKW, 19KW AWKW and 6KW AWKW. So based on that, the cold intercooler ie fan gave a better result than the gas conversion. So for less than $100 you can achieve better results with an intercooler fan in performance terms than a gas conversion worth $4000. At least when the vehicle has the DPK kit anyway. That means for less money than a gas conversion you can buy a genuine Toyota DPK and an intercooler fan and achieve better performance than diesel LPG conversion. That is,if I have got the logic right - I am not sure the LPG industry will like those results.

For those who are more technical I would appreciate your comments - have I got it right here? It bears some thinking about though doesnt it :?:

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Re: Intercooler Upgrade D4D

I must admit I am struggling with this. On a dyno you are not getting real world airflow across the intercooler so I am not sure how much difference there really is once the car is moving. Even the big mother fans that are used when you dyno a car are not as effective as a full stream of moving air on the road. So perhaps the dyno power figures are artificially low and it is possible that the fan makes up for this + a bit. How do the power curves compare against factory charts? Shape not actual figures as every dyno is different. I am guessing Toyota san (or sensei if you are easily impressed) simulates intercooler airflow when he tests his engines to make the engines look as good as possible. As far as I know there is no information about airflow across the intercooler, could probably do a test with differential pressure columns to get an idea though. Hmmmm. DocK what brand of fan did you get? Do you have any airflow curves? If it is a thermo type fan from a radiator they take about 10 or 15A (?) so for a cost of less than 200W you are seeing 27kW improvement? Sorry seems awfully unlikely but I am willing to be convinced. Need some airflow curves though. And some factory power curves. Do you have any seat of the pants evidence with and without the fan? With so many other mods to the engine it is hard to work out the effect of a single change. From memory Mrs Nissan added a fan to the top of the intercooler on the early 3.0 Patrol turbos but I think that was to cool the thing after it shut down so it wouldn't cook itself? Need to do some more research...

[DocK Member Find all posts View Profile Close DocK]

Re: Intercooler Upgrade D4D

I used a Brown Davies fan with a dash mounted switch so I could turn it on and off as desired. It draws 10amps so you are right about 200w goes in and a bit comes out. Some people have apparently wired the fan to a boost switch that only turns the fan on with boost - that was a little too hard for me.

From what I remember of the original power curves these were not as flat as the fan on curve and perhaps when the airflow in normal driving is occurring it makes little difference. I am sorry I don't have air flow differentials before and after fan on and off. I am aware that is possible but have not tried it as I don't have the gear to test it.

It really is hard to be objective about the seat of the pants feeling but I thinks it does make a difference at low rpm. Cruising around town is the most notable - take off and slow cruise and I am not putting the foot down as much. Also the engine temp seems lower with the fan on. Another example, at 60kph now it is only doing 1200rpm - I think that is the torque converter locking up - but it now holds this for much longer when approaching hills and so on. I am assuming that is because the torque has improved. Before the torque converter would lock up at about 65kph. Having said that though the auto transmission specialist I spoke to recently suggested this may not be a good thing and leave it in 4 rather than D for the transmission's sake - but that is another topic altogether. So what I do - at the moment unless cruising over 80kph I leave the fan on all the time. I will check the economy over the next couple of weeks so see how it goes.

It is an interesting phenomenon - explaining it is more difficult than doing it :!:

[yetiboy01 Senior Member Find all posts View Profile Close yetiboy01]

Re: Intercooler Upgrade D4D

You could try plugging a scan gauge in & checking the inlet manifold temp with the fan & fan on, if the fan makes a difference at low speeds you will see the intake manifold temp drop close to ambient temp as it does when cruising down the hwy, in traffic or low speed off road work you will see on the scan gauge that the intake manifold temp rises as there is not enough air flow across the intercooler & the engine acts as a heat sink,

[MickL Addicted PP Member Find all posts View Profile Close MickL]

Re: Intercooler Upgrade D4D

It really is hard to be objective about the seat of the pants feeling but I thinks it does make a difference at low rpm

You would certainly notice a 24 kw at the wheels improvement :!: :!:

Your data is flawed. You need to re-evaluate it.

There is no way on Gods earth you are getting a 27 kw improvement with just an intercooler fan.

27kw at the wheels is approx 34 kw at the fly wheel (35-40% drivetrain loss on a Prado)

That like the difference between a naturally aspirated engine and a forced induction one. (for example you are only 11kw shy of the difference between Toyotas very own supercharged Hilux and a standard one.)

You are claiming 150kw+ from the chip, then another 34 kw from the fan :?: 184kw at the fly wheel :?: No way Dude.

I'd say you have your graphs ballsed up. "22KW AWKW, 19KW AWKW and 6KW AWKW" would be expected from the gas

plus a couple( 2-3) of kw from the fan... so " 24Kw AWKW at 31kph, 24Kw AWKW at 41 kph and 8Kw AWKW "


If you read the Patrol forum, Prjero Forum, or even any of the Subaru forums you'll find plenty of guys running fans or even water sprays.... they claim a few kw at best. Biggest advantage is to stop heat soak when vehicle is stationary waiting to do a quarter mile run, once you hit 15-20kph any advantage is over.

Patrols have the biggest advantage with a fan because once you fit a bull bar it restricts airflow into the bonnet scoop. Even those guys only claim a couple of kw on their dyno charts.

Like I said, look at your charts again... something is not right.


Mick