Re: Where can you access to blast air other than the front grill?

Yesterday, I fished out a crap load of leaves, small pebbles, cig butts, etc from my radiator ducts. I pulled the bumper off once to give it a good clean, but really do not want to go thru that exercise again. Figured putting in screens would fix the problem for good. Any truth to the thought that it would limit airflow significantly to the radiators to matter?

grabbing some



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That might be the case, but look at the GT3 and GT4 radiator inlets--that have screens across them. In the case of those two models, Porsche thought it made sense to protect them--but not so on the Carrera S which has essentially the same motor

Add to that, the 981 base boxster (manual) has a partial plastic grid that protect the radiators from direct strikes while allowing air in: the PDK and S models do not have this, suggesting that airflow restrictions are an issue.

There are plenty of people that have installedtheir own grids on the the various porsche forums and haven't burned their engines up, but I think this is a case where you have to error on the side of airflow, rather than protecting the radiators. Less is better?

[static.cargurus.com]

Not the best view, but on the driver side radiator opening you can see a dark grid in front of the silver radiator; on the PDK/3.4L models there is no grid.
This grid covers about half of the opening, protecting the radiator from direct hits, but open on the inner side for air to move through freely.
My thought here is that if Porsche thought it was uneeded, they wouldn't have included it and likewise, Porsche felt that fully open openings were needed on the PDK and 3.4L models.



Edited 1 time(s). Last edit at 10/20/2015 09:28AM by MikenOH. (view changes)

No. First there is IIRC warning in either the owners manual or the factory manual about installing any screen in the radiator openings. ('course, that is probably going to be (mis)interpreted by some owners that it is OK to do this as the belief of some owners is Porsche doesn't know squat about anything.)

Sure some will point out that some newer Porsche models come with mesh. But I would expect the car's aerodynamics to take what the negative affect the mesh has on area size and air flow and compensate for that. IOWs, I would no more remove the mesh from a car that came with it present than I would add mesh to a car that didn't come with it originally.

Ignoring the faotory's guideline on this subject, there are several problems with adding mesh.

The mesh reduces the area of the opening. Depending upon the wire size and spacing the area can be reduced by 15% to 54%. I have a chart somewhere that gives the mesh design, block opening in inches, the wire diameter in 1/16th's of inch, the open area in %, and the reduction in % from the total area. A fine enough mesh to filter out some stuff would probably tends towards the upper end of that area reduction number.

Another problem is the mesh would instead of letting a large piece of plastic or paper go through/into the opening the plastic/paper would instead plaster itself across the mesh and block some, most or possibly even all air flow through that radiator duct. Once in a while I spot an oncoming car with sometimes a rather large piece of paper or a plastic shopping bag plastered across the front the radiator grill work so this is not an uncommon thing.

While I have found that both of my cars can keep their cool with one radiator fan non-operational I have never experienced a situation in which air flow through one radiator was mostly to completely blocked and I don't want to.

Even with the mesh one doesn't get excused from having to keep the ducts cleaned out. The radiator duct would still have to be periodically cleaned out. The mesh doesn't keep the finer stuff out which will still accumulate and without the fluffier stuff -- leaves and such -- compact to a much denser and harder material -- think baked mud -- which would be much harder to clean out and remove. I would not want to have to go at this stuff with a screw driver or any sharp object to break it up and remove it.

It is not hard to clean the ducts out. If one keeps up on the accumulation of trash every so often a blast of air from an air nozzle from the right places from under the car will blow the stuff out. I have this done every time I have my cars in for an oil/filter service. Based on my usage this occurs at least twice a year. Those that service their own cars must remember there is more to servicing these cars than just doing an oil/filter service every once in a while.

If one lets this go the stuff go it can collect to the point the compressed air may not blow all of the stuff out and then the bumper cover has to come off and condensers unbolted and swung out of the way to allow for a thorough cleaning. Afterwards then the blast of air can be used to clean the accumulation of trash and dirt out of the ducts.

Don't know specifically, but I've never asked. I have however watched and the tech just goes a bit behind the front bumper cover and shoves the air gun nozzle in and lets it rip. You don't want to be standing in front of the car when he does this or you will get a shower of dirt, sand, and trash. The tech moves from where the air exits out to prying apart the overlapping panels and blasting air in. The tech can also attack this from the front with an extension on the nozzle. After all the excitement a goodly amount of material is blown out and the shop floor around the front of the car is quite littered with trash and stuff. A peek inside the ducts sees no remaining trash.

I will prob try the screens to see if there's any difference in cooling. There's ones I can get that you can attach without removing the bumper to do so. Thanks for the opinions all.

Would like to hear from those who have added them and what they thought of them.

Quote
boxtaboy
I will prob try the screens to see if there's any difference in cooling. There's ones I can get that you can attach without removing the bumper to do so. Thanks for the opinions all.

Would like to hear from those who have added them and what they thought of them.

I installed screens on my 981 S a little over a year ago. I haven't noticed any difference in running temperatures. Of course, here in Ontario it seldomely gets over 90 F.

Thanks Guenter for the feedback. I will prob give it a try.

I also installed mesh on my 986 (after I pulled the bumper and gave the rads and condenser a thorough cleaning) this spring. I haven't noticed any increase in temperature since doing so. Now that the leaves are falling the mesh has stopped a lot of debris getting in. I still plan to pull the bumper ever couple of years and do a full clean out.

Its bigger than screen door material, almost like an 1/8-1/4" lattice. Keeps the big stuff out, lets the air through.

Quick search of that auction site came up with this similar product...
Mesh

Steve

Steve
Guards Red 1999
I'm not a race car driver, but I play one in 2nd and 3rd gear

Thanks Steve. I do remember now that you have it in your bumper now. Looks pretty good too.

I installed screens on my 986S a few years ago after seeing them on a GT3. So far no issues with temps or debris blocking air flow. I live in SW FL so we have plenty of 90+ degree weather in the summer followed by really cold 70+ degree winters (sorry to all my Canadian friends I couldn't help myself ).

BTW, there are a number of vendors selling "specially designed screens" at great cost, turns out it's the same mesh you can buy at Lowes/Home Depot for 8 or 9 dollars. All you need to do is make a paper/cardboard template then cut out the mesh.

I didn't bother installing screens in mine because I remove the radiator every now and then anyway. If I didn't, I'd probably just get a long vacuum extension. I'm not a fan of the mesh look. And yes, it necessarily blocks airflow.

GEt out the popcorn, I'm sure this will get the armchair and regular engineers going...
The mesh will not limit airflow more than the radiators do as the it is the fan functions to pull the air through the radiator and whatever other restriction once the car is up to speed. The biggest limiting factor is the radiator...

Discuss!!

Steve
Guards Red 1999
I'm not a race car driver, but I play one in 2nd and 3rd gear

The air flows past the radiators. That is why they work.

If you're saying that the diversion of air by the radiators causes more backpressure of the outflow than mesh does of the inflow then I can throw it back to you and ask how you know that.

I agree also that it blocks airflow to an extent, as you're putting something in front of the radiators. However, it seems some folks here have done it without seeing rising temps or negative effects. Perhaps not enough blockage to matter much, as the fans still suck in air when needed? Long vacuum extension sounded good to me too, but what about the errant gravel pebble or something that could rupture a line? I once had a bird get sucked into my SUV's radiator and had to clean out the mess.

but I've never heard of such a thing happening. From the design I think it would be nearly impossible given the size of the opening and the positioning of the lines.

… 987 and on Porsche redesigned the air inlets up front, making them substantially bigger.
The 981's intakes are even bigger than the 987s.
Mesh on the restrictive 986's does make them run hotter.
I know. Been there, done that.
[pedrosgarage.com] [pedrosgarage.com]
On the 987s it's negligible as I would also guess on the 981s.
Happy Meshing,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

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... simply don't get THAT much junk in there. Yea, a few leaves down in that deep corner, but it blocks about 5% of the radiator. And even with the hard use my car(s) get (tracks, WOT and 6k rpm continuously) - i don't get elevated water temperatures. So the concern over blockage seems unsubstantiated, and the concern over mesh creating restriction is an absolute fact - relevance TBD.

So my opinion is dont sweat it.

G

Grant

gee-lenahan-at-gee-mail-dot-com

the buildup of debris allowing moisture to accumulate in the corner area leading to corrosion.

Grant

gee-lenahan-at-gee-mail-dot-com

My concern is the amount of gravel pebbles that I pull out each time. I don't want a rock to puncture a line.

When I cleaned mine out this spring the amount of crud was substantial, but I don't have any idea how long it was (if ever) since the last cleanout. I wish I took a photo of the crud and weighed it!

I didn't weigh it, but I took a pic. This is only the driver's side. The other side was equally as bad. Mostly leaves, ciggie butts and pebbles. I also used my leaf blower to blast out the smaller particulate.

I'm definitely thinking about getting the meshes now. I haven't looked at what is available for my 986.2, but hope they are just snap-in.