Another Pedal..

[Nick_USA]

Page 8:

https://www.manthey-racing.de/MTH541561undMTH541562_air_intake_grids_718_Cayman_GT4_CS.pdf

As a MS part it will have another 3 zero after the otherwise sensible price.

btw. Only the Germans can have a work procedure that involves taking the sill off.

 

[ralphmusic]

Nick, thanks I have that catalogue. The interesting thing about Manthey parts is they are not defined as Porsche OEM so depending on warranty situation, could cause denial of cover. If I had a really switched on competition based Indy nearby I would be tempted back into the modifying game but with this car I am being careful lest my pepita seat inserts have somehow affected the engine compartment purge fan. []

On a related subject, the stock aero is designed to take air flow along the side and into the intakes, so why not have an additional grill at the opening to the side vents? The recently seen rear three-quarter light air intake pictured below would reduce the risk of OPR ingress and provide cooler air although I haven't seen anything about the pressure at that higher intake point.

 

[Nick_USA]

Don't worry Ralph it's only the houndstooth inserts that invalidate warranty []

btw. Care to take a stab at how much the 718 GT4 CS rear wing assembly costs (if you could order one).

 

[ralphmusic]

I was told it was €14k + IVA. Quite cheap when a set of Clubsport cats which probably last a year at most cost $7.5k

 

[lowndes]

Not a GT4 owner here, but I found this all very interesting so thanks for taking the time to post.

I've also taken a chance on warranty with Houndstooth inserts, I blame Porsche for making drab interiors[]

 

[Motorhead]

On a related subject, the stock aero is designed to take air flow along the side and into the intakes, so why not have an additional grill at the opening to the side vents? The recently seen rear three-quarter light air intake pictured below would reduce the risk of OPR ingress and provide cooler air although I haven't seen anything about the pressure at that higher intake point.

Not great for over-the-shoulder visibility though Ralph; although it looks as though we'll be seeing something like it on the GT4 RS, so it could well be an expensive retro-fit on other 718s.

Jeff

 

[JohnCRS]

It would be interesting to see the ducting the inside Ralph. I wondered whether the additional volume would be an attempt to get the overall engine bay temperatures down a bit.

 

[ralphmusic]

John,

Here you are .....

Developer's (BGB Motorsport) comments "This was good enough to reduce the intake air temperatures on the 4.2L PDK GT4 Clubsport to within 5F of the ambient. On the race car we are seeing an additional 2 - 3 mph on the straights from this intake now that the car is not sucking hot air!"

 

[Brian_Innes]

Ralph,

That's an amazing piece of kit. I can fully appreciate the power and torque benefits deriving from such an installation. It would be interesting to see the comparative dyno power graphs with, and without, this kit in place.

Expensive certainly. But for a track day car or a competitive motorsport car, this is an essential modification if you want to improve lap times.

For we racers, speed is everything.......

Brian

 

[ralphmusic]

The car into OPC yesterday to investigate CEL, turns out fan blocked by OPR. Cleaned out but can't collect car as the rear diffuser was damaged reversing it out of workshop this morning. It happens, new part on order can collect tomorrow but it will be Saturday for me.

More interesting point, here is the ducting (981) version.

The air enters the side duct and travels past a fairly open grill to a bifurcated duct, one side to air filter/throttle body and the other to the purge fan. My question this morning to OPC is do we need to check the air filter/throttle body route for ingress of OPR and debris?

For information, I contacted Manthey this morning and a pair of their 718 side intake grills is €180 inc VAT excl postage. Seems a good idea....

I await further info from OPC

 

[Motorhead]

Ralph,

With their track experience, presumably Manthey developed the side intake grilles for a reason! Much the same as having the grilles on the front intakes?

Item 35 in the pic only appears to cover the fan side of the duct but not sure what function it performs other than as an air guide - doesn’t the fan extract air from the engine bay?

From your previous post I would imagine that although the side grilles aren’t expensive their fitment could perhaps incur a significant labour charge?

Jeff

 

[Twinfan]

You've also got the warranty issue of non-standard parts and failure of a future 111-point check to consider...

 

[ralphmusic]

Ralph,

With their track experience, presumably Manthey developed the side intake grilles for a reason! Much the same as having the grilles on the front intakes?

Item 35 in the pic only appears to cover the fan side of the duct but not sure what function it performs other than as an air guide - doesn’t the fan extract air from the engine bay?

From your previous post I would imagine that although the side grilles aren’t expensive their fitment could perhaps incur a significant labour charge?

Jeff

Jeff,

You may be right on the grill being effective only on the purge side "leaving" the air filter to collect all other debris. It may also be the case that the air filter side of the bifurcated duct is further protected but perhaps only by the air filter.

The Manthey 981 GT4 version of the grill is pictured below. I've asked for fitting instructions.

I like the comment about the purge fans..

Back to the internal arrangements, here is the internal intake ducting to the air filter ('cleaner' in Porsche terminology) and secondly an image from the Workshop manual (all 981 GT4)

So as I interpret these drawings (second image PET file) air enters part #6 from the bifurcated duct, and heads to the air filter which is mounted within the rear bulkhead, this video shows filters being changed and helps envisage how it all connects.

[tube]https://youtu.be/CNbHYVnHwro[/tube]

I have ordered an endoscope so I can take a peek up the various ducts to ensure all are clear.

On warranty, if you are only running a car on the road I would not see this as an issue. If you are a regular track driver then it is in the lap of the gods as to whether you will have a problem, but for me I'd rather not go through this again. Cleaning out the debris is not a warranty job. Fitting grills may invalidate the factory warranty if Porsche can prove they were the cause of damage, and severely risks the success of a claim under the insurance approved warranty.

So logically if they are not fitted and OPR enters the car though the side intakes and damages the engine, it is not covered under any warranty, if grills are fitted and there is otherwise unconnected engine damage under approved warranty then any claim can be denied. So in fitting grills supplied for race track use by a Porsche AG majority owned company that runs Porsche's WEC race programme, I would lose approved warranty but would not need to pay £150/hour to a Porsche distributor to remove track detritus. Or to retain warranty I need to pay the £150/hour... Who said warranty made sense but we all know and live with the rules.

Ralph

 

[AndrewCS]

What this does not show ... is that there is another grille in 18, that protects the air filter tract. I believe that these were a recall / retro fit to the 718`s

My intake / purge fan `side pods' act as perfect stone catchers hence as I live off road are on a routine inspection / clearance regime . Stones etc. get caught in the grilles and also lodge in the base of the pod where there is the water drain to the sill ... small stones also pass in to the sill. If you `tap` the sill you`ll hear them !

Pod drain water to the sill drains out in front of the rear wheel

Item 2 `grommets` can probably be removed to attempt stone removal. Also, the sill is flexible enough to bend away from the inner frame

 

[ralphmusic]

....What this does not show ... is that there is another grille in 18, that protects the air filter tract. I believe that these were a recall / retro fit to the 718`s.....

Thanks Andrew, we'll see when the OPC sends me copy of the PET file, although I may go and get it independently.

I have received the Manthey fitting instructions (forgot Nick posted them earlier) - they involve removing large swathes of body panels [X(], so I'll look at alternatives.

 

[AndrewCS]

Welcome ...

Out of interest / reference, last weekend I looked at the Le Mans RSR`s … they had the Manthey style mesh fitted

Sidepods … mine are well `pitted` on the leading edge and internal wall, having only done 10k upon receipt, the previous CS had next to nothing in this area

 

[Motorhead]

Ralph,

Rather stating the obvious but I can’t see any significant debris making its way past the considerable bulk of the filter element having first found its way past the additional grille that Andrew mentions which should be present on your GT4 [ https://www.porscheclubgb.com/forum/tm.aspx?m=1011013 ].

Maybe the best thing to do first is to get your PC to pull the filters to see if there is an accumulation of debris in the inlet tract upstream of them and base subsequent decisions on that finding?

Jeff

 

[ralphmusic]

Jeff,

My incoming endoscope (no jokes please) will help me take a peek up the various ducts to ensure all are clear. The OPC did say the debris mostly consisted of small particles but they are keeping them for me as I am thoroughly curious.

Ralph

 

[ralphmusic]

The car is back from OPC and my take on all this.

The intake is bifurcated with one duct to the throttle body the other to the purge fans, both have fairly coarse plastic grills to deter debris. Debris cleared out from the purge fans/shroud (after the grills) is pictured below:

The debris consists of some OPR rubber pieces and presumably, road debris (left is nearside). The clearance between the purge fan blades and fan shroud housing is tiny so that any blockage, partial or otherwise can cause the fan's drive to be reduced by the electronics or by physical resistance, respectively.

We did not check the air filters, reasoning that they would stop any of the debris from getting near the throttle body and I always have these changed regularly anyway and it will be interesting to see what they have captured.

The Manthey grill is positioned at the common intake point so is designed to protect both air intake and purge fan ducting. It clearly would not stop any of the smaller particles. Did my fan stop working because of the small size particle road debris (stones) or one of the larger OPR pieces? - it was not possible to determine which caused the problem.

Running on track days where cars can run slicks will risk this happening again. Running on Club track days and circuits which generally don't allow slicks such as Combe and Goodwood will be very low risk.

I will study the ducting some more and look at putting a custom grill in front of the OEM grill protecting the purge fans, leaving the air intake as Porsche intended.

Ralph

 

[Motorhead]

Ralph,

Maybe you can fashion some mesh material to fit in front of the coarse grilles you describe? That way they’ll probably be invisible to prying “PC warranty police” eyes.!

Jeff