How much does Challenge grill help.

A lot. I installed one a few years back. Noticeably cooler engine bay.

 

I have no data but I dissagree with Dave a bit depending on when he measured temperatures.

I would agree with Dave when you stop and get out and then measure temps I believe it would show considerably less.
That being said at hiway speeds I do not think it would help too much over the original.

If you are driving hard like in a racing or even moderate track day event or even in stop,and go traffic I think it would help a lot again.

I base this on my experience with engine temperatures while driving.

What I can share is our engine bays after a spirited drive are smoking hot and I am suprised we do not have more wiring problems.

 

See this thread for a discussion of the Challenge grill's effect on air flow out of the engine bay: 458 Speciale Spec Challenge Grill for F355 ?

A thread made famous by drbob101's video...

 

It's really simple. Reduction in surface area is more air flow. It works. If it didn't, the challenge grill would have never been designed.

 

watch the video Barry posted. It’s effect is negligible which is why challenge cars ran without the grills often and just the open squares and most likely why later challenge grills had a more porous pattern as well.

The hole pattern in the 355 challenge grill is marginally more porous than solid. The data is in the prior thread.

 

Yes, the Challenge grill certainly helps. My car was the test bed in early 1995...


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Note the prototype Challenge exhaust.




My car still has its 1995 Challenge grill...


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That's your video, Bob. I still say you should've had Olivia host it...

 

It helps somewhat, Grant. It gets awfully hot in there on the track. The techs always open the rear deck as soon as the car gets into the paddock.

 

The idea that it doesn't help much is insane. Less area, more air flow, lower temperatures.

 

Has anyone made any temperature measurements?

 

Its a matter of opinion but in my book it looks cool. Makes the car look more agressive and gives the rear a great look. First mod i made.

 

Even still, marginally more porous than solid flows a lot more than solid.

Cover the radiators with sheetmetal and then challenge grill material. One will reduce cooling efficiency and the other will kill it 100%.

I don't think the fan test is comparable to how this is actually working in the car. Higher pressure in the engine compartment from incoming air looking to escape is different than blocking a fan blade.

Also, there's a lot more surface area to the grill than the holes in the panel ahead of it so doesn't have to be wide open to equal the area.

Would be interesting to take temp readings with/without. Also put a pressure sensor between the grill and engine compartment panel to see if there is a build up of pressure at speed with the stock panel which may be relieved with the challenge grill.

 

One more thing to consider is airflow around the vehicle at speed (not my illustration). The Challenge grill is in the area of vacuum so it would seem even a greater pressure differential between engine compartment and outside when moving (vs atmospheric pressure).

I think this is the similar reason for the exhaust tip placement just above the rear diffusers.






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Massive difference in my opinion. It's dumb NOT to have one installed...plus it just looks 100x better.

Should've came with them installed on all of them from the factory.

 

For what it's worth my F1 system was overheating in traffic and causing shift issues...never happened again after the grille install. Much more room to breathe even if you're just moving up 20-30 feet at a time.

 

I agree, Jim. The nolder lip on the F355 rear deck would affect airflow as you diagram indicates. Perhaps a 308/328 roof spoiler would enhance airflow into the engine bay. This early 348 design cutaway shows that a roof spoiler was originally considered for the car whose nolder lip was less pronounced...


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sorry for my lack of science here.

but i don’t see how a challenge grill is not more beneficial for airflow.

i see the square cut outs in the frame but no one drives with no grill.

therefore a challenge grill should offer more air flow out the engine bay versus the solid grill.

where with the solid grill the air has nowhere to pass after the squares in frame.

 

As Dave said I think its a no brainer to think that it does not help. What I do think is that. At hiway speeds in top gear it does not help that much from my experience. I think the vacume created from the rear bonnet does a pretty good job of vacating some heat.

Ido not think that in stop and go traffic or if your driving it hard that it would do even close to as good a job

 

Stay tuned science will prevail...

 

I have all ready used a heat gun so I know what I am saying is true.
I also know and have said it many time our engine bays get smokin hot.

 

Even if it didn’t have any measurable effect for street driving.... it just looks better and is a factory part.

It’s such a unique design feature to me. Oddly enough, on my old 360 I didn’t care either way- so I kept the body color rear panel, but a 355 looks so much better with the challenge grill to my eye. One is the first things I did when I got my car is the challenge grill

 

I did notice from Barry's pictures above that it appears the largest benefit is the flatness in the corners which appears to be a direct result of the grill and possibly the wing(likely the grill though)

 

Thebes one for sale in the ads section LOL