Air circulation in the 'stock' engine bay.

[KBruno]

Originally Posted by edgehead2000

Kbruno, good explanation. Didn't mean to challenge your knowledge, just thought I'd bring it up before I purchase the ZL1's for my SS. After looking at some pics of it, the pan only covers the front half of the engine bay thereby still allowing hot air to exit and keeping the engine a bit cleaner.

No worries. I like the ZL1 pan. It uses some of the air to help cool the tranny and brakes. Very cool. Still better with a good extractor hood to compliment it. I like the look of the Siebon TSII but can't get anyone, including Seibon, to post good pictures of the hood without all the watermarks or showing the underside or decent pictures of the ports so I'm waiting... :emoticon7:

I really hate it when vendors answer a different question than the one I ask...

[JustaCamaro]

I do run the Texas Mile, and from what I can determine more air is packed in the engine compartment than can get out at speed. On my car, both front wheel well liners were driven back so that they contacted the tires. I have since reinforced the front bottom edges with aluminum, and repaced some of the plasctic clips with rivnuts and screws.

[Rangore]

What would be the affects at high speed...will it throw off stability? Just brain storming.

[KBruno]

Originally Posted by JustaCamaro

I do run the Texas Mile, and from what I can determine more air is packed in the engine compartment than can get out at speed. On my car, both front wheel well liners were driven back so that they contacted the tires. I have since reinforced the front bottom edges with aluminum, and repaced some of the plasctic clips with rivnuts and screws.

That's pretty cool. Texas Mile I mean. That's a great place to pick up some great real world knowlege and experience too. Some of the tricks you'll see there will translate to regular driving while some will only work for pure speed trials like that. But your speed there is a perfect illustration of aero effects. From the half mile it took you another half mile to accelerate 25mph while the first 25mph took what, less than 100ft? I'll bet that front end feels pretty floaty and light at those speeds with all that air pushing the nose up.

Originally Posted by Rangore

What would be the affects at high speed...will it throw off stability? Just brain storming.

As is the mailslot mod would probably cause more drag since closed, air will mostly flow right over it and with this mod the slot is opened up to flow right into the hood latch & the hood seal rubber behind that (Yeh, I don't know why either).

[PAUL SS]

Originally Posted by js19racer

Have any of you guys actually looked at the front of your Camaro? Ever notice the size of the upper and lower openings? There huge! So opening up the mail slot wont make much difference. Especially at highway speeds. The only way you will see a difference is if you put it in the wind tunnel. If you open it up it will reduce front down force. Not enough for high way driving. It will let more air in so it would probably slightly reduce under hood temps.

But those openings feed directly the a/c condenser and radiator (and intercooler if you have one) which will actually put more hot air in the engine compartment. The Mail slot conversion at least introduces ambient air under hood. At any rate, heat rises and the best way to get rid of it is hood vents or some type of flow through ventilation (remove rear hood seal).

Keep the ideas/discussion moving.

[KBruno]

Originally Posted by PAUL SS

But those openings feed directly the a/s condenser and radiator (and intercooler if you have one) which will actually put more hot air in the engine compartment. The Mail slot conversion at least introduces ambient air under hood. At any rate, heat rises and the best way to get rid of it is hood vents or some type of flow through ventilation (remove rear hood seal).

Keep the ideas/discussion moving.

If the car's moving/engine running, there's really no point to air going into the engine bay that doesn't go through the coolers. It's a water cooled engine. Heat extraction alone is only useful at a stand still. Worthwhile for heat soak, but a scoop won't do that. I think part of the problem is that people started calling extractor hoods ala the ZL1 "heat extractors". That's a side benifit but not their primary function. Listen to the ZL1 commercial. They say "extractor" and never mention heat. That's because they were trying to get all that air out from the engine compartment without dumping it under the car causing lift.

[JustaCamaro]

The drag increase is exponential. I got to 150 in the first half mile and just 175 at the mile. I tried removing the air seal at the cowl under the hood, couldn't tell any difference.

[KBruno]

Originally Posted by JustaCamaro

The drag increase is exponential. I got to 150 in the first half mile and just 175 at the mile. I tried removing the air seal at the cowl under the hood, couldn't tell any difference.

Yeh, I checked out your speeds on the other thread before I replied. Again, . The cowl is a high pressure area. That's why cowl induction hoods work, better than ram air in some cases. Could try cutting slots or louvers in the front of those inner fender liners where they're bare to the engine bay to relieve some of the pressure. Could even do it without removing any material, like small flaps. That way you don't get a bunch of dirt & water up in there when you're not doing 150+. My friend's wife has a 500SL that has that in the front & rear fender liners.

Oh, and BTW the overall drag is actually worse. While the aero drag is increasing exponentially the rolling resistance continues to increase on a liniar curve as well.

[JustaCamaro]

That's in idea.
I have lowered the car an inch-that should help some. I have also pullied up the Vortech, and getting a race gas only tune. I'm shooting for 180 this November.

[KBruno]

Originally Posted by JustaCamaro

That's in idea.
I have lowered the car an inch-that should help some. I have also pullied up the Vortech, and getting a race gas only tune. I'm shooting for 180 this November.

Is E85 worthwhile where you're at? Kills your mpg but if it's cheap there it has way more power than gas and runs cooler. Alot of race cars are going that way even here where E85 is well over $4/gal. That's way cheaper than $10+/gal. for race fuel. I don't remember who but there's at least one guy on here that's supercharged running E85. Do a search and see what's involved. Might be cheaper, faster & more fun in the long run.

[JustaCamaro]

I don't believe E85 is available in that area, besides my injectors and fuel system wouldn't support the required fuel flow. I also have purely political objections to E85 and govt. subsidized, forced ethanol use in our fuels.

The cost of 10-15 gallons of race gas a couple times a year isn't prohibitive.

What would help the most down there would be cool dry air and no wind.

[hapisok]

Originally Posted by KBruno

Is E85 worthwhile where you're at? Kills your mpg but if it's cheap there it has way more power than gas and runs cooler. Alot of race cars are going that way even here where E85 is well over $4/gal. That's way cheaper than $10+/gal. for race fuel. I don't remember who but there's at least one guy on here that's supercharged running E85. Do a search and see what's involved. Might be cheaper, faster & more fun in the long run.

+1 on E85

[ChrisBlair]

Hi

E85 has less power than 'straight' gas- about 66% of the power. It has a higher octane

You can design an engine (or tune it) to take advantage of that higher octane and see some results, but just using E85? No sir, I don't believe you'll be reducing your ETs

I like the idea of the mail-slot doing something. I'm an old time musclecar guy and I like my 'Ram-Air', even if there's no real ram effect at all. I do know that finally finding a factory ram-air setup for a Buick GS455 and installing it in my car required enriching the carb at idle and new jets. but the question does exist: did I raise tangible performance, or just burn more gas? Jury has been out on that for some time!