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Why would the air be fresher or colder there rather than the side vent it already draws its air from? Have you checked your IATs versus ambient? Would it be cheaper to insulate the air box and intake tubes and get better results.
I have done that already, the air intakes for the box run above the cats, and the air box is bolted to the transmission. it heatsinks. so the results were, a bunch of insulation and gold tape for no benefits. It will require cool air from a dedicated place.
The side scoops have tubes that run to the air filter housing.
Originally Posted by killian96ss
A solution for a problem that doesn't exist.
Ah, yes my old boss's statement if he saw someone in our Lab he thought doing something irrational; "You're solving a problem not known to exist using a method know not to work!"
When installing a low restriction air filter, I looked for the passage Tadge said they made for the good sucking sound to pass close your ear as the cabin is so quiet. Found it.
Air intake ducts go to each rear fender.
Used my fiberoptic flex head camera to see where they went.
Found the passage Tadge mentioned in his 1+hour Autoline Afterhours C8 interview of the passage that is on top of the rear fender air intake. He said was "close to your ear." It's actually just closer to the thin side window glass than the very thick cabin glass in a Coupe they coped from the Ferrari 488. As he said when they stripped the Ferrari, they found that glass was twice as thick as the windshield and Ferrari does NOTHING that adds weight unless needed! He said they had to insulate the cabin as the noisy parts of the engine are right behind your ear (AC Compressor, Alternator, water pump and timing chain etc inches from firewall.)
First I will say Tadge is a politician, he will tote GM's line no matter what,(that is his job) even if the evidence says he is not forthcoming, C7Z, LS7 valve guides....
the air intakes on the C8 are acceptable if you are not tracking the car, If you are tracking the car everything in that air box is not optimal. that is bolted to the transmission, and that has the intakes running over the catalyst converters' heat sinks and causes an increase in the IAT. this car is very particular about IAT numbers and coolant temp numbers. So those that track our cars are not "looking to solve a problem that doesn't exist", we are looking to solve a problem that does exist.
^^^
Yep, but the ducts to the fenders are a short distance over insulated CATS and near headers. Heat does take time to transfer.
Now if you want cold air could use a big air scoop placed high over the roof like a NHRA ProStock or perhaps similar to I have on the 8.2 Liter BB with a low restriction 14" X 5" high K&N in my Street Rod. Mine, as Tadge said and I quoted, the C8 ducting was placed closer to your ear to get the "good intake sound" closer to your ear. He said nothing about increasing HP.
My large surface area K&N oiled cotton air filter (with black K&N Nylon prefilter (in my case for looks) on top of the 850 CFH Holley Double Pumper makes as much "noise" at WOT the long tube headers and 3" pipes exiting just before the rear wheels on my street rod!
Don’t see what a BBC and a 850 DP has anything to do with this discussion. The air intakes heat soak, yes it does take time, like 10 minutes into a 20 minute track session. Do you track your car? If so this is a problem. if you don’t track your car, it is not a problem. Quoting Tadge is about the same as quoting Rickey Bobby. Tadge and his team built a good street car, but it has faults on the track. People on this thread are trying to make it a better track car. To fix issues that the factory didn’t have to be concerned with. Once again, if you don’t track your care why do you care, if you do track your car you should care. Increased horsepower would be great, we are trying to figure out how not to lose horsepower, due to the IATs putting the computer in the low octane table.
nice picture of your other ride, I noticed that you have plenty of vents stamped into the side covers, why is that? To vent heat from the engine compartment? Why would you need to do that? Probably because you don’t want that Holley to vapor lock?
^^^ Although I agree Tadge is a good marketer he does have 2 engineering degrees and started with GM then the GM team as an engineer (he also has an MBA so good corporate exec supporting the company line as well!) But I differentiate when he is quoting things where "puffing" can help sales. In that case he was not, just discussing what they did to get some "good sound" in the cabin! It is too quiet.
It's like the other thing I often quote from that Autoline Interview. In his words, "He was Paranoid and deathly afraid of trailing throttle Oversteer when they were designing the C8." He said they did everything necessary to make the car benign handling so it was not like his Dad's early Porsche! I was racing a 60% rear weight car about the time of his was a teenager and driving his Dad's Porsche. Understood exactly what he meant.
Nope at 80 my racing days are over BUT still like to test max lateral "g" where it's safe! Will have fun seeing just what my planned E-Ray with front wheel drive vectoring control can achieve in a turn!
BTW, my '34 is close to Henry's original with metal engine compartment louvers as was needed at the time to keep engine compartment temps down for the ~100 hp flathead. Was not so easy getting my ~550 hp BB to run sufficiently cool. Those are the OEM type louvers. It also has a 6-blade aluminum engine driven fan and two electric motor driven pusher fans. They are only needed when crawling along at low speed!
At 80, my racing days of thrashing my own car are over. BUT I still like to test max lateral "g" capability where it's safe. In my rural area lots of places with no homes, people, often no cars and just farm fields to have fun! And understand the desire if an avid tracker to get better performance, stiffer springs, larger sway bars, brakes etc and more HP. Just not needed for my street driving.
Cool, for what you are doing, this post is not applicable to you. For us that do lots of track days, it matters when on my 3rd lap I am 8-9 mpg slower down the front and rear straights.
^^^ BUT still follow improvements. Thought this K&N system had promise. they say 22 hp and like aFe, who I also like, have to take hp claims with a grain of salt.
Thought this had promise. Now if air scoops directed air in an insulated trunk?
I looked at that also, several issues, 1st the fresh air intake still comes over the exhaust, and the trunk has no independent way of getting fresh air. #2, with that particular filter the air has to make a 90 degree turn, which kill’s velocity (I don’t know if it has a velocity tack built in. Bottom line is any intake that uses the factory inlets are going to get heat sunk after 10 minutes. Keep in mind the z51 cars have a radiator on the right side that is heating the air coming into the engine bay. The pod on the left has a fan, and no radiator so that helps.
Cool, for what you are doing, this post is not applicable to you. For us that do lots of track days, it matters when on my 3rd lap I am 8-9 mpg slower down the front and rear straights.
Do you run telemetry? What are your iats getting up to on lap 1 peak vs lap 3 peak?
I log with HPT. The delta is based on the ambient temperature. From lap 1 to lap 3 it increases by 15 degrees but it doesn’t stabilize ( track dependent). Lots of factors on the IAT. If I do a cool down lap they will go down, but not to ambient temp.
I log with HPT. The delta is based on the ambient temperature. From lap 1 to lap 3 it increases by 15 degrees but it doesn’t stabilize ( track dependent). Lots of factors on the IAT. If I do a cool down lap they will go down, but not to ambient temp.
Generally if you can keep them below 140f you avoid the most aggressive timing offset tables but in my logging I've noticed GM uses a very mild and progressive iat timing offset so the lower the better of course.
If you can keep them 20f higher than ambient you'll be doing well and that will not be the lap time issue. If you see them creeping to 140+ you are losing a lot of power. A lot.
I don't see mine go that high.
If I did I'd look into header wrapping BOTH the exhaust tubes that run under the intake as well as the plastic intake tubes and then gold foil the box.
I'd take telemetry again and see where it's at.
With drawing in air from the engine cover only netting a few degrees id wonder if it's an issue of venting the entire engine compartment as opposed to just the intake tube positions.
This is an interesting post on cars sold in Germany for sustained high speed driving....
I have headers. Had them coated to protect engine bay temps. At the time, it was just common sense thinking. I wasn’t even discussing the air inlet tubes to air box. So glad I did. I understand you shouldn’t wrap coated headers. Like the idea of gold wrapping air box, but C5R did all that already with no benefit. (But it can’t hurt)
What if we removed back glass on track days? And removed air box cover? Aero totally ruined? Probably. Can u remove rear glass? Can you remove air vents/rain guards?
I log with HPT. The delta is based on the ambient temperature. From lap 1 to lap 3 it increases by 15 degrees but it doesn’t stabilize ( track dependent). Lots of factors on the IAT. If I do a cool down lap they will go down, but not to ambient temp.
C5racr1 appreciate the fight your are fighting, you are running into the same reason I so rarely post on the forums anymore; it just gets annoying being told you are wrong when you have done all the research and lead the way to figure stuff out. Happy to see that many people are starting to see what i found years ago; i knew we'd get there eventually!
The other side of the heat issue is with even a cooldown lap you can never get the car to go back to the high timing table, once the car switches to a lower timing table you cant go back until you turn the car off and back on again... Thats been my finding at least.
Keep pushing man! Love the progress you are making with the cooling system.
C5racr1, the problem is that this product comes nowhere close to solving the problem you are seeking to solve. The scoop on the GT is great, it is in a good position, and probably feeds directly to the air intake ox. The product in thOP does not do that. It blocks the design airflow to remove heat from the engine bay, and at significant cost. Build one like the GT for the track, a move the rear view camera, so you have some rear visibility. The actually duct and seal it to the air filter box and block the tubes to the side vents.
Could you spend time and use these as intakes to a sealed and insulated air path to a modified air box? Sure. The product in OP probably does nothing to solve any issue it claims. It may well make it worse.
If you are going to go to the trouble of modifying something that is not well suited to the task, you might as well use the same time, effort and money to make something that will work better.
Isn't that the part @Antiriad is looking for the GM part number for? The car that came from Germany? Is that really what it does? If so, should we all be ordering it to cool the engine bay?
Isn't that the part @Antiriad is looking for the GM part number for? The car that came from Germany? Is that really what it does? If so, should we all be ordering it to cool the engine bay?
Correct. It's made to cool the engine compartment for cars that see continurd high speed use on the Autobahn. You can see it scoops fresh air into the engine compartment from below and the air continues to evacuate from above
Although I agree Tadge is a good marketer he does have 2 engineering degrees and started with GM then the GM team as an engineer (he also has an MBA so good corporate exec supporting the company line as well!) But I differentiate when he is quoting things where "puffing" can help sales. In that case he was not, just discussing what they did to get some "good sound" in the cabin! It is too quiet.
BUT still follow improvements. Thought this K&N system had promise. they say 22 hp and like aFe, who I also like, have to take hp claims with a grain of salt.
