|
|
11-27-2017, 11:07 PM | #23 | |
Lieutenant General
2445
Rep 11,667
Posts |
Quote:
The air entering the engine compartment via the front grill & rad causes a high pressure area under the hood (lift). The vents provide relief for this high pressure so the net result is more downforce. ...as well as heat reduction.
__________________
'21 M2C Hockenheim Silver
'18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold) |
|
Appreciate
0
|
11-27-2017, 11:08 PM | #24 |
Lieutenant General
11650
Rep 12,757
Posts |
i would be interested in getting rid of the front oem kidney scoops that lead to the intake and making a scoop from behind the heat exchanger leading to the vents. not sure if there is room for it or not, but its a thought.
__________________
Instagram; @roastbeefmike
|
Appreciate
0
|
11-28-2017, 12:26 AM | #25 | |
Captain
382
Rep 875
Posts |
Quote:
|
|
Appreciate
1
inTgr8r2444.50 |
11-28-2017, 09:58 AM | #26 |
Major General
2768
Rep 5,483
Posts |
iirc these cars only lift about a dozen lb at the front and have a little bit of rear downforce stock, so you might actually be into negative lift with the hood vented
__________________
|
Appreciate
0
|
11-28-2017, 10:11 AM | #27 | |
just another M3
520
Rep 1,158
Posts |
Quote:
http://www.m3post.com/forums/showthread.php?t=402401 http://www.m3post.com/forums/showthread.php?t=476271
__________________
///M3... Don't want more power, Just want it to turn sharper one step closer each time. -Ohlins TTX Raceline, PolePostions seats, Akrapovic EVO, ARC-8, 1/2 Cage, Seat Delete, Stoptech BBK, solid Subframe and diff bushing, spherical bearing on everything.
|
|
Appreciate
0
|
11-28-2017, 10:25 AM | #28 |
Lieutenant
450
Rep 465
Posts |
http://seiboncarbon.com/products/dv-...mw-e92-m3.html
I know stock hood is not heavy, but this relatively inexpensive CF vented hood looks interesting I think
__________________
"Racing is life. Anything before or after is just waiting." Steve MCQueen
|
Appreciate
1
inTgr8r2444.50 |
11-28-2017, 12:37 PM | #29 | |
Lieutenant General
2445
Rep 11,667
Posts |
Quote:
I know I would have a real hard time cutting up my hood. I think the trackspec are a more efficient design, as they did some leg work to find the right locations. For a pure track car its a pretty easy decision.
__________________
'21 M2C Hockenheim Silver
'18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold) |
|
Appreciate
0
|
11-28-2017, 12:58 PM | #30 | |
Major General
2768
Rep 5,483
Posts |
Quote:
__________________
|
|
Appreciate
0
|
11-28-2017, 02:05 PM | #31 | |
Captain
468
Rep 818
Posts |
Quote:
Something else to consider. I have the smaller N15Design vents on my hood. My last time out at Buttonwillow, the car wanted to oversteer in Riverside under neutral throttle. With bigger vents and a front lip, you may need to balance that out with some rear aero. Last edited by macdude357; 11-28-2017 at 02:15 PM.. |
|
Appreciate
1
tlrid3r519.50 |
11-28-2017, 03:38 PM | #32 | |
Major General
3232
Rep 6,217
Posts |
Quote:
__________________
|
|
Appreciate
0
|
11-28-2017, 04:33 PM | #33 |
Captain
468
Rep 818
Posts |
|
Appreciate
1
M3 Number 863232.00 |
11-28-2017, 05:27 PM | #34 |
Captain
186
Rep 940
Posts |
Just ordered hood vents from these guys. Anxious to get them on over the winter. Their stuff looks like good quality compared to other companies making them
__________________
You'll find me at the track
BMW CCA Club Racing #905 Instagram: scottynotpippen |
Appreciate
1
tlrid3r519.50 |
11-28-2017, 05:44 PM | #35 | |
Colonel
5380
Rep 2,813
Posts
Drives: '09 E90 M3 - IB
Join Date: Feb 2012
Location: 93 million miles from the Sun
|
Quote:
You have a solid technical grasp of these cars, so I'll ask you: If you were to make a general guess-----how much change in lift/downforce do you think you might see from a vented hood? I saw in that linked article that the M3 is making 22lbs of front-end lift at 124mph. If you say that a "negative lift" situation might be the result of hood vents, I'm assuming you're thinking the change in force is more than 22 lbs. How much change in force do you think it could be? And do you think the effects of the vented hood are overshadowed by having a lip and 5" splitter and canards in place already? (The addition of the lip and splitter changed the car DRAMATICALLY for the better.) Or would they all work together to create even more downforce? Anyway, I'm curious to hear your thoughts. |
|
Appreciate
0
|
11-28-2017, 05:55 PM | #36 |
Lieutenant General
2445
Rep 11,667
Posts |
Another consideration is drag.
Adding lips , wings, canards etc.... almost always adds drag to go along with the benefits. It may possibly be, that adding hood vents is a free lunch with respect to drag.
__________________
'21 M2C Hockenheim Silver
'18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold) |
Appreciate
0
|
11-28-2017, 08:50 PM | #37 |
Lieutenant General
11650
Rep 12,757
Posts |
i'm liking this discussion about "reducing lift vs. adding downforce." i had never though about the two before as not being the same thing. there was some talk in another thread about reducing lift in the rear through a pretty hefty diffuser that extended way under the car. i simply hadn't thought of reducing lift in the front until the discussion in this thread.
one experience i can possibly relate, is losing my front center belly pan at the track last weekend. it was in rough shape, as well as the corners. the air pressure entering between the lip and the bumper was enough to blow the worn bottoms off my side felt pieces. shortly after that, the center belly pan got completely ripped out from under my car. i didn't go off, and i didn't hit anything- this was 100% the belly pan being tired, and air pressure. that being said, i came around turn 8 at big willow with guns blazing and immediately knew something was different with the car. it sort of felt like fluttering. i pulled into the hot pit and hopped out to check my tires for something obvious... nothing. eyeballed my brakes real quick... nothing obvious. shrugged my shoulders and went back out for a few more laps. i sort of attributed it to an unbalanced wheel/tire, or maybe a big wad of rubber inside one of the barrels of the wheels. it wasn't until a few sessions later when my brake pads were finished and i swapped them out that i discovered the entire front belly pan was gone. there was some crap on the track at the bottom of the hill of turn 6, but i didn't quite recognize it as mine. lol thinking back, it was probably my belly pan. i've always thought of it to be an aero piece (it is shaped like an air foil and plays a role in cooling), however, i just didn't realize how it would feel without it. if something like the undertray could cause a noticeable effect, i'm optimistic that these vents can help as well.
__________________
Instagram; @roastbeefmike
|
Appreciate
1
inTgr8r2444.50 |
11-28-2017, 09:56 PM | #38 |
Captain
382
Rep 875
Posts |
^ I think you bring up a good point about the importance of the underside aero.
I think there should be more potential to reduce lift by focusing on the underside of the car. A faster moving/less turbulent airflow underneath the car helps to reduce lift even further than say, hood vents (although hood vents are less costly and easier to implement). Ferrari, Nissan GTR, Porsche, and other high performance cars from the factory come with full underside panels for this purpose. I read that for F1 cars, around 60% of total downforce is from front splitters and rear wings. The remaining amount is mostly from underside aero. Food for thought. |
Appreciate
0
|
11-28-2017, 10:03 PM | #39 | |
Major General
3232
Rep 6,217
Posts |
Quote:
Think of a silhouette of a car. It's basically an airfoil. Shaped like the ones on planes. That's why cars have lift because it's natural shape is a damn wing trying to fly off the ground. Lol Smoothen out the air underneath let it exit wide with a real diffuser should suck the car downwards enough to generate real downforce as opposed to reducing lift.
__________________
|
|
Appreciate
0
|
11-28-2017, 10:04 PM | #40 | |
Major General
903
Rep 9,034
Posts |
Quote:
What did you replace the under panels with? OEM or one of the metal units out now? .
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
|
|
Appreciate
0
|
11-28-2017, 10:11 PM | #41 | ||
Lieutenant General
11650
Rep 12,757
Posts |
Quote:
__________________
Instagram; @roastbeefmike
|
||
Appreciate
1
aus903.00 |
11-28-2017, 10:18 PM | #42 | |
Major General
2768
Rep 5,483
Posts |
Quote:
The F1 comparisons are uh...not useful for hopefully obvious reasons But one useful takeaway... they don’t dump their radiators under the car Last edited by Richbot; 11-28-2017 at 10:29 PM.. |
|
Appreciate
0
|
11-28-2017, 10:58 PM | #43 | ||
just another M3
520
Rep 1,158
Posts |
Quote:
__________________
///M3... Don't want more power, Just want it to turn sharper one step closer each time. -Ohlins TTX Raceline, PolePostions seats, Akrapovic EVO, ARC-8, 1/2 Cage, Seat Delete, Stoptech BBK, solid Subframe and diff bushing, spherical bearing on everything.
|
||
Appreciate
1
macdude357468.00 |
11-29-2017, 01:43 AM | #44 | |
Colonel
5380
Rep 2,813
Posts
Drives: '09 E90 M3 - IB
Join Date: Feb 2012
Location: 93 million miles from the Sun
|
Quote:
As a novice to this topic, I'm working under the assumption that the 5" splitter is doing all the heavy work, and that everything else is extra bits of flavor by comparison. My splitter may not sit super low when the car is at rest, but when I'm pressed into a turn, it's quite close to the ground. In a bowl type of turn, it's almost rubbing the ground. (I don't run super stiff springs.) Anyway, the main goal of this hood vent project was to flow more air through the engine bay and perhaps cool it down a bit in there. If there's any negative lift/downforce to be had, I will consider it a gift from the gods of grip. |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|