Front end aerodynamics
#16
Laugha,
1- keep your gas tank full
2- make an opening (big mouth) on the front bumper/lip and create an air trap pocket :lol:
Honestly, we all know/heard of 911 has the best downforce. I was so happy when I first bought/drove my car. Now, somehow I feel I need more because the steering wheels feel a little loose at high speed, also too much left/right (even wind is not that strong) and I don't think my tires condition change that much. Is it the human thing or something change? I am not sure but I do want more. Do you yuor car drive/response better when you have a full gas tank compare to empty tank? I do feel it.
1- keep your gas tank full
2- make an opening (big mouth) on the front bumper/lip and create an air trap pocket :lol:
Honestly, we all know/heard of 911 has the best downforce. I was so happy when I first bought/drove my car. Now, somehow I feel I need more because the steering wheels feel a little loose at high speed, also too much left/right (even wind is not that strong) and I don't think my tires condition change that much. Is it the human thing or something change? I am not sure but I do want more. Do you yuor car drive/response better when you have a full gas tank compare to empty tank? I do feel it.
#17
Burning Brakes
Thread Starter
Yes, a full tank of gas definitely improves in my car's front end traction. However, it was with a full tank that I felt a little 125 MPH lift recently.
I'd better at least get a chin spoiler. I should probably get a cheap used one since my front end already scrapes my driveway if I'm not extremely careful, and my driveway is almost level with the street.
If I don't find a used spoiler I want the $185 splitter from Gt Racing that KRA993tt mentioned.
I'd better at least get a chin spoiler. I should probably get a cheap used one since my front end already scrapes my driveway if I'm not extremely careful, and my driveway is almost level with the street.
If I don't find a used spoiler I want the $185 splitter from Gt Racing that KRA993tt mentioned.
#18
Same as what I'm experiencing now. Also my scrape so bad already. If I add anymore to the lip, it will be breaking, not scraping anymore. Here how it looks like. Can you post pic of the one you are talking about?
#19
Originally Posted by LaughaC
Thanks EarlyApex! That hood vent is exactly what I was wondering about. It looks like those guys at Elephant Racing did it right and definitively proved the downforce it creates.
Sherwood
#20
Addict
Rennlist
Lifetime Member
Rennlist
Lifetime Member
What are your fender lip heights? From your description and your avatar, your car looks a little low to me. I think my car is a little too low and it does not scrape the chin spoiler even driving on the trailer.
#21
Hi Laugha,
A thought. When i installed Ruf front and rear fiberglass bumpers on my 911S 3.6 conversion, I bought a material from McMaster-Carr that is actually a conveyor belt that comes in varied thicknesses. I cut it to fit and attached it with speed clips. Upon contact with any curb, road kill etc. the clips just break loose, without damaging the car body. Easy to clip it back in place. The look is black with a slight sheen, it-looks very much like the OEM chin spoiler (Which by the way bolts to your valance and does not give way). www.mcmaster-carr.com p/n 6001k803 is the 0.19" thickness; p/n 6001k808 is the 0.22 thickness. Roughly $2.00/ft. The car is used primarily on track with some street use, this has worked perfectly.
hope this help,
///Nick
A thought. When i installed Ruf front and rear fiberglass bumpers on my 911S 3.6 conversion, I bought a material from McMaster-Carr that is actually a conveyor belt that comes in varied thicknesses. I cut it to fit and attached it with speed clips. Upon contact with any curb, road kill etc. the clips just break loose, without damaging the car body. Easy to clip it back in place. The look is black with a slight sheen, it-looks very much like the OEM chin spoiler (Which by the way bolts to your valance and does not give way). www.mcmaster-carr.com p/n 6001k803 is the 0.19" thickness; p/n 6001k808 is the 0.22 thickness. Roughly $2.00/ft. The car is used primarily on track with some street use, this has worked perfectly.
hope this help,
///Nick
#22
Burning Brakes
Thread Starter
That's awesome, Nick! It soujnds like you have solved something very useful and cost-effective for all of us.
Do you have pics of the clips, or can you recommend the part numbers? Slap this solution into a box and I'd pay $150 for it right now.
Do you have pics of the clips, or can you recommend the part numbers? Slap this solution into a box and I'd pay $150 for it right now.
#23
Hi Chris,
This solution was actually described by folks on another forum some time ago who were doing the Ruf conversion front and rear bumpers. Ruf's lower lip spoiler was NLA so solutions were being bandied around. This is one that was overwhelmingly supported, so i checked it out. I bought both of the above part numbers as i wasn't sure of the flexibility/pliability of the material, and wanted both to compare-can't remember which is which as far as the one i chose. You can also cut it to the width you want as well... If you go to www.pelicanparts.com and do a search under Ruf conversion thread in the technical forums you might find it with pics.
As far as attachment, most people used a piece of aluminum to sandwich the material and then drilled and riveted it to the underside of the Ruf front bumper. I was worried that if i had any impact to it that it would destroy or crack my fiberglass bumper, so i set out to fabricate something that would tear away easily and could be put back. After several tries, the speed clips fit the bill. this was tested one evening when i hit a rabbit and it broke loose the corner of the lip spoiler>>> no damage, 10 minutes and it was all back together. I keep spare clips with me in the car. They are available at Lowe's in all sizes and tension strengths. You might have to manipulate them a little, but it is easy to do. I beelieve their true purpose is to attach body/fenders together.
///Nick
This solution was actually described by folks on another forum some time ago who were doing the Ruf conversion front and rear bumpers. Ruf's lower lip spoiler was NLA so solutions were being bandied around. This is one that was overwhelmingly supported, so i checked it out. I bought both of the above part numbers as i wasn't sure of the flexibility/pliability of the material, and wanted both to compare-can't remember which is which as far as the one i chose. You can also cut it to the width you want as well... If you go to www.pelicanparts.com and do a search under Ruf conversion thread in the technical forums you might find it with pics.
As far as attachment, most people used a piece of aluminum to sandwich the material and then drilled and riveted it to the underside of the Ruf front bumper. I was worried that if i had any impact to it that it would destroy or crack my fiberglass bumper, so i set out to fabricate something that would tear away easily and could be put back. After several tries, the speed clips fit the bill. this was tested one evening when i hit a rabbit and it broke loose the corner of the lip spoiler>>> no damage, 10 minutes and it was all back together. I keep spare clips with me in the car. They are available at Lowe's in all sizes and tension strengths. You might have to manipulate them a little, but it is easy to do. I beelieve their true purpose is to attach body/fenders together.
///Nick
#24
Originally Posted by Steve Weiner-Rennsport Systems
Set them up with 1 degree nose-down rake to reduce lift & drag.
There is a shot of my '84 in my link below if you want to know what it looks like with the nose down look.
Best,
Jay
84 3.2, 90 964
#25
Race Car
Yeah, this is a discussion that really should be about rake and suspension settings (toe, caster, camber).
If you're trying to settle your front end with aero, you're chasing something you're never going to catch. The pre-1990 911 develops a huge amount of lift with no front and rear aids, and it also develops lift with all the poular wings and spoilers in place. In other words, with Porsche's aero pieces you're going to be lighter in the front whenever you're moving than you are when you're parked in your garage. The best that aero is going to do is mitigate some portion of that lift.
Generating actual net downforce requires stuff that you really can't practically run on the street, and it also requires speed that you also can't safely use on most roads.
What you don't want is to get a lot of high-pressure air under the car (rake is a good way to address this), and you also want a front end that behaves itself when it's moving (suspension settings address this).
If you're trying to settle your front end with aero, you're chasing something you're never going to catch. The pre-1990 911 develops a huge amount of lift with no front and rear aids, and it also develops lift with all the poular wings and spoilers in place. In other words, with Porsche's aero pieces you're going to be lighter in the front whenever you're moving than you are when you're parked in your garage. The best that aero is going to do is mitigate some portion of that lift.
Generating actual net downforce requires stuff that you really can't practically run on the street, and it also requires speed that you also can't safely use on most roads.
What you don't want is to get a lot of high-pressure air under the car (rake is a good way to address this), and you also want a front end that behaves itself when it's moving (suspension settings address this).
#26
Originally Posted by JackOlsen
Yeah, this is a discussion that really should be about rake and suspension settings (toe, caster, camber).
#27
Porsche 101: If one runs a rear tea tray spoiler (as it appears Chris does), one has to balance that with a front chin spoiler, and vice versa. The integration of power (motor), stopping capability (brakes), and
handling (suspension/settings) are a constant variable provided the car is (a) stock or (b) has been modified by someone with experience. Obviously, if someone kludged it together at some point, THAT is the point to address and be rectified. Has someone ****ied your car without your prior knowledge ???
///Nick
handling (suspension/settings) are a constant variable provided the car is (a) stock or (b) has been modified by someone with experience. Obviously, if someone kludged it together at some point, THAT is the point to address and be rectified. Has someone ****ied your car without your prior knowledge ???
///Nick
#28
Burning Brakes
Originally Posted by LaughaC
Has anyone seen some ways to improve front end downforce, perhaps by routing air through the lower valence and out through an opening in the front lid like a Lotus Exige?
Also, where do I find the best covers to reduce the drag caused by our headlights?
Also, where do I find the best covers to reduce the drag caused by our headlights?
My spoiler-free race 356 gets very very light at 125. But if I am going that fast in it, it's on a long straight with minimal steering input. As soon as I get off the throttle and get on the brakes, the front end sticks like glue. On a 2.5 minute per lap track like VIR, front end lift is a problem for about 5 seconds every lap.
Steve
84 Carrera Targa
64 356C race
#29
Addict
Uber, you give me reason to chime in. Drag, down force, all this is so funny to me. my car is bone stock and is as stable at 125 as it is at 80. I (yes I'm insane) drove 125 for several minutes with the top down over the weekend and the car changes lanes only on command and doesn't wander at all. I have gone 145 with the top up and it just hugs the ground.
I think IMHO that it is the tail on Chris's car that is the problem. if it isn't that it is soft shocks, bushings, T. bars and S. bars, or stance. it's much simpler to blame the tail.
I think IMHO that it is the tail on Chris's car that is the problem. if it isn't that it is soft shocks, bushings, T. bars and S. bars, or stance. it's much simpler to blame the tail.
#30
What douglas bray said made sence to me. or yearssss, I have always heard 911 has good handling, cornering and all. I have never heard 911 has lifting problem until I experience it. I think it must be something added to the car, or worn part, or maybe alignment. Otherwise, why 911? Why not mustang or transAm?
Actually, let me correct myself, I wouldn't say I have lifting problem, but more like "loosing steering wheel" or "too much steering power".
Actually, let me correct myself, I wouldn't say I have lifting problem, but more like "loosing steering wheel" or "too much steering power".