-
Sign Up! To view all forums and unlock additional cool features
Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!
Woods247 BrokeFiST Build
- Thread starter Woods247
- Start date
Thread Starter
#647
Now that the trailer is finished, I’m definitely going to travel. I’d love to come up there. If you ever want to run Road Atlanta, Charlotte Motor Speedway or Barber let me know. Barber is a blast in our cars.
I really want to roll out to CA and hit as many tracks as possible on the way out and back. Kinda my own “one lap” without the stress of competition..
I hit 48k miles on the track yesterday. I can’t believe my engine still works lol. The X47 is still fine too even with repetitive 3-4-5 wot pulls all day long. Maybe it’s the LiquiMoly 5w40 and big ass radiator keeping them alive.. I think I’m going to go with injectors and HPFP after talking about it with my tuner. The question is, do I wait and do that on a new motor or send it now??
Let me know what you think about the LSD. I bet you’ll enjoy it 😉
I really want to roll out to CA and hit as many tracks as possible on the way out and back. Kinda my own “one lap” without the stress of competition..
I hit 48k miles on the track yesterday. I can’t believe my engine still works lol. The X47 is still fine too even with repetitive 3-4-5 wot pulls all day long. Maybe it’s the LiquiMoly 5w40 and big ass radiator keeping them alive.. I think I’m going to go with injectors and HPFP after talking about it with my tuner. The question is, do I wait and do that on a new motor or send it now??
Let me know what you think about the LSD. I bet you’ll enjoy it 😉
Very interesting reading and build!
I did study aerodynamics for a few years, although for a different purpose. I was working on reducing drag and turbulence on my car to gain mpg. I went to what some might call extremes. However I also drag raced and saw substantial improvement there as well. I could chat about aero for hours, but the lowest hanging fruit is the turbulence off the back of the car and on the sides. Most racers only think about the air traveling over the top, but ignore the sides of the car.
If I was going to track my car like you, I would build the front dam and spliter just as you did, however I would also experiment with blocking the top part of the grill opening as this is a high pressure area and you may not need all of that grill opening now that you have a good and low dam. The grill opening on my ecomodded car was half the size of a license plate and as low as possible. I'd also make a sealed duct around the radiator so I could shrink the grill opening even further. There is a lot of drag thru the grill and I'd want to make sure none was wasted by leaking around the radiator.
The next area I'd address is the back of the car. Differently from you, I would not go with a wing until I had exhausted the fight against lift. Keep in mind that both downforce and lift cost Hp. A flat bottom underbelly will always help reduce turbulence. Diffusers help, but this must be well thought out in order to work correctly. A proper diffuser may only rise slowly, not steeply in order to maintain attached air flow. It would be easier to just extend the pan out past the bumper. Id also build a kamback type spoiler. And work towards getting attached airflow over the top and extending as far back off the car as possible. I'd also put skirts over the rear wheel wells. Those three things may be enough to counteract lift and bring stability without taking away hp.
I did study aerodynamics for a few years, although for a different purpose. I was working on reducing drag and turbulence on my car to gain mpg. I went to what some might call extremes. However I also drag raced and saw substantial improvement there as well. I could chat about aero for hours, but the lowest hanging fruit is the turbulence off the back of the car and on the sides. Most racers only think about the air traveling over the top, but ignore the sides of the car.
If I was going to track my car like you, I would build the front dam and spliter just as you did, however I would also experiment with blocking the top part of the grill opening as this is a high pressure area and you may not need all of that grill opening now that you have a good and low dam. The grill opening on my ecomodded car was half the size of a license plate and as low as possible. I'd also make a sealed duct around the radiator so I could shrink the grill opening even further. There is a lot of drag thru the grill and I'd want to make sure none was wasted by leaking around the radiator.
The next area I'd address is the back of the car. Differently from you, I would not go with a wing until I had exhausted the fight against lift. Keep in mind that both downforce and lift cost Hp. A flat bottom underbelly will always help reduce turbulence. Diffusers help, but this must be well thought out in order to work correctly. A proper diffuser may only rise slowly, not steeply in order to maintain attached air flow. It would be easier to just extend the pan out past the bumper. Id also build a kamback type spoiler. And work towards getting attached airflow over the top and extending as far back off the car as possible. I'd also put skirts over the rear wheel wells. Those three things may be enough to counteract lift and bring stability without taking away hp.
Thread Starter
#650
I’m glad to hear you mention reduction in lift. That’s really all I’m trying to achieve. It’s working, but I’m in the beginning of a learning curve. I haven’t changed tires or suspension settings because I want to keep them consistent until I figure out how to setup the aero.
The open grill and lack of shrouds are a huge penalty at the moment. I’d also like to string the hood to locate low pressure zones, so I can open it for evacuation. I can feel the air shoving the nose over 115mph. It’s on my list for the off season..
The wing has proved helpful with stability in places where the car struggled before. It works, but there’s too much drag. I dropped it quite low on the mounts and picked up 5mph, which is huge. I lost a little stability under HEAVY braking from 130mph after dropping it, but it’s still far better than it was without the wing. I’ll be replacing the element this winter with something more appropriate from 9Lives.
I have mixed feelings about the splitter experiment, particularly with the material. I can see stress marks from deflection in the Alumalite now. I will likely pull it and build one out of plywood in the next couple of weeks. The bottom extends no further than the center of the axles. I did this to meet rule requirements in the event I decide to compete. The airdam seems to be doing its job, however I need to remove the decorative trim to smooth out the flow. The splitter needs to be completely rigid and it’s not. Correcting that is a priority.
I’d really like to spend time designing skirts. I think they’d be helpful. I need to shroud behind the grill, open the hood, build a more rigid splitter and replace the rear wing element first. That’s a lot to do lol. Fun stuff though. I enjoy throwing ideas at the car and testing them. The good news is, my lap times are improving with each modification. I’m definitely lazy about recording myself, but when I do I see significant improvements. I’ve regularly driven this track for 7 years. I find it crazy that I have new experiences each time I go out now. The car can certainly go faster than my brain will accept. I’m having to learn to carry more speed, adjust suspension settings and fine tune tire pressures more than I did before. Aero changes many things..
The open grill and lack of shrouds are a huge penalty at the moment. I’d also like to string the hood to locate low pressure zones, so I can open it for evacuation. I can feel the air shoving the nose over 115mph. It’s on my list for the off season..
The wing has proved helpful with stability in places where the car struggled before. It works, but there’s too much drag. I dropped it quite low on the mounts and picked up 5mph, which is huge. I lost a little stability under HEAVY braking from 130mph after dropping it, but it’s still far better than it was without the wing. I’ll be replacing the element this winter with something more appropriate from 9Lives.
I have mixed feelings about the splitter experiment, particularly with the material. I can see stress marks from deflection in the Alumalite now. I will likely pull it and build one out of plywood in the next couple of weeks. The bottom extends no further than the center of the axles. I did this to meet rule requirements in the event I decide to compete. The airdam seems to be doing its job, however I need to remove the decorative trim to smooth out the flow. The splitter needs to be completely rigid and it’s not. Correcting that is a priority.
I’d really like to spend time designing skirts. I think they’d be helpful. I need to shroud behind the grill, open the hood, build a more rigid splitter and replace the rear wing element first. That’s a lot to do lol. Fun stuff though. I enjoy throwing ideas at the car and testing them. The good news is, my lap times are improving with each modification. I’m definitely lazy about recording myself, but when I do I see significant improvements. I’ve regularly driven this track for 7 years. I find it crazy that I have new experiences each time I go out now. The car can certainly go faster than my brain will accept. I’m having to learn to carry more speed, adjust suspension settings and fine tune tire pressures more than I did before. Aero changes many things..
It took me 7 years of experimentation to work ot the aero for my car. Its a time intensive process. Consider doing A-B-A coast down testing when making aero drag changes. Mock up your idea in cardboard and tape it on. Find a long flat road and let it coast down from 70mph to 30. Time it with the mod -A-, without -B- and then with again -A-. Tally up the results and see if it worked.
Tuft testing may not help you find low pressure zones. A manometer will be much more useful. You should have a low pressure zone somewhere after the leading edge of the hood. That is why so many radiator ducts are there. Often, on street cars, the low pressure zone is not in a convenient place to duct the radiator. If not. You can evacuate out the front wheel wells.
Rear skirts are easy and can help dramatically! After I put them on I was shocked at the improvement. They should be on every race car, you'd be silly not to try them. I set a quarter mile drag record with my car and it was so much lower than the next guy that no one believed it possible.
Once they saw the great care and thought I put into and the extreme measures I went to, they believed. My focus was on parasitic losses, rolling resistance and aero load. Everything I did to help mpg resulted in better times at the track.
Tuft testing may not help you find low pressure zones. A manometer will be much more useful. You should have a low pressure zone somewhere after the leading edge of the hood. That is why so many radiator ducts are there. Often, on street cars, the low pressure zone is not in a convenient place to duct the radiator. If not. You can evacuate out the front wheel wells.
Rear skirts are easy and can help dramatically! After I put them on I was shocked at the improvement. They should be on every race car, you'd be silly not to try them. I set a quarter mile drag record with my car and it was so much lower than the next guy that no one believed it possible.
Once they saw the great care and thought I put into and the extreme measures I went to, they believed. My focus was on parasitic losses, rolling resistance and aero load. Everything I did to help mpg resulted in better times at the track.
No specific manometer recommendations, buy the best you can afford.
Do you have a wind tunnel near by? It might be helpful to get to know those guys.
I need to be careful not to give to many opinions. I'm just a well read amateur aerodynamicist.
Just my opinion, I know you spent a lot on the wing and are moving forward on a new design and the purpose of the wing is to provide downforce to improve cornering traction. I think that that the wing may be fighting lift. If this is the case, then you are spending hp on both lift and downforce. If you address the lift, then you will not need as much downforce to achieve the same traction. That's why I'm suggesting that you go after lift first, then address downforce.
Stopping lift might also calm the instability you are feeling as well.
Do you have a wind tunnel near by? It might be helpful to get to know those guys.
I need to be careful not to give to many opinions. I'm just a well read amateur aerodynamicist.
Just my opinion, I know you spent a lot on the wing and are moving forward on a new design and the purpose of the wing is to provide downforce to improve cornering traction. I think that that the wing may be fighting lift. If this is the case, then you are spending hp on both lift and downforce. If you address the lift, then you will not need as much downforce to achieve the same traction. That's why I'm suggesting that you go after lift first, then address downforce.
Stopping lift might also calm the instability you are feeling as well.
Thread Starter
#654
I don’t have access to a wind tunnel but I do have access to multiple aeronautical and mechanical engineers. One of them quickly identified the issues with my wing. I didn’t fully understand what he was explaining but as we develop the replacement, I’ll learn. In short, he wants to reduce lift at high speeds without producing downforce or significantly increasing drag. This method won’t load the suspension or 200tw tires, which totally makes since..
He has software that can simulate what’s happening. I wouldn’t be surprised if he has access to a wind tunnel but it could prove to be excessively expensive and impractical for the car’s purpose. If not, I’d sign up in a second.
In regards to the manometer, I’ll research them. Surely I can find something reasonable. I have no clue how to use one so off to YouTube I go lol. Thanks again for the insight.
He has software that can simulate what’s happening. I wouldn’t be surprised if he has access to a wind tunnel but it could prove to be excessively expensive and impractical for the car’s purpose. If not, I’d sign up in a second.
In regards to the manometer, I’ll research them. Surely I can find something reasonable. I have no clue how to use one so off to YouTube I go lol. Thanks again for the insight.
Thread Starter
#656
Ya I gotta let it out somewhere. No clue what I need to do other than lean on friends with more experience and proper tools. I’m going to buy a different hood to chop up when we determine where it needs to be cut. Did you ever find any data suggesting your vents are in the best location? It seems like big money players put them there but I can’t find anything explaining their purpose. I was thinking about building something similar to yours if that’s the best location.
One of many helpful places to find info regarding ventilating the radiator.
https://ecomodder.com/forum/showthread.php/radiator-hood-vent-aero-cooling-wai-all-one-29689.html
Make sure to read the whole thread, its loaded with good info and so.e guys who actually executed it well.
Check out this diagram and note that the low pressure zone is immediately after the leading edge of the hood, in front of the radiator.
I imagine it is the same for our car, manometer testing will guide the way.
https://ecomodder.com/forum/showthread.php/radiator-hood-vent-aero-cooling-wai-all-one-29689.html
Make sure to read the whole thread, its loaded with good info and so.e guys who actually executed it well.
Check out this diagram and note that the low pressure zone is immediately after the leading edge of the hood, in front of the radiator.
I imagine it is the same for our car, manometer testing will guide the way.
Last edited:
![[wink]](/images/smilies/wink.gif "Wink [wink]")
| Thread starter | Similar threads | Forum | Replies | Date |
|---|---|---|---|---|
|
September 2019 Fiesta of the Month Winner - Woods247 | Fiesta of The Month Winners | 5 |
Similar threads
-
September 2019 Fiesta of the Month Winner - Woods247
- Started by MKVIIST
- Replies: 5
