Aerodynamic Mods
I am designing a front splitter and a rear diffuser right now. Need to do a few more tests and get a prototype made but the rear diffuser SHOULD decrease drag pretty dramatically. Also for those who track it will increase the downforce if you have a rear wing. I plan to make them out of both carbon and aluminum and should be really cheap to produce, therefore cheap for everyone to buy. No guarantees on when I will start getting them out but will keep you posted on it. And if anyone is interested I can try to create a simple, effective, and hopefully cheap full length undertray.
This thread should be the "Aero mod ideas that vill0169 has already done that no one knows about" hahahaha 
Yes, I have full up front brake ducts on mine, 100% custom made by yours truly.

Yes, I have full up front brake ducts on mine, 100% custom made by yours truly.
I am designing a front splitter and a rear diffuser right now. Need to do a few more tests and get a prototype made but the rear diffuser SHOULD decrease drag pretty dramatically. Also for those who track it will increase the downforce if you have a rear wing. I plan to make them out of both carbon and aluminum and should be really cheap to produce, therefore cheap for everyone to buy. No guarantees on when I will start getting them out but will keep you posted on it. And if anyone is interested I can try to create a simple, effective, and hopefully cheap full length undertray.
These guys said they could get the versus bumper for me quicker than versus was estimating. I sent them the payment in full, and 6 months later when I'm looking for my part all I get is a bunch of excuses. So I called versus and they said they never placed the order for me. Then it took me a few more months to get my $ back from these a**holes.
If you want quality service, go elsewhere!
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When i'm done with that i'll try the Evo VIII front splitter fabrication on the TL-s
^^^Well Lumyeinjun, keep me on the list cuz i'm definitely going to want some under trays and a diffuser
also I just had a thought today as i was passing a newer EVO
has anyone attempted using the rear diffuser off of the evo on the TL?
also I just had a thought today as i was passing a newer EVO
has anyone attempted using the rear diffuser off of the evo on the TL?
hmm diffuser from Evo on TL....that sounds doable in theory!!! I mean Accurate or whatever his sn is that had that white TL on Honda tuning managed to fit a spoon sports diffuser on the TL!!! and the EVO seems it would work a little better!!!
so....whos going to be the guinea pig on that....wheres the ppl with EVO buddies lol!!
so....whos going to be the guinea pig on that....wheres the ppl with EVO buddies lol!!
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Front Underspoiler Tweek for Type-s A-spec Owners
So I was in my garage studying the aerodynamics of the TL when I noticed this:

This is a picture of the lower fasica of my TL type-s a-spec bumper. I'm not sure if I installed it wrong or not, but there seems to be gaps where the stock type-s bumper grilles used to mount on to the bumper (notice holes in the lower plastic part).
From what I know about aerodynamics, I've concluded that these gaps will cause turbulence in the air entering the grille. It will also cause drag and possibly lift. I know it's a minor thing, but i'm for efficiency and these turbulence-creators were a big no-no. So I decided to take 40 minutes of my time to clean the area up and use my trusty black electrical tape to smooth the area out. Here is the end product:

I'm not sure if this will even do anything in the real world, but to me it was worth the 40 minutes of my time. In theory it should allow the air passing over the grill to flow more smoothly and cause less drag.
Another thing that caught my attention was the big Acura caliper badge on the front grille of our car. The best way to reduce drag is to have a smooth front end that catches as little air as possible. The "A" badge is surrounded by 1 inch of deep hollow space.

If there were a way we could "fill in" this empty space, i'm sure we could significantly reduce our drag. Any ideas on materials we could use that wouldn't be noticeable to the untrained eye? The goal is to create a very smooth front end with very little "canyons" and protrusions that could increase drag or create turbulence.
Another thing to note is that an easy way to reduce drag is to cover up the grille openings of the front end. Car manufacturers give modern cars HUGEEE grilles for an aggressive look, but big grilles aren't actually necessary in day-to-day driving. If you don't really push your car, you can actually cover up the majority of your grille to minimize drag. Now that I think of it, my 1992 Lexus SC300 didn't even have an upper front grille haha
but it did have lower bumper grilles.
A quick google search on eco-modding and saving mpg will lead you in instructions on the grille mod. I wouldn't try this if you demand a lot from your engine though.

This is a picture of the lower fasica of my TL type-s a-spec bumper. I'm not sure if I installed it wrong or not, but there seems to be gaps where the stock type-s bumper grilles used to mount on to the bumper (notice holes in the lower plastic part).
From what I know about aerodynamics, I've concluded that these gaps will cause turbulence in the air entering the grille. It will also cause drag and possibly lift. I know it's a minor thing, but i'm for efficiency and these turbulence-creators were a big no-no. So I decided to take 40 minutes of my time to clean the area up and use my trusty black electrical tape to smooth the area out. Here is the end product:

I'm not sure if this will even do anything in the real world, but to me it was worth the 40 minutes of my time. In theory it should allow the air passing over the grill to flow more smoothly and cause less drag.
Another thing that caught my attention was the big Acura caliper badge on the front grille of our car. The best way to reduce drag is to have a smooth front end that catches as little air as possible. The "A" badge is surrounded by 1 inch of deep hollow space.

If there were a way we could "fill in" this empty space, i'm sure we could significantly reduce our drag. Any ideas on materials we could use that wouldn't be noticeable to the untrained eye? The goal is to create a very smooth front end with very little "canyons" and protrusions that could increase drag or create turbulence.
Another thing to note is that an easy way to reduce drag is to cover up the grille openings of the front end. Car manufacturers give modern cars HUGEEE grilles for an aggressive look, but big grilles aren't actually necessary in day-to-day driving. If you don't really push your car, you can actually cover up the majority of your grille to minimize drag. Now that I think of it, my 1992 Lexus SC300 didn't even have an upper front grille haha
but it did have lower bumper grilles.A quick google search on eco-modding and saving mpg will lead you in instructions on the grille mod. I wouldn't try this if you demand a lot from your engine though.
Last edited by lumyeinjun; Mar 18, 2012 at 01:12 AM.
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But I hope you win
Another thing that caught my attention was the big Acura caliper badge on the front grille of our car. The best way to reduce drag is to have a smooth front end that catches as little air as possible. The "A" badge is surrounded by 1 inch of deep hollow space.

If there were a way we could "fill in" this empty space, i'm sure we could significantly reduce our drag. Any ideas on materials we could use that wouldn't be noticeable to the untrained eye? The goal is to create a very smooth front end with very little "canyons" and protrusions that could increase drag or create turbulence.

If there were a way we could "fill in" this empty space, i'm sure we could significantly reduce our drag. Any ideas on materials we could use that wouldn't be noticeable to the untrained eye? The goal is to create a very smooth front end with very little "canyons" and protrusions that could increase drag or create turbulence.
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Epoxy resin is a good choice, but is there a less permanent route to filling this in? I don't want to hate the look and then have to buy a new front grille from the dealership 
Also, going back to blocking the front grille:
The way I see it, if the front grille is open, wind penetrates and catches further inside the car's body, acting like a parachute. I'm beginning to wonder if we really need air to pass through that front grille at all. Covering it up would be a very easy thing to do, and it wouldn't even effect the appearance of the car if we cover it up with some sort of black lining from the inside.
Nascar stock cars don't have openings/grilles anywhere in the front end of the vehicle. They have amazing aerodynamics. I'm not familiar with how a stock race car works though. Does anybody know how the engine gets cooled? Does the engine just let the heat out to the driver? I believe they have radiators, but how does the radiator get air?

And if you haven't seen a stock car in person before, those "grilles" aren't grilles at all. They're painted on to make the stock car look like a street car. Same goes for the headlights, foglights, etc. The front end is just a closed rounded piece of whatever material they use.
Also, Nascars use Carburetors on their front engine V8s; if the front end has no openings, where does the engine intake its air from? It would be interesting to see if we could wall off all of our grilles, but I wouldn't want anyone to risk overheating their engine in the process.

Also, going back to blocking the front grille:
The way I see it, if the front grille is open, wind penetrates and catches further inside the car's body, acting like a parachute. I'm beginning to wonder if we really need air to pass through that front grille at all. Covering it up would be a very easy thing to do, and it wouldn't even effect the appearance of the car if we cover it up with some sort of black lining from the inside.
Nascar stock cars don't have openings/grilles anywhere in the front end of the vehicle. They have amazing aerodynamics. I'm not familiar with how a stock race car works though. Does anybody know how the engine gets cooled? Does the engine just let the heat out to the driver? I believe they have radiators, but how does the radiator get air?

And if you haven't seen a stock car in person before, those "grilles" aren't grilles at all. They're painted on to make the stock car look like a street car. Same goes for the headlights, foglights, etc. The front end is just a closed rounded piece of whatever material they use.
Also, Nascars use Carburetors on their front engine V8s; if the front end has no openings, where does the engine intake its air from? It would be interesting to see if we could wall off all of our grilles, but I wouldn't want anyone to risk overheating their engine in the process.
Last edited by lumyeinjun; Mar 18, 2012 at 02:17 AM.
I'm pretty sure NASCAR's CoT has a lower grille:

Also, I think it'll be very hard to get proven reductions in drag from tacking pieces onto your car. Blocking certain things off make sense, like smoothing the Acura symbol. But it's very hard to see how adding a lip spoiler under your front bumper will reduce drag. Increasing downforce yes, but not lowering the Cd.
Just my
.

Also, I think it'll be very hard to get proven reductions in drag from tacking pieces onto your car. Blocking certain things off make sense, like smoothing the Acura symbol. But it's very hard to see how adding a lip spoiler under your front bumper will reduce drag. Increasing downforce yes, but not lowering the Cd.
Just my
.
Aman is right about the NASCAR car's having an open lower center grill. As you can see in the pic, they tape up as much of it as possible though to get the best aero possible while still getting air to the radiator and carb.
Here are my front ducts on my bumper, completely closed up except for the intakes for my brake ducts. Just thought I'd bring some of the ideas and concepts to life. Is this kinda what you're thinking about OP?

Here are my front ducts on my bumper, completely closed up except for the intakes for my brake ducts. Just thought I'd bring some of the ideas and concepts to life. Is this kinda what you're thinking about OP?

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Epoxy resin is a good choice, but is there a less permanent route to filling this in? I don't want to hate the look and then have to buy a new front grille from the dealership 
Also, going back to blocking the front grille:
The way I see it, if the front grille is open, wind penetrates and catches further inside the car's body, acting like a parachute. I'm beginning to wonder if we really need air to pass through that front grille at all. Covering it up would be a very easy thing to do, and it wouldn't even effect the appearance of the car if we cover it up with some sort of black lining from the inside.
Nascar stock cars don't have openings/grilles anywhere in the front end of the vehicle. They have amazing aerodynamics. I'm not familiar with how a stock race car works though. Does anybody know how the engine gets cooled? Does the engine just let the heat out to the driver? I believe they have radiators, but how does the radiator get air?

And if you haven't seen a stock car in person before, those "grilles" aren't grilles at all. They're painted on to make the stock car look like a street car. Same goes for the headlights, foglights, etc. The front end is just a closed rounded piece of whatever material they use.
Also, Nascars use Carburetors on their front engine V8s; if the front end has no openings, where does the engine intake its air from? It would be interesting to see if we could wall off all of our grilles, but I wouldn't want anyone to risk overheating their engine in the process.

Also, going back to blocking the front grille:
The way I see it, if the front grille is open, wind penetrates and catches further inside the car's body, acting like a parachute. I'm beginning to wonder if we really need air to pass through that front grille at all. Covering it up would be a very easy thing to do, and it wouldn't even effect the appearance of the car if we cover it up with some sort of black lining from the inside.
Nascar stock cars don't have openings/grilles anywhere in the front end of the vehicle. They have amazing aerodynamics. I'm not familiar with how a stock race car works though. Does anybody know how the engine gets cooled? Does the engine just let the heat out to the driver? I believe they have radiators, but how does the radiator get air?

And if you haven't seen a stock car in person before, those "grilles" aren't grilles at all. They're painted on to make the stock car look like a street car. Same goes for the headlights, foglights, etc. The front end is just a closed rounded piece of whatever material they use.
Also, Nascars use Carburetors on their front engine V8s; if the front end has no openings, where does the engine intake its air from? It would be interesting to see if we could wall off all of our grilles, but I wouldn't want anyone to risk overheating their engine in the process.
These nascar cars are constantly above 180mph and the wind at that point is a lot more and hence a small opening can/will do the trick....
even Rex (villo)'s TL is a dedicated track car....
the minute you take that concept into a street car, your engine is gonna get hot as a bish !!!
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Aman, thanks for the clarification! I do agree that the reduction in cd will probably be unmeasurable in the real world without a wind-tunnel test, but like Rex said I just want to apply theory to the real world and hopefully get something out of it haha.
Rex, I was actually planning to leave the lower grilles exposed and just block off the center grille to see if I could notice an increase in highway mpg haha. Did you leave your center grille open? If so, why did you decide to block off the lower grilles as opposed to the higher center grille?
Thanks for the pics though! I completely forgot about your lower grille fabrication. Seems like you're always ten steps ahead of me
Anil, you're right about the dedicated track car vs street car. I'm not exactly sure how blocking off the front grilles while also having a front splitter will affect engine temps during rush hour traffic here in L.A. The are many ecomodders who have completely blocked off all of their front grilles albeit a small slit for the radiator while also implementing a full length undertray on their daily drivers to maximize mpg. I'm planning to do this to my Toyota Sequoia because it's not driven hard, but I can't say I know what's going to happen if I do this to my spiritedly driven type-s.
Good input guys! I appreciate the ideas and constructive criticism, lets keep them coming
Rex, I was actually planning to leave the lower grilles exposed and just block off the center grille to see if I could notice an increase in highway mpg haha. Did you leave your center grille open? If so, why did you decide to block off the lower grilles as opposed to the higher center grille?
Thanks for the pics though! I completely forgot about your lower grille fabrication. Seems like you're always ten steps ahead of me

Anil, you're right about the dedicated track car vs street car. I'm not exactly sure how blocking off the front grilles while also having a front splitter will affect engine temps during rush hour traffic here in L.A. The are many ecomodders who have completely blocked off all of their front grilles albeit a small slit for the radiator while also implementing a full length undertray on their daily drivers to maximize mpg. I'm planning to do this to my Toyota Sequoia because it's not driven hard, but I can't say I know what's going to happen if I do this to my spiritedly driven type-s.
Good input guys! I appreciate the ideas and constructive criticism, lets keep them coming
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Also Rex, have you considered hood spacers to ease the transition of air from the hood to the front windshield? I would never do this to my car because I think it looks funny lol, but in theory wouldn't it help?
Aman, thanks for the clarification! I do agree that the reduction in cd will probably be unmeasurable in the real world without a wind-tunnel test, but like Rex said I just want to apply theory to the real world and hopefully get something out of it haha.
Rex, I was actually planning to leave the lower grilles exposed and just block off the center grille to see if I could notice an increase in highway mpg haha. Did you leave your center grille open? If so, why did you decide to block off the lower grilles as opposed to the higher center grille?
Thanks for the pics though! I completely forgot about your lower grille fabrication. Seems like you're always ten steps ahead of me
Anil, you're right about the dedicated track car vs street car. I'm not exactly sure how blocking off the front grilles while also having a front splitter will affect engine temps during rush hour traffic here in L.A. The are many ecomodders who have completely blocked off all of their front grilles albeit a small slit for the radiator while also implementing a full length undertray on their daily drivers to maximize mpg. I'm planning to do this to my Toyota Sequoia because it's not driven hard, but I can't say I know what's going to happen if I do this to my spiritedly driven type-s.
Good input guys! I appreciate the ideas and constructive criticism, lets keep them coming
Rex, I was actually planning to leave the lower grilles exposed and just block off the center grille to see if I could notice an increase in highway mpg haha. Did you leave your center grille open? If so, why did you decide to block off the lower grilles as opposed to the higher center grille?
Thanks for the pics though! I completely forgot about your lower grille fabrication. Seems like you're always ten steps ahead of me

Anil, you're right about the dedicated track car vs street car. I'm not exactly sure how blocking off the front grilles while also having a front splitter will affect engine temps during rush hour traffic here in L.A. The are many ecomodders who have completely blocked off all of their front grilles albeit a small slit for the radiator while also implementing a full length undertray on their daily drivers to maximize mpg. I'm planning to do this to my Toyota Sequoia because it's not driven hard, but I can't say I know what's going to happen if I do this to my spiritedly driven type-s.
Good input guys! I appreciate the ideas and constructive criticism, lets keep them coming

There are a couple of reasons for my current front aero setup. The lower grills really do next to nothing. At least on my 04, only the inner most part of each lower grill had a little deflector to direct air towards the radiator. Other than that, 90% of the opening had no direct purpose. Some would argue that the intake on the left needs air from the front bumper but there are still openings beneath my filter that give it plenty of air.
The reason I have my upper grill still open is A: it's the primary air source for majority of the radiator. And B: because I have done the biggest ultimate cooling mod to date, any air than passes through the upper grill can go thru the radiator and then out through either the holes in my hood or the gap between the hood and the windshield.
Only reason I'm "ahead" is I've been at it for a year and a half already.
kinda answered this above without knowing but with the ultimate cooling mod (UCM), I have a pretty large opening between the hood and windshield that lets a massive amount of air of the engine compartment.
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Anil, you're right about the dedicated track car vs street car. I'm not exactly sure how blocking off the front grilles while also having a front splitter will affect engine temps during rush hour traffic here in L.A. The are many ecomodders who have completely blocked off all of their front grilles albeit a small slit for the radiator while also implementing a full length undertray on their daily drivers to maximize mpg. I'm planning to do this to my Toyota Sequoia because it's not driven hard, but I can't say I know what's going to happen if I do this to my spiritedly driven type-s.
Good input guys! I appreciate the ideas and constructive criticism, lets keep them coming
Good input guys! I appreciate the ideas and constructive criticism, lets keep them coming

here is a pic for reference:

i went a little crazy with PS on this one LOL:

I think it could be done with minor modding if we could get a hold of one.
And honestly it'd still be cheaper than what spoon or apr would want for a custom job. We need to get one and get rollin on this cuz i want one!
I was looking into that UFC mod myself as the black plastic piece on the bottom windshield is severely color faded, looks nasty. Is the primary purpose of that to stop rain from getting in? So without it, hard downpours might lead to electrical problems? I raise the same question with hood scoops and hood vents for daily drivers. I'll have to do a hose test and see if there's a way get better air flow instead o removing completely.
I notice the gap between hood and bumper has a black plastic piece which goes directly on top of the radiator. If you were able to lower the radiator ~1-2 inches you could have air pouring in instead of being stopped at black plastic and radiator.
If you had a wide body fender or something similar, our cars are setup perfectly to intake from the fender to save room/less bends/distance. then put vents on the fender! haha
I notice the gap between hood and bumper has a black plastic piece which goes directly on top of the radiator. If you were able to lower the radiator ~1-2 inches you could have air pouring in instead of being stopped at black plastic and radiator.
If you had a wide body fender or something similar, our cars are setup perfectly to intake from the fender to save room/less bends/distance. then put vents on the fender! haha
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^^^ 
not UFC, UCM (ultimate cooling mod)....
well i have driven thro torrential rains and never had a problem, reason being, the water just slides off from the hood to the glass.....
also if you read the thread, there are variations to the UCM which you can do, so you do not need to remove the crowl....finally, if you see the pix i posted above, i put some washers (hood pop) under the hood and because of the ~8mm raise in the hood angle, the water leaves the cabin filter nice and dry as well

not UFC, UCM (ultimate cooling mod)....
well i have driven thro torrential rains and never had a problem, reason being, the water just slides off from the hood to the glass.....
also if you read the thread, there are variations to the UCM which you can do, so you do not need to remove the crowl....finally, if you see the pix i posted above, i put some washers (hood pop) under the hood and because of the ~8mm raise in the hood angle, the water leaves the cabin filter nice and dry as well
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^^^ yes....the grand canyon....and it works very very well in moving the water away from the electronics
but I have to agree with him that when you take the crowl out you are exposing your internals to water and moisture....not that its gonna hurt anything but yeah if you are that worried about water and moisture then do the modified version of the UCM !!!
but I have to agree with him that when you take the crowl out you are exposing your internals to water and moisture....not that its gonna hurt anything but yeah if you are that worried about water and moisture then do the modified version of the UCM !!!
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would removing the cowl increase drag? I'm up for a modified UCM; gotta look over that thread to find the modified version that keeps the cowl in place :/ such a long thread.....
I don't see how it would. If anything, it should help lower the pressure build ups in the engine bay from the air taken in from the underbody and front of the car by letting it escape over the windshield and behind the car.
well the reason i say the evo is because there are already some compatible parts from the evo to the TL.
I think it could be done with minor modding if we could get a hold of one.
And honestly it'd still be cheaper than what spoon or apr would want for a custom job. We need to get one and get rollin on this cuz i want one!
I think it could be done with minor modding if we could get a hold of one.
And honestly it'd still be cheaper than what spoon or apr would want for a custom job. We need to get one and get rollin on this cuz i want one!





