lumyeinjun

iTrader: (1)

Did a quick search and i'm surprised to find that there are ZERO dedicated threads to aerodynamic modifications for the 3G TL

"For highway driving conditions, it is estimated that driveline uses about 15% of the total energy to required to push your vehicle down the highway, tire rolling resistance represents about 25%, and air drag is about 60%!"
-Recumbents.com

Aerodynamic modifications can serve a great deal of benefit on the track and for everyday highway cruising. If we could find a way to lower our coefficient of drag (Cd) we would have essentially found a way to increase traction, top speed, and MPG. I would assume that this would appeal to ALL enthusiasts on Acurazine because if you're on here, chances are you care a little more about your car than the average Joe.

Here is an extreme example of somebody who took his '92 civic and turned it into a 95 MPG Prius eater: http://www.aerocivic.com/

Of course, his car looks odd to say the least and I don't expect any 3G TL to do what he has done to his car. I'm interested in aero mods for the MPG and the performance benefit (quicker acceleration times). The Hyundai Genesis Coupe guys have a great discussion going on about it here:
http://www.genxcoupex.coxm/exterior/47764-aerodynamic-mods.html

I'm no expert, but I'm hoping I can get some experts on here to chime in on what would help up achieve a lower Cd and more down-force at speed.

Here are some basics that I learned from my physics classes in college and from browsing around different forums/websites:

-Having a lower Cd of drag is good
-We want to reduce the amount of "lift" on our cars at speed
-We want to increase the amount of "downforce" on our cars at speed (for performance, not mpg)

We can attempt to achieve the above objectives by several methods. Here are where the mods come into play. My goal here is to create an educated discussion about how we can improve the aerodynamics of the 3G TL, I welcome you all to chime in with any helpful information or any questions that come to mind. I want you all to share your knowledge and curiosity with the rest of azine on this one!

Here are some modifications that I can think of at the top of my head:

Front wind-splitter

generates more down-force and reduces lift by channeling air out of the underside of the car more quickly

Rear diffuser

reduces drag, need someone to chime-in on how and why

Undertrays


The TL already has plastic undertrays that help smooth out the airflow underneath the car. I'm glad the engineers at Acura did that for us, but I'm sure it can be improved with aftermarket modifications as well

Rear Wing

Hold up... I know giant GT wings don't look good on our daily drivers, but I'm just putting the idea out there for informative purposes and completeness. Like it or not, those HUGE wings DO help with aerodynamics a lot! A few hundred pounds of downforce at 90mph is to be respected! Look at the THR race TL, it has one! The type-s comes with a rear decklid spoiler as well, but i'm not sure if it's functional or just for aesthetics


Front bumper canards

Redirects air and does something fancy. I believe ACCURATEin has/had them on his beautiful WDP

Front air dams

The a-spec front bumpers incorporate this

Aero body kits

There aren't many lip kits available for the TL, but I am so proud of Acura for making a beautiful one and making it functional! The 04-06 a-spec kit has been proven to reduce the coefficient of drag (see THR TL article in Honda Tuning). Not so sure about the type-s a-spec kit or the 07-08 base kit, but my guess is that they do the same thing.

I am not sure if these mods will benefit or hurt our aerodynamics; just throwing ideas out there and my speculation. Feel free to correct me if i'm wrong. Not all aero mods work the same way on all cars. For instance, as stated in the gencoupe forum, vortex generators (those spikes that you see on the back of Evo 9s) will serve ZERO BENEFIT to the Genesis Coupe because there isn't a steep drop-off point where the roof meets the rear windshield. We need to keep in mind the factory design of our body.

Feel free to list anything else I may have missed. Again, I am farrrr from an expert on the subject and I would be happy to be enlightened!

I also used this website for reference in starting this thread: http://www.recumbents.com/car_aerodynamics/ I know these guys aren't the most credible authors in the world, so take their info with a grain of salt. It does, however, provide a good foundation to build our knowledge on.

Oh and please, let's not keep the "why waste your time on a FWD" comments to a minimum. The 3G is a proven sports sedan that has won numerous titles under Team Honda Racing and other Honda race teams. Lets also not forget Best Motoring's comparison of the 2008 TL type-s vs the is350 and G37; the "underpowered" FWD beat the two 300+ hp RWD cars by two seconds at Willow Springs speedway. That very laptime is one of the best laptimes at Willow springs till this day (top 25 I believe) and if you don't believe me, google it yourself. There's a video on it too.

Keep modding Onto the discussion!

lumyeinjun

iTrader: (1)

darn 15 minute editing window! Had a few typos in there but here is one that I need to seriously correct:

" let's not keep the "why waste your time on a FWD" comments to a minimum "
I meant to say keep it to a minimum!

and for the front air dams, I believe the type-s bumper has one built in and the 07-08 base has a teeny tiny one. The 04-06 model front bumpers fall straight down at the nose though

also, a member on here had a custom rear diffuser made that looks pretty good on the TL imo:

https://acurazine.com/forums/car-parts-sale-361/custom-rear-diffuser-775631/

and if you're interested in mpg savings do look at the aerocivic and recumbents website; there's some neat stuff on me! The mods on there would be silly on a TL, but it's still something worth acknowledging

All-in-all, if you want the best performance out of your vehicle, you simply can't ignore aerodynamics!

lumyeinjun

iTrader: (1)

Also, I wonder if it would be beneficial cut vents in the plastic lining in our wheel wells. There's the possibility of it reducing lift and maybe (strong emphasis on maybe) reduce engine temps?

And we could also help reduce drag by reducing the size of our mirrors. I wouldn't do it because I love the luxury of my mirrors tilting down when I throw it in reverse. Helps with curbside parking a lot However, ACCURATEin has some aerodynamic mirrors that most likely drag the car down less than the oem mirrors. If you're extreme, you may want to replace the mirrors with mini spy cameras altogether. I believe there's a concept car that did that already though

gwiffer

iTrader: (7)

Cool thread!

I tried contacting racingrubberlip.com about getting a front lip made for my Accord...I got no response.

I also wanted to do something similar with the sideskirts...pure function!

I was thinking about making my own...http://www.rubbersheetroll.com/

lumyeinjun

iTrader: (1)

for the front lip you could try APR Performance. They do custom work
http://aprperformance.com/index.php?...d=72&Itemid=48

libert69

iTrader: (7)

in

TheChamp531

iTrader: (3)

Ive thought about this before but I just don't see it happening without ruining the curves of the TL. But subscribed wish it can happen

justnspace

iTrader: (1)

Vill069 has done undertrays

SharksBreath

iTrader: (33)

sub'd.

callahan

Subd!

04TL4P3

iTrader: (1)

I almost ordered a front wind splitter like the one in the first pic but then read that our tl needs the opening under the front bumper area for proper airflow through our radiators :/ im not stating this as fact but just somethjng to look into cuz it seams to make sense

lumyeinjun

iTrader: (1)

Yeah I agree. A lot of the mods needed to maximize aerodynamics would clash with the styling of the TL. Whether or not to perform the modifications will be up to the owner and what they want out of the car, but I'm looking to do subtle mods at try to decrease my Cd. Look at the link to the '92 civic, that thing looks like a space ship! but man... 95mpg with nearly ZERO drag

Thanks for the heads-up, Justin. I just took a glance at his track build thread and the introduction of the undertray starts on page 6. Vill comes back on page 8 with pics of his fabricated undertrays. The most complete stuff is on page 15 of the thread.

https://acurazine.com/forums/showthr...=805334&page=6

I will take a good look into his build thread when I get home. Anybody else with valuable information like this? Don't be afraid to chime in!

I've heard of this as well. Maybe vill069 can help us out on this as well as he has a functional wind splitter

BostonSilverTypeS

sub'd.........been trying to look for a functional front lip for the longest but nothing yet and as well as a rear diffuser(carbon fiber even betteer)....but no luck yet maybe this thread will change that.....!!! Im in for the ride of ideas and custom builds!!! btw if anyone knows who could make custom rear diffuser for the TL-S let me know I want one bad they look super nice IMHO!!

phatrick

Always wanted to get a custom cf front full splitter made..

I know there was one on the other acura forums that someone on this forum owns now, but that one is a little too thin for me. I wanted to get one that fits perfect.

lumyeinjun

iTrader: (1)

I wish we could get a hold of the guy who made the rear diffuser in the TL above That's a beautiful piece of work!

No idea what company will fabricate a custom rear diffuser for the Tl but I came across a rear diffuser build on ecomodder: http://ecomodder.com/forum/showthrea...read-8313.html

The guy is building a custom rear diffuser and they're discussing the optimum angle on incline to set the diffuser at to maximize fuel efficiency. There is also a wiki link on post #3 that might help!

APR performance makes custom front splitters! You can try calling them to see what they can do for you

Also, here are some drag coefficients that I pulled up from wikipedia:

2004-2008 TL: 0.29 (same as pre 2004 Prius and 1-series)
Current Lexus IS: 0.28
G35 and Genesis Coupe (and TL with a-spec kit) 0.27

But faster acceleration at high speeds isn't all about Cd. For instance:
370z has a Cd of 0.30
That's the worst Cd of all the cars i've mentioned, but it is the fastest car of the above mentioned Nevertheless, Cd is an important factor and I am certain that if the 370z had a better Cd it would be even faster than the beast that it already is.

The a-spec kit is reported to reduce the Cd by 0.02 which puts us in G35 and Genesis Coupe territory

but keep in mind, if your purpose is simply to increase mpg, focusing on decreasing your drag would be fine; however, if you are performance oriented you have to also worry about decreasing lift and increasing downforce for stability.

The a-spec kit has been wind-tunnel proven to increase downforce while lowering the Cd. Other products may be a compromise, so make sure you do your research before you pull the trigger. You don't want a car with a super low Cd but a tremendous amount of lift on high speed turns; your car may and probably WILL flip in the case of road imperfections.

Source: http://en.wikipedia.org/wiki/Automob...ag_coefficient

Xiomaro

iTrader: (5)

Sub'd

I've been waiting for this for a while.
Definitely interested in the diffuser and wing

Morrissey25

iTrader: (4)

Nice read...

Sub'd...

Popee

iTrader: (1)

Good read, interested in this

Otacon

iTrader: (1)

In. I can't remember where I saw it but I remember someone modifying a Type S Aspec fron lip with an air dam and it looked great and was probably functional.

213swampy

iTrader: (1)

man i want that versus front bumper so bad, they don't make it anymore anybody know where i can get one
http://img40.imageshack.us/img40/4936/017pid.jpg
http://img359.imageshack.us/img359/1...7983f0f74b.jpg

KN.TL06

I'm actually trying to make a front splitter out of fiberglass right now, trying to make something functional as well as look good, I'm about half way done just need to refit, figure out how to mount it, and finished fiber glassing and painting it. i have the basic layout though.

Toddy

iTrader: (5)

Versus will make the bumper if they have 10 orders. $150 non refundable deposit and then they bill you afterwards. I waited 18 months before I cancelled my order. They will refund the deposit if they do not make the order requirement within 12 months IIRC.

lumyeinjun

iTrader: (1)

I'm using this thread as my personal journal lol. Found a few links that might help. I'm hoping to fabricate my own undertrays in a few weeks if my UA7 seems to be in good enough shape. Here are two links of custom undertray builds that i'm going to use for reference:

http://forums.evolutionm.net/evo-how...heap-easy.html

http://ecomodder.com/forum/showthrea...1-a-12816.html

Sounds like Fiber Reinforced Plastic (FRP) pannels from Lowes or Home Depot are the material of choice to use due to its cost effectiveness. Hopefully someone on here will start the project and get it done before me. We'll see if mine ever even goes through lol

Also some things to note: I wonder if this will affect the cooling of the transmission. Also should probably keep in mind the effect it has on the exhaust or the effect the exhaust has on the FRP material. The evo guy said the plastic hasn't melted yet, but he doesn't track his car. Only one way to find out!

I might have to stay away from the front end though. We need to find out if the radiator really does need to be cooled from the bottom. I would think that the grille and openings in the front lower fascias would provide enough cooling for the radiator, but . Also, it will be a PITA to have to remove this thing at every oil change. A lot of bugs that I need to sort out before I go through with this.

Xiomaro

iTrader: (5)

The group buy I was in was just completed.
Just waitinnhg for my shipping!

I wouldn't hold out. They seemed to make it like this was the last group buy

213swampy

iTrader: (1)

Where was the group buy was there a link to it, is it possible if I can join to get one order? Lmk

jptl04

iTrader: (1)

Interesting, I was...or am planning the same thing. I should
Have been done with it months ago. But work and other projects got in the way. I'm gonna continue going through with making this next month for sure. I already have a universal splitter sitting in my garage it's fiberglass and plenty wide enough it's just too damn thin. I'll have to reinforce it and make it a little thicker plus I will be wrapping it in 2x2 twill weave carbon fiber. It's gonna be added to my a-spec front spoiler. I've posted pics before, here are some mock ups using plain cardboard I painted.



I'm going for this look


I know i can make it. Its just a matter of finding time. I'll definitely be posting any progress on it in my build thread.

vill0169

iTrader: (4)

Racingrubberlip is not in business anymore, at least they won't be for a while as one of the partners recently left.

thanks justin.

It really doesn't need as much as you'd think. My splitter attaches behind the radiator and my lower front grills are sealed off for my brake ducts and even at Road Atlanta in August, I've never had any over heating issues. With the slight rise in the center of the bumper and the upper grill still open, my radiator is getting plenty of air while on track.

If it were me, I'd steer away from the FRP stuff. It would probably do the job but I'd always be worried that normal vibrations and road bumps tearing up the mounting points and it possibly getting loose and dangerous over time. Not to mention the whole exhaust issue. I know the guy in the picture at the end of the Evo thread that used the aluminum instead. It's what I used for my amazing rear diffuser and I would trust it a whole lot more than the FRP. Yes the cost would be higher, but worth it in the end IMO.

I would agree that basically leaving the front subframe area open would be a good idea. Yes, the tranny will need some air, especially an 5AT if you have one and oil changes/servicing will be easier.


Another warning I would give to anyone is to not underestimate the challenges of the proposed projects. Everything on my car I've made myself which means I've had to fabricate 100% of the parts needed to make the part secure and functional. It's an incredibly hard to take an idea and make it what you want, so if you're going to start any of these projects, you have to be committed to finishing. And I'm totally guilty of this right now...I'm only half done with my vented front fender project and have just been too tired and busy to get the whole thing finished up.

Good luck with the projects and I'll be happy to offer advice when I can.

lumyeinjun

iTrader: (1)

i believe in you! keep us updated on your splitter project!


So from what I'm envisioning, air is flowing to your radiator from the small (maybe 2"?) gap between your front splitter and your lower front bumper, correct? That's awesome! I don't know why I didn't think of it before! The rear of the front splitter would then stop at the plastic radiator air-catch/scrape guard thingy and still direct air into the radiator! Genius!

And yeah I was also wondering how long the FRP would last with all the vibration it would have to endure on the streets. I was actually planning to do an undertray prototype on my Toyota Sequoia (purely for mpg savings) using FRP and a hell of a lot of zipties to see how it would last on the SUV haha. Might still try it, but for the TL i'm going to have to think a hell of a lot harder.

Thanks for all the knowledge guys!

phatrick

The thing with front full splitters is that our cars are really rounded in the front. Definitely looking forward to seeing it though.

Xiomaro

iTrader: (5)

There was no link on here. It was direct from versus. The group buy is over now

213swampy

iTrader: (1)

oh man that sucks ass, you want to sell me yours when you get it lol, jk
maybe next time!

lumyeinjun

iTrader: (1)

I also got my hands on an apr front splitter from an evo VIII (for free) that I will be trying to modify and use for my type-s. Planning to start the project in two weeks. Ill be sure to keep you all posted.

swoosh

iTrader: (5)

sub'd

Xiomaro

iTrader: (5)

Ooo tough decision

I have no front bumper of my own right Now so this is a necessity

ez12a

unfortunately wings for downforce and reducing drag are opposite ideals.

You'll have to find a balance in between the two.

an extreme example is the Bugatti Veyron. In it's "super speed" mode it reduces the profile of the rear wing to allow less drag to achieve that top speed and at the same time sacrifice downforce.

forget about downforce if you want low drag. Your focus should be then to reduce lift.

vill0169

iTrader: (4)

^yes^

BSpecialist

Pretty cool information, I never knew the A-Spec kit was tuned to lower drag. I'm just curious if there is any information on the Type-S A-Spec kit as it looks much different than the standard A-Spec kit. I did a quick search and didn't find much of anything...sorry I'm lazy

Xiomaro

iTrader: (5)

Its not so much the wing itself, but the wing style. If you put a giant sail of a wing up off the deck, its going to add more drag even though you're reducing lift.

However if you change the style to a lower in line profile the wing becomes part of the overall profile of the car. It will reduce drag and lift, but it will move the draft distance of the air coming off the back of the car.

baggy22

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.

lumyeinjun

iTrader: (1)

This sounds more in line with what i've read. The first part at least, I know nothing about the second statement so I'll refrain from commenting on that lol. But a wing works in conjunction with a rear diffuser and other aerodynamic parts of a vehicle.

Sounds great! Any idea on how soon and where these parts would be manufactured (i.e. USA, China, Taiwan, Mexico, Japan)? I myself am already going to build my own undertrays and front splitter because I already have the materials, but i'm sure other members on here would be interested!