Aero work and new products to make you slippery

[David Buschur]

As some of you know our black car has recently run 169.59 mph. We had done a little aero work to the car and of course made even more power than before. The work we did to the car was simple so far, just sealed off some of the air that was going through the fascia. No rocket science, same stuff we did to the tube chassis cars years ago. The EVO has a lot of frontal area and way too many openings in the fascia, all of which act just about like a parachute. Sealing them all off on a street car isn't feasible as the car will over heat. On the drag car we sealed up the entire front except for the FMIC opening. We also just built a rear wing for the car, the back end has always been sealed up under the bumper and we are putting a new undertray on the front.

This brings me to a more streetable car, my EVO RS. I had a goal this spring with the car to reach 150 mph trap speeds, on E85. I have tosses the E85 goal for now and just want to hit 150 mph with the car. Being "heavy", running on radial street tires and not wanting to go up in turbo size (35r being the largest I am willing to tolerate for lag) means I have started looking elsewhere for some additional MPH.

My first change was to seal up the two larger holes that are to the right and left of the FMIC. The one on the drivers side is worthless, the one on the passenger side goes to the oil cooler. I don't run an oil cooler so I didn't need it. I made flat carbon fiber panels and glassed them in. I now have templates made and I am considering having them sent out to be made into bolt in pieces so anyone can do this. My first question is, any interest here for those parts?

The next thing I am working on is a flat undertray for the front. I have never liked the undertrays as they are a HUGE PITA to tie down on the dyno with them and they seem to gather tools and nuts/bolts when working on the car. My car hasn't had one on it since the first week I bought it. With our race FMIC the undertray has to be cut to fit, the stock undertray is not smooth and has a large cavity that protrudes up that hits the race FMIC. I know there are many guys that want the undertray back on.

I am working on a reasonably priced, flat undertray that will have wicker bills in front of both front tires. They will add some rigidity to the undertray and help move the air around the tires. Should be quite simple/inexpensive and will fit nicely under our intercoolers. I should have the first 3 of these done this week. When I get them done I will post pictures of it installed and some of the other details of what I have cleaned up aerodynamically on the car. Next question, any interest in the undertrays? Should be close to $100. Shipping is what will suck as they are 65" wide and almost 4' long.

I want to test the undertray on multiple back to back runs at the dragstrip. I think the largest gain is going to be from the two holes being plugged in the front end, they collect an enormous amount of air that gets trapped in the fascia and causes a huge drag. Imagine sticking a small garbage bag out the window of your car with an opening about the size of one and half hands, now multiply that times two openings. HUGE drag. The force if the air in those openings is so high it has pushed both inner fender wells back into the tires of my car. I figure now that they are blocked I won't have to replace them for the 3rd time.

I also have the EVO9 JDM rear bumper on the car which I think has helped a lot with the 148.32 mph trap speeds the car has already reached. There is a huge amount of air that gets trapped under the factory EVO8/9 rear bumpers. The JDM 9 is flush with the spare tire well in the rear.

So let me know what kind of interest there is. I'd like to offer both these but will only do it if there is some interest.

Thank you,

[antilag_200]

David,

if you make the "plugs" for the two holes on the sides of the FMIC , I would definitely consider buying them. Now as far as an undertray goes, have you had a chance to look at the beatrush underpanel ? It is a pretty straight forward design, with louvers in it to evacuate some of the air in the bay. It is a two piece design with 6 allen head bolts holding it all together. Just a thought as a far as an underpanel goes. Good luck with everything.

[funcars]

One hundred is great for an undertray. I spent 3something on my beatrush. Its 3 pieces that bolt up pretty strong, but just one good ditch this last winter and I had to remake the rear piece. But didnt tear up anything else. For 1 hun. I'd buy three. You allways get great products from Buschur. Rock On

[blackout]

Dave you can put me down for both. How needed is the oil cooler Dave if the car isn't used on the road course or autoX?

[vwjeff]

Count me in. When can I pick this shit up?

You sound like me man... I am looking to make my non AEM car ET and MPH better

** EDIT** I'll try that tray out Monday at Norwalk and bumper hole cover (just the leftside)? And give it back at the end of the day.

[DragNRacing.com]

David,

I had planned to do as much aero work to the Magnum as possible for next season. Any parts you can provide would be GREAT!!!

[David Buschur]

We finished the first undertray this morning. Below is a picture of our black drag car with it on. The underside of this car is slightly different as the center member is different than stock or the one we sell. (The center member is the brace that runs the length of the car with the front engine/trans mount on it). On our black car it hangs down a bit, that's why there is a slight bow in the undertray.

We also put a flat "wicker" in front of both tires and then directed the air hopefully down the center of the car. It looked good so we figured what the hell.

The front under the "Do luck" lip is fastened in with 5 Dzues fasteners and the rear is held in by the two tie bar bolts. On the center member we ran two zip ties through it for extra support.

The undertray is heavier than I'd like but without going to an expensive "exotic" material it's the best we can do, 10.8 pounds, it is longer than the stock undertray.

Anyway, here's the first shot of it:

[David Buschur]

So check it out. I got a call, not sure if the gentleman wants to be revealed or not, yesterday about wind tunnel testing. There is someone here on the forums who owns an EVO himself and works at a wind tunnel. While I am not able to get an EVO over there for testing he was extremely helpful and interesting to talk to. (Thank you for the phone call again!!)

We were talking and he told me it is fairly easy to test the products I am trying to build without a wind tunnel. Just to check to see if the airflow is smooth, turbulent, seperating etc. The trick is quite simple and I never even thought of it. I was told if I simply put some light oil over the surface I wanted to test and then drove the car it would show how the air was flowing. FREAKING GENIUS!

Tonight I got home, put my RS up on the jack and sprayed it down with WD40. I then took it out on the road and drove it easily up to 100 mph where I stayed steady for about a mile. I turned around and came back the same way. I freaking couldn't wait to see if it worked.

I pulled in the garage and jacked the car back up. Sure as **** it worked. I have to give him a call now with a few questions as there are some very interesting things going on.

First thing that is on a positive side, the oil streaked perfectly from the front lip almost all the way to back of the undertray. I don't think I sprayed the rear of the tray very well when I did it, so I can't tell if the air is seperating at that point or if the oil just ran out. I think it just ran out. So the undertray works perfectly, smooth straight streaks from the front to almost the very rear.

Next thing. The "Do luck" ( I keep putting Do Luck in quotes because it is not an actual Do Luck lip, it is a cheaper knock off of that design) seems to work too, atleast in some of the areas. My car is white so the oil was extremely hard/impossible to see on the nose of the car. If there was some dust on the road it sure would have helped. Anyway, on the front lip on the left and right front corners it is flat, almost like a small splitter just on the corners. This areas was perfectly streaked on the top, so you can tell the air is flowing over this flat area, I would guess helping with some downforce from the looks of the top and bottom of the car in that area.

The holes that I plugged on the far left and right of the fascia is hard to tell what is happening there. This area and the wickers I put infront of the tires are both areas I have questions about and will get some answers next week, I hope.

Very promising right now. I figure worste case the wicker I put infront of the tires may have to come off.

Looking good. I can't wait to build the rear section and do some testing there!

[DragNRacing.com]

Very cool stuff

[vwjeff]

I am getting excited

Doesnt that just piss you off when someone else thinks of something so simple like that?

[evoenvy]

I think the front panels are a awsome idea.. But being i drive the car on the street too i would like to see them be easely installed/removed so they could basicly "pop on" in minutes. And i also drive the car to the drag strip it would be even better to see this done without removing the undertray or even the bumper for that matter. Plus removing the bumper every time you come or go from what ever from of racing you do means the bumper a good chance if geting scratched up during the prosess

The undertray is a badass idea as well !! I was just asking myself the other day why spend the money on a beatrush when u almost dont need it and could get by with even the stocker and some cutting. But then i thought the undertray probaly served a good purpose maybe helped air flow through the IC to the radiator better. I even said maybe this its mitsu's funny idea of like a skid plate since it the car was desinged for rally. I didn't think it was to prevent air from going into the engine bay and as david said "acting like a parachute" . So i could not see myself not reinstalling some sort of tray and most likley spending the money on a beatrush cuz it is truly a PITA to remove the stock . Also it probaly takes more time to take the darn stock one on and off than the work u do to the car after you struggle with removing it. Then you get reinstall it and hope it will hold up there with only half the lame plastic clips cuz you lost and broke half them taking it off!!

2nd ... Maybe a hole for the drain plug could be a order option or even a "flap" where the drain plug and filter are . One or two tapered allen head bolts sunk is still going to be easyier then taking off the whole thing. Personaly if had to take heavier aftermarket undertray off just to change the oil i probaly wouldn't have much intrest in it! And again we get into how it would take twice as long to remove and install the tray than the just the oil change would. Maybe if it took a second off my 1/4 mile times i would

Last thing is i noticed on the stock undertray what looks like channels on the left and right side of the undertray.It looks like they were engineered there for a good reason . It could be either to help cool the front brakes better.
Or they could be there to help prevent uplift at high speeds by guide a portion of the air out the front wheel wells this would or could help prevent uplift because here wouldnt be as much air volume flowing the whole lenght of the car. This could also help with the amount of wind resistance being created on the cars underside.


But i could be dreaming and they serve no purpose at all . Or i might have figured out a way to get a even better trap speed or even a faster lap time out of your better solution to an undertray .

Maybe see if the wind tunnel evo owner could put his car in the wind tunnel using your prototype and one with the channels. It would truly show you how good they work . Or help you improve on whats indefinetly going be 2 great new parts.

You always bring us really informative parts comparisons with all the companys who don't care if it actually performs better or not. As long as its cheaper than
then big name company parts. Theres always gonna be some sucker gonna waste there money on it. And there going to try to get rich off of it.
Such as the ebay ic's and tbe's and such . I would interesting to see a compairison done here be real interesting to see how much better the part is in wind tunnel testing compared to the stock one and such.



Again these are my thought on the prototype parts . David you might not like or agree with my thoughts and suggestions. You just keep proving to us all the u never know till you try it. That why you have so many loyal customers . Because we know we can't go wrong with any of your parts .

[Danimal]

Wanna do a real rear diffuser next?

I still think you guys do this stuff just to tempt me to spend more money.

[David Buschur]

We tested the front undertray today on the black drag car. We already had a rear panel on the car that we made last season. We also added a short aluminum rear wing like you see on Pro Stock drag cars. The car was very very unstable before, "spookey" feeling as my brother said.

Today we ran teh car with the new rear wing and front undertray. We set a new personal best ET with it and the MPH was right there with our best ever. 8.88 at 169.4 mph. The great news is the car is so stable now it doesn't move around at all. Daniel didn't pull the parachute at the end of the first run because he said the car felt too SLOW!! He told me on the way home he's ready for a few hundred more horsepower now! haha

So it would atleast seem at this point that the undertray has some good effects on the feel of the car at high speed. The other good news is it has been tested at high speed and there were no problems what-so-ever with it coming loose. It is held on in the front with 5 dzus fasteners, in the rear with the two tie bar bolts and then there are 2 zipties in the center.

Also, about the rear diffuser. That's what I worked on last night

[antilag_200]

Congratulations David on your accomplishment. I am in great anticipation for your aero products to be released.

[David Buschur]

First picture. This is the rear tray as seen from the back of the car. You can see it is just flat and straight. Looks like a "line" in the picture. I put the tray under the cover so no air can get trapped in the bumper cover, if it makes it there.



2nd picture. This is to show the break I put in the tray in the upper area near the rear sway bar. I didn't know if it would work to divert the air back under the undertray or not. Let me tell you, IT FREAKING WORKS!!! I drove here in light rain today and that angle was nicely streaked with water when I got to the shop.



3rd picture. Side view of the completed/installed rear tray. I have mine put on around the edges with 3/16" diameter aluminum rivets. There is really no reason to take the rear tray on and off, so rivets worked perfectly. Probably will be what I ship the rear kits with. You will need to buy a rivet gun capable of installing a 3/16" rivet or you can use a screw or something but that will be up to you. You will also notice the DEI heat shielding that is stuck onto the undertray to keep the exhaust from burning it.



4th picture. This is just a shot of how the tray uses the rear two bolts to hold it up and secure and the cut out around the hanger.

[David Buschur]

5th picture. Here's the completed front tray. Everything can be seen in this single picture. The tray attaches on my car with Dzus's. I will not ship/sell the kits like this. Too much added expense and I am not sure how many guys can do the intall. I will ship the kits with SS screws. I am not going to pre-drill the front where it attaches to the lip. It will be too hard to line up. As you can see the tray fits on top of the lip so no air can get in. You will simply drill a small hole through the lip, into the tray and put a screw in it. In the rear of the tray you can see the heads of the two tie bar bolts that hold up the rear. This paricular tray has the wickers installed in front of the tires. I am still on the fence as to the results of the wickers, so I will not be doing this on the trays. When I find out whether what I am seeing is good or bad I can supply these later. They install with a 3/16" diameter aluminum rivet too. Something you don't see is the DEI heat shield that is stuck on the tray on the top side to protect it from the downpipe heat.



Side notes. IF you are NOT running the lip like I am on the front I am guessing that the front undertray is going to be pushed hard against most downpipes. I can't gaurantee that the DEI shield is going to protect the undertray if it is pushed hard against the downpipe. In my case I have quite a bit of room and it isn't an issue.

On the rear tray. IF you are running someone else's exhaust or any style other than what is pictured here then the tray will have to be cut to fit around the muffler. I am not sure how that is going to work out. I will attempt to get one on a different style car when I can.

[David Buschur]

Yes, I am going to make a rear tray for the US EVO8-9 bumpers, eventually.

Good news for now is I just finished up the front undertray for the EVO8 with the stock lip on it. We pulled Trent's car in here and finished it. So, now I can supply the undertray for the EVO8 with the Do luck STYLE lip I have, stock EVO8 lip and the rear undertray for the JDM EVO9 bumper.

Here is a picture of the tray on Trent's car with the stock lip. For those of you that have had your stock undertray on and off you will notice that on the stock tray it fits UNDER the little tabs that are on the stock front lip. I took a pair of snips and cut off ALL of Trent's little tabs. Then I slid the undertray all the way into the stock lip. You can see in the picture we just used 5 #12 SS screws to secure it. To be honest, with the rigidity of this tray and the two rear tie bar bolts holding it I think you could slide it into the lip and not do anything. It's not worth the risk to find out I am wrong though. Trent's car does have our Race FMIC on it and header GT35R kit, you can see how well it all fits under the FMIC. The center has two zip ties going around the stock center member to hold it up. The ends are zip tied to the inner fender wells just like we did on the other two cars. Fitment is even better with the stock lip as it fits up to the inner fenderwell pieces better.



Here is what I am talking about for the screws we used to secure it in the front.



Let the ordering begin

[David Buschur]

I did some other work on my RS. The idea was to block off the huge amount of air that is pushed into the two holes on the far left and right side of the front fascia. The passenger side is used for the oil cooler, so this isn't going to be for everyone. There are other ways to get air to the oil cooler but that's for another discussion. These flat plates we made from carbon fiber to block those holes off could have new holes put in them to be used for brake cooling or other things.

Anyway, here's a picture of my RS with the holes blocked off. I am considering making these as a bolt in piece. My car I put them in permantently with fiberglass but that isn't feasible for most guys. I'd like to have them made to just use a few small clean allen head bolts to hold them in.

Check it out and give me some opinions on the look and if you'd be interested. I have to do a run of 30 lefts and 30 rights in order to have them made. Not a big deal if we can sell them. Also, as of right now I have absolutely NO idea what the cost would be.

[Danimal]

Ok, thats it. I give in.

I'm calling work to ask for more overtime now.

[antilag_200]

thats perfect david I love it.