Vented hood + solid underbody

[Fazed Out]

Originally Posted by Raptor13x

Aerodynamics is the last thing a typical auto manufacturer is thinking about while designing a car.

True to an extent, but for the MKII they spent a very substantial amount of time working on Aero. Of course, it was a balance between mass production/cost/aerodynamics.

There's tons of pictures of rejected designs and windtunnel/driving tests for the MKII. About twice the planning of the MKI and MKIII.

[Raptor13x]

^ And yet there's tons they didn't get right on the mkii. It had very poor radiator airflow management, the notchback design creates turbulence and poor airflow, the underbody is not incredibly aerodynamic, especially from the engine back, and the wing is nearly useless. They did do a decent job overall of keeping a low coefficient of drag, but the coefficient of lift was almost completely ignored, and it shows in the end result- the car isn't incredibly stable at high speed.

[metheores]

I've never been in a car that makes me feel "safe" or stable at high speed....

[Raptor13x]

I have.

[Gairloch]

So have I. It's incredible when you can feel the car squatting down into the pavement the harder you push it.

chicago, what exactly do you want to accomplish?

This is a good example of an MR2 that has had some development in terms of aero. February 2006 MR2 Showcase

[metheores]

I wanna drive one of these cars

[chicagoisonfire]

Originally Posted by Gairloch

So have I. It's incredible when you can feel the car squatting down into the pavement the harder you push it.

chicago, what exactly do you want to accomplish?

This is a good example of an MR2 that has had some development in terms of aero. February 2006 MR2 Showcase

I'm looking for a little more front end stability but something i dont have to worry about driving around on the street. I was thinking of getting a splitter as well but i have a hard enough time as it is keeping my front bumper from scraping things (pulling out of parking lots with steep exits are the worst >_<)

I have pretty sticky summer tires on right now (205/40 in front 225/45 on the rear) and i'm having understeer issues and my front end floats a little at 100+ (not a dangerous float but the car doesnt feel quite solid, almost like air is getting trapped under the front bumper)

any suggestions?

[Mark_Dorman]

Originally Posted by metheores

I wanna drive one of these cars

Drive a BMW...most of the ones I've been in squat and hug the road at high speeds and feel incredibly stable.

As for the design flaws of the mr2 in terms of aerodynamics, I'm with Raptor13x. Auto makers don't seem too concerned with this when designing cars. Also, I feel like anyone who's taken physics should be able to understand airflow and how it affects stability. Most factory cars can be improved upon seeing as most weren't and aren't as painstakenly designed as ferrari's and other high end cars.

[Raptor13x]

^ The most stable car I've ever driven at high speed was a BMW 3-series. It felt rock solid at 135.

[chicagoisonfire]

Originally Posted by Raptor13x

^ The most stable car I've ever driven at high speed was a BMW 3-series. It felt rock solid at 135.

Weird, cause my 2 feels better than my dad's 3series wagon ('01 325xi) around 120

although a guy I know has an E36 M3 thats been all raced out and it feels like it holds 2+G when going through corners (I know it doesn't but it holds like glue)

[Bak@EMSPowered]

You guys would be extremely surprised how well Mercedes and BMW's are set up as far as underbody aerodynamics. Both my 500sl and 325Cic have all sorts of cool things going on underneath the car. It's amazing how much thought and time they put into it compared to the equivalent American made cars. And wow, let me tell you... the 500sl sticks to the ground at 120+ like no other. Dam, I need to hurry up and change the oil pan on that thing.

[Mark_Dorman]

^ I know what you mean. My 328is and M3 stuck to the road all the way up to 155. I actually felt like the car was more stable the faster it went. I feel like the Autobahn is part of the reason for such good engineering...

[Raptor13x]

^ You realize that "autobahn" is simply the German word for "highway", right? And we thus have thousands of autobahns over here?

[Mark_Dorman]

^ Yes but I was making a generic reference to the euro highways that don't have speed limits (and yes I know some of them do).

[OldSkool]

Originally Posted by Raptor13x

Aerodynamics is the last thing a typical auto manufacturer is thinking about while designing a car. You're giving those engineers a little too much credit. Much more prominent concerns for them are visual appearance, manufacturing ease, marketability, cost, etc. All too often, aerodynamics are at best improved by accident.

Just look at cars like the Audi TT- they designed the car with no thought whatsoever to the aerodynamic properties of the rear end, then they found that their cars were spinning off the road and crashing as drivers exceeded 100mph because the massive amount of lift at the back end of the car nearly pulled the rear wheels off the ground. They had to go back to the drawing board and add a spoiler to the back of the car, which was little more than a patch on a fundamental design flaw.

If automakers cared- I mean really cared about aerodynamics, cars on the road today would be getting 50+% better fuel economy on the highway.

I'll buy that line of reasoning, Raptor. I know it applies to engines as well. Main driving forces there are emissions, manufacturing ease, marketability, cost and "good enough" economy to keep
big bro off their backs. My next rebuild will hopefully get major HP and mileage increases, and pass the sniffer.

[Levi]

Originally Posted by Raptor13x

^ You realize that "autobahn" is simply the German word for "highway", right? And we thus have thousands of autobahns over here?

We have to go 65 on our "autobahns", in Germany some don't have speed limits and cars routinely go 130+. I doubt the MR2 while being produced was ever driven going 130, or else they would of realized something was wrong.

On most MR cars, the front end will be very light at high speeds, its simply the fact that there is no weight in the front to provide stability. Thus, we need to add downforce in the front to increase the stability.

Border did windtunnel test their aero products (hood, cowl, mirrors, roof spoiler) when they built the Border MR2

[HarrisRacing]

My findings:

My first outing since cutting hood will be this weekend. I will report back with some data. I was having problems getting the nose down on our hardest turn at the roadcourse I usually run at (turn 1 is 110 mph and I have trouble getting front bite on 225 hoosiers). These cars get light in the front and to alleviate that I cut the heck out of my hood and ran airflow over the front. I also just ordered Greddy lip (not here yet) and will be blocking off the bottom of the car w/ a large splitter. It does not seem right to route air UNDER the car the way they did. They figured out how to put a spare in the car is what I'm figuring.

Here is what I did to my hood - it is a FULL RACE CAR.

I am assuming this is going to make a BIG difference on front end handling at high speed. Also look at all the GTC cars - they do the same thing by moving radiator ducting over or out of car.

Patrick

[HarrisRacing]

put more pictures on streetfire

100_2212.JPG- Album

Patrick

[bretleg]

i really hate it over 100 the front end seems to get really light as stated above. my car isnt a daily driver so i was wondering what kind of front splitters are out there.

[Bak@EMSPowered]

One of the major problems on the majority of MR2's that leads to instability in the front end at higher speeds is lack of any sort of air dam forward of the front tires. Get youself a set of these, and I'm sure that most of your front end instability will be fixed: Speed Flaps Toyota MR2 Front Aerodynamic Speedflaps [] - $64.99 : EMSPowered, High Quality, Great Service, Low Prices