818 Project Updates From Dave

[Drew2.0]

"rear end up in the air" tends to be a trait of mid engine platforms... I personally like it, its a feminine quality if you know what I mean

[Dave Smith]

Concept 4 (posted by Dave Hodgkins) has a fairly low and wide rear. Keep in mind that these designs (at least the first 4 that we are unveiling.. the 5th is probably not going to make the SEMA deadline) these designs pretty much all lend themselves to hardtop, soft top, and in two cases a good targa design. Sticking to a simple roadster launch with elemental soft top is a likely start point, but the end game is still to market some very distinct models using the shared platform. The low drag/low frontal area/coupe requirement of a hyper mpg car is as important as a track car and a rock-star roadster... also the ford di stuff is very exciting on the eco-side and I have a DIRECT line to some unbelievable R&D at Ford with this eco-boost engine line.

[Dave Smith]

I also want to remind you guys that as many of you are focusing on the car, I am almost more fixated on the proocess of the development. I think that once the initail 818 is launched, be it an affordable roadster/soft top at first (likely), or a track car etc, the truth is that the same body development process that was so challenging because I gave the community such open parameters, can be narrowly focused on a low CofD car body. Take into consideration that Solidworks and their latest versions/add-ons can do human scaling and ergos as well as flowanalysis and you might see why Im so excited. Rapid model development even if these initial models dont hit every category Ive wanted.

[Justen]

I think they both look great! I like the roadster better but I think I would have to go with the Coupe for practicality living in RI where the weather changes 5 times a day.
Either way, Great Job on the designs!

[crackedcornish]

Concept 4 (posted by Dave Hodgkins) has a fairly low and wide rear. Keep in mind that these designs (at least the first 4 that we are unveiling.. the 5th is probably not going to make the SEMA deadline) these designs pretty much all lend themselves to hardtop, soft top, and in two cases a good targa design. Sticking to a simple roadster launch with elemental soft top is a likely start point, but the end game is still to market some very distinct models using the shared platform. The low drag/low frontal area/coupe requirement of a hyper mpg car is as important as a track car and a rock-star roadster... also the ford di stuff is very exciting on the eco-side and I have a DIRECT line to some unbelievable R&D at Ford with this eco-boost engine line.

I suppose it wouldn't look to high if you could delete the headrest fairings. sorry just not a fan of them, maybe make optional engine covers so builders can pick and choose (besides a smooth rear cowl would make adding/sealing a top easier)

Dave, would you happen to know how much clearance there would be between the top mounted intercooler and the body on say, the first place design yet?

As most people who were talking about the spec racer were saying that it probably should run a normally aspirated engine, any chance the track body will be redesigned around one, so it can have a minimum of body work and be a much sleeker body visually

[BipDBo]

This is very exciting. Every thing I've seen so far looks great. I also enjoy looking through the design submissions. There's a lot of good stuff there. Even when the sketch work isn't very good, you can tell what the artist had in mind.

Dave, from the beginning of this contest, I had in mind that what you were looking for was an open roadster with probably no doors and no windshield. You said, something like the Aerial Atom, but with a bit more body so as not to be terrifying to drive on the highway. It wasn't until much later during the competition that we got an idea of the verastility that was intended. I see some beautiful roadsters that would make great daily drivers, but I haven't seen anything like the Aerial Atom or the Lotus 211 so far. Is there, hiding away from cameras somewhere, such a lightweight track monster?

[Someday I Suppose]

Dave, wondering if you could comment some on the color plan. I guess I have been wondering from a supply standpoint how far out you will build and hold bodies in inventory.

I guess what I am getting at I am wondering if the body lay-up process is short enough will you be able to manufacture bodies to order which would allow you to offer a pretty broad range of colors / body styles without having to have 1000 bodies sitting in the racks.

-Scott

[Dave Smith]

Color plan is up in the air right now. As far as intercooler sapce, there is alot of considerations for the running gear and fitment of variables as this, especially in track form for downforce, cooling ducts etc. I also think the open chassis design (atom) is not dead, but the early decisions were, based on some design submissions, that we couldnt focus enough market interest in that configuration. Still we can make cahnges, but the next nodes will follow hard and fast with production decisons and timelines coming after body selection and at least initial model green light.

[olpro]

They look great, I'm surprised to see them at all though. Thought they were to be 1/4 scale only to start with. This new supplier is kind of a miracle worker, I'm in awe.

Kach, take another look at that photo. They ARE 1/4 scales, on a table, cleverly lined up with the background.
Very convincing.

[Steve91T]

Kach, take another look at that photo. They ARE 1/4 scales, on a table, cleverly lined up with the background.
Very convincing.

That is hilarious....I thought they were full size also.

[mentatbashar]

Spy shot of concept 1 roadster and concept 2 coupe scale models.

Jim - Dave said it was ok. Sorry!

Please please please tell me those wheels will be a part of the kit package!!

[16g-95gsx]

That is hilarious....I thought they were full size also.

Add me to the list of folks who thought they were looking at full scale models on a shop floor.

[kach22i]

This one fooled me too, I'm such a sap sometimes.

http://thefactoryfiveforum.com/album...achmentid=4392

[mekeys]

Right in the comment no. 485, of the picture showing the two rear ends.It says scale models..

Mel

[Inthenameofweez]

DAVE THIS IS AWESOME.

I also agree with a lighter and neutral gray/silver to show the body lines in the same hue. Also, the black accents will still be visible.

I'm itching with excitement to meet you and these beautiful creations in November. How are we supposed to choose when all of the designs are so blindingly stunning?

[shinn497]

That is hilarious....I thought they were full size also.

I was wondering when people would figure that out. You can tell becahse some of the lines are softer. Also "vertical sivler things" on the coupe are exhausts. exhausts.

[mentatbashar]

I'm in if those wheels on either model come standard in the kit!!

[AVIONX]

Kach, take another look at that photo. They ARE 1/4 scales, on a table, cleverly lined up with the background.
Very convincing.

Dude!!! They totally got me too. And I've looked at them like 200 times Very CLever

[Draco-REX]

I was wondering when people would figure that out. You can tell becahse some of the lines are softer. Also "vertical sivler things" on the coupe are exhausts. exhausts.

Yup. They match the brake ducts in the front to create a continuity in the design.

[Silvertop]

Dude!!! They totally got me too. And I've looked at them like 200 times Very CLever

Snookered me too. I'm guessing that probably got most of us. Nice catch, Olpro. I guess that shows why you really are the "ol' pro".

[D2W]

Yup. They match the brake ducts in the front to create a continuity in the design.

One aspect of the car that I do not like at all. The rest rocks.

[BipDBo]

Color plan is up in the air right now. As far as intercooler sapce, there is alot of considerations for the running gear and fitment of variables as this, especially in track form for downforce, cooling ducts etc. I also think the open chassis design (atom) is not dead, but the early decisions were, based on some design submissions, that we couldnt focus enough market interest in that configuration. Still we can make cahnges, but the next nodes will follow hard and fast with production decisons and timelines coming after body selection and at least initial model green light.

Dave, here are some thoughts for your consideration. You've probably already considered all of these issues, but in the spirit of open source design, here's my two cents:

I am hoping that you are planning to keep the existing WRX top mounted intercooler position. Moving it would increase building cost, time and weight. Also, the top mount minimizes the duct length and longer duct creates more turbo lag. The downside to the top mount would be heat soak. To help out with this, what do you think about having an opening or vent near the top of the "transom" to allow convection to bring hot air out of the engine bay? Even better, leave the majority of the rear of the car open so that the guy you just passed can admire your boxer.

Getting air into the intercooler is a bit more difficult on the 818 than it is on the WRX. Many designs featured intakes right in front of the rear wheel, but I'm a little partial to an intake on the B-pillar, like the Miura. Here, it is higher off the ground so as to take in less dirt and rain water.

As for downforce, it's easy to get it on the rear wheel with the addition of a spoiler. Driving the front wheels down is the tricky part, and having a low, sloped hood is crucial. Having the radiator discharge out of the top of the hood is also important. When I did my design, air flow directed nearly every decision. I designed it exactly per the template, except for one change I made to allow for a lower hood. I tilted the radiator forward a bit. I assumed that this could be done considering that the radiator on the GTM is sloped very far forward. I made my front bumper tall enough to allow for a European licence plate.

[Steve91T]

Dave, here are some thoughts for your consideration. You've probably already considered all of these issues, but in the spirit of open source design, here's my two cents:

I am hoping that you are planning to keep the existing WRX top mounted intercooler position. Moving it would increase building cost, time and weight. Also, the top mount minimizes the duct length and longer duct creates more turbo lag. The downside to the top mount would be heat soak. To help out with this, what do you think about having an opening or vent near the top of the "transom" to allow convection to bring hot air out of the engine bay? Even better, leave the majority of the rear of the car open so that the guy you just passed can admire your boxer.

Getting air into the intercooler is a bit more difficult on the 818 than it is on the WRX. Many designs featured intakes right in front of the rear wheel, but I'm a little partial to an intake on the B-pillar, like the Miura. Here, it is higher off the ground so as to take in less dirt and rain water.

As for downforce, it's easy to get it on the rear wheel with the addition of a spoiler. Driving the front wheels down is the tricky part, and having a low, sloped hood is crucial. Having the radiator discharge out of the top of the hood is also important. When I did my design, air flow directed nearly every decision. I designed it exactly per the template, except for one change I made to allow for a lower hood. I tilted the radiator forward a bit. I assumed that this could be done considering that the radiator on the GTM is sloped very far forward. I made my front bumper tall enough to allow for a European licence plate.

My experience with intercooler pipe length is that it doesn't really matter. Unless you're adding 6 feet of length, you won't notice the lag, because it really won't add anything at all. Look at the rear mount turbo kits out there.

What really matters, and what you WILL notice is heat soak. Mounting the IC where it will get plenty of cool air won't add much at all to the cost.

The problem with getting air from the top of the car is it's a low pressure area. Not much air to be had. From the bottom or the sides is where it'll be most effective.

Sitting on top of a hot engine is not a good place at all for an IC, no matter how much air you try to bring in from the top.

Steve

[BipDBo]

My experience with intercooler pipe length is that it doesn't really matter. Unless you're adding 6 feet of length, you won't notice the lag, because it really won't add anything at all. Look at the rear mount turbo kits out there.

What really matters, and what you WILL notice is heat soak. Mounting the IC where it will get plenty of cool air won't add much at all to the cost.

The problem with getting air from the top of the car is it's a low pressure area. Not much air to be had. From the bottom or the sides is where it'll be most effective.

Sitting on top of a hot engine is not a good place at all for an IC, no matter how much air you try to bring in from the top.

Steve

It seemed to me from what Dave said that they were considering moving it to the front. I believe that would cause significant turbo lag. Since this car is so light, turbo lag will be more of an issue than normal. The car might accelerate faster than the turbo. I don't see why heat soak would be any more of a problem with the 818 as it is with the WRX. The problem should be lessened in the 818 because there is no fire wall behind the engine, so there is a larger volume of air in the engine cavity and more opportunity to vent it out.

[305mouse]

My experience with intercooler pipe length is that it doesn't really matter. Unless you're adding 6 feet of length, you won't notice the lag, because it really won't add anything at all. Look at the rear mount turbo kits out there.

On a V8 with a rear mount turbo you won't notice the lag. On a 2.0 liter 4 banger, you bet you'll notice the lag. Also, a FMIC with the oem td04 turbo will be a disaster. A larger turbo, like an 18g or so will compliment a FMIC quite well. I think it goes back to the individual who's building it and what they want out of it.

I'm going to play around with using a twin scroll in a different location since I think we'll have the room to move it. Think the newer Legacy GT location.

[Steve91T]

Don't forget that that big V8 with a rear turbo also requires a much larger turbo to feed it.

I'm going to use the MR2 turbo as an example again, because I'm very familiar with them, and they have a similar situation. Heat soak has always been a huge issue with the MR2. No matter what you do with the IC, and how you duct it, getting the proper air flow is a problem. Space is also an issue. Because there isn't enough room for a large front mount, a small, but thick IC is used, which isn't as efficient. Serious MR2 guys use Powerstroke IC that they mount in the trunk. This adds pipe length, but the lack of heat soak makes up for it.

Also, I never said that you wouldn't notice the lag if a front engine 4cyl car had a rear mounted turbo. I used the rear mount turbo as an example.

Getting enough air to the IC on the 818 is going to be an challenge.

Stee

[kach22i]

There is always more than one way to solve a problem.

http://www.velocetoday.com/archives/263
t33-1.jpg

[PhyrraM]

Reverse flow. Don't get stuck on forcing air through the top of the intercooler.

High pressure engine bay will only require a simple vent over the intercooler for a very suprising amount of air across it.

[kach22i]

Reverse flow. Don't get stuck on forcing air through the top of the intercooler.

High pressure engine bay will only require a simple vent over the intercooler for a very suprising amount of air across it.

How would you create a "high pressure engine bay"?

[BipDBo]

How would you create a "high pressure engine bay"?

Engine bays tend to be high pressure by nature, because the large front opening receives ram air at high speed, and the air has to find its way out. For an engine bay up front, the air usually exits under the car. Unfortunately, this all usually creates uplift in the front wheels. Getting air into a rear engine bay isn't as easy.

[kach22i]

Getting air into a rear engine bay isn't as easy.

That's exactly what I was thinking.

[crackedcornish]

There is always more than one way to solve a problem.

http://www.velocetoday.com/archives/263
t33-1.jpg

I get this message at the link:

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[kach22i]

I get this message at the link:

To continue reading, you must be a VeloceToday Premium Subscriber.

Sorry about that, the link should still work if the image does not show up for some reason. I'll try attaching the image in lieu of hot-linking.

I was looking for a Ferio with an aftermarket periscope snorkel intake, but this old Alfa is way cooler, which is why I posted it.

Alfa Romeo T33
t33-1.jpg

[Twinspool]

NACA vent and ducting, fan, IC airflow problems all done. steal the water sprayer from an STI if you're paranoid.

And this talk about IC piping increasing lag? Even with 60mm piping the volume added is negligible compared to what the engine is gulping at 6000rpm. If'n one was motivated to look instead of speculating, those parameters can all be calculated. Hmm.

[Steve91T]

I think the best option for air flow is taking air from under the car, ducting it upwards, through the IC, and out the top of the engine bay. This obviously wouldn't work if the IC is sitting on top of the engine.

Steve

[PhyrraM]

In the OEM location the I/C is above the bellhousing area of the transmission.

Rotating tires create high pressure that will bleed into the engine area. Most of the designs have side vents that will provide air to the engine area. And most car undersides are also high pressure areas.

Most rear decks will be a low pressure area that can be used to pull air out of the engine area.

Almost every mid-engined car has accomodations to relieve engine bay pressure. Fiero, MR2, X1/9 all have vented engine covers. All of those have front radiators and still build rear engine bay pressure. Most of the exotics have the same, or a vented rear panel. Put that naturally occuring flow to work.

I'm not saying it will be, or has to be, that way - but with careful attention during the design phase, I'm pretty certain it would be easier (and more subtle) to design small details that accentuate a naturally occuring flow than to design something that has to overcome a reverse flow.

[kach22i]

I'm pretty certain it would be easier (and more subtle) to design small details that accentuate a naturally occuring flow than to design something that has to overcome a reverse flow.

Aren't you saying air flow comes out of the top?

If so, then are you proposing or promoting going with the flow, and in effect reversing the flow when compared to the original front engined model?

Will the intercooler work with reverse air flow?

[kach22i]

"rear end up in the air" tends to be a trait of mid engine platforms... I personally like it, its a feminine quality if you know what I mean

Every time I read this I think of the Porsche Boxster and think it's not true.

http://www.porschetuningmag.com/tech...oxster-side-2/
TechArt-Porsche-Boxster-Side-2.jpg


Please provide an example of what you mean other than the contest entries.

[Admiral Doom]

Side scoops, b-pillar scoops, and the fact that the air rushing over the vent on top creates a low-pressure zone combine to provide ample airflow

[Ks2]

since the fuel tank isnt under the seat perhaps there is enough room for a large intercooler mounted underneath the seats, air is brought in from underneath the car and vented out the back or top (or wherever) much the same tube routing as in the standard front mount intercoolers for the 02-07 though i dont think we could get that lucky (unless that has been the plan all along)