My NA becomes a track car (Build thread)

[NuWing]

Originally Posted by Wonko_The_Sane

Is this car still street legal?

Why would it not be? As long as it has front windshield and blinkers, then it is pretty much street legal unless you live in an emissions tested area.

[tanakapz]

Originally Posted by NuWing

Why would it not be? As long as it has front windshield and blinkers, then it is pretty much street legal unless you live in an emissions tested area.

cali means nothing about this car is legal anymore. my msm with just the FM intake kit isn't even street legal : /

[ThePass]

Well I drive it to and from every event

Registration is current, I have smog papers in the center console saying it passed with the turbo kit on it, and it has lights. Sure there's a lot of little things that a cop could nit pick about... but they haven't

[hnguyen037]

Well I shouldn't have said it would reduce the downforce created by the wing as that would depend on how close the spoiler is to the wing, but it will decrease the efficiency of the underbody aero and the actual spoiler itself. The underbody is very sensitive to base pressure, which is pressure immediately behind the car. A car is an example of a "bluff body," a body with a chopped off, blunt rear end behind which a wake exists. The wake is a low energy and turbulent region, and adding spoiler will actually help draw more air out from the underbody. The adverse effect of this is that more drag is created, thereby lowering the efficiency (L/D)

[NuWing]

Originally Posted by tanakapz

cali means nothing about this car is legal anymore. my msm with just the FM intake kit isn't even street legal : /

Ah yeah, I forgot they have that CARB stuff there, never quite understood. It has to be labeled as CARB to be "street legal?"

[asianrice02]

Originally Posted by ThePass

Well I drive it to and from every event

Registration is current, I have smog papers in the center console saying it passed with the turbo kit on it, and it has lights. Sure there's a lot of little things that a cop could nit pick about... but they haven't

that is cool all you need to do is pass tail pipe.

[ThePass]

Originally Posted by hnguyen037

Well I shouldn't have said it would reduce the downforce created by the wing as that would depend on how close the spoiler is to the wing, but it will decrease the efficiency of the underbody aero and the actual spoiler itself. The underbody is very sensitive to base pressure, which is pressure immediately behind the car. A car is an example of a "bluff body," a body with a chopped off, blunt rear end behind which a wake exists. The wake is a low energy and turbulent region, and adding spoiler will actually help draw more air out from the underbody. The adverse effect of this is that more drag is created, thereby lowering the efficiency (L/D)

So then what about the opposite then - a trunk that slopes downwards more as it goes back? I have a trunk sitting in my closet that is already shaped into something very similar to this for a mold, just need to throw some carbon fiber over it and make a lightweight skin. It was a project from years ago that I sidelined when I decided to go the spoiler direction:

[320icar]

Originally Posted by NuWing

Why would it not be? As long as it has front windshield and blinkers, then it is pretty much street legal unless you live in an emissions tested area.

Lol!!! Oh man I'm jealous of where you live. Stock civics get handed VI's all the time where I am.

[TurboTyla]

i want the garage one hundred trunk so bad.

[ThePass]

Just dug this up from the back corner of the garage to snap a pic. I started this like 4 or 5 years ago. Shape is 90% done, and I have carbon fiber as well as carbon kevlar sitting around, plus a vacuum pump that I've never used yet... I've never made a composite piece out of anything other than fiber glass, and have been itching to try carbon fiber.



-Ryan

[Wonko_The_Sane]

I say paint that thing up in some gelcoat and pull a mold off of it.

Surely there is others here with a NA who would have some interest in one. You've already done the hardest part. Making a mold of it and nocking a few out shouldn't be to hard.

[NuWing]

Originally Posted by 320icar

Lol!!! Oh man I'm jealous of where you live. Stock civics get handed VI's all the time where I am.

Most Southern states are rather lenient to the point that I forget some states aren't. Big cities in La and Tx have emissions, but it isn't hard to get around it. Just throw the tech a few bucks or find a buddy who will just let you slide. You will get a ticket for being obnoxiously loud or if you have lights not working, but that is about it. Heck, my bro in Georgia doesn't have inspections even.

[TurboTyla]

after you make a carbon piece or a mold would you be willing to sell the trunk lid to me ?

[nabdab]

Originally Posted by tanakapz

cali means nothing about this car is legal anymore. my msm with just the FM intake kit isn't even street legal : /

Yup, can't do anything to your car in California without any state official trying to tax you.

[maxc]

Originally Posted by ThePass

Just dug this up from the back corner of the garage to snap a pic. I started this like 4 or 5 years ago. Shape is 90% done, and I have carbon fiber as well as carbon kevlar sitting around, plus a vacuum pump that I've never used yet... I've never made a composite piece out of anything other than fiber glass, and have been itching to try carbon fiber.


-Ryan

Use glass instead of carbon fiber. Carbon fiber is not worth the extra money and glass is 95% as strong in most cases. Also defiantly vacuum bag to maximize the weight savings. Here is one of the better mold releases I have used
http://uscomposites.com/moldrelease.html

[hnguyen037]

Originally Posted by ThePass

So then what about the opposite then - a trunk that slopes downwards more as it goes back? I have a trunk sitting in my closet that is already shaped into something very similar to this for a mold, just need to throw some carbon fiber over it and make a lightweight skin. It was a project from years ago that I sidelined when I decided to go the spoiler direction:

my initial response is to say this might create more lift, but I am going to have a deeper look at this to give you a better answer.

[ThePass]

Much appreciated! I see where the idea goes - trying to taper the rear of the car more, but my understanding is that unless you can really get the rear down to a really gradual smooth taper (as in the rear of a teardrop, joining at no more than a 15* angle), then you're better off with a sharp edge that terminates abruptly - like a spoiler at 0-5* aoa or something...
Not going to put any effort into that trunk lid unless its the right direction to go, but thought I'd throw that option out there.

-Ryan

[1vicissitude]

I would personally think something like this, with the wing as far back as possible, would be most beneficial. In fact, I'd love to see carbonmiata come up with something like this. I would think squaring up the rear, giving it a straight edge/drop, and lengthening the rear deck would all be beneficial especially with all the under aero work you have done. Only thing that would improve it further would be a fastback of sorts.





My thoughts on the sloped trunk are if high pressure air is actually following the slope of the trunk and falling off the edge, it would now be guided directly into the low pressure zone, which could in theory reduce the pressure drag.

However, using a standard hardtop the high pressure air flow on the trunk lid isn't being directly fed straight off the trunk edge, at least from various tuft tests I have seen. I would think a trunk like that would be best with a fastback, and possibly well placed vortex generators.

Although since you have the trunk, and seeing as we don't have any real analysis of the car, why not just install it and bust out the yarn? Put some on the rear edge as well to see where it waves too. If the yarn points backwards at a downward slope while moving, I would infer that as the trunk is probably working.

Now while it could be beneficial, I think this is starting to get into the realm of stuff that is very hard for a hobbiest to test the validity of the modification. That is why I prefer what lightspeed built over the sloped trunk, its easier and less complex to see why that design has benefits.

[ThePass]

Lightspeed's stuff in that pic is what I am leaning towards. In fact, If I were to extend my wing's endplates down to the car, I think they'd hit the sides of the car just about the same as where the sides of his spoiler do in that pic, or maybe half an inch inwards...

I could throw together a second version of endplates that extend lower and double as sides to the spoiler... that might work well..

[Blackbird]

It's almost funny to see the replies in your thread, I'm constantly having deja vus of things we were already talking about months ago, like that longer square tail...

Moti

[ThePass]

So true. We come up with ideas faster than I can make them! Haha. The uprights took almost 3 weeks of my free time between work and everything else! I'm going to try to spend some time today remaking the flat underbody. After that I need to get the trunk mounted - the gutted steel one for now - then do the exhaust revisions - and then work on the spoiler.

Then the front aero begins...

It never ends!

But I was curious about the possible merits of the downwards sloping trunk - I think we discussed that very shortly a while back but didn't come to any decision about it.

-Ryan

[ThePass]

Didn't feel like beginning to tackle the new version of the flat underbody today, so I worked on the exhaust.

Removed the rear section and started measuring, etc.:



Here's how much I cut off the old setup. I'm re-using the short section with the flange and the hanger on it:



And here's what the new setup will look like. It's just tac welded in place right now. The muffler itself still just slips on with that slip clamp, so the muffler will be for the street, and then for the track I can just undo the 14mm nut on the clamp, slip the muffler off, and slip on a straight pipe
It looks like the muffler sticks out a lot, but the diffuser actually sticks out a little bit beyond that even, so it will look more like it belongs with the diffuser mounted.

[Blackbird]

Is there enough clearance between the muffler and the bodywork?
From where I'm sitting it looks a bit tight.

Moti

[rory_a]

Muffler does look super tight at the top. And doesn't look like you have any thing back there to support it - that planned or just leave it hanging? Maybe a hanger on the permanent section right at your coupler?

Also, what tow hook/strap is that?

[ThePass]

Gap from muffler to body is 1/2", which is tight but it sits pretty close to the diffuser too, and this is only the street muffler. The 3" pipe for track use would of course have tons of room.

Definitely will do a hanger at the rear, just not doing that until I'm satisfied with the muffler placement. I am on the fence about how it looks pointing straight back like that, so I'm just leaving it tac welded in that position while I mull it over for a few days. I am considering angling it slightly to the left.

The tow strap is the shorty fixed length from I/O Port Racing: http://www.ioportracing.com/Merchant...egory_Code=TOW

[Skinnyroadster]

Thats going to look so good, with the aero back on

[1vicissitude]

Definitely cool, have you given any thought to starting to trailer the car? Things going to look like something out of madmax once you get going, can't imagine socal cops not pulling you over everytime they see you. Even with the smog paper work, going bumperless and that cannon sticking out are going to give them a heart attack. Heck, around my parts just driving a lowered car will get you tailed.

[ThePass]

Originally Posted by 1vicissitude

have you given any thought to starting to trailer the car?

Nope

The wing is an attention grabber, that is for sure... and I admit I haven't had that one on the car before, but the majority of my experiences driving this car on the street is that the cops ignore me. I drive like a grandma on the street with it though. But ultimately, most of what they could get me for is fix-it ticket stuff, and I'm pretty used to that with the motorcycles anyways (just got two tickets signed off just the other day for the 1000RR). And as things have been going, I get much more trouble on the motos than in this car.

I'm trying to send out good karma

[ThePass]

Time to put some hours into the car. Happy new year's eve everyone!

Flat Underbody is off the car. Here's a pic in all its post-ACS-win glory. As you can see, the whole length near the exhaust warped, with the worst section being under the cat. The section where I put aluminum because the exhaust got really close there was OK, and I'm sure that would have been even worse if that had been ABS there. Version 2.0 coming soon!



And here's a better pic of where the exhaust is sitting right now. I kinda like it the more I look at it:



Weighed the section of exhaust piping I cut off plus the heat shield that bolts to the underside of the trunk that had still been on the car and is now appropriately removed: 5 lbs saved!

And there will be more weight to be saved in track trim with straight piping to replace the muffler

-Ryan

[ThunderFox]

Originally Posted by tanakapz

cali means nothing about this car is legal anymore. my msm with just the FM intake kit isn't even street legal : /

Welcome to Portugal, where even a sticker is illegal!