Plastic Fantastic 2

Now you're starting to see how I build. Spend time on the foundation, then burn through to get it on the street. Once that's done, come back and fill in the blanks

onward
had to buy new ends because I'm sure I tossed the vacuum stuff years ago
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install bumpers
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grind clean
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take springs off
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the controller needed to go on an inner fender that no longer exists (and the alternator is now on the opposite side of the motor
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not sure what their plan was on wiring, but I shortened some, lengthened others
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hiding wiring
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lights are done, outside of a bit of trial and error on shaft length, they seem to work fine.. at speed? it'll be a day or 50 before I can test
speaking of testing
Last year, I couldn't run at Portland Raceway because my car is a bit louder then the 105 db that the track allows.edited Just a bit - 2 db.edited This is the fix
should get me under 100 db at full song - with no attendant loss of performance... we will see

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likely the configuration
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10" overall, according to my calculations, I only need 8"
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roughly here
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but much playing with these is going to happen between now and Optima in July.edited I may reduce the length of the inserts or simply change them to a different style... I do know that PF3 will have long tube headers that have much shorter primary tubes then lined sidepipes.... worst case is I put a diverter on the tip or make the tips removable so that the exhaust doesn't aim at the measuring device
 
nice, i always credit the people i pilfer ideas from, but there is no profit motive just my own build, i am guessing when you add commercial interests people get very closed mouth about where they get their ideas from.
 
nice, i always credit the people i pilfer ideas from, but there is no profit motive just my own build, i am guessing when you add commercial interests people get very closed mouth about where they get their ideas from.

it's okay, I'll just publish how I did it and add their tips. That said, I ended the thread on CF, so I'm sure that's the end of that...

in other news
and they say converting to 5 speed is hard
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" ended the thread on CF, so I'm sure that's the end of that... "

Well, that is a different crowd over there. I'm not surprised you packed it up.

Looking forward to PF3.

Interested in how your new mufflers work. I tried using a video camera once to compare before and after and it failed miserably. :). Apparently you need to turn off any kind of auto equalization or auto Volume.
 
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Interested in how your new mufflers work. I tried using a video camera once to compare before and after and it failed miserably. :). Apparently you need to turn off any kind of auto equalization or auto Volume.

I bought a db meter - I will quantify with measurements. While they may not be relevant for the space/place (e.g. PIR has a measuring device 50 feet off the ground and 100 feet from the track - and on a corner -I figure that if I get a good measurement where I can control the variables, then I should get usable data... but whether that relates to what their meter will pick up... no idea. One thing to keep firmly in mind, rear exit exhaust will have double the potential nose as sidepipes because both Leguna Seca and PIR measure only one side
 
You probably already thought of this. Just a suggestion, do a before and after with the db meter. That might give you a good idea of the db drop.

One other suggestion, devise a method of slipping some extra baffles or a mini glass pack in the outlet of the side pipe in case you are just over the limit. :). Maybe even a mini cone insert. An easy track fix.

I had a cut-out valve on the spiral turbo muffler that was activated by reaching in the outlet. It leaked too much when closed, so ended up welding them up. :). So much for that.
 
You probably already thought of this. Just a suggestion, do a before and after with the db meter. That might give you a good idea of the db drop.

One other suggestion, devise a method of slipping some extra baffles or a mini glass pack in the outlet of the side pipe in case you are just over the limit. :). Maybe even a mini cone insert. An easy track fix.

I had a cut-out valve on the spiral turbo muffler that was activated by reaching in the outlet. It leaked too much when closed, so ended up welding them up. :). So much for that.

I forgot to mention that there will be a before/after on the same day (so the atmospheric conditions are the same)... I am also thinking about buying a second set of tubes to make the changes simple... the problem with the OBX system is they pre-install their glass packs inside and they don't appear removable without damage.

I dunno about this, but I'm also thinking of sending the noise at a 45 degree angle back under the car.... I like the idea of an adjustable cut-out valve.
 
In today's news, Corvettes work in the snow
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I bet I drove a whole 50 feet without slipping, sliding or running over children
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Luigi, though, doesn't want to take chances
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clever solution to a problem
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they remove the springs from the lights - which means the headlights can flop up and down, but if you jam the slots with bolts... no jiggle, no flop
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and they go up
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I swear I should put the dash on with velcro
rewiring lights
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but it's 3 degrees in my shop.... so I spent time trying to decide what I'm going to do about a stereo (soundbar suggestions are welcome)

I also talked to CIRO today about a rear wing.... he runs a C3 as well, so lots of talking there....edited

dual element? I don't know, I'm a wing virgin so I have no clue
 
It would be great to hear their thoughts on multi-vs single element planforms.
Size can be an issue for some racing associations.

Tuning has both a plus and a minus. Certainly easier to manufacture a smaller wing as a multi-element than an equivalent high lift (downforce) extreme cambered wing. No doubt, both would have endplates to improve efficiency.

I bet they have developed some mounting solutions specific for the C3 - so that would be a plus too.

I see they have done some carbon fiber splitter work too (not C3 - yet?). Might save you from getting all "stickey." Some nice looking canards too.

Keep us posted!

Cheers - Jim
 
This guy has some aero upgrades. His wing is high, and is a ht convert. A typical c3 t top car would probably need the wing a bit higher due to dirty air from roof.

https://www.digitalcorvettes.com/media/blowing-doors-off-944-turbo-and-gt3.44065/

You'll need a dc login.

Aren't most auto-x guys running the wicker bill on the back? Single vs double element really comes down to speed and how much downforce vs drag penalty. You'd need lift drag curves from manufacturer. Or, get a copy of the paper back naca book and play with different profiles. I'll get that reference for you later.
 
If you go to the APR Products web site, they have a lot of detail about different wing configurations. The link below is an example of their discussion of their dual element wing. If you scroll down, there is a link to the CFD data that gives detail about the relationship between downforce and drag for the wing. Each of their wing options has the same basic data for that particular configuration.

https://aprperformance.com/racing-product/gt-1000-dual-element-adjustable-wing/
 
This is pretty old, hence the paperback sells for under 20$.

Theory of Wing Sections: Including a Summary of Airfoil Data
Book by Albert Edward Von Doenhoff and Ira Abbott

The manufacturer data mfain refers to above would be better and account for the angle of attack variation in the wing.

If you played with the height you might be able to use the dirty air off the roof to your advantage. Like the supercar with the dimples in the aero thread.

That 4takr car had anti dive brakes in addition to the aero pieces. But, you've got a modern suspension so that wouldn't help you.

If you look at some of the successful c3 auto x cars, they seem to be running the flap/spoiler/wicker-bill.

Edit. Maybe not, Danny Popp and Detroit Speed don't have the rear flap, but the 48 hour Corvette does. The c2 of Brian Hobaugh has the flap.
 
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I'll relate what Richard Jung (Rick) has told me. Some of it relates to the discussion above.

1) Optima seems to only only a single wing *I'll post the rule at the bottom

2) In Optima, 8" above the deck is it

3) The suggestion, since SCCA doesn't limit the height, is have two sets of uprights (and Rick directly said "buy my tall one, then copy it for the Optima version")

4) good question about attack angle, and whether or not its adjustable. For Autox, you'd want far more downforce because you won't be suffering the consequence of high drag at speed - since the max speeds is 50 mph or so.

5) I can get either a single or dual element, I've sent the rule I've attached below to Rick too - it seems that as long as the cord width is less than 12" that multi-element wings are okay... of course, that does question whether the 12" is total or per wing - e.g. two 12" wings complies or 1 9" plus a second 3"

6) duck bills, they all use the 73 and older rear spoiler - which is both shorter and straighter side to side. Add to that issue, I don't want to drill holes to mount it and the mountain that needs to be climbed to convince me is quite a bit taller then just going with a radar arch style.

7) Isn't the test (I can't remember who, just it was a yellow C3) with the yarn still on here? - the video - I'll look later, but that was interesting in where the yard was going. I'll have to copy that test once this is stuff is installed

8) I've spent a lot of time on the AFR site - that is so helpful

9) he doesn't do splitters, yet. With that said, I'm ordering material to start laying out mine - there's a company in California that will get sticky for you if you send them a pattern; I'll probably go that route. long ago I learned that it is sometimes cheaper to have someone else do it then do it yourself because they get volume discounts that you don't get nor do that have to do it 4 times to get a professional result.... Carbon Fiber is, most especially, that to me

10) I plan on making a cover that fills the gap between the door and the side pipe out of CF - but I still need to find out what its combustion point is (and more importantly, what degree it can tolerate without deforming).

11) he doesn't have a brace, but I will have a design for one when I'm done. Probably I'll make that (at least in drawing form) available on here - especially since the distance from the frame to deck is stock

12) my wing width (according to the rule) cannot be wider then the car - the car is 79" wide from tip to tip... most wings are for tuners, so max width is 71".... and here's where my inexperience again shines through - does it matter?

13) Splitters... I think I'm okay here, that said, nothing stated about belly pans or defusers :) I love no rules

14) wickerbills - Rick has competed against the 24 hour Vette, which has a wickerbill, (embarrassingly, I confused his car for theirs), and he beat it - the only real difference, it seems (aside from the driver) is wickerbill v. wing. Which brings me to my question of wouldn't a wickerbill be rotten for the high speed portion of the challenge? I can flatten the wing if more top speed is needed (and PIR has a really fast straight)...

Appendix
13. AERO – participant vehicles are allowed to have any factory installed aero packages available on their specific vehicle platform. If it came from the factory on the vehicle platform (including active aero), regardless of size, it's legal

GTV - any spoiler or wing configuration with a maximum of 8" tall from the highest point on the rear of the decklid or a maximum height of 6" above the lowest point of the rear window, whichever is less. The maximum width of the spoiler/wing must be no wider than the original panels of the car and must not extend more than 6" past the furthest point of the rear of the car. No wing may exceed 12" in chord length (front to back) at any point.

Splitters and wickerbills – Splitters are unregulated in all classes. Wickerbills will be allowed on any wing, however, the maximum height of any wickerbill is limited to ¾" from any mounting point and must be between a 45 and 90-degree angle to the wing. Wickerbills on spoilers will be measured as overall spoiler height.
 
then onto my other concern

All vehicles must run a complete exhaust system with mufflers (except EV) and must not exceed 103dB at 50 feet if tested. Tested vehicles exceeding 103dB will be immediately removed from competition and given an opportunity to correct the problem. Two noise violations during a single event will result in disqualification from the event and no championship points will be awarded.​


I'm at 107 now.... but that was imprecise measuring.... but I know PIR measures (even where they measure).... what might save me is that my exhaust is true dual, so only 1/2 the noise aims at the measuring device.

what is interesting about this is there is no way any of the new Mustangs met this rule at Willow Springs.... if you want to know where I think the drama is going to hit.... it's right here

and I wonder if a cross over from sidepipe to sidepipe would be helpful or just extremely annoying....

so my plans... a) start with the baskets, b) pull the inserts out and modify them, c) replace the system with shorty headers, a muffler, then side tubes...
 
so there's a much larger discussion about requirements of Optima and SCCA.... suffice to say Ciro Racing is helping then making the wing for my car.... and this is the information they need
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the tl;dredited
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find the center line, then make a straight line above it (roof line)
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an issue that is important is that the spoiler isn't straight
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and the furthest point (as required for the rules)
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the angle at the point where the spoiler will live
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the legs will drop onto or beside the frame rails - this is where the frame rails are
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and the total width of the legs
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again with dimensions
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center line is 4"

this is more for info purposes only and not directly related to the issue at hand
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Isn't the test (I can't remember who, just it was a yellow C3) with the yarn still on here? - the video - I'll look later, but that was interesting in where the yard was going. I'll have to copy that test once this is stuff is installed

That was JPhil. The pictures are still on here but he never started a topic.
 
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