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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: AZ Troy ()
Date: June 20, 2022 06:26PM

You stated that you will process your scans in GeoMagic X.

Do you know of a less expensive option to the GeoMagic X software?



.

Troy G. / Scottsdale Arizona

'65 140 Corsa Coupe, White with light blue guts
'66 140 Corsa Coupe - Crown Converted in the '60's, Black with 3 Yellow stripes




Edited 1 time(s). Last edit at 06/20/2022 06:26PM by AZ Troy.

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: thumper477 ()
Date: June 21, 2022 11:18AM

detroitdude Wrote:
-------------------------------------------------------
> Welcome, I'm jealous of your
> age, nice to see a young guy
> interested in our favorite cars.
> Very cool project. Can't wait
> to see and read your progress.


Yup,you said it all for this 70 yo guy!

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: nirvairna ()
Date: June 23, 2022 04:43PM

SeanKile Wrote:
-------------------------------------------------------
> A few questions I have:
>
> Any AutoX guys out there that have a good knowledge of the classes. What class would I be running in? I am modifying the firewall, swapping the engine & transmission, technically changing the power train layout (rear engine to rear-mid engine), and doing a tubular subframe with entirely different suspension and brakes. I am unsure of how to interpret the rules.

with those mods you will probably be in E/M which is E Modified

>
> Also, what Caster, Camber, & and Toe are the AutoCross guys running? Not sure if anyone has "bible" numbers for what works. I am reading a few books like Tune to Win & Race Car Vehicle Dynamics to get some insight into this but experience trumps all so. I was thinking
> Front: 7-8 degrees caster, 2-3 degrees camber, 0 degrees toe
> Rear: 0 degrees caster, .5 degrees camber, 0 degrees toe
> Let me know if I am off my rocker with these numbers, please!

go to the corvair autocross page for some guidance

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: SeanKile ()
Date: June 30, 2022 10:24AM

AZ Troy Wrote:
-------------------------------------------------------
> You stated that you will process your scans in GeoMagic X.
>
> Do you know of a less expensive option to the GeoMagic X software?
>
>

I think Autodesk may have software that would work. It’s called Fusion 360. Haven’t tried it but I believe some have used it. It’s $60 a month.

Other than that you might be able to get by on free trials.

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: Autoxer62 ()
Date: June 30, 2022 11:58AM

SeanKile Wrote:
-------------------------------------------------------
> A few questions I have:
>
> Any AutoX guys out there that have a good knowledge of the classes. What class would I be running in? I am modifying the firewall, swapping the engine & transmission, technically changing the power train layout (rear engine to rear-mid engine), and doing a tubular subframe with entirely different suspension and brakes. I am unsure of how to interpret the rules.
>
> Also, what Caster, Camber, & and Toe are the AutoCross guys running? Not sure if anyone has "bible" numbers for what works. I am reading a few books like Tune to Win & Race Car Vehicle Dynamics to get some insight into this but experience trumps all so. I was thinking
> Front: 7-8 degrees caster, 2-3 degrees camber, 0 degrees toe
> Rear: 0 degrees caster, .5 degrees camber, 0 degrees toe
> Let me know if I am off my rocker with these numbers, please!
>
> Are there any good LED aftermarket taillights available for these cars? I see many people replace the lights with LED bulbs, but I didn't know if someone sold a full assembly like there is for the 5.75" headlights.

Hi Sean,

I can comment on the first two, at least a bit. At the National level you're building an E-Mod car, which is pretty open (thus the name).

There are also a set of regional level rules based around CAM called Xtreme Street that may better fit your build, if you're building a street car - you're allowed to do all sorts of mods including suspension/engine swaps, but you have to have a finished interior and be street licensed and insured.

The really big difference between the two in my view is that Mod allows race tires, while XS allows 200TW street tires. That will greatly affect the suspension setup (springs, shocks, alignment, etc.)

If I were building a car like this for 200TW tires, I'd allow for camber up to 5 degrees static without screwing up the camber curve. You probably wouldn't need that much, but 2 to 4 degrees is what most of these tires like. I wouldn't assume any Corvair settings are especially applicable here since it's really not a Corvair from a suspension perspective. Maybe talk with the Vette guys to see what they run. FWIW I'd probably also put in air conditioning :-)

Sounds like a great project, good luck!

Bryan Blackwell | Fairfax Station, Va. | bryan@skiblack.com | [autoxer.skiblack.com]
Corvairs: '62 700 Wagon, '64 Greenbrier, '66 Corsa
"Why do something if you're not going to obsess about it?"

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: SeanKile ()
Date: August 21, 2022 08:02PM

END OF SUMMER UPDATE:

Hey all, sorry for the lack of updates - I quickly realized I was not going to end up where I wanted with the build process and hammered down the last few weeks to get what I could done. I start school tomorrow and will be working 20 hrs a week so getting car time is hard

I would like to thank everyone for the suspension advice as well as the autoX class info.

Picking up where I left off, I finished creating watertight meshes of my suspension scans. After getting all these models completed, I started researching what I wanted my suspension geometry to be.

Caster and KPI were predetermined by the stock spindles. Technically, I could put in more caster, but without simulating the whole car it would be tough to justify this.

Camber, I went for 2.5 degrees of static camber at ride height.

Roll center heights - I went for ~3.5" off the ground in the front and ~5.5 inches off the ground in the rear.

Anti-squat and anti-dive geometries are really not well understood from what I can tell. There are a lot of videos that explain how to calculate it they get close but are generally wrong about calculating the rear anti geometry. For rear anti-squat geometry, one must draw the intersection line from the Instant center of the arms to the center of the rear wheel (not the center of the rear wheel's contact patch as many show). I realize this isn't a clear explanation. Question me if you want to know more.

The best explanation of anti-geometry that I believe to be correct was in the book Suspension Geometry and Computation by John C Dixon. Chapter 10 lays out a very clear path to modeling this geometry.

I worked on most of this a few weeks ago so it isn't fresh in my mind but if anyone has questions or critisms I would love to talk and learn suspension.

Pictures are of the solidworks model of the subframe I created.

Attachments:

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: SeanKile ()
Date: August 21, 2022 08:15PM

Next up is tube bending.

I made my subframes out of 1.625x.083 4130 round tubing. Bending on a JD Squared Model 3 bender. 5.5" CLR - this is a very tight radius for chromoly. Initially I was getting a lot of flattening on the outside wall of the bend area.

To remedy this, I had to make sure the tubes were completely oil and grease free. The tube groove of the bend die (the round die with a tube profile cut into it) also had to be completely oil-free. If there is oil between these parts, there isn't enough friction to keep the tube from pushing out of the tube groove and thus causing a flattening of the outside wall.


The outside of the tube (part not in the tube groove) needed to be oiled and the follower die (some call this a compression die) also needs oiling. This helps reduce the force pushing the tube out of the groove.

The first picture is of a bad (flat) bend. The second is of my bender. The third is the end results I was able to achieve.

Tube bending is a science and an art and (in my opinion) a lot of fun.

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: SeanKile ()
Date: August 21, 2022 08:25PM

Next is the fabrication of the subframes. This is where I'm at currently.

After picking all the desired geometry, I began to connect the dots with tubes and brackets. I got the brackets cut at a local sheet metal shop. Obviously I bent the tubes myself.

For the copes, Solidworks allows you to use individual parts to cut other parts. This allows you to get an idea of what your cope will look like. There is then a trick one can use in the sheet metal tab to flatten this cope. Once flattened, one can print the cope on a piece of paper at a 1:1 scale. Cut out the shape on paper and tape it to the ends of the tubes to get perfect copes every time.

This method seriously saved me so much time and scrap getting the copes right. I just use an angle grinder with a cut-off wheel and flap-disc to dial in the copes. I have a tube notcher but have never found it to be faster.

There were many reference points I designed in and a lot of angles I used to check my fit up. I also made manual adjustments where necessary to get the sides to match.

The first 2 pictures are a half-completed front subframe. The last picture is the rear subframe still being tacked together.

I am welding these on an AHP 201-XD Alpha TIG machine - 4130 must be TIG welded. It works great - I run it on 110 and had no problems getting enough power of the .25" brackets. I do need a water-cooled torch though - next upgrade for sure.

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: American Mel ()
Date: August 21, 2022 10:08PM

Impressive!
Nice work.

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WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: toms73novass ()
Date: August 22, 2022 04:39AM

Great progress and love the ingenuity! Keep up the good work.

-Tom


63' Monza Spyder Convertable (in process) MY Build Thread
62' Wagon rebuild MY Build Thread
65' Monza MY Build Thread
73' NovaSS 454 Big block (Sold)
86' BMW 325es
67' UltraVan 211 "Violet"
NFCC, UMCC
Grand Island, NY

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Re: 1966 Corvair Swapped w/ Cobalt SS motor
Posted by: doug6423 ()
Date: August 22, 2022 01:05PM

WOW!!thumbs up

Doug
65 Monza
Cincy, OH

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