BUILD-OFF CHALLENGE: Tygaboy's '75 LS3, It seemed a good idea at the time... Options

[tygaboy]

If anyone asks, it appears that a Boxster 6-speed slots right in and the 993 axles are the correct length.
Is it too early for a "so far, so good"?

[mb911]

@tygaboy looks great.. Hey in retirement you just need to enjoy things and it takes as long as it takes as long as you enjoy it.

[jd74914]

(IMG:style_emoticons/default/agree.gif)

Nothing wrong with fixing the rear suspension geometry too. (IMG:style_emoticons/default/smile.gif)

[Joemo5]

Very interesting with the 993 rear suspension (IMG:style_emoticons/default/popcorn[1].gif) Is there a 993 front suspension lurking around the corner that we can't see?

Also curious about the change in suspension dynamics: roll center location and how that plays with your chosen front suspension.

[dan10101]

I love your out of the box thinking!

And,,, why not?

[mepstein]

I remember a 914 race car with 993 suspension and a driver's seat in the midline of the car. It's too late tonight for me to search but it was a pretty cool set up.

[tygaboy]

Very interesting with the 993 rear suspension (IMG:style_emoticons/default/popcorn[1].gif) Is there a 993 front suspension lurking around the corner that we can't see?

Also curious about the change in suspension dynamics: roll center location and how that plays with your chosen front suspension.

Plans for the front are still in the works but it's not going to be 993. As to the change in dynamics, that's a more difficult question to answer. I've done a bit of research and talked with a couple suspension experts who have proven designs in production. It sounds like you may be versed in suspension stuff and know FAR more than I do so please feel free to chime in or PM me. I'd love to hear more.

My target is that the handles in a safe and predictable manner. When you look at things regularly done to our cars (911s, too), like nearly doubling wheel widths and/or adding inch plus spacers behind wheels so they fill out flares, and what that does to the scrub radius, contact patches, etc., I've wondered how it is these cars seem to work OK.

The info I've been able to uncover suggests (and I'm happy to be proven wrong) that unless things are pretty significantly "wrong" in some element of the design, changes I have planned should work, given the performance parameters I'm after.
The 993 rear set up does have the Kinematic toe adjustment that complicates things but it wouldn't be my project if I didn't add all the complication I could possibly find! (IMG:style_emoticons/default/huh.gif)

Details to follow as I make progress or talk myself out of going this direction.
Your comments always welcomed.

[Andyrew]

If anyone asks, it appears that a Boxster 6-speed slots right in and the 993 axles are the correct length.
Is it too early for a "so far, so good"?

(IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/cheer.gif) (IMG:style_emoticons/default/popcorn[1].gif)

This looks FUN!!

[Cracker]

I dunno...at this rate Chris - Lori can't stop working and you might have to go back! (IMG:style_emoticons/default/rolleyes.gif)

T

Details to follow as I make progress or talk myself out of going this direction.
Your comments always welcomed.

[Joemo5]

Plans for the front are still in the works but it's not going to be 993. As to the change in dynamics, that's a more difficult question to answer. I've done a bit of research and talked with a couple suspension experts who have proven designs in production. It sounds like you may be versed in suspension stuff and know FAR more than I do so please feel free to chime in or PM me. I'd love to hear more.

My target is that the handles in a safe and predictable manner. When you look at things regularly done to our cars (911s, too), like nearly doubling wheel widths and/or adding inch plus spacers behind wheels so they fill out flares, and what that does to the scrub radius, contact patches, etc., I've wondered how it is these cars seem to work OK.

The info I've been able to uncover suggests (and I'm happy to be proven wrong) that unless things are pretty significantly "wrong" in some element of the design, changes I have planned should work, given the performance parameters I'm after.
The 993 rear set up does have the Kinematic toe adjustment that complicates things but it wouldn't be my project if I didn't add all the complication I could possibly find! (IMG:style_emoticons/default/huh.gif)

Details to follow as I make progress or talk myself out of going this direction.
Your comments always welcomed.

I'm very very excited to see someone else go down this road. Inspired by the lotus suspension 914 that's on several different forums, I have tossed around similar ideas (hint: miata) with my build but havn't committed yet.

I know just enough about suspension dynamics to be dangerous. One of the best resources is "Tune to Win" by Carrol Smith. That book came recommended by a road vehicle dynamics professor. Two or three chapters of the book are devoted to the effects of load transfer with varying suspension geometry, which is different than altering scrub radius or the tire contact patch. The roll center is a point that is defined by suspension geometry. The vehicle body rolls or pivots around that point when cornering. "It is also the point through which the lateral forces transmitted from the tire's contact patches act upon the chassis." -Smith

The new 993 suspension will likely have a different roll center than the swing arm 914 suspension. Thus, cornering forces will affect the car differently.

Given the awesome metal work you've done, I bet you would also enjoy "Prepare to Win" by Smith that discusses sheetmetal, mounting brackets, fiberglass etc.

I would agree that predictability and safety is key. I know nothing about the 993 Kinematic toe adjustment though. I'll have to read up on it.

[Andyrew]

Plans for the front are still in the works but it's not going to be 993. As to the change in dynamics, that's a more difficult question to answer. I've done a bit of research and talked with a couple suspension experts who have proven designs in production. It sounds like you may be versed in suspension stuff and know FAR more than I do so please feel free to chime in or PM me. I'd love to hear more.

My target is that the handles in a safe and predictable manner. When you look at things regularly done to our cars (911s, too), like nearly doubling wheel widths and/or adding inch plus spacers behind wheels so they fill out flares, and what that does to the scrub radius, contact patches, etc., I've wondered how it is these cars seem to work OK.

The info I've been able to uncover suggests (and I'm happy to be proven wrong) that unless things are pretty significantly "wrong" in some element of the design, changes I have planned should work, given the performance parameters I'm after.
The 993 rear set up does have the Kinematic toe adjustment that complicates things but it wouldn't be my project if I didn't add all the complication I could possibly find! (IMG:style_emoticons/default/huh.gif)

Details to follow as I make progress or talk myself out of going this direction.
Your comments always welcomed.

I'm very very excited to see someone else go down this road. Inspired by the lotus suspension 914 that's on several different forums, I have tossed around similar ideas (hint: miata) with my build but havn't committed yet.

I know just enough about suspension dynamics to be dangerous. One of the best resources is "Tune to Win" by Carrol Smith. That book came recommended by a road vehicle dynamics professor. Two or three chapters of the book are devoted to the effects of load transfer with varying suspension geometry, which is different than altering scrub radius or the tire contact patch. The roll center is a point that is defined by suspension geometry. The vehicle body rolls or pivots around that point when cornering. "It is also the point through which the lateral forces transmitted from the tire's contact patches act upon the chassis." -Smith

The new 993 suspension will likely have a different roll center than the swing arm 914 suspension. Thus, cornering forces will affect the car differently.

Given the awesome metal work you've done, I bet you would also enjoy "Prepare to Win" by Smith that discusses sheetmetal, mounting brackets, fiberglass etc.

I would agree that predictability and safety is key. I know nothing about the 993 Kinematic toe adjustment though. I'll have to read up on it.

Britain's car has quite a bit of work into it. The suspension certainly let him take it to the next level. One of the quickest autox 914's in the country for sure.
http://www.914world.com/bbs2/index.php?sho...=113579&hl=

It really let him put the power to the ground and get maximum use of his tires.

[Cracker]

I don't think it probably matters from a pure application viewpoint...I highly doubt this car will ever see more than 7/10 driving anyway. Its already been proven how capable even the stock suspension can be made to perform. Now, I think it is "way-cool" and am looking forward to seeing it come together but I also realize that by the time this is done Chris will have bought the rear suspension to a 991.2 Cup-Car and decided that was a better choice! (IMG:style_emoticons/default/poke.gif)

All in love, Chris, all in love...!

T

[Joemo5]

@Cracker Your right, suspension geometry becomes much less important if the car will never be driven at full tilt.

[burton73]

The motor is out and almost on its way to a session on the engine dyno to get a base map/tune.

As I was looking at all that space I thought, "I wonder how much work it would be to get 993 rear suspension in this thing..." (IMG:style_emoticons/default/idea.gif)

Let's find out!

And yes, this likely means tube chassis-ing the rear of the car.

Oh, and go ahead and say it. I know you're thinking it:
"He's never going to get this thing on the road..."

Maybe not, but think of how much fun I'll have trying!

(Anyone need fully rebuilt, tricked out complete 914 trailing arms w/911 e-brake set up or a Tangerine Racing rear suspension pick up point kit?) (IMG:style_emoticons/default/wacko.gif)

Chris,

I know nothing!!


Bob B

[tygaboy]

I don't think it probably matters from a pure application viewpoint...I highly doubt this car will ever see more than 7/10 driving anyway. Its already been proven how capable even the stock suspension can be made to perform. Now, I think it is "way-cool" and am looking forward to seeing it come together but I also realize that by the time this is done Chris will have bought the rear suspension to a 991.2 Cup-Car and decided that was a better choice! (IMG:style_emoticons/default/poke.gif)

All in love, Chris, all in love...!

T

2 things:
1. 7/10 is plenty fast for me!
2. If some people would stop sending me work, I could get more done on my own car...!
All in love, Tony, all in love...! (IMG:style_emoticons/default/laugh.gif)

[Cracker]

Ok. I wanted to wait until I got it on the car before bragging on you but you beat me to it!

Real Story! Two days ago (7 pm ET or so) I called Chris and asked if he would do me a favor. I needed the aforementioned tunnels and diffuser support for my D-Sportsracer. Not only did Chris immediately say "yes" he had it in CAD the next morning and finished later that day (yesterday)! He dropped what he was doing to help me - I did NOT ask him to do that - he is just that selfless and gracious!

THANK you Chris for being so willing to help, my friend. You did ruin my opportunity to "pat you on the back myself"...first that is! The really cool thing about Chris, beyond his ability to fabricate parts; and having all the cool tech toys; and having time in retirement to do what he wants; is he is very KIND! (IMG:style_emoticons/default/beerchug.gif)

Tony

[tygaboy]

One for the OCD and/or fabrication crowd:
In stamping the firewall side panels, I initially used a 2-piece stamp (left, in the first pic) The, ahem, "problem" is that the male die has to be manually positioned which means a low likelihood of repeat-ability or even exactness as it's a crap shoot that nothing moves during the setup/stamping process.

In fact, though difficult to see in the earlier firewall pics, the "ledge" of the stamp wasn't consistent across the entire length of the panel edge... And as I'm sure @bbrock would agree ( (IMG:style_emoticons/default/biggrin.gif) ), this simply won't do!

So, I redesigned the stamping die and made it one piece. Yep, it's the one on the right. Essentially it's a reversible "flap" so I can stamp the mirror image sides and guarantee that the male/female areas stay perfectly aligned and give me a repeatable, controlled result! The 2nd pic shows the earlier style panel in mock-up placement in the die.

Sharp eyes may notice I increased the length of the lower, front edge - which is why this earlier piece doesn't really fit. This was needed to create a bit more room for a fastener I need to add. More on that as I get to it.

[tygaboy]

Here's the first blank of the new version.

[tygaboy]

The die is cut to the same outside shape as the blank. This make it pretty simple to get the blank positioned correctly and consistently. (Geez, it sounds like I'm going into production vs just making two of these!)

The oval cut outs are just to make it easier to verify the blank is correctly aligned in the die.

Here's the blank in position, ready to be pressed.
Just need to be sure to reverse the die before doing the other side's panel! (IMG:style_emoticons/default/wacko.gif)

[tygaboy]

Fresh out of the press!