Build Thread: Restoration and New School V8, Photogrammetry: Pics to CAD Options

[Maltese Falcon]

(IMG:style_emoticons/default/welcome.png) looks like the PO had an aftermarket a/c going on in the front trunk (IMG:style_emoticons/default/sawzall-smiley.gif) If you plan to exit your spent radiator air out the bottom, you have a head start ...just close up what you don't need !

Generates to much lift under the car at speed. Wheel well or hood exhaust would be my only choices

Absolutely what Andyrew is saying...however I've used small portions of the trunk floor (The 2 knockout circles ) for my oil cooler spent- air exits... NO high speed lift whatsoever ; but on my current v8/ radiator build I'm going out the top^^^ Ford gt40 style all the way (IMG:style_emoticons/default/thumb3d.gif)

[Joemo5]

(IMG:style_emoticons/default/welcome.png) Good looking project there. Love the v8 setup & hope you do the Boxtser S transmission. Awesome LS setup. Looking forward to that coming together. Lot's of metal work needed. That is a little easier when you aren't as concerned about it being stock. Give's you more options on how to do things. There are quite a few great build here that really go extreme on metal fab work. You are in the right place

Thanks! That transmission is definitely what I'm leaning towards at the moment. Specifically the G86.20 out of 2000-2004 Boxster S. Mostly because there seems to be the most support for that model and it has acceptable gearing for a V8. Thats also the go to trans for Renegade hybrids. I wonder if there is anyone on 914 world with that trans that could share their experience?

[Joemo5]

I have been tied up doing transmission repairs on my daily, a 06 Subaru LGT. So in the mean time I've been playing around with an excel sheet left over from a college assignment. The idea being to get an idea of how the Boxster gearing plays out with a 914 and 5.3L EcoTech. Hopefully, the screen shots are legible.

Here are my inputs. Note that the 7000 rev limiter is high. Realistically, 6500 would be a better limit point with valve spring and push rod changes for the 5.3L to live happily.



I pulled my torque data from the stock graph shown here

2014-2016 CHEVY/GMC SILVERADO/SIERRA 5.3L 1500 TEXAS SPEED & PERFORMANCE L83TR-2 CAMSHAFT

Plotted my points and calculated and equation



Found gear ratio's for the G86.20 trans from here

PORSCHE 986 BOXSTER TRANSAXLE SPECIFICATIONS

Below shows engine speed in each gear. Note this is for a rear 275/40R17 tire. (flares are definitely in my future) The blacked out area's are above the rev limiter or below idle.



Using the equation calculated above and the gearing for the G86.20 determined the force the tire could potentially exert on the road in each gear "tractive force". I then used the drag coefficient and frontal area found in this link...

Cassidy-Online Areodynamic Aids

... to determine aerodynamic drag for the range of speeds shown. Note the drag coefficient and frontal area are for a narrow body car without a spoiler or front splitter. So realistically, I imagine the drag force would be higher. I also calculated a force induced by rolling resistance of the tire for range of speed shown. However, I feel less confident in that calculation but figured it plays a role so I included it. Below is a graph of "resistive force" (areo + rolling resistance) and "tractive force" in each gear shown in the Y axis and speed in the X axis.



Subtracting the resistive forces from tractive forces gives an overall force applied to the car causing acceleration. Using the weight of the car (~2300lbs) you could come up with an acceleration in G's shown below in each gear, at each speed. Again, blacked out area's are either above 7000 rpm or below idle.



It's probably worth taking all this with a grain of salt.. there are a million and one variables not included that could affect any of the above. The car probably won't accelerate at 2G's either. More likely is a smoke show and a slightly smaller tire diameter. (IMG:style_emoticons/default/aktion035.gif)

[Joemo5]

Well I have been busy and hope to stay busy. With as much metal work as this car needs, a rotisserie is in needed. So I'm going to build one based off the blue sky motorsports plan. In the process of stripping the car I realized there is a lot of rust to the passenger side frame rail along with a nice dent (pics to come later). Thus I need a good way to keep the car straight while repairs are made so I came up with this.



The idea is that triangles are stiff and tying each support to one another should do a good job at preventing any sagging or deformation. This is my first go at a rotisserie restoration so those who are experienced, please feel free to chime in on ways you have prevented the dreaded sagging frame that I've read about. When the doors were removed the gaps looked great. Lets hope they stay that way.

Here's some more detailed pics









The entire system is modular and bolts in except for the vertical tube in the center that is tack welded to the underside of the windshield frame.



All the small diameter tubing is clamped to the larger tubing via shaft collar. Which should allow adjustments to be made to the length of the larger tubing members if the chassis where to flex.



Lastly, heres a start on the rotisserie.

[mgp4591]

Wow, that's an amazing bracing system - great job! Now I'm fearing that mine isn't going to be enough... (IMG:style_emoticons/default/shades.gif)

[mepstein]

(IMG:style_emoticons/default/welcome.png) looks like the PO had an aftermarket a/c going on in the front trunk (IMG:style_emoticons/default/sawzall-smiley.gif) If you plan to exit your spent radiator air out the bottom, you have a head start ...just close up what you don't need !

Generates to much lift under the car at speed. Wheel well or hood exhaust would be my only choices

Absolutely what Andyrew is saying...however I've used small portions of the trunk floor (The 2 knockout circles ) for my oil cooler spent- air exits... NO high speed lift whatsoever ; but on my current v8/ radiator build I'm going out the top^^^ Ford gt40 style all the way (IMG:style_emoticons/default/thumb3d.gif)

I did the same thing. The two knockout circles are easy to remove and easily reversible.

[Joemo5]

(IMG:style_emoticons/default/welcome.png) looks like the PO had an aftermarket a/c going on in the front trunk (IMG:style_emoticons/default/sawzall-smiley.gif) If you plan to exit your spent radiator air out the bottom, you have a head start ...just close up what you don't need !

Generates to much lift under the car at speed. Wheel well or hood exhaust would be my only choices

I am fond of the hood exit however, with a radiator and the front tower support there isn't much room a smooth transition. With either the hood exit or the fender well exit, I guess getting caught in the rain wouldn't be good? Some deutsch connections would take care of the electronics but it still seams like it would trap water.. assuming the car still had a complete trunk floor unlike mine.

[Joemo5]

Wow, that's an amazing bracing system - great job! Now I'm fearing that mine isn't going to be enough... (IMG:style_emoticons/default/shades.gif)

Thanks! I'd imagine it depends on how much of the longitudinal your planning on replacing. Since mine are nearly gone, I need all the stiffness I can get.

[Joemo5]

So the rotisserie is starting to take shape. Trying to hold back and go by the KISS method since this is just a means to an end..





I went decided to veer away from the blue sky motorsports plans slightly with a different locking mechanism. Theres a plate with holes and spring pin that will catch the holes a set locations and a nut/bolt clamp that locks on that plate to really keep things from moving when needed.

[Joemo5]

The rotisserie is complete and the car is mounted. Here is the finished rotisserie. I wish I made a beefier tie bar between the front and rear supports. That may be a wise investment.



Heres a overview of the locking end.



And here she is mounted up. We have had ridiculously humid weather recently, so I painted all the bare steel on the door supports and the rotisserie.

[Joemo5]

Here's some good pics of the worst section on the car. The passenger long is not only rusted through near the hell hole, it's also crushed from who knows what.





So at this point I'm wondering if it would be easier in the long run to get the entire thing blasted or dive in repairing the major problem areas?

On a less serious note..

[mbseto]

This looks like the start of a really cool project.

[Joemo5]

With a ton of sheet metal work still to do, it wasn't my intention to move forward with purchasing drivetrain components but I found a deal I couldn't pass up.

I had been looking at wrecked Boxster S's on Copart, a online auction website. The thought was; it might be possible to buy one, keep the transaxle and part out the other stuff too re-coupe most of the initial cost. Ironically, a junkyard a few minutes from my house bought a 2003 Boxster S I had my eye on. After talking to the guy, I got to see it run and drive and point out exactly what pieces and parts I wanted, so I went for it.

Ended up taking home the G86.20 trans, mounting brackets and rubber isolators, shifter cables, the shifter, the boxster center console and the Brembo brakes.







I didn't get the rotors because it looked like most people are using a rotor off a 930 carrera but that's with the non-S caliper's. I can't help but wonder if the Boxster S rotor's could be used with the correct caliper adapter? The bolt pattern for 5 lug conversions is 5x130 and so is the Boxster S.

[Mueller]

That is going to be a really nice build.

Many of us use the standard Boxster calipers since they will fit under 15" rims.

[76-914]

What is the going rate on the G86 trans? (IMG:style_emoticons/default/beerchug.gif)

[Joemo5]

What is the going rate on the G86 trans? (IMG:style_emoticons/default/beerchug.gif)

$1700 for trans, shifter, and cables. It's got 98,000 miles on it which is high in comparison to other ones on the market but I got to see it run and drive which counts for something.

That is going to be a really nice build.

Many of us use the standard Boxster calipers since they will fit under 15" rims.

Thanks! I figured there was a reason there's less info out there on the "S" calipers.

[jimkelly]

good amount of rust but clearly you are up for the challenge.

might want to consider a long reinforcement kit on top of all the repair you are gonna do?

https://www.pelicanparts.com/More_Info/INLO...z0aAmwgEALw_wcB

[Joemo5]

good amount of rust but clearly you are up for the challenge.

might want to consider a long reinforcement kit on top of all the repair you are gonna do?

https://www.pelicanparts.com/More_Info/INLO...z0aAmwgEALw_wcB

I'm definitely going to add reinforcements. A roll cage is a no brainer but tying in to the suspension points, rear roll hoop and A pillars should help add in torsional rigidity. While I haven't done enough research into this yet, it seams like a lot of these V8 swaps end up turning a 2100 lbs car into a 2600+ lbs sled. Since my engine and drivetrain choices have added ~250lbs without including the cooling system and supporting equipment, I will try to add reinforcements (weight) very wisely.

[914forme]

If your not into originality this is the best system I have found to fix bad rockers, they really stiffen up the car. Still need o fix the rust but these and the Maddog kit, makes a very stiff chassis.

"Excellent for repairing longitudinal and jack receiver rust. Also extensively used for competition chassis stiffening and large engine installations. The panels are .100 thick (very strong) and extend from front wheel house to the outer rear suspension console. Welding is required. The rear section of the panel sandwiches between the outer suspension console and the trailing arm. Permanently restores door gap and eliminates flexing problems. Provides a base to weld to if additional repair is needed in floors, inner longitudinal, or firewall area. Excellent installation instructions included plus my personal assistance if you have questions. I have been selling and installing these for 28 years. There is nothing on the market for 914 chassis repair that is this strong, proven or easy to install. Porsche repair and restoration expert for 38 years.

Free Shipping.
"

Lifted from 914LTD Here is where you can order, Brad is a very nice guy and supporter of our hobby.

[914forme]

BTW, Brad's front and rear sway bar mounts are very nice. The front design is great and does not require cutting the car inner box section under the fuel tank.