PVX build thread: one view from the slope

[Kroggers]

Outstanding work... Any more details on the rear LED light set-up?

[petevb]

Originally Posted by RWebb

you can either route oil up front to a cooler or route water up front to a cooler..

Originally Posted by lateapex911

In this case, you've avoided what to me are the issues with many of the water cooled cars...

That's pretty much what I was thinking and going for. The goal for the water cooling was to impact the original metal as little as possible, so that the result was not only effective but clean, elegant and almost hidden even when you open the trunk. The clearances around the radiators are very tight in order to pull it off.

Power to weight ratio... As I said we haven't dynoed it so I'm not sure, but it should be a bit over or maybe at 5:1 depending on exhaust and tune. So right around a Carrera GT at the moment?

LED lights- I've got some pics of the rears to give you an idea:



We also did the front turn signals that way, and with the custom wiring harness it's a very lightweight solution. You can see the quick reaction in that first video I posted- they are flickering under left foot braking entering the corner: brake lights

[Kroggers]

Nice solution, where do you get those LED lights from?

[TWIN911]

Will we see you 1/1/10 on the Bay Area Run?

[DW SD]

Are those breakers or fuses for the wiring panel? Who makes it?

Doug

[petevb]

Doug- they are circuit breakers. They seem identical to the mil spec ones we used in the U2 spyplanes I crew chiefed once upon a time, but I'm not sure who manufactures them. The breaker panel is another WEVO piece. I'm not sure if they actually sell any of this stuff, unfortunately...

I'm also not certain where they sourced the LED lights. I know it's not a totally straightforward replacement...

Unfortunately it looks like I won't make the 1 Jan drive- I'll be away skiing and they're finishing up the gauges, etc. I'll be at most of the GGR autocrosses when those start up again, and I'd love to give rides as an instructor if you guys are driving

Another detail- the motorsports ECU has provision for three maps, and we've got a switch to toggle between them with an indicator light in the gauges. So we can flip between 100, 95 and 91 octane maps depending on the fuel available. Nice feature...

-Pete

[RWebb]

ability to switch multiple ECU maps is a great thing to have!

- any idea as to whether Wevo has plans to manf. & sell the LED lights, breakers, etc. ?

and how are the tail light lenses held on, since the heavy pot metal housing is no longer in place?? -- is it anything other than that small (welded on?) tab?

[petevb]

Originally Posted by RWebb

- any idea as to whether Wevo has plans to manf. & sell the LED lights, breakers, etc. ?

and how are the tail light lenses held on, since the heavy pot metal housing is no longer in place?? -- is it anything other than that small (welded on?) tab?

I could be wrong, but I don't think wevo has plans to productize this sort of feature. I'm not sure if they would play nice with a stock harness, etc... I'll ask to double check, but last we spoke all of this was for internal use only or one off...

The fiberglass panel has multiple retaining points and the lens bolts to it- I'll try and get more images next time I'm there.

-Pete

[cdrik915]

Incredible and fantastic job !!!!!

The perfect 911 on my own.

Congrats!!!

[MichiganMat]

So Pete...

you gonna let your wrench drive this one?

(friggin badass too, can't wait to sit in her in '10 GGR)

[pksystems]

any pics of how the front a-arm tie in is attached on bottom of car?

[wesayso]

Awesome buid! I allready compimented you on the looks of the car prior to knowing what was underneath. Crazy combo! Crazy details too!

[sancho]

well done, great build....

[petevb]

Originally Posted by pksystems

any pics of how the front a-arm tie in is attached on bottom of car?

Sure- here you go:

This actually attaches to some of the tubing running inside the body of the car. The threaded rods are turned to be pre-loaded to take up the slack in the rod ends...

[ScottKelly911]

Pete, congratulations, this is such a great build. I first saw it when you posted it over at 6Speedonline.com You really set the bar high with this one! What are your plans for a rear spoiler for track duty? I know with Autocrossing it's not so much a factor as speeds are kept relatively low, but for tracks, I imagine you'll want to throw a nice big spoiler to plant it to the ground. Perhaps something long the lines of a moded 2010 997 GT3RS spoiler? Also, with such an amazing car and well documented build, have you gotten in touch with any publications for them to do a story on it? This car is certainly deserving of an article in Excellence or other publications!

[sammygon1]

Your radiator solution seems ideal. Are the radiators custom or are they available online? Are the flares required for clearance or would they fit in a non-flared car. Beautiful build!
Sam

[lateapex911]

Also, and I hope this isn't annoying with too many questions, the whole PCCB brake conversion has blown past without a comment. So, you converted 69 to PCCB? And to do so, you made custom hats? Care to share some of the details and steps? That's a pretty cool bit of work!

[John S]

Pete,

This is a nice project.

I love the retro charm of air/oil cooled 911s, but am equally a fan of modern Porsche technology and mixing the two as you have done has raised a lot of interest here. I think this build, and your documentation of it, will encourage others to have a go. Maybe not to the degree you have gone to, but at least the water cooled aspect of it.

I wonder how long before we see a DI/ PDK converted pre '74 or for that matter pre'90 911?

Thanks for sharing and inspiring.

[petevb]

I'll post some pics of the aero as it gets done, and yes they are custom radiators. Clearance is very tight, but in concept they should fit under stock fenders...

Originally Posted by lateapex911

Also, and I hope this isn't annoying with too many questions, the whole PCCB brake conversion has blown past without a comment. So, you converted 69 to PCCB? And to do so, you made custom hats? Care to share some of the details and steps? That's a pretty cool bit of work!

Not annoying at all- happy to share

So the PCCBs are takeoffs from a RUF as you'd guess from the pictures. Because of the whole Gen I PCCB scare I got the whole set- rotors, calipers and all- for barely more than my old 930 brakes. A number of the big HP 996 turbo guys are taking gen I PCCBs off to go to 380mm cast iron brakes for track work. After some research through factory contacts I decided that while there can be some issues with the PCCBs, especially Gen I, they largely stem from overheating. On my car, which is 2/3 the weight and has less power than most of the cars having issues, I decided that overheating is likely going to be difficult to impossible. So I felt comfortable trying out Gen I PCCBs for cheap- we'll see how they wear.

Designing the adapters was trickier than I'd expected- there is a fair bit involved in getting it right. I used the stock rear hat, but designed a custom front hat that sits behind the hub rather than in front of it to save around a pound over the stock Porsche hats. The tricky bit has to do with temperature- the PCCBs have less thermal mass than cast iron rotors, and thus they reach higher peak temperatures. If you're not careful this can cook or mechanically stress the hubs and bearing grease, weaken hats and cause other issues. Thus much of the design problem revolves around thermal management.

Porsche used stainless for the hats in the early PCCBs and I did the same, using high temp 17-4 to minimize thermal issues. Ideally you machine the hat from a special stock to prevent warpage. Unexpected was the fact that the PCCB rotors themselves are not well balance from the factory; unlike steel rotors they can't machine away material from the rotors themselves to balance the assembly. Thus they use an innovative method- the bolts and floating T lock nuts that hold the rotor to the hat are a combination of stainless and titanium hardware. By strategically placing the ti hardware where the rotor is heaviest they can get the rotor/ hat assembly to be fully dynamically balanced. This is why the rotors are only available from the factory pre-assembled to the hats, and part of the reason they are particularly expensive. Interesting tidbit...

For the design I used FEA to optimize the hats, the thermal properties and the adapters front and rear. Believe it or not the rear would have worked perfectly with the standard 911 handbrake assembly, though we chose to drop that assembly in favor of a line-lock to save weight.





Clearance under a custom 17" wheel is tight- most 17" 3 piece wheels won't clear the front rotors:


To finish the system off we used a cockpit adjustable dual master cylinder setup and an adjustable bias valve.

So far I'm impressed by the results. They seem to have significantly better feel and modulation than the 930 or 928 S4 brakes I'd had on my previous cars, they are slightly lighter overall, can clearly dump significantly more energy and should last extremely well (hopefully) in this appication. We'll see how they do in anger, but if the used market for gen I PCCBs stays low I think they may well be a very viable option for the light weight early cars. We'll see how it goes...

[sl951]

Originally Posted by ScottKelly911

This car is certainly deserving of an article in Excellence or other publications!

Hmm, what would the title be?

"40 years of evolution literally in one car"

"What do you get when you mix Porsche's iconic 1960 chassis, 1970 suspension, 1980 transmission, 1990 brakes, 2000 engine"

Or just ....
"Holy &*^!" - which is pretty much the reaction you have the first time you roll-on the throttle.

5.37 lbs/hp (2150/400) is on the conservative side

it could be up to

4.77 lbs/hp (2150/450) for an unrestricted cup motor