PVX build thread: one view from the slope

[petevb]

Originally Posted by Mahler9th

I'd guess there has been a great technical/creative/design collaboration between WEVO and the owner/poster, perhaps unlike most of the "unlimited" hot rod Porsches we have seen in the past 25 years or so.

GGR AX driving for this car? I may have to check one out this year, or perhaps drive my car in one, just to see this car and my friend's Atom.

Sure, come out and bring your monster, Mike. It'd be nice to see what a real race car would do out there.

Any yes, it was great working with WEVO on this- I learned a lot...

Originally Posted by 911teo

Pete...
Love the colour... and everything else!!!

Thanks very much Matteo, yours is still one of my favorites.
BTW, the down-side of going water cooled vs the 9M route you took is weight. Between the heavier motor and all the water a Cup motor is closing on 100 lbs total heavier than an air cooled solution. I suspect the water cooled options still go to higher powers at equal durability, however...

A couple more pics- first the inside of the tail lights. You get a pretty good idea of how these are done here:


Also a couple of the clutch setup. Part of the reason, with the superlite flywheel, Ti rods, etc, that it revs like a light switch.




Randy, I actually think the metal work around the rear suspension is my favorite bit. If you look closely the swaybar mounts are relocated for extra ground clearance, the trans mount is custom, etc. It just all blends together in such a way it's subtle how much was actually done. All wevo...

-Pete

[sc_rufctr]

Thanks for posting these photos. Great car and build story. Thanks for sharing.

I've always wanted to see the fabled 964 based GT motor.

It looks beautiful with the traditional centres, water cooled cylinders and heads.

[wax105]

Pete!!!

Absolutely spectacular work! The engineering and design is outstanding, very well thought project…

I’d be very interested in getting some details on the torsion tube mods?!?

Best,
Carl

[1990C4S]

Time for a poll: Would you choose this car or Black Beauty? Decisions decisions....

[DW SD]

Originally Posted by 1990C4S

Time for a poll: Would you choose this car or Black Beauty? Decisions decisions....

No brainer....Pete's car is light years ahead. This has set a new bar for early 911 hot rod execution.

Doug

[JeremyD]

Originally Posted by DW SD

No brainer....Pete's car is light years ahead. This has set a new bar for early 911 hot rod execution.

Doug

amen brother!

[1990C4S]

Originally Posted by DW SD

No brainer....Pete's car is light years ahead. This has set a new bar for early 911 hot rod execution.

Doug

Mechanically yes, appearance-wise also? And does Pete ever include a self-portrait?

[petevb]

Originally Posted by 1990C4S

Time for a poll: Would you choose this car or Black Beauty? Decisions decisions....

The cars are really so different that's a difficult question to answer. They seem similar on the face, but Jack's car's going to be much easier to live with. It will be much quieter- the cage doesn't pick up the suspension points, it's got a real exhaust, etc. He's got removable door bars. He's got a street motor with idle control- no need to warm up, just jump in and go.

PVX is really a thinly disguised race car, and as such is much less livable. The cup motor needs to warm up before it's driven, and even when it does it idles north of 1500 rpm. It's loud, it has no heater, no defrost... It's just all around more hard-core. So it's an apples and oranges comparison. Which one you'd prefer depends on what you plan to do with it.

[1990C4S]

I am really going to need both for a weekend in order to post a valid reply.

They are both great. These are THE salient points in my mind, it's all about personal preferences at a certain point, and you have both crossed that point.

Originally Posted by petevb

He's got a street motor with idle control- no need to warm up, just jump in and go.

Originally Posted by petevb

PVX is really a thinly disguised race car, and as such is much less livable.

[Mahler9th]

The tail and brake lights look indeed like the age-old "Ultimates" sold by Pegasus, HRP and others. 4 x $49 just for the lights. One our racers uses these on his '69 911 car. There are other LED choices from the motorcycle world-- I plan to use some of these when I fab up some light brake lights for my car as they are much cheaper.

This project is really cool for a number of reasons, but comparing to Jack's or any other is a very hard thing to do. We must note that many, many hot rod projects have been executed and chronicled based on 911 family cars and engines through the years-- not many are discussed here. Excellence and Pano have had many articles on such cars, including at least one 911 with a 962 motor that was, as I recall, put together years ago. In the future, we may see a GT3 RSR or Porsche Daytona protoype engine in a 914-- I might expect to see that.

As far as comfort for street driving, there are lots of variables of course. One of the cool things about Porsche's family of cars, particularly the 911, is all of the fun things that can be done to them.

Consider a car like mine from a few years ago... mid-70's 911 with composite later-model bodywork and a modest interior, a cage and a weight of about 1950 pounds. Then consider (unlike mine) a 3.8 twin turbo motor installed in it. Who knows how much power-- north of 700 for sure. Now this car also has heat, and is driven, not infrequently, on the owner/builder's ~45 minute commute to work (on street tires, not slicks). Now consider that this car is also raced, and it shows up at PCA Club Racer at Laguna and beats all of the other cars, including highly modified GT3 Cups. Now the car has different body work, an engine with slide valves and is active in vintage racing.

Lots of things can and have been done with these cars. To me, what makes this project so cool (and I can't wait to see the car again) is the clearly collaborative design process that went into it, as well as the owner's realization of his personal dream.

[BoxsterGT]

Really enjoying this. Spectacular results.

Can you tell us more on the cooling system design & size of pipes?

Did you calculate the BTU loss required for this motor?

Glad to see you kept the nose intact.

Has it worked out to your satisfaction?

Len

[BoxsterGT]

I like your coolant line layout so much I am planning something similar.
Any difficulty with bleeding the system?
It appears that the coolant tubes are higher at the fenders than the expansion tank.
Please correct me if I am wrong.
Len

[sl951]

Originally Posted by BoxsterGT

I like your coolant line layout so much I am planning something similar.
Any difficulty with bleeding the system?
It appears that the coolant tubes are higher at the fenders than the expansion tank.
Please correct me if I am wrong.
Len

The water expansion tank is on the left side of the engine. It's higher than the coolant tubes. The tank in the trunk is oil.

[petevb]

Originally Posted by BoxsterGT

I like your coolant line layout so much I am planning something similar.
Any difficulty with bleeding the system?
It appears that the coolant tubes are higher at the fenders than the expansion tank.
Please correct me if I am wrong.
Len

The ultimate compliment... Thanks.

The expansion tank/ air spring is the highest point in the system save the bleed lines, which is why it's located so high at the back.

The system is self-bleeding. The high points of the tubing each have spigots with small diameter lines running back to the air-spring. You can see one of these lines coming off here:

The lines then run along the roof behind the cage back to the expansion tank. This eliminates the need to bleed the system...

The systems is working great so far, but it has yet to get hot enough for a worst case test.

[petevb]

Quick update:

We're continuing to get the car ready for One Lap of America next month. That means a number of changes for that event:

Given that the rules require 140 or greater treadwear street tires, and the best tires are only available in lager sizes, we've got a second set of race wheels- 9x18 front and 11x 19 rear for 235 and 305 tires. Those are getting mounted today with Bridgestone RE050A N1 tires- we'll see how they do in the wet shortly.

We're also mounting a wing from a GT3 cup car with a splitter to complete the aero package. Finally we're going to a revised equal length header system for the exhaust which should improve power and torque...

Whether or not the car actually needs more power is debatable. So far, despite the fact that the car is geared to 60 mph in 1st, I haven't been able to get it to stick that gear despite the 315 V710s. We're playing with settings to get it to put power down better. Not a bad problem to have, but wheel-spin in a straight line up through 3rd gear on occasion (geared to a bit over 100 mph) keeps you on your toes...

More to follow. So far it's great fun

[Steve W]

Pete: any reason you selected the RE050As vs. the RE-11s?

[petevb]

Originally Posted by Steve W

Pete: any reason you selected the RE050As vs. the RE-11s?

Basically wet performance Steve- I chose them after quite a bit or research and some discussions with an OEM tire tester who give me some very good input with regards to wheel diameter, etc...

The points system at One Lap heavily favors consistency, and there are always a few wet events. The way the points stack up almost always mean it's better to be slightly slower in the dry events and faster in the wet rather than vice-versa. I've had a set of regular RE-050As before and haven't been blown away, but the following quote from Excellence Magazine by a Porsche engineer swayed my into thinking the N1 spec is significantly better, especially in the wet:

"Interestingly, says project manager August Achleitner, Bridgestone recently introduced a normal high-performance tire called the Potenza RE050A. The N1 version is Porsche-specific and used on the new Turbo. The surprise, says Achleitner, is that its grip levels are not far off Michelin’s Cup tire. Being a normal tire, it also has enough tread depth when new to offer good aquaplaning resistance in wet-weather conditions.

“Pirelli has a new PZero N2 on the way that will also be good in the wet, but not quite as good as the Bridgestone,” he says."

The few test of cars on the N1 spec Bridgestone seem to confirm that it's very good. Road & Track tested the Boxster Spyder at 1.01 Gs in the dry on them, while the new turbo was tested by EVO at 0-60 in 3.2 seconds and 60-0 in 113 feet in the wet. They certainly have more void area than the also very good RE-11, which is neck and neck with the PZero N2 spec for my second choice. I suspect all three tires are very good. We'll see...

[lateapex911]

I read today that the 2010 turbo was clocked at 0-60 in 2.9 ...which aint shabby! That 3.2 in the wet is astounding. of course, it is AWD...but still!

[petevb]

So we've had a couple trials and tribulations, but we're making progress.

The only significant issue we've had so far is the starter. The 13:1 compression ratio from the GT3 Cup motor has eaten two starter ring gears so far in about 200 starts. Hayden's got a little writeup on the wevo blog here:
Welcome to Windrush Evolutions - WEVO Blog
Basically the shortened bell housing required the use of an early starter, unsupported on the end of the pinion. First we tried a lightweight starter, then we tried a regular early starter... Same result:

Not ideal...
It looks like Hayden's come up with a good solution, however:

Above is a 993 Tiptronic starter next to an early starter. The 993 tip starter is supported on the far side of the pinion- much stronger. The fact that it saves a three pounds and starts the car better is a bonus. Hot tip- I suspect it fits a 915 as well

We stripped the starter ring gear at an autocross Sunday afternoon and the car was back on the road by Tuesday! Nice...

Other than the starter issue the car's been reliable so far. Given that basically everything is new that's almost surprising... We made it to another event on Sunday, still trying to shake the car down for One Lap, which is now just a month and a half away. Sunday was fun:

The car's wearing the new set of Forgelines for One Lap. Rear tire clearance is tight (!) but no rubbing...

Steve, you were probably right about the RE050A N1s. After doing a couple events on them the are not terribly impressive on such a light car. One way or another we're massively traction limited, though it does stick first gear (.9 Gs, 60 mph!).

I've got a set of RE-11s- we should get to try them this Saturday at another event. Good times

[BoxsterGT]

Curious as to how the 993 Tiptronic Starter is working out?

Len