The Bumpin' Pumpkin - The tale of one 964's rebuild
08-31-2009, 06:31 AM
#1
Racer
Thread Starter
The Bumpin' Pumpkin - The tale of one 964's rebuild
I've had a few requests from Rennlisters who don't frequent certain other Porsche forums to run through the build process of my rebuilt 964 (a.k.a., the "Bumpin' Pumpkin") here on Rennlist, so here it is…
This project is truly a realization of a dream that started when my father used to stick me in the back of his '91 965 (Turbo I) when I was a kid. The “click” and “ka-ching” of the doors opening and closing, the faint smell of gasoline underscoring the smell of the leather interior, the sound of an air-cooled flat six cranking to life, and the feeling of sheer power (even in the back) when the whole thing got under way, all stuck with me through my initial forays into car ownership until late late-2007 when I was finally able to buy my very own 964.
My particular 964 started life as a Guards Red Carrera 4 (right hand drive) which rolled past the doors of one of the red brick buildings in Zuffenhausen sometime in late-1989. It was then shipped to and registered in Singapore sometime in 1990 by its first owner, and its log card (title) was subsequently passed through the hands of 3 owners before landing in mine.
During its tenor with its previous owners, my 964 accumulated around 110,572 km (68,706 miles) of driving adventures in Singapore, Malaysia and Thailand, and was saddled with such aftermarket additions as a “basket-handle” CHMSL originally designed for the 911 (993) Cabriolet models, and an awful sounding ICE system built around a decent Blaupunkt headunit and subwoofer, but using really bad speakers and tweeters.
After purchasing my 964, I decided to spend a few months getting familiar with its driving characteristics, while simultaneously crystallizing the kind of car I wanted at the end of the project. First impressions of driving the original Carrera 4 were in line with contemporary road test reviews of this particular model in that the car was very stable at highway speeds and quite comfortable for long cruises. It’s characteristics on the track were also no surprise, where the car tended to understeer significantly with an uncanny likeness to a front wheel drive car. What it came down to was that I wanted an experience that was closer to the prototypical, air-cooled 911 experience (i.e., lighter weight, a looser tail, etc.) with some more power – basically something that would surprise drivers of the modern, water-cooled Porsches on the road and track. With this goal in mind, I began the parts acquisition process for the parts that would eventually form a car inspired by the 964 Carrera Cup series, with significantly more power and some modern-day touches.
To keep myself amused in the meantime I stripped out the ICE, carpeting and interior trim pieces, and replaced the electrically adjustable seats with a spare Sparco bucket seat I had lying around. This amounted to a trimming of at least 100 kg (220 lbs) of insulation, carpeting and interior parts and the difference in handling was immediately apparent. The car accelerated much faster on the road, and tended to far less understeer on the track, to the point where I was actually debating keeping the 4WD system and building a replica 964 Carrera 4 Lightweight (http://www.qv500.com/porsche964p10.php) – until I found the “Sputnik” 4WD system kicking in and throwing the car into understeer.
At the end of the day, the spec / parts order list roughly ended up looking like this:
Body
Seam-weld all spot-welded areas on chassis
Remove and sealed sunroof panel
Bare metal repaint
Interior
Lightweight interior (no insulation, carpeting, ICE, etc.) (curb weight ~1,150kg / 2,535 lbs, 40 / 60% f/r weight bias)
Replica RS door panels / door parts
Manual window winders
Diamond plate, aluminum floor boards
Custom, lightweight A/C system
OEM Carrera RS windows (thinner glass)
Plexiglass front/rear -quarter windows and rear window
Lightened wiring harness (this was a time consuming, manual labor process that my mechanic hates me for)
Heigo half roll cage
Recaro Pole Position bucket seats
Schroth 6-point harness for driver
Schroth 4-point harness for passenger
Momo Prototipo steering wheel
Engine / Drivetrain
3.8l rebuild (dynoed at 355 hp at the crank, redline at 7,200 rpm)
JE Pistons
Carillo connecting rods
LN Engineering “Nickies” cylinders
CMW Motorsports heads
Custom camshafts
Turbo studs for crankcase
PMO individual throttle bodies
SARD fuel pressure regulator
Custom oil catch can
Motec M600 stand alone engine management system
Fabspeed "RSR" exhaust
OEM 993 G50/21 gearbox (6-speed)
Suspension / Brakes
Bilstein / H&R suspension
OEM 993 GT2 Evo wheel carriers
Adjustable front tie rods
Adjustable rear spring plates
OEM 993 Turbo / Carrera RS "Big Red" brakes
OEM 965 “Cup” wheels
OEM Carrera 2 ABS controller
OEM 944 Turbo brake wiring harness
Foglight delete / brake cooling ducts
After the parts largely arrived, the rebuild process began in earnest, which I’ve documented below. All in all, the entire project took over a year to complete and was perhaps not the brightest of ideas in retrospect, especially given the financial crisis… Nevertheless, I was finally able to drive the car in April of this year, and after ironing out several issues (call them “growing pains”), the car is nearly complete. Some of the growing pains included having to drive the car with the rev limiter set artificially at 5,000 rpm for 1,000 km; the engine dying on me one a night and refusing to restart; the ABS brake pump ceasing to function; and getting high on gasoline fumes multiple times, among other interesting experiences.
It is difficult to describe how the car handles, it is the prototypical, air-cooled 911 experience with lots more power, yet it is also some how more modern at the same time. At this point in time, the car still needs a few hundred more kilometers on the odometer, after which we will be doing some high-speed runs to fine tune the Motec and a track shake-down to sort out the suspension.
Enough background, on to the eye candy… Enjoy!
This project is truly a realization of a dream that started when my father used to stick me in the back of his '91 965 (Turbo I) when I was a kid. The “click” and “ka-ching” of the doors opening and closing, the faint smell of gasoline underscoring the smell of the leather interior, the sound of an air-cooled flat six cranking to life, and the feeling of sheer power (even in the back) when the whole thing got under way, all stuck with me through my initial forays into car ownership until late late-2007 when I was finally able to buy my very own 964.
My particular 964 started life as a Guards Red Carrera 4 (right hand drive) which rolled past the doors of one of the red brick buildings in Zuffenhausen sometime in late-1989. It was then shipped to and registered in Singapore sometime in 1990 by its first owner, and its log card (title) was subsequently passed through the hands of 3 owners before landing in mine.
During its tenor with its previous owners, my 964 accumulated around 110,572 km (68,706 miles) of driving adventures in Singapore, Malaysia and Thailand, and was saddled with such aftermarket additions as a “basket-handle” CHMSL originally designed for the 911 (993) Cabriolet models, and an awful sounding ICE system built around a decent Blaupunkt headunit and subwoofer, but using really bad speakers and tweeters.
After purchasing my 964, I decided to spend a few months getting familiar with its driving characteristics, while simultaneously crystallizing the kind of car I wanted at the end of the project. First impressions of driving the original Carrera 4 were in line with contemporary road test reviews of this particular model in that the car was very stable at highway speeds and quite comfortable for long cruises. It’s characteristics on the track were also no surprise, where the car tended to understeer significantly with an uncanny likeness to a front wheel drive car. What it came down to was that I wanted an experience that was closer to the prototypical, air-cooled 911 experience (i.e., lighter weight, a looser tail, etc.) with some more power – basically something that would surprise drivers of the modern, water-cooled Porsches on the road and track. With this goal in mind, I began the parts acquisition process for the parts that would eventually form a car inspired by the 964 Carrera Cup series, with significantly more power and some modern-day touches.
To keep myself amused in the meantime I stripped out the ICE, carpeting and interior trim pieces, and replaced the electrically adjustable seats with a spare Sparco bucket seat I had lying around. This amounted to a trimming of at least 100 kg (220 lbs) of insulation, carpeting and interior parts and the difference in handling was immediately apparent. The car accelerated much faster on the road, and tended to far less understeer on the track, to the point where I was actually debating keeping the 4WD system and building a replica 964 Carrera 4 Lightweight (http://www.qv500.com/porsche964p10.php) – until I found the “Sputnik” 4WD system kicking in and throwing the car into understeer.
At the end of the day, the spec / parts order list roughly ended up looking like this:
Body
Seam-weld all spot-welded areas on chassis
Remove and sealed sunroof panel
Bare metal repaint
Interior
Lightweight interior (no insulation, carpeting, ICE, etc.) (curb weight ~1,150kg / 2,535 lbs, 40 / 60% f/r weight bias)
Replica RS door panels / door parts
Manual window winders
Diamond plate, aluminum floor boards
Custom, lightweight A/C system
OEM Carrera RS windows (thinner glass)
Plexiglass front/rear -quarter windows and rear window
Lightened wiring harness (this was a time consuming, manual labor process that my mechanic hates me for)
Heigo half roll cage
Recaro Pole Position bucket seats
Schroth 6-point harness for driver
Schroth 4-point harness for passenger
Momo Prototipo steering wheel
Engine / Drivetrain
3.8l rebuild (dynoed at 355 hp at the crank, redline at 7,200 rpm)
JE Pistons
Carillo connecting rods
LN Engineering “Nickies” cylinders
CMW Motorsports heads
Custom camshafts
Turbo studs for crankcase
PMO individual throttle bodies
SARD fuel pressure regulator
Custom oil catch can
Motec M600 stand alone engine management system
Fabspeed "RSR" exhaust
OEM 993 G50/21 gearbox (6-speed)
Suspension / Brakes
Bilstein / H&R suspension
OEM 993 GT2 Evo wheel carriers
Adjustable front tie rods
Adjustable rear spring plates
OEM 993 Turbo / Carrera RS "Big Red" brakes
OEM 965 “Cup” wheels
OEM Carrera 2 ABS controller
OEM 944 Turbo brake wiring harness
Foglight delete / brake cooling ducts
After the parts largely arrived, the rebuild process began in earnest, which I’ve documented below. All in all, the entire project took over a year to complete and was perhaps not the brightest of ideas in retrospect, especially given the financial crisis… Nevertheless, I was finally able to drive the car in April of this year, and after ironing out several issues (call them “growing pains”), the car is nearly complete. Some of the growing pains included having to drive the car with the rev limiter set artificially at 5,000 rpm for 1,000 km; the engine dying on me one a night and refusing to restart; the ABS brake pump ceasing to function; and getting high on gasoline fumes multiple times, among other interesting experiences.
It is difficult to describe how the car handles, it is the prototypical, air-cooled 911 experience with lots more power, yet it is also some how more modern at the same time. At this point in time, the car still needs a few hundred more kilometers on the odometer, after which we will be doing some high-speed runs to fine tune the Motec and a track shake-down to sort out the suspension.
Enough background, on to the eye candy… Enjoy!
08-31-2009, 06:36 AM
#2
Racer
Thread Starter
Some pre-rebuild shots:
A mildly modified 964 C4 - a good runner in general, aside from some cold start issues
The custom aftermarket exhaust sounded great
Interior has held up well in general after 18 years of use
The aftermarket soundsystem was decent - at best...
The deconstruction begins... Seats and non-essential wiring are the first to go
After that goes the sound insulation - at least 50 kg of it...
Look at how much junk there is under all that carpeting...
Spare Sparco bucket and a stripped interior make for a fun 4WD experience...
A mildly modified 964 C4 - a good runner in general, aside from some cold start issues
The custom aftermarket exhaust sounded great
Interior has held up well in general after 18 years of use
The aftermarket soundsystem was decent - at best...
The deconstruction begins... Seats and non-essential wiring are the first to go
After that goes the sound insulation - at least 50 kg of it...
Look at how much junk there is under all that carpeting...
Spare Sparco bucket and a stripped interior make for a fun 4WD experience...
08-31-2009, 06:56 AM
#3
Racer
Thread Starter
After the sanding and paint prep
Practically brand new
The lower panel in the front boot was redone because multiple scraps with low lying objects had allowed rust to start setting in
Hard not to be impressed by these painters...
... their paint work is better than the "official" body shop that the local Porsche dealer uses!
Shiny engine bay to go along with shiny engine
Sadly most of the under side of the chassis will get mucked up by dirt, so I'm glad this photo got taken
It's hard to believe that a sunroof was removed and a panel welded into place...
... though there is a tiny bit of evidence on the under side of the roof
Why the steering column and ignition assembly were left in during painting, I will never understand...
One of the hardest decisions was whether or not to carpet the rear... still deciding...
Last edited by roadsleeper; 09-01-2009 at 03:23 PM. Reason: Fixed an image...
08-31-2009, 07:04 AM
#4
Trial Rennlist
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wow, i am very envious, that looks amazing ! I love Orange 911s 
Must be a great feeling to strip down to a bare canvas like that and create the car of your dreams.
Thanks for sharing.
Must be a great feeling to strip down to a bare canvas like that and create the car of your dreams.
Thanks for sharing.
09-01-2009, 10:10 AM
#6
Rennlist Member
This project is truly a realization of a dream that started when my father used to stick me in the back of his '91 965 (Turbo I) when I was a kid.
I would love to go into the same detail... seam welding the tub, reducing the cable harness, lightweight A/C, etc.
It is difficult to describe how the car handles, it is the prototypical, air-cooled 911 experience with lots more power, yet it is also some how more modern at the same time.
Best,
Udo
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09-01-2009, 02:19 PM
#10
Three Wheelin'
Join Date: Jul 2007
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Must have taken some courage to bust open a perfectly good looking 964.
Well, they say you have to break a few eggs................
Looking forward to the "after" pics..........and performance specs.
Well, they say you have to break a few eggs................
Looking forward to the "after" pics..........and performance specs.
09-01-2009, 03:28 PM
#11
Racer
Thread Starter
Thanks guys 
Today's installment:
The brake system ended up being one of the big conundrums of the build, given that I wanted to strike a fine balance between improving the factory system (i.e., being reasonable with expenditure) or replacing the majority of the components (i.e., going nuts... ceramics anyone?).
In the end, I decided to go with:
- Front calipers: Big Reds on 2-piece 322 x 32 slotted rotors, 44 / 36 mm pistons, 132 x 58 mm Pagid Yellow pads
- Rear calipers: MY95+ 993s on 299 x 24 mm slotted rotors, 30 / 34 mm pistons, 98 x 44 mm Pagid Yellow pads
- Retained 23.8mm master cylinder from the PDAS set-up (part # 964.355.903.00)
- Removed differential lock dual solenoid valve (part of PDAS)
- Replaced C4 ABS/PDAS brain with ABS brain from C2 (wiring harness modified accordingly, the pins have to be moved around)
- Removed ABS wiring from wiring harness and replaced with standalone ABS wiring harness from 944 Turbo
- Replaced brake hydraulic boost pressure accumulator, ABS hydraulic unit and hydraulic boost pump
- Installed 12mm stainless steel braided hoses
Master cylinder and brake fluid reservoir go in...
C4 ABS/PDAS brain still in place
Front rotor, sans caliper
Rear rotor / caliper
My 997's track wheel on the front rotor showing dinkiness of old school brakes
Today's installment:The brake system ended up being one of the big conundrums of the build, given that I wanted to strike a fine balance between improving the factory system (i.e., being reasonable with expenditure) or replacing the majority of the components (i.e., going nuts... ceramics anyone?).
In the end, I decided to go with:
- Front calipers: Big Reds on 2-piece 322 x 32 slotted rotors, 44 / 36 mm pistons, 132 x 58 mm Pagid Yellow pads
- Rear calipers: MY95+ 993s on 299 x 24 mm slotted rotors, 30 / 34 mm pistons, 98 x 44 mm Pagid Yellow pads
- Retained 23.8mm master cylinder from the PDAS set-up (part # 964.355.903.00)
- Removed differential lock dual solenoid valve (part of PDAS)
- Replaced C4 ABS/PDAS brain with ABS brain from C2 (wiring harness modified accordingly, the pins have to be moved around)
- Removed ABS wiring from wiring harness and replaced with standalone ABS wiring harness from 944 Turbo
- Replaced brake hydraulic boost pressure accumulator, ABS hydraulic unit and hydraulic boost pump
- Installed 12mm stainless steel braided hoses
Master cylinder and brake fluid reservoir go in...
C4 ABS/PDAS brain still in place
Front rotor, sans caliper
Rear rotor / caliper
My 997's track wheel on the front rotor showing dinkiness of old school brakes
09-02-2009, 01:33 PM
#14
Professor of Pending Projects
Rennlist Member
Rennlist Member
I need 5 minutes alone...
Wow! Keep those photos coming!!! This is why I want my '83 painted orange. That thing looks awesome!!!
Thank you for sharing!!
Wow! Keep those photos coming!!! This is why I want my '83 painted orange. That thing looks awesome!!!
Thank you for sharing!!
