Weight reduction ideas - Rennlist - Porsche Discussion Forums

Notices

Weight reduction ideas

Reply

Old 08-18-2017, 08:29 PM
  #1  
Cloud9...68
User
Thread Starter
 
Cloud9...68's Avatar
 
Join Date: Mar 2011
Location: Austin, TX
Posts: 859
Default Weight reduction ideas

I know a ton has been posted on this topic, but the information is scattered through many threads, making the search I attempted less than fruitful, so I thought I'd start a new 944/968 specific thread. Mine is a track-focused 968. I drive it to and from the track, so it has to remain street legal. I don't want to remove the carpet, or the door panels at this time. Here's what I've done so far to take weight out of it:

-Sparco Evo drivers seat, some sort of Corbeau fixed-back fiberglass racing seat on the passenger side that I bought used
- Fiberglass hood, with aluminum louvers. Removed struts, but kept hinges and latches. I'm guessing total of 10-15 lb savings
- 4 lb Battery Tender lithium ion phosphate battery
- Fixed headlights (featherweight Hella bi-halogens) ~30 lb savings
- Removed front bumper bar - 15 lb savings
- Removed fog lights, and replaced with fiberglass brake duct scoops
- Removed rear bumper bar - 20 lb savings
- Removed windshield washer reservoir - 12 lb savings
- Removed cruise control
- Removed passenger side air bag and control module
- Removed the surprisingly heavy eyelets that I think were used to strap the car down on the boat ride from Germany
- Converted electric sunroof to manual
- Removed stereo and speakers (almost always drive with the sunroof off, so I can't hear it, anyway) - Saved about 12 lbs
- Removed AC compressor, radiator, drier, and assorted plumbing. Built my own brackets to relocate the alternator to the A/C compressor’s spot – Saved about 25 lb.
- Removed fuel rail cover
- Removed rear seat
- Removed rear quarter interior panels, cargo area carpet and pad
- Removed rear window wiper and motor
- Removed hatch opener motor (converted to manual operation)
- Removed spare tire, jack, and tools
- Replaced stock exhaust with RS Barn cat back
- Single-mass aluminum flywheel – 17 lb, I believe

It has a weld-in roll bar/half cage from Hanskville Hotrods, which adds back about 30 lbs, iirc, along with a harness (drivers side only), in addition to standard inertia reel seat belts I bought off eBay. It also has Racers Edge heavy duty A-arms, which add several pounds back as well. I know a lot of people on this forum track their cars, so I was wondering if there are any opportunities I've missed. I think I'm reaching the point of diminishing returns in terms of cost/benefit, but I'm curious as to other peoples' ideas. Obvious things I haven't done yet include a plexiglass hatch window, a proper racing steering wheel, a lighter alternator, and a lighter passenger seat. Anything else?
Cloud9...68 is offline  
Reply With Quote
Old 08-18-2017, 09:44 PM
  #2  
951and944S
Super User
 
951and944S's Avatar
 
Join Date: Dec 2001
Location: New Orleans/Baton Rouge
Posts: 2,881
Default

Originally Posted by Cloud9...68 View Post
I know a ton has been posted on this topic, but the information is scattered through many threads, making the search I attempted less than fruitful, so I thought I'd start a new 944/968 specific thread. Mine is a track-focused 968. I drive it to and from the track, so it has to remain street legal. I don't want to remove the carpet, or the door panels at this time. Here's what I've done so far to take weight out of it:

-Sparco Evo drivers seat, some sort of Corbeau fixed-back fiberglass racing seat on the passenger side that I bought used
- Fiberglass hood, with aluminum louvers. Removed struts, but kept hinges and latches. I'm guessing total of 10-15 lb savings
- 4 lb Battery Tender lithium ion phosphate battery
- Fixed headlights (featherweight Hella bi-halogens) ~30 lb savings
- Removed front bumper bar - 15 lb savings
- Removed fog lights, and replaced with fiberglass brake duct scoops
- Removed rear bumper bar - 20 lb savings
- Removed windshield washer reservoir - 12 lb savings
- Removed cruise control
- Removed passenger side air bag and control module
- Removed the surprisingly heavy eyelets that I think were used to strap the car down on the boat ride from Germany
- Converted electric sunroof to manual
- Removed stereo and speakers (almost always drive with the sunroof off, so I can't hear it, anyway) - Saved about 12 lbs
- Removed AC compressor, radiator, drier, and assorted plumbing. Built my own brackets to relocate the alternator to the A/C compressor’s spot – Saved about 25 lb.
- Removed fuel rail cover
- Removed rear seat
- Removed rear quarter interior panels, cargo area carpet and pad
- Removed rear window wiper and motor
- Removed hatch opener motor (converted to manual operation)
- Removed spare tire, jack, and tools
- Replaced stock exhaust with RS Barn cat back
- Single-mass aluminum flywheel – 17 lb, I believe

It has a weld-in roll bar/half cage from Hanskville Hotrods, which adds back about 30 lbs, iirc, along with a harness (drivers side only), in addition to standard inertia reel seat belts I bought off eBay. It also has Racers Edge heavy duty A-arms, which add several pounds back as well. I know a lot of people on this forum track their cars, so I was wondering if there are any opportunities I've missed. I think I'm reaching the point of diminishing returns in terms of cost/benefit, but I'm curious as to other peoples' ideas. Obvious things I haven't done yet include a plexiglass hatch window, a proper racing steering wheel, a lighter alternator, and a lighter passenger seat. Anything else?
Go lexan on the back deck glass. If done right (with a center brace) you'll never miss the glass.

If you ever had a complete door off and carried one fully loaded just 20 feet, then picked up a gutted door, you'd see where the real weight is. We don't run windows at all (all track and tow with trailer) but you could make some tracks and do manual raise/lower lexan on those for street.

Other than that, pull your fender and scrape all the sound deadening, while they are off, pull the fender liner and do the same on the whole wheel house.

T
951and944S is offline  
Reply With Quote
Old 08-18-2017, 10:08 PM
  #3  
sm
Super User
 
sm's Avatar
 
Join Date: Oct 2001
Location: Northeast
Posts: 2,151
Default

Cloud,

What's your car weigh now?
sm is offline  
Reply With Quote
Old 08-18-2017, 10:26 PM
  #4  
sm
Super User
 
sm's Avatar
 
Join Date: Oct 2001
Location: Northeast
Posts: 2,151
Default

Regarding the hatch, has anyone used Percy's Speedglass for the 944/968 hatch? I hear great things about their lexan, but can't find someone who's used it for the hatch on these cars.
sm is offline  
Reply With Quote
Old 08-19-2017, 12:08 AM
  #5  
V2Rocket
Rainman
Rennlist Member
 
V2Rocket's Avatar
 
Join Date: Jan 2007
Location: Rancho Cucamonga, CA
Posts: 41,508
Default

FWIW the stock glass rear hatch with rubber spoiler is 52 lbs.
Lexan should be about half that.
V2Rocket is online now  
Reply With Quote
Old 08-19-2017, 01:26 AM
  #6  
rlm328
Addict
Rennlist Member
 
rlm328's Avatar
 
Join Date: Aug 2007
Location: Houston, Texas
Posts: 3,515
Default

Fiberglass hood
Fiberglass front fenders
As stated by you Lexan rear window
Side quarter windows Lexan
Excess wiring harness
If you want to retain your carpet (fire hazard), temporarily remove it to get at all the sound deadening material under it.

You need the front metal bumper bar for tow ring attachment. Drill it for weight savings.
rlm328 is offline  
Reply With Quote
Old 08-19-2017, 01:37 AM
  #7  
rlm328
Addict
Rennlist Member
 
rlm328's Avatar
 
Join Date: Aug 2007
Location: Houston, Texas
Posts: 3,515
Default

Here is an old weight reduction list I found. Please note I am not the author, though I wish I were.
Attached Files
File Type: doc
Weight list for reduction.doc (115.0 KB, 136 views)
rlm328 is offline  
Reply With Quote
Old 08-19-2017, 07:57 AM
  #8  
PorscheFanatic202
User
 
PorscheFanatic202's Avatar
 
Join Date: Jan 2013
Location: Cherry Hill, NJ
Posts: 474
Default

Originally Posted by 951and944S View Post
Go lexan on the back deck glass. If done right (with a center brace) you'll never miss the glass.

If you ever had a complete door off and carried one fully loaded just 20 feet, then picked up a gutted door, you'd see where the real weight is. We don't run windows at all (all track and tow with trailer) but you could make some tracks and do manual raise/lower lexan on those for street.

Other than that, pull your fender and scrape all the sound deadening, while they are off, pull the fender liner and do the same on the whole wheel house.

T
Just got a full door... they are stupid heavy. I was surprised. I'll weigh mine today for a reference.
PorscheFanatic202 is offline  
Reply With Quote
Old 08-19-2017, 12:26 PM
  #9  
Noahs944
Addict
Rennlist Member
 
Noahs944's Avatar
 
Join Date: May 2013
Location: Calgary, Alberta, Canada
Posts: 2,892
Default

Originally Posted by 951and944S View Post
If you ever had a complete door off and carried one fully loaded just 20 feet, then picked up a gutted door, you'd see where the real weight is. We don't run windows at all (all track and tow with trailer) but you could make some tracks and do manual raise/lower lexan on those for street.
I completely agree the doors are pigs.
I have converted to a strap with holes rather than the motors. Still running glass. One thing I'd be concerned with is scratching the lexan on the weatherstrip, so for myself this wouldn't be idea. I have realized if don't correctly I can pop the glass out very quickly for track use if I must. But I don't knot what the best solution is. Right now I'm considering sliding windows in lexan. Do most racing sanctioning bodies allow for these?
Noahs944 is offline  
Reply With Quote
Old 08-19-2017, 12:42 PM
  #10  
Noahs944
Addict
Rennlist Member
 
Noahs944's Avatar
 
Join Date: May 2013
Location: Calgary, Alberta, Canada
Posts: 2,892
Default

Cloud,

Imho the weightlose concept is a double edged sword. In my 944, all steel and all glass. Street legal with a/c retained. Weight measurement was 2500lbs with one seat & half a tank. That was like 2 years ago. I was proud, but later feel embarrassed by certain choices I made (some which I can't undo).
In a daily driven cars sometimes we go to far.

Food for thought: You have a roll bar (nice start)
In a rollover your doors & windows play a HUGE part in supporting the roof front collapsing. The rollbar isn't going to save your neck or back in a rollover; it really isn't much more than a shoulder harness mount. I know because I also have the Hanksville roll bar and have assessed this critically. My advice is to retain glass & either manual or electric window regulators until you install the rest of the Rollcage. The reason being at this point the Porsche body as a unit -with glass up) is what is will protect you from injury until you go full cage.
Noahs944 is offline  
Reply With Quote
Old 08-19-2017, 12:56 PM
  #11  
Cloud9...68
User
Thread Starter
 
Cloud9...68's Avatar
 
Join Date: Mar 2011
Location: Austin, TX
Posts: 859
Default

Originally Posted by sm View Post
Cloud,

What's your car weigh now?
Unfortunately, I didn't weigh everything I took off the car, but my guess is around 2800-2850 pounds.
Cloud9...68 is offline  
Reply With Quote
Old 08-19-2017, 01:01 PM
  #12  
Cloud9...68
User
Thread Starter
 
Cloud9...68's Avatar
 
Join Date: Mar 2011
Location: Austin, TX
Posts: 859
Default

Originally Posted by rlm328 View Post
You need the front metal bumper bar for tow ring attachment. Drill it for weight savings.
Actually, I built a tow hook mount that I attached to the original mounting points for the bumper bar. It works great - have had to have the car towed a few times.

Name:  Tow hook.jpg
Views: 966
Size:  199.8 KB
Name:  IMG_1113.jpg
Views: 962
Size:  177.2 KB

Also, thanks for the weight reduction list. I can verify that many of the figures in the list are accurate. However, some, like the bumper bars and hood, which I weighed, are way off. I think the person who compiled the list put the weight in pounds in the kg column on some of the items, and then erroneously multiplied this number by 2.2 to come up with the figure on the lbs column.
Cloud9...68 is offline  
Reply With Quote
Old 08-19-2017, 01:23 PM
  #13  
Cloud9...68
User
Thread Starter
 
Cloud9...68's Avatar
 
Join Date: Mar 2011
Location: Austin, TX
Posts: 859
Default

Originally Posted by Noahs944 View Post
Cloud,

Imho the weightlose concept is a double edged sword. In my 944, all steel and all glass. Street legal with a/c retained. Weight measurement was 2500lbs with one seat & half a tank. That was like 2 years ago. I was proud, but later feel embarrassed by certain choices I made (some which I can't undo).
In a daily driven cars sometimes we go to far.

Food for thought: You have a roll bar (nice start)
In a rollover your doors & windows play a HUGE part in supporting the roof front collapsing. The rollbar isn't going to save your neck or back in a rollover; it really isn't much more than a shoulder harness mount. I know because I also have the Hanksville roll bar and have assessed this critically. My advice is to retain glass & either manual or electric window regulators until you install the rest of the Rollcage. The reason being at this point the Porsche body as a unit -with glass up) is what is will protect you from injury until you go full cage.
Nicely thought out and well put. Yes, safety always has to come first. Also, it's important to keep things in perspective. I just use the car for sessions at the local driving academy. I look at it as a training tool for my ultimate goal, which is to participate in an arrive-and-driver series (when my kids are out of college) like the Simraceway series at Sonoma International Raceway. I just want to strike a balance between a car that is capable, responsive, and can pass other cars at least as often as it gets passed (there's a lot of high dollar hardware at Driveway Austin), without costing a fortune to run. At this point, I'm just looking for any items that I may have forgotten about. The lexan rear hatch and a lighter passenger seat may be the next, and possibly the last, things I do in the weight reduction department. Unless my friend with the trick Miata adds a turbo - then it's game on
Cloud9...68 is offline  
Reply With Quote
Old 08-19-2017, 01:49 PM
  #14  
Humboldtgrin
Addict
Rennlist Member
 
Humboldtgrin's Avatar
 
Join Date: Jun 2014
Location: NORTHERN CALIFORNIA
Posts: 1,927
Default

I didn't see the list but it's probably for a 944 not a 968 so the 968 hood is probably a lot lighter in stock form. My 944 stock hoods are heavy and my fiberglass hood is supper light compaired.
Humboldtgrin is offline  
Reply With Quote
Old 08-19-2017, 01:58 PM
  #15  
V2Rocket
Rainman
Rennlist Member
 
V2Rocket's Avatar
 
Join Date: Jan 2007
Location: Rancho Cucamonga, CA
Posts: 41,508
Default

i think i weighed a stock 944 hood at around 42 lbs once upon a time.
V2Rocket is online now  
Reply With Quote

Thread Tools
Search this Thread
Quick Reply: Weight reduction ideas


Contact Us Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: