Lightening your car

[joetiii]

I am in the process of fixing the body on my 69. I opted for a fiberglass S spolier up front and am considering a Rennspeed rs style rear bumper in FG as well. What other things are there to consider to get the car lighter?

[Jim Richards]

Remove all cabin sound deadening and engine sound deadening pad, if your car still has it in place.

[billyboy]

http://rennlight.com/ see this site.

[kmhemi]

I went with fibergalss 930 fenders and fiberglass full quarter panels from Rennspeed. I removed all of the original carpet and sound proofing. Also removed the power antenna, rear speakers, rear seats, rear seat backs, trim panels, rear deck , engine sound proofing pad and heater system. I got the lightweight RS plush carpet kit from Appbiz which replaced the items removed from the rear interior I'm done for now.

[joefrantz]

I agree with Jim Richards.

There is close to 50 lbs of sound deadening material in an early car interior. That is free weight reduction -- although some of it (like the material on the floor boards) is tough to remove.

You can drop another 15-16 lbs by removing the rear seats and seat backs.

That's 60 - 65 lbs free. Interiors are heavy.

Next I would replace the factory seats with light weight after market seats if original appearances are not important.

The cost per pound starts to escalate pretty quickly after that.

You should also bias your spending on weight reduction to the rear of the car given the weight bias.


Joe

[randywebb]

Download these files I compiled: http://www.penaltykicker.com/911/data/

Rennspeed rs style rear bumper in FG
- I made the mistake of buying one of those - my advice, get a lighter part from a competent vendor that will fit.

There are thousands of things to do to lighten your car - the real question is which ones make sense. Search on 'church'
as in church of light weight for many of my previous posts on what to do and what does not make sense.

Thom's site is good for race car level things to do.

[dd74]

A lot of what's outlined here you can do in one two two hours time. Be warned, though, after that, the price per pound of lightening increases substantially.

[joetiii]

Thanx for the useful sites. All good stuff, especially the sound deadening material.

Curious if anyone else had fit problems w/ Rennspeed FB panels?

[randywebb]

results have varied with them - Jack Olson had good results some time ago

do a search on their name, also GT racing, and some others and you will find a lot of threads. Since you are back East, find the post by Bill Verburg on where he bought his FG parts (he's in NY state) - that way you can avoid a huge shipping bill as most others are in Calif.

There are modern light wt. sound deadeners available if you find it too loud after removing the old stock stuff.

[randywebb]

more info here for a true street car with lighter wt. ...

Yet Another Boring Hot Rod Rgruppe Car - Part V, Exterior & Paint

note the things I did NOT do - those are the costly ones that don't save that much wt. ...

Jack's series of write up on Black Booty II give a higher level of mods for a track oriented car that is still streetable...

[FastCarFan]

The cheapest (i.e., no-cost) way for me to lighten my car 40 lbs is for ME to lose 40 lbs! If only it were so easy....

[Formerly Steve Wilkinson]

Remember that though it's obvious you get the most benefit from removing weight from the rear of the car, it's not quite as obvious that the higher up the weight is--sunroof and glass, mainly--the better in terms of CG.

[JP911]

Mb911's mufflers (M&K) are very light compared to the stock system. I would guess that you'll shave 10-15 pounds in the right place.

[joetiii]

Interesting to read through Randys compilation of data. From what I've discovered so far, my carbed 3.0 w/ SSIs weighs about 14 lbs more than the stock magnesium 2.0 engine. It seems the mag 911 trans weighs about 16 lbs less than the earlier 901s. Since my M&K is easily 12 lbs lighter than stock muffler, I'm confident my total powertrain weight is less than stock. Though I'm not sure if that center of mass has moved further aft.

I like the idea of stripping out the back seat insulation up top and replacing it with the sound deadening coatings available. That will help lower the COG and make up for the extra weight in stereo speakers and subwoofer installed. Those Recaros don't help any either but they sure are much better on the old back than the stock seats. ouch!

[randywebb]

Joe - I'm glad it helped. YOur stock seats were prob. fairly heavy - in '69 they still used horsehair padding. The seats got lighter over time. The Recaro SE is pretty light too.

some folks have made subs that they remove for track days - you could have the amp mounted on the sub box and lose that too.

[bob barnes]

Guys,

To go fast-remove the weight from the Drive-train, and rotating items. This after you have removed the easy interior stuff.

Bob

[Shaun @ Tru6]

Originally posted by joetiii
Thanx for the useful sites. All good stuff, especially the sound deadening material.

Curious if anyone else had fit problems w/ Rennspeed FB panels?

Joe, my experience with plastic panels:

Series900: dash and doors: excellent fit. In fact the passenger door fit as stock with no massaging. Damon is up in NH, but quite a drive.

Renspeed: front bumper, hood, rear quarters: Rear quarters were terrible, no so much from a fit perspective, but finish. The compound curves over the arches were a series of bevels. Hood was good. front bumper had a high level of finish, but was not symetrical.

GT Racing: carbon duck tail and carbon 911R front fenders: all of these were either very good or excellent in terms of fit, duck especially. The fenders should have had a better level of finish IMHO.

Hope this helps. Good data points on the weight of the motors and gearboxes. Do you have a source? I'd like to see a year by year weight for our motors. I love my little 2.0 in the E in part because I "think" it's light versus a carbed or MFI 3.0.

[joetiii]

Originally posted by Shaun 84 Targa


Series900: dash and doors: excellent fit. In fact the passenger door fit as stock with no massaging. Damon is up in NH, but quite a drive.

Good data points on the weight of the motors and gearboxes. Do you have a source? I'd like to see a year by year weight for our motors. I love my little 2.0 in the E in part because I "think" it's light versus a carbed or MFI 3.0.

Shaun, regarding weights, refer to Randys excel file at the "penaltykicker/911" link above. He's got the weights from nuts and bolts to smugg box covers etc.

Regarding the FG parts, I have a line on "better bodies.com". They are actually a body kit manufacturer and have been making these parts in SanDiego for 19 years. Though their price is less, their RS rear bumper requires slight modifications to fit my narrow body. I'd rather not have to do any extra work. If you can forward me the name of the guy in NH< that would be great! I've got to make a run up to Vermont in the next week or so so crossing into the white mountains shouldn't be too far.