How To Get To 1800 lbs, How to Lighten My Racecar Options

[motorvated]

Just put in my fresh 2.0 liter motor, replacing my stock 1.8 liter and it is definitely a much stronger motor and my lap times have gone down. I’m still a little slower than I would like to be, but driver skill aside, I’m wondering how best to shave some weight from the car. It already has fiberglass Chalon fenders and bumpers on it, but stock hood, trunk, and door skins. One racing seat, no top, fake Fuchs, header exhaust, fuel cell, 6-point cage. Don’t know what it weighs right now, but I’m sure it’s not anywhere near 1800 lbs. So where do people find the weight savings? My door panels don’t weigh very much, and I can remove them and the door glass too. I prefer to keep the stock windshield but could remove the rear window if that would help aerodynamically but that may be unsafe from a fire spread perspective. Could remove headlight assemblies and install fiberglass hood and trunk. I usually run without the engine cover. Any thoughts on this?

[mepstein]

Estimated

10 - Firewall pad
10 - floor tar
60 - lids
10 - engine lid
5 - rockers
20 - glass bumpers
20 - targa top
5 - carpet
15 - exhaust
10 - Backpad
20 - air control
5 - door hardware
185
10 - Seat sliders
5 - interior padding
20 - headlights
10 - steel crossbar
10 - Heat flappers & lever
30 - battery and
5 - battery tray
265
20- Headers

310

Pedal board
Targa latches
Vent window & trim
Shortened sub dash
Sun visors
Glove box & ashtray
Trunk locks F & R
Glove box lock
Windshield wipers
Windshield washer
Trunk heat shield
Brake caliper shields
Radio & speakers
Engine lid latch & cable
Front trunk latch & cable
Front carpet board
Spare tire
Center tunnel covers
Shift knob
Antenna
Door cards
Door pocket

[914 Ranch]

When I was thinking about making it lighter I bought a plasma cutter. Now the car is not street worthy. Crash able. My goal was just to make it lighter. Now she is just above 1600 pounds and not safe for Door to door but I only do A/X.

[914 Ranch]

My car would weigh in at about 1750 with a cage, windshield frame and a plexiglass windshield. Sill not crash able.



And now I have probably gone over the deep end.

[URY914]

Mine. (IMG:style_emoticons/default/biggrin.gif)

[infraredcalvin]

Driver? I know I could stand to lose 15lbs or so...

[914 Ranch]

Paul's car shows something about a spot that I could lose more weight in the front suspension and brakes. I had changed my front suspension to 911. The torsion bars were too strong for the weight of the car and I changed them back to -4 but I didn't change the hubs and brakes back which I believe is a mistake as some of those pounds are part of the rotating mass. I don't believe that the brakes on an A/X only car ever get hot therefore don't need to be vented.
Paul has the lightest 914 in the world and I have the lightest 914-6 in the world.

[URY914]

Paul's car shows something about a spot that I could lose more weight in the front suspension and brakes. I had changed my front suspension to 911. The torsion bars were too strong for the weight of the car and I changed them back to -4 but I didn't change the hubs and brakes back which I believe is a mistake as some of those pounds are part of the rotating mass. I don't believe that the brakes on an A/X only car ever get hot therefore don't need to be vented.
Paul has the lightest 914 in the world and I have the lightest 914-6 in the world.

(IMG:style_emoticons/default/beerchug.gif)

[campbellcj]

As @mepstein 's list shows, the frunk/trunk lids are one of the biggest changes you can make plus that weight is up high. Totally worth it if in the budget. FWIW the lightest my car (-6) has been in full track-race trim is about 1945 which is with (heavy) 10-pt welded cage, full fire system, 2 seats+harnesses... The tub is intact, actually reinforced vs cut/lightened.

Definitely keep current and future applications for the car in mind - it would be super easy to do things to it for autox for example that wouldn't fly for track use and/or be road-legal. Once you start cutting and welding metal, it's way harder to go back!

[mepstein]

As @mepstein 's list shows, the frunk/trunk lids are one of the biggest changes you can make plus that weight is up high. Totally worth it if in the budget. FWIW the lightest my car (-6) has been in full track-race trim is about 1945 which is with (heavy) 10-pt welded cage, full fire system, 2 seats+harnesses... The tub is intact, actually reinforced vs cut/lightened.

Definitely keep current and future applications for the car in mind - it would be super easy to do things to it for autox for example that wouldn't fly for track use and/or be road-legal. Once you start cutting and welding metal, it's way harder to go back!

Only thing I'd like to add is my numbers are off the cuff. Actual weights are +/-.
I was bored while waiting at an airport when I made the list.

[stownsen914]

I probably missed it in the list, but doors on later cars are heavier than you think. On a properly caged car, you can drop well over 100 lbs going to fiberglass doors. If you have a 75-76 car, bumpers are anchors too.

[Racer]

Is this an AX car or a "race car" or a DE car? Are there class rules to worry about? Street legal?

If a 1.8, it sounds like a '74. "Fresh" 2.0 is vague... Carbed and cam? Euro pistons? just factory rebuild?

Can you ditch the windshield/pillars?
Lexan?
Rear bumper
I bet Fake Fuchs are heavier than factory fuchs..
Cages are heavy - ditch that if not needed (IMG:style_emoticons/default/wink.gif)
Chalon Kit is heavy, even if fiberglass. I bet regular GT flares would have been lighter, but you work with what you are dealt with.
Wide wheels with 100hp never works well. Lots of drag and weight to overcome

I see some pretty serious builds in this thread. If your car is the one in your avatar, well then, going to those extremes might not be reasonable)


The lightest I could get my stock , early 70 1.7 (ie, no spare, jack, toolkits, floormats but otherwise "stock" was 1990lbs with a full tank of gas)


And then the old adage "seat time, seat time, seat time"... seriously it helps.

[motorvated]

It’s the car in the avatar, a ‘72 now with a Weber IDF carbed 2.0 liter with a lightened flywheel and headers. I race it with Vintage clubs and SCCA. It has a six point cage and one seat. It definitely is faster than the ‘75 L-Jet 1.8 that I ran in it for a few seasons while I began learning how to race. Compared to the Sprites, Minis, and Spitfires that I’m now passing, I get the feeling that their light weight really helps them get the most performance out of their cars. So it got me thinking about how I might lighten my car and see some benefit. Although I have current plates and insurance for it, it’s not a street car. The Chalon fenders are very light, but the bumpers may be a bit heavier. Car handles great in the corners and with 5-lug 911 bits and Koni’s all around, it corners flat and out-brakes many other cars. I readily admit that I definitely need more seat time, but this season has been tough. Bigger motor means all my brake and shift points at my local tracks now are quite different, but despite that I have managed to shave a few seconds off my old 1.8 lap times. Hope to get out more before the season ends.

[Racer]

Bumpers are heavy.. especially those rear bumperettes I see. If they are the later wide ones, that could be 20lbs right there.
Look at everything in/on the car and ask yourself two questions:

1) Do the rules require it?
2) does having it make me faster?

And if the answer is no, remove it!

Roof off, might not be helping.. Sure its lighter, but there might be an aero benefit to running it. Sure its 8-10lbs.. but if running it adds a few mph on the longer straights, it might be worth it.

Get it on a scale (local waste transfer near you? local club scales? SCCA scales?) and then just start removing as the rules allow!