+1....So much so that I wanted to quote the whole thing again....

 

Edited my post - muffler is okay... forgot to delete it from the list

 

I have a feeling that the exhaust is going to be a place that's tough to lose weight. I've been looking in to that lately, and the OEM axle-back portion doesn't weigh more than 12#, if my cruddy scale works at all. May be as light as 9#, according to my other cruddy scale, and those numbers will be tough to beat. I had secretly hoped that they would weigh a lot more, like many of the OEM exhausts do, but "sadly" they're already quite light. A straight pipe might be the easiest way to drop some pounds, and may even boost power a tad even at the same stock (1.67" !! ) pipe size. That's the same size as the primary tubes on my big car's headers...

WRT the battery, I thought the rules said you couldn't go with a lighter battery for weight-loss purposes. I like the Hawker batteries, and I think a tiny battery like that could start a Fit easily enough. Was planning on using one on my SM Valiant on race day rather than relocate the full-size battery to the trunk. If I misinterpreted the rules and the small battery IS legal for SM, that would be a 10-15# weight loss, and from up high, too.

 

Small battery is legal. I've run the Odyssey PC-680 in every autocross car I've owned.

 

Gimp, thank you for correcting your exhaust comment earlier. As the rules state at 13.10 (E), the exhaust may be modified post-cat in any way, as long as you meet any noise limitations required by a particular venue. If you look at the posts in the exhaust forum here, removing the rear muffler on the Fit does not significantly increase noise levels, because that OEM middle muffler is still doing it's job.

Hemi-Fit, I'm surprised the rear muffler is so light. But 9 pounds is 9 pounds! Another option to shave some weight might be to shorten the exhaust closer to the cat and mount a 90 degree turnout that sends the exhaust out the passenger side just ahead of the rear wheel.

As for the other stuff on my list, see the rules again. Section 13.2 (A) Bodywork reads as follows: "Accessories, gauges, indicators, lights and other appearance, comfort and convenience modifications which have no effect on performance and/or handling and do not materially reduce the
weight of the car are permitted."

The stuff I'm talking about would fall into the "appearance, comfort and convenience" category and all weighs well under a pound. The dictionary definition of "materially" is similar to "significant," and no one could argue that removing a few parts that together weigh less than 2 pounds is significant. So it's all permitted by my reading.

OK, except for the wipers maybe. You may have got me there, since they are not "comfort and convenience" items.

BTW, after reading the rules I became confused about whether coilover shocks are legal. For example, see Section 13.5(A)(3) of the rules. So I posted this question on an SCCA board and the response was that coilover shocks are legal IF you use OEM springs with them. So this opens up another suspension tuning option for us -- if you're willing to modify an expensive set of coilover shocks to accommodate the stock springs. But the benefits could be big because it opens up some huge custom shock-tuning options and adjustable spring perches would allow you to dial in the corner-weighting.

 

Section 13.2 (A) Bodywork reads as follows: "Accessories, gauges, indicators, lights and other appearance, comfort and convenience modifications which have no effect on performance and/or handling and do not materially reduce the weight of the car are permitted."

This allows for the addition of accessories, gauges, indicators, etc.... Not the removal.

If what you said was true, you'd see a lot more grill-less, light-less, gauge-less cars running at nationals.

As far as coilovers, I've always been told no. You cannot move the spring perch, so even with stock rate springs they are not allowed. You can only do shocks. Can you link me to your post on the SCCA forums?

 

The only problem I could see with that might be with local traffic laws. Side exist exhausts may have to exit behind the passenger compartment to satisfy Johnny Law or the CARB types, as I think they see that a a potential health hazard to the vehicle occupants. It's certainly the lightest way to go. FWIW, there are some NICE flattened oval tubes out there from the NASCAR world to keep ground clearance high, but they ain't cheap. Then again, we're talking about a 1.67" pipe here...

I guess you COULD argue that point, but it doesn't seem to meet the INTENT of the rule, to me at least. Seems like a lot of effort for minimal potential gain.

I had this discussion (specifically about the Koni racing strut inserts) on a Mopar-related autoX group I'm on, and here's the reply I got from a guy who races in the stock classes, and covers the National Solo for Sports Car magazine:

The same line of thinking is what I applied to the battery situation. P. 62 of the 2007 SCCA rules, Chapter 13 "Stock Category", paragraph 5 on wear parts: "Alterrnate components... may be used provided they are essentially identical to the standard parts (e.g. have the same type, size, hardness, weight, material etc.), are used in the same location, and provide no performance benefit." To me, a battery that drops 15# off the nose of a nose-heavy car is a pretty substantial performance benefit. Nobody may care until you're leading points at the nats, but unless it's spelled out differently elsewhere, I'd bet it's not legal.

 

I will correct myself on the coiilovers - I looked it up and yes, using the stock spring you can go to a coilover, but the spring perch MUST be in the same location, negating your ability to corner balance the car.

I also have to correct myself on the battery. Must be stock weight in stock category. Sorry, I haven't been running in "stock" in a long, long time.

 

Hemi-Fit: That is basically the same response I got.

And BTW, adjustable spring perches are explicitly allowed by the rules in Section 13.5(A)(3), which reads as follows: "Adjustable spring perches are allowed, but the spring loadbearing
surface must be in the same location relative to the
shock mounting points as on the standard part. Shims may be
used to achieve compliance."

So again, if you want to custom fab a set of coilovers that will accommodate OEM springs, it's legal. You could simply cut the stock spring perch off the OEM struts and set it on top of the adjustable perches on a coilover. I suspect it may still be possible to do some limited corner-weighting with adjustable perches because the adjustment range is quite fine. Some nice results might be possible without radically altering the measurements prescribed by the rules.

The rule does not say "additions", it says "modifications," a definition that could include complete removal. But removing lights and gauges would not be allowed under these rules because these are not "appearance, comfort and convenience" items but items essential to safe street driving (i.e. knowing how fast you are going, how much gas you have, etc.).

 

spare tire and jack would probably take out 5-10 pounds. but would be best during competition.

 

The J's Racing Titanium Mid Pipe is super lite. You can lift the whole pipe up with one finger! And from what I have been reading here the cat back is legal. I know the BEST way would be to go to a full TITANIUM exhaust for maximum weight savings.

 

well when i tried to go to race legal (forgot registration)

i take out almost everything possible.
seatbelts plus retractors, all the seats but the drivers of course, the mats, the panels,glove box, basically all is nice looking is the dash.


it really does make a big difference.
normally i borrow my buddies rpf1's 15" with azeniz tires. they are great. it made a big difference when i was practicing my launching on a back road.

i

 

Carbon fiber hood and trunk lid/door, I saw those on Vivid Racing's site. Not sure if anyone has Carbon fiber/fiberglass fenders and doors. Not sure if they're legal, but that's some weight savings.
Chris

 

I believe it depends on the type of carbon fiber. There are two types wet and I believe dry carbon.
Anyone else have any input?? Thx

 

Since we have been talking about stock class, none of that carbon fiber is legal.

I've never heard of dry vs wet carbon, but the main difference between a real lightweight carbon part and a poser part is the core. Most are fiberglass with a carbon layer for looks.

 

If you goto JDM Honda Parts, JDM Honda Engines / JDM Nissan Motor Swaps, Used JDM Parts - Password JDM it explains the two different types of carbon fiber/ click on carbon composites on the left hand side....for those of us that do not know

 

I thought about a carbon hood and/or hatchback. Racing legality issues aside, the cost-benefit calculation on these items doesn't compute for me. The OEM hood is so small and light that the savings from a carbon item aren't worth the $800+ cost or whatever it is.

 

Good point on the hood, but I wonder what the savings is on the rear hatch?

 

I've gotta go with Skimmer on this. Going to a fiberglass hood on my 1981 Camaro was a substantial weight savings, but with such a small hood, there isn't much benefit.

The bigger amount of weight in the hatch is the rear glass. To me, a carbon hatch with lexan rear glass is not street friendly. You are asking someone to drive up and park in your back seat.

The hood and hatch are the wrong places to look for weight reduction on these cars. Unsprung weight and rotating mass reduction are going to make the biggest difference in how the car performs.

Lightweight wheels, coilovers, etc may not be as big of a loss on the scale, but will have a far great effect.

 

I am with Gimp on this one, schools and seat time will make a bigger difference than removing one of the two rear plate light bulbs. The wind or temperature outside will make more of an impact on your car that that would.

You could put your rear seats into "Magic flat mode" to try and lower the center of gravity of your car.