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Discussion Starter #1
No, not internal engine rather suspension, brakes & driveline...wasn't sure of what forum would be most appropriate, so being I run N/A classes, here we are ;)

I run a N/A bbc setup trying to refine it as much as possible without going crazy with it.

Been thinking about any potential performance benefits of say light weight race brakes, specifically Strange Engineering recommended by a local chassis shop. Car currently has factory discs up front and drums out back (79 Malibu). According to the shop owner, the car can lose every bit of 80 lbs with the brake swap front & rear (including aluminum master cylinder to replace the iron stock one). Now that sounds good as the car is overweight for the class, but will this expendature yield measurable gains on the ET slip? I've always heard that unsprung weight is the best place to lose weight for performance, but can such gains be quantified?

Same goes for the TRZ chromoly A-arms...one fellow racer did the swap and said he measured a weight loss between 20 to 25 lbs from the stock A-arms.

The car still has heavy street M/T Sportsman street tires almost 10 years old which are due for replacement. By the manufacturers charts, I can easily lose 8 lbs per tire up front.

Out back I run a 275/60 M/T ET Street Radial...weight is 32 lbs...I see the Hoosier D/R in the same size weighs 8 lbs less per tire at 24 lbs.

Are the tire weigh losses of measurable benefits?

Lets add this up...

brakes F&R = 80 lbs (or so)
A-Arms = 20-25 lbs
front tires = 16 lbs
rear tires = 16 lbs

potential loss upwards of 130 lbs

Now, I'm not talking the old rule of thumb of 100 lbs equaling a tenth. With unsprung weight, I've read the weight losses are more dramatic in regards of performance...true? or not?

On another side note, I've considered redoing my M/S cage out of chromoly which by my measurements would knock another 50 lbs off the car, plus adding some additional bracing in specific areas.

Any thoughts on potential gains from these proposed weight losses? I certainly don't want to spend money on such items if the gains are so small they aren't measurable. Right now the car runs 132 mph and stops quite well with the factory brakes...don't want to piss money away on this type stuff if it's of no real performance benefit.

thanks for any input
Todd
 

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In the most general terms, the qickest cars will actually be underweight for the class by a couple of hundred pounds and be able to meet class rules by using ballast, and placing that ballast where it does that particular car the most good. Scales are a good place to start when placing the weight, then finally at the track.
 

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Discussion Starter #3
79rustbucket79 said:
In the most general terms, the qickest cars will actually be underweight for the class by a couple of hundred pounds and be able to meet class rules by using ballast, and placing that ballast where it does that particular car the most good. Scales are a good place to start when placing the weight, then finally at the track.
I realize that, but that is not what I was asking. My question is if there's any performance to be gained on track by the lightening of components that are for the most part unsprung weight? Are these measurable gains, or so small that you likely wouldn't notice them on the time slip.

Either gains from less caliper/pad drag, less reciptocating weight, or even incremental improvements due to less unsprung weight to move.
 

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If you do the whole thing at once I would say yes there will be an improvement, especially with lightening the tires and rims, that's a bunch of weight with a large moment of inertia, mass on a big circumfrence.
 

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Just noticed this thread........Been working on the issue's.

On my a-body (70 skylark) the a-arms I got from PA Racing were a total of 15lbs lighter than stock.

It's a real committment,But you can find alot of little stuff to remove weight.
It will make the car "better" as a whole and as noted you can't take advantage by moving weight around to see what you car likes.
 

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I can say from A B A testing on my car that lighter wheels and tires made no differance on my car. Went from radials to an ET front with no change.

I also went from stock k-member,arms,and steering box to tubular chromoly with a rack. It was 80 pounds off the front and the car picked up .05 average.
 

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you probably won't see much from just changing wheels.Its the entire package if you are starting from scratch.Or just do 1 or 2 things each offseason to help achieve the final goal,,,what do you see on"fast" cars????? lightweight brakes/driveshaft/a-arms/wheels,,,etc...not including the things you can't see. Thats why they 60' good and e.t.. look at super stock or top stock cars,most of them don't run what I call fast and they still have the killer axles/brakes and such.no matter how fast a car is (E.T) that stuff matters. :-D
 

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i'd say brakes and rear tires would make a noticeable difference in your 60' after thatit's a lot of money for just a bit of go......
 

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Sure, there absolutely comes a point where $ spent, for gains returned begins to flatten out.... and you're left working for very small gains. It also depends on your goals in racing.... I often get caught up in my own world of heads up class racing and I forget that not everyone has that kind of goal...
 
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