I'm looking into weight reduction on my 2003 Sunfire. So with carbon fiber hood and trunk, any idea how much weight reduction that is (and the trunk filler)? I know the hood is a heavy thing, but the trunk doesn't feel so beefy. Is there any real benefit to swapping that out for CF? Also, any ideas what the seats weigh? The car has dynamat and I'm okay leaving that in for noise reduction, as this will be a daily driver and cruiser. Any other ideas on things that can be taken out, if with a little bit of reinforcement? I had a friend suggest that any metal in the inner fender area be cut and reinforced with tubular. I haven't really considered that becuase I haven't actually looked at it, but my assumption is that it was part of the engine cradle and I'd rather not ditz with that unless I can get better than 500hp to the ground, and then I'll start doing a fab'd cradle. It's gotta have a spare wheel in it, so yet another drawback. Rear seats are very easy to take out and put back, so there's another option. Let me know what you guys think and what kind of gains can be expected. Oh, and weight of OEM wheels vs traklites.

Good luck on the Carbon trunk for a sunfire coupe.

Also most cheap carbon hoods are fiberglass hoods with a single layer of carbon fiber on top to make them look like Carbon.
Personally I'd just get a cheaper, and often lighter, fiberglass hood and paint it.

Also I think your money in making the car faster would be better spent on a turbo or supercharger.



I miss my Cavalier, even if it made 100 hp on a cold day and had more suspension then it deserved.

To say I'm not interested in cheap is a lie, however I'm more bent on doing it right. If fiberglass hoods are really proving to be lighter than CF, then to hell with CF. Cheaper? Lighter? Cool.

For now, I'm simply interested in reducing weight as much as possible but without sacrificing too much comfort.

I plan to install a turbo kit probably after March. At the same time I will be installing new Eagle rods, Wiseco reduced compression pistons, OEM crank (will be sending out newer crank to be knife-edged, balanced, and cryo-treated along with pistons and rods), bearings, rings, head work (intake side porting, exhaust side porting and polishing, 5-angle job, bronze guids, zzp springs and retainers, new roller rockers, Comp 113300 cams), and taking it to a local tuner shop for a flash. Of course the car won't be complete without 3.5" or 4" turbo-back exhaust and an LS throttle body on a fabbed intake manifold with direct-port injection and whatever fuel injectors I will pick for the horsepower level I'm going to go in at. I haven't figured that part out quite yet, but I know what I'm doing. Part of consideration should be that I will be installing a catalytic converter, resonator, and probably keeping two mufflers out the back. Basically I'm probably going to install 4" pipe to a splitter with 2.25" pipes going to two quiet exits.

So with some of that knowledge, we can deduce that, even with the extra muffler and resonator, it's going to be a bit noisy with the dynamat removed, so, again, I don't want that taken out. Where else can weight be reduced without sacrificing driveability? Second, if I sacrifice creature comforts then what kind of reduction is possible? Is there some steel behind the dash that I can remove and maybe fab some brackets for? Anything particularly heavy that can be reworked?

Reducing rotational weight will be most beneficial.

Lightweight wheels (smaller the better) will not only shave weight but be easier for the motor to turn, the brakes to stop, and the suspension to react to changes in road surfaces.

Realistically, you'll have to get pretty drastic to save significant weight. Ditching carpet, sound deadening, back seat, spare, etc may net you 100-150ish lbs

Maybe jump right to a Hahn kit and a balanced, upgraded rotating assembly.

I'm going to agree in some respect here but it goes a bit further in my experience
It is rule of thumb that every 100 lbs removed from sprung weight is good for a tenth in the quarter if all else was left alone .. sprung weight is any weight such as gas or cargo fenders glass etc. and it is also said that every 10 lbs of unsprung weight is worth a tenth in the quarter .
Unsprung being wheels tires breakes everything that is not riding on the suspension
.. if you reduced 20 lbs in tires and wheels alone you would in theory go from a say 15 flat to a 14.8
And that would be the same effect as removing the average passenger who weighs 200 lbs
I hope this helps

What would the increase be for every pound taken from the rotating assembly? Same tenth? That's an interesting concept, in addition to widening rpm range.