Originally Posted by Pete_vB
It's an individual call if the benefits are worth the weight or not, but that's very nearly the last place you want to add weight.
The stock IC is 6.5 lbs.
Looks like Forge claims 16.5 lbs.
ETS is 15.6
Helix ~23 lbs (?)
For every ten pounds you add there you add 12 lbs to the front wheels and subtract 3 lbs from the back. Put another way, adding your Forge IC has more impact on your car's weight distribution as swapping your motor for the M3's V8. For a car that is already too nose heavy that's an issue- no it's not a huge change, but every little bit helps putting power down, etc.
In light of this, and the big differences between the brands weight, I personally feel pretty strongly that weight is a factor that need to be taken into consideration. But I autocross, I don't drag race.
You are correct in a few things:
1. It is an individual call/choice (like everything else I suppose
). For people running tunes and in hot climate (raises hand), benefits of a proven FMIC clearly outweigh a 10 lb 'penalty', every day of the week and twice on Sunday. Would I have been happier if there were no weight penalties, surely, but as the saying goes...'gotta pay to play'.
2. Nearly the last place you wanna add weight - I can think of others far worse, like rotational mass (wheels, wider tires, spacers, some BBKs), but overall yes better not add any weight if possible, especially on a RWD drive car weighing more than 50% up front.
3. Weight is a factor that needs to be taken into consideration. It is, again it is in the eye of the beholder. 20" wheels are not optimal for the car, yet many have them, so I suppose to each their own.
So in your example above, should we all consider adding the Akrapovic titanium exhaust actually a detriment to the car as it lightens the rear and only adds to the front heaviness and even more unfavorable weight distribution? Or driving always with a 1/4 tank as it improves weight distribution? Not trying to be argumentative, but there is a point where you have to draw the line. I bet the winter rubber mats people put in the car add more than most IC would (granted at midsection), but my point is 10lbs in the grand scheme of things is not necessarily worth hairsplitting, unless we are running an open wheel racing series team.
PS: I don't drag race either, but I suppose I am used to driving a front heavy performance car, so going from a 52/48 to a 52.05/47.95 ratio isn't that badly felt...
2011 BMW E82 1///M: AW, all options; Renntech, Akrapovic, Forge, P3, RevoZ CF bits, many mods
1988 BMW E30 M3: Lachssilber on Silver, Dinan S14, 17' BBS rims, stock
2016 Porsche 981 GT4: Sapphire Blue, Factory bits, Xpel, stock
1998 Porsche 993 C4S: Zenith Blue, last aircooled widebody, Bilstein PSS10, Fister exhaust, mostly stock
2008 Audi B7 RS 4: Sprint Blue, Audi Exclusive Euro Bucket Interior, Premium+Titanium, many mods