Bullwings

I"m excited to see where this goes. In 10 years, the used ND market will be awesome. My s2k will be 22 years old by then and likely a giant pain in the ass to maintain if I still have it.

I can see an ND-RF in my future. Yeah, it's an extra 110 lbs. over the convertible, but if they put the sky active motor in there, i'm sure it will still be a fun 2400 lbs. car making ~190hp. It'll be like a poor mans slowtus that's reliable that doesn't get automatically get totaled due to an off track excursion that damages the clam shell made out of crystal and gold leaf.

budgy

The drive train and lug design is not going to matter with an extra 26 horsepower. The limit on those parts is more a function of grip, so weight of the car and type of tires. The power is also going to come in the form of a longer torque curve, not a fatter one...so there will not be significant additional force really at play on these parts.

vader1

If it were the Skyactive X it would have the added weight of the supercharger, but one of the linked articles suggests that it is just a change of some components in the head, which should not make a huge difference. I could see maybe a little larger brakes, but I agree with you, they should not have to beef up the whole car. Another article I read about turbocharging the thing said you don't need to beef up things like rods and pistons until you get above 225 hp.

jeffbrig

I didn't mean the hp would cause it, it would be a casualty of growing the overall weight. Mazda engineers commented that their initial commitment to keeping the weight down is what allowed them to keep the 4-lug design (just barely).

Saki GT

So the S2000's F20/F22 weighs around 325 lbs. I wonder how much the MX-5's Skyactive engine weighs...

white98ls

You guys are forgetting brakes as well. More power = more energy = need bigger brakes. I just bought some new rotors and holy hell they're heavy.

My #1 deterrent from getting an Elise...
I dunno - you used to see 3,000+lbs Accords with 4-lugs all the time.

budgy

Exactly.

My point is that if people think a minor power bump is enough to change the lifespan or safety of these components that it must be built like a porcelain doll with only 155 horsepower as is.

Im building a 400 horsepower 240 Z and its gonna run 4 lug on very grippy tires.

vader1

I am reminded of the old Ford F150 commercial where they take one of the four bolts used to secure the bed to the frame and demonstrate that the bolt is strong enough to support the entire weight of the truck.

Yeah, they might up the brakes a bit, and it could add a few pounds to the engine, but I would bet that the total weight gain is less than 50 pounds if even close to that. We are talking about adding 27 horsepower.

WolfpackS2k

Don't forget that the old Fox body 5.0 Mustang had 4 bolt hubs as well!

roel03

Unfortunately designing production components isn't like modding a car at home. Going from 150hp to 190hp will make numerous components fall under the required safety factors. It doesn't mean it will fail, but it will be under the safety factors they are required to design to. (I'm a mechanical design engineer in aeronautics)

They'll have to analyze the hubs and axles being launched by reckless drivers and it will not react nearly the same as a 150hp/150lbft car.

Also, a bolt holding the entire truck means nothing. That is not the load case that bolt is designed for, it's just a neat marketing technique.