mesa87

Anyone have any idea how much a sport seat with heaters and electric controls weigh?

I'm trying to figure the weight savings by switching around to a fiberglass shell seat.

Thanks,

Phil

I would guess over 50 lb's per seat

TheOtherEric

Yup, factory hardback electric sports seats without heat weigh 50 lbs (I had weighed mine once). Heat would add another couple pounds I suppose.

Flying Finn

A ton...

As already mentioned, it's about 55 lbs for one sports seat (no heat). Regular seat is couple of pounds more so, a ton. So switching to bucket seats will save about 100 lbs, very nice saving.

mesa87

Thanks guys, that's a lot of weight...is there truth to the 7lbs = 1hp theory?

993_Pilot

If a 3000 lb. car makes 300 hp, then the wt. to hp ratio is 10/1. Adjust as needed to suit your cars specific wt. & hp.

Wilder

Josh, I recently installed GT3 seats. My OE seats were 12 way, supple leather and weighed in at a whooping 78lbs each with rails. The GT3 seats are ~22lbs with rails. I took out over 110lbs and the car felt significantly more responsive.

wayne993

For someone looking for a large change, removing 3% of the weight of the
car is not a huge deal. I'd wager in a blind test you would not be able to
tell the difference unless you're a professional driver.

If you want to see the difference beforehand.... drive your car with a 100 lb
kid in the passenger seat, then kick out the kid and drive again. You may
be able to notice a small difference.

For most things, humans need a 10% difference in 2 quantities to tell if
they are different. (there are notable exceptions though such as frequency
of light and sound where tiny differences can be resolved) So using that
as a benchmark, you have to get 3 times the seat weight change before
you can eally tell the difference. The guy who did a C2 -> RSCS clone
conversion reduced maybe 300 lbs so he should be able to resolve the
weight change in his car with not much difficulty.

edit: I think most of the "more responsive" is your butt being told much better
what is going on with the car than your ability to tell the car is lighter.

All that said though.... you can see from my sig what I want to do next.

Wilder

Wayne: The main purpose for my seat swap was lateral support and holes for harnesses. Weight reduction was secondary at the time so I wasn't looking for the car to feel any different after the swap but it did. Once you do your seat upgrade yourself, if you manage to shed the same weight I did (I went from the heaviest OE seats to the lightest Recaros), you'll be able to judge from experience.

mesa87

Guys, anything that saves me 100lbs or so is worth doing, since any real HP mods are crazy money it seems like the easiest way to go is to shed weight. I dumped my catalytic and save roughly 25lbs from the rear end...could I tell the difference? No, but everything helps...

On another note, my wife says I could lose 20lbs myself and gain some HP

wayne993

Shedding 112 lbs on a 3060 lb car is 3.66%.

So reducing 112 lbs as far as motive power is concerned is about like adding 10.4 HP.

To a first order, there is no difference between turning and braking performance because coefficient
of friction is a linear function of the force normal to the road surface.

But after repeated stops there is 3.6% less heating of the braking system and it's doubtful but
possible this might be noticeable.

THere are other reasons to reduce weight though such as reducing moment of inertia, tire wear,
less roll, and there are probably subltle second order effects also that I'm not an expert on and
an expert driver under controled conditions might be able to probe those.

I don't have particularly heavy seats to begin with so in terms of weight loss I have less in it
that you did Louis. But I am looking forward to the better feel that everyone describes with the
GT3s or PPs.

Wilder

To be fair, I forgot that I actually lost more than ~115lbs. I removed the rear seats and seat belts at the same time, so total weight loss might've been closer to ~140lbs.

Big power in our cars is expensive but making the car light can create a similar effect at a fraction of the cost. I recently did a one-day course on a Formula Renault open wheel cart. The car had ~160HP but it was a full CF body and chasis (don't know the weight) and in gross terms, the car was much quicker than a 300HP street car.