Originally Posted by technicaltom
YES the weight of the engine surely has an impact on the overall power to weight ratio of the car.I know you know what im saying, but A 500 LB v8 USA Engine versus a Fiat 2 cylinder that is less than a 1/4 of its weight .
I agree i have done a lot of research on engine weight as well.
!READ AT YOU OWN RISK!
These are the majority of the links I found when I was researching that a few weeks ago. My deal is this on that - aside from the placement of the weight of the engine and how much power it can make reliably and efficiently for how much the engine weighs, it really doesn't matter too much terribly much.
This is my reasoning in that statement - if my engine weighs 400 pounds and is an inline 6 then more than likely it has two cyl in front of the front axle so you have 4 behind it. Lets divide that straight 6 into 6 hunks, that is 66.667 pounds for every cyl (basically). no lets lop off 2 of them that 133.33 pounds of weight hanging in front of those front wheels. that is a 267 pound 4cyl the ca18det weighs in at about that weight fully dressed and makes 200hp lets say the 400 pound monster l6 makes only 135hp. (if you can't figure out i am using my z in comparison you're dumb
) now i have a gain of not only the 75 hp of the motor- but for every 10 pounds lost its close to making 1 more hp for the power to weight ratio. so that is like having a car that not only has a better weight distribution BUT it also has 88 more hp (relatively). In this equation it matters.
Here is the other side to that. cost- and goals
the motor trans and ecu cost about 1500 on average plus shipping so lets just say 1800 to be safe.
Now lets pretend you can't fab or are too lazy to (which is likely the latter around here) so you have to fab exhaust motor mounts fuel lines drive shaft misc hoses wiring the the interior gauges etc.
so lets just say we are at about oh 2800 or so just to swap in the ca18det in the z. you gained 75 hp saved weight so add 13 to the seat of you pants. but did this for 2800 bucks. that is a lot of cash for little gain.
Now there are a few reasons I am talking about a swap. There is not one car out there with the motors these have in them (180sx for example) that is a good car out of the box. the 180 is a horrible car- for that motor. the best setup i have seen in any car is the miata - the new z cars- the new vettes, and the caymans. all the rest have a horrible setup. at one point i read somewhere for example the 911 is like running around with a full diaper - and its true. honestly not many of us can afford the cayman (best setup imho) to own or fix by that matter. even to work on that car ourselves in our garages is a pita. so the next best thing is the front midship engine rwd car. the miata, the z, or the vette. notice these 3 cars- not one has the type of motor i am talking about - the vette is the closest to it. NOW to get off my soap box and go back to what I am talking about.
If for example i take that 2800 bucks I could spend on the ca18det swap and put it in swapping in stronger transmission (z32 5spd) and change the ecu out and put a blower on the engine at low boost i should be making more power with less money spent.
what would be best is if a car had a light weight engine that made power from 2000 rpm to 9000 rpm but was varied for mpg and power (much like vtec) was large enough to put down the tq for throttle response but not so large that it would weigh too much for the car. make the car again front midship engine rwd with independent suspension at 4 corners of the car. Also make the engine balanced and smooth. so not that limits us to a l6 or a v12 and l6 does is not very efficient for space. so that leaves the 12. but the 12 is too much weight (generally) So make it of a small displacement say a 3.0lt give it itbs that go to two upper intake plenums each having a blower on them- now had 4 turbos 2 small to spool up the two bigger turbos and a large enough outercooler for each side intake to handle all the heat plum this into each upper intake the itbs. Now i am starting complicate things. I think you get my point and this post is already too long winded- and "soapboxy" just too many thoughts going on in my head for the past couple weeks spewing out at once from all the research I have done.