Power To Weight

[storm_rider_]

I was looking at the respective powers you guys are getting out of the lexus v8's. Some are pretty awesome, I was noticing to the 1/4 times aren't super fast which got me thinking. Even the conversions where they are used in lighter bodies that they are still not as quick as i would have thought.

Does that come down to weight of the cars and gearing??

You look at all the supercars out there with the exception of the old s4 lotus esprit all have atleast 6 cylinder engines. Even subaru are doing it now.
which brings me to my main thought. There must be a point or is it just for reliabilty issues the car manufactures switch between 4 to 6-8 cylinder engines. Also there must be a point to where the hp being put out evens out the additional weight of the car its in and the additional weight of the engine and driveline.

Heres a bit of food for thought to. This fiat 124 cc belongs to a guy in oz. It puts out 500+ hp and runs consistantly 9.8 second quaters at 133mph.
Its a 2ltr Fiat turbo. Granted it is 1000kg car

 

[cribbj]

Weight is definitely the enemy when trying to accelerate anything, and gearing can help this, of course. There's a huge thread here on Lextreme(like any other gearhead forum) about gearing, torque and power. Do a search on Torque vs Horsepower, or similar, and you'll find it.

As to why the OEM's "upgrade" from 4 to 6 to 8 cylinders, IMO it also has to do with the NVH (noise, vibration, harshness) of the car, which plays a big factor in the attractiveness of the car for a potential buyer.

 

[XR8tt]

Fiat block and Lancia heads...

 

[storm_rider_]

It does have a lancia head but in saying that doesn't mean alot because they are of very similar design used on both fiat and lancia's being that they are both owned by the fiat group to. Suttle things were changed like water entry into the head and the like but valves and chambers and really the things that matter are the same. The big reason why they used a lancia head is purely because they are easy to get, Usually from a lancia intergrale.

Anyway thats besides the point, still an iron block 2ltr with 16valve head and turbo and very quick and light.

All the point i was trying to make is if I was to chuck a large chunk of cash at a lex getting a turbo(s) or supercharger setup and still be only doing mid 13-14 second quaters i'd be annoyed. Sorry if it sounds like i'm bashing the lex because i'm not. I've been in enough jet boats and hiluxs with them in and think they are pretty awesome bang for your dollar.

 

[bigblockford545]

You can't get away from basic physics:

F= M x A so A= F/M

So if you increase either the force (torque) or decrease the mass (weight) all else being equal, the car will accelerate harder.

have fun

Simon

 

[rms]

The biggest thing the Fiat in the picture has going for it is TRACTION.
Traction seems to be a forgotten word, yet it is just as important as bhp and weight.