High Preformance Engine Output?

Question

I was just wondering why American car manufacturers have to have such large displacement V-8 and V-10 engines to get the horse power that ou can get out of say A Turbo Charged 4 or 6 cylinder engine. The reason being is I saw some power ratings for the corvette and the dodge viper and what there making with 8 and 10 cylinders, can easily be made with 4 or 6 cylinders. The Toyota Supra's 3 Liter Inline Six, Twin Turbocharged makes allmost what some of these large displacement V-8's make. And Nissans inline six and V-6 are the same way.

Answer 1

The bottom line here, is torque. Torque is what moves the car it's what you feel in the seat of your pants. Period. Horsepower is simply a number for compairing amount of work per specific time frame engine is capable of. Not how much power it has. V-8 pushrod design engs. produce much more torque @ lower rpm's than a smaller eng w/less reciprocating mass. exampl; while suburu should be recognized for achieving 300+HP fromtheir turbo'ed 4cyl, it wouln t fair so well in my 1970 Monte Carlo w/300hp 350v8. The 4cyl would be hard pressed to move that car w/auto trans & A/C. While they both produce 300hp, the v8 has the lower rpm torque needed, whereas the turbo4 makes its power much higher in the rpm band. The v8 is done around 5500rpm+/- , while the the t4 is just coming alive! You must also consider that the U.S. uniquely experienced the `Muscle Car Era' who's credo was `There's no replacement for displacement!' many of us remember those days & want a perf.car to sound the part. Vipers & Stangs, will never sound like an angry beehive!!!!

Answer 2

American drivers prefer a V8, if they buy anything else, they kind of feel ripped off, The V8 and V10 (V10 usually used for trucks) delivers more "Off the line" pull than the in line 6 cylinders with a turbo, don't forget that the "Turbo" on the in-line six cylinder must "Spool up", to match the H.P. and Torque of the V8 Engine, that has an extra two cylinders. I have an 87 Mustang GT, 5.0 liter V8 with a "Supercharger", A kid in a Subaru WRX twin turbo was feeling a bit frisky, one day on an open road with NO side streets that ran for at least 2 miles, "Junior" decided it was time to "Waste" the ol' Pony, He did'nt plan on an "Old School" hot rodder behind the wheel, I hit it, and the "Supercharger" is belt driven, so there is NO "spool up" needed, the kid was able to get about 100' feet behind me but, lacked the "Punch" to pass the Mustang, he could keep up but, "JUNIOR" got "SPANKED" BIG TIME !

Answer 3

yes and tourque figures? if you pay attention to the graph for hp and tourque versus rpm, you will notice that the american v-engines as well as the toyota and honda(guessing on the last 2) have a nice wide power band that works at a low rpm where to make the small displacement engines have those numbers, they have to have a higher power band.

this is the concept behind the v-tec. mellow cam at low rpm, slightly wilder at higher rpms. kinda like using rhoads lifters.
ok so you know about friction, heat and vibration? at higher rpm's, friction isnt as big a factor, but the heat and vibrations will kill your engine. remember drive a machine tached all the time, you wont make 35,000 miles. now imagine that small engine in a truck pulling 10,000# and think how long it would take it to get to its power band versus the v-8. now since the v-8 has more rotating mass, there is gonna be less lash due to lugging.

besides, ever build a machine up in hp? i guesstimate around 300 hp i got out of a stock 302(135 hp originally)for a very small cost and no nitrous and it had a 2 bbl. build a 4 cyl without any goodies to reach 300 hp, you'll break the bank.