The Great Debate - Na Vs Turbo

[jono1986]

Hey guys, I recently had quiet an extensive argument with a mate of mine about a NA car vs a turbo car. Basically what I was saying is if two cars lined up to each other and they both were making the same power but differently aspirated (turbo and NA) the NA would have more chance of winning, as the power is all done internally and doesn't rely on a turbo. My boss was saying that it would depend on how the NA car was tuned as in what Cam/headwork/blockwork was done.

 

So what do you guys reckon?

[ke70dave]

4 words dictate the arguemnt. in regards to a torque/power curve.

 

"Area under the curve"

 

you say "both cars making the same power"....what does this mean?

 

say both cars make 100kw, at what rpm? and what do they both make 1000Rpm lower, and 1000rpm higher?

 

you just can't compare the two by saying "both cars make the same power".

 

get some torque/power curves of 2 motors, that "make the same power", and one is N/A and one is turbo. then compare the two curves, work out which one has more area under the curve, that car will theoretically be "faster". assuming all other variables remain consistant between the two cars (gear ratios, tyre size, suspension, driver skill...) which isnt really possible, so you can't compare them at all!

[jono1986]

So what your saying is if a NA motor has a greater "area under the curve" this theoretically means it would be quicker than a turbo motor.

[Istartfires]

I don't think there is a real answer

[ke70dave]

So what your saying is if a NA motor has a greater "area under the curve" this theoretically means it would be quicker than a turbo motor.

 

potentially.

 

so much else comes into it though, as its not area under the entire curve, its area under the part of the curve that is being used by the gear ratios.

 

see if you can find some real dyno charts of cars with simliar peak power, and compare the lines. you probably can't directly compare them (with numbers) but you can get a good idea.

 

agreed with mr fires. its far to general to make a call.

[Des]

Torque will be different between motors so that will have an effect.

[philbey]

All the typed characters I'm going to waste on this fairly pointless debate are as follows:

 

The turbo's making the same power more efficiently, therefore he doesn't use as much fuel, therefore he's heavier at the end of the race, thus he loses.

 

Ok somewhat tongue in cheek, it really is pointless discussion.

[jono1986]

All the typed characters I'm going to waste on this fairly pointless debate are as follows:

 

The turbo's making the same power more efficiently, therefore he doesn't use as much fuel, therefore he's heavier at the end of the race, thus he loses.

 

Ok somewhat tongue in cheek, it really is pointless discussion.

 

 

:down:

[Jono.C]

For everything bad said and all the hate towards turbo's i love them.

 

That sudden burst of power when you hit boost is awesome.

 

Everyone goes ner ner ner it'll blow up, yes, it will, but only if you chalk 25psi through a stock motor or bash the living hell out of it all day.

 

All the turbo motors ive worked on or driven or been a passenger in have been great.

 

Keep it happy and it'll be great.

 

Skimp of services and parts and it'll be crap.

Edited February 21, 2011 by Jono.C

[Sloth]

As people have said there's a lot more to it than that. What if one of the cars was a bike making half the power, it would probably be much quicker. Also there is turbo lag.

[philbey]

:down:

 

Sorry couldn't help myself... :lolcry:

 

 

 

That sudden burst of power when you hit boost is awesome.

 

 

Yeh turbo kick is ok but I still reckon the kick of a really nasty NA cam is a whole lot more exciting!

Edited February 21, 2011 by philbey

[LukeAE71]

Everyone knows that its not how you stand by your car, but how you race your car

[Evan G]

Sr20det that is all

[Jono.C]

Also there is turbo lag.

 

I've never had a problem with lag.. Most turbo's i've driven or been in have been fine off boost they just picked up a lot once boost hit.

 

The only time ive seen like proper lag is when yobbo's with hektik vl's and skylines put some redculously massive turbo on it and don't get a tune or bigger injectors or anything.

 

Mate was looking into getting a rising boost pressure regulator or something similar, don't know how far he got with it..

[ke70dave]

agreed with jono.

 

unless you are going for rediculous horse power, a properly sized turbo for a street driven car will not have any dramas with lag.

 

the problem with most people and their "lag" is like jono sais, they put a huge turbo on, with a garbage exhaust manifold, rubbish exhaust, horrible intercooler and piping, don't tune it properly and then say "oh its because the turbo is soo big, thats why it lags".

 

you really need to make sure every part of the system is designed for maximum flow.

 

in the SR in my s15, its making 0.8bar by around 3300ish rpm, probably making 0.5bar by 2500, and holds 0.8bar all the way to redline, sure below 2500 is "off boost" but turbos inherintly do have that "lag", its just the nature of the mechanics of it all, but i think it can be minimsed by good parts choice.

 

also my 4age in the ke70...has nothing below about 3000rpm anyway...so thats N/A lag....

 

also one last point, when the engine is "off boost", the turbo is still blowing air, and i think that it is still helping the engine out, although there may not be positive pressure in the inlet manifold i think it is a higher pressure than if there was no turbo at all.