N/A vs. FORCED INDUCTION

[Michael172]

Well. Here is another one for you. Like the Diesel Vs. Petrol thread. This is


IN THEORY

You take 2 cars. They weigh the same and have the same driver.

One engine has a turbo, or if you want, a supercharger.

The other has throttlebodies on it(im presuming this is naturally aspirated).

Both cars run the same BHP and have the same gearing.





Which would win on the 1/4 mile lol. Debate.

 

[jamesp24]

Throttle bodies im guesing.

 

[jayxx83]

depends on how the power is delivered i guess. would say throttles as well

 

[Cookie]

They wouldn't have the same gearing tho would they?

 

[Michael172]

They wouldn't have the same gearing tho would they?

look. just f**k off. its people like you that make my life as stressful as it is. :approve:

 

[DrR]

I think the turbo would win.

They wouldn't have the same gearing tho would they?

Why?

 

[Pettsi]

Edde? Fred?

 

[Martin]

What about torque and the at what rev is peak power made....tbh it's a stupid question, there is no definative answer

 

[sh33n]

Depends which gets the most peak power the soonest.

 

[Michael172]

What about torque and the at what rev is peak power made....tbh it's a stupid question, there is no definative answer

hence why I asked it. becauise i knew it would spark an interesitng conversation which will lead to a debate on all kinda of things. and in

 

[Fred@BTM]

on the flat i'd say the NA car would win (just)

race up a hill and the turbo car would win

 

[Martin]

turbo car will have more torque than the n/a but I'd don't give a feck.... I prefer n/a faster or not!

 

[GordonD]

Same power, same weight, equals same quarter mile time. Its the laws of physics. Power is the measured ability to do work. The same power does the same amount of work no matter whether its generated by an turbo engine an normally aspirated engine, steam, electric or clockwork.

Ditto top speed, though one or the other may happen to have more or less ideal gearing.

On the road though they could be quite different to drive because they may have quite different shaped torque curves, and on the road unlike on the track you use the whole range of revs, not just the ones that maximum power is produced at.

If it was the same engine then you'd almost certainly be able to get more horsepower with a turbo than with throttle bodies. So if they were producing the same peak power the turbo engine would a lowish boost one that developed a lot of torque. So the one with the turbo would have a little bit of turbo lag when you opened the throttle, but it'd have more torque.

 

[wozzaa]

I reckon the turbo would win. More torque is going to pull it off the line quicker.

 

[trile]

average joe in a turbo would win over an average joe with throttle bodies, cause he'll launch better (easier)...

 

[Monkey_beast_182]

I agree with GordonD. Same power, would equal same quarter mile time.

HOWEVER, it all depends with how the power is delivered. If you think of a Turbo, it's gonna give you a little turbo lag to begin with, and then dump the power in one big lump. Where as an NA is going to give you give your power sooner, but ultimatly it'd drop off quicker. Torque and Power curves play into as well - do you map your ECU so your power comes in sooner, or later?
I think, it's all subjective, and you'd get 100 million different setups!

 

[stan*]

what colour are the cars?

The blue one will be fastest.

 

[_Tom]

Vtec would win...

 

[TeZ]

Vtec would win...

YO'

 

[stan*]

In all seriousness....

If they made the same peak power (I assume you meant this when you said "same bhp"), then as always, the turbo engine will make more torque lower down, obviously...and as said by a few others already.
What has been said about same power = same SQM time ISNT strictly true. IF the engine was kept at peak power through the whole run, then yes this would be the case. HOWEVER they arent..that isnt how an enign eworks, it pulls through the rev range, as we know. Therefore at lower engine speeds, where the turbo is making more torque, the turbo is also making more power, and since we know power is the rate of work done, AND torque is the ammount of work done, it follows the turbo engine will provide the quickest time, since the average ammount of work done by turbo the engine will be greater.

This is assuming that obtaining traction isnt a problem.

 

[fmp_]

why would the turbo car have lag?

are they both pulling away on tick over?

if not, get the launch right and your boosting already.

I say turbo would win, due to extra torque.

But i would be praying for n/a supremacy!

 

[MarkM]

If the gear ratios are tightly stacked it would be pretty even. ie the NA car never drops out of its peak power band. Turbo car would get off the line faster, marginally, as it would take advantage of the higher torque at lower revs which would be used for a very short time to drag the car from a standstill up to peak power.

The turbo car would nose it but the driver of the ITB'd car would have a bigger smile on there face due to the sound of the ITBs.

 

[jayxx83]

The turbo has more potential for wheel spin though as the boost could spike in. I rekon ITB will be easier to modulate the wheelspin off the line hence being the winner. ITB also will be revving higher and will always be in its power band.

Ask the same question and chuck a whole day of qtr mile runs into it. I know which will be the most reliable.

 

[youngsyp]

From your example, there are too many variables to give even an educated guess. There is just too much information missing.

Do they both have the same displacment engines ?
Are the bore and stroke of the engines the same ?
Are the gearboxes identical ?
What transmission layout does each car have ?
What are the peak torque figure of each car ?
Do they make the same amount of torque over the same rpm band ?
Etc...

If the cars are identical, except for air induction methods, have the same peak bhp etc... If the driver could get the most out of each car, they'd run identical times. Why would there be any difference between the two ?!

 

[Michael172]

From your example, there are too many variables to give even an educated guess. There is just too much information missing.

Do they both have the same displacment engines ?
Are the bore and stroke of the engines the same ?
Are the gearboxes identical ?
What transmission layout does each car have ?
What are the peak torque figure of each car ?
Do they make the same amount of torque over the same rpm band ?
Etc...

If the cars are identical, except for air induction methods, have the same peak bhp etc... If the driver could get the most out of each car, they'd run identical times. Why would there be any difference between the two ?!

....................allways one isnt there.

 

[Henry]

i think it's impossible to answer too; casual observation though - the gearing would likely have to be different as the characteristics of each engine's output would likely be very different; a powerful turbocharged engine would (typically) produce it's peak well before an identically powerful NA engine. in order to make the most of the delivery, the car would obviously have to be geared accordingly.

i always thought that torque was equated with acceleration and power with top speed, so will vote for the turbo anyways.

when are you building it?
:clown: , etc


geeky and perhaps irrelevant, but might be interesting:
FRS - 169bhp/ton - 0-100 in 14.9
CTR - 166bhp/ton - 0-100 in 16.9

 

[stan*]

If the driver could get the most out of each car, they'd run identical times. Why would there be any difference between the two ?!

read my reply a few posts up...that explains how/why.

 

[Lunner]

I reckon the turbo would win. More torque is going to pull it off the line quicker.

Turbos don't instantly come on boost.......

 

[Steve2004]

geeky and perhaps irrelevant, but might be interesting:
FRS - 169bhp/ton - 0-100 in 14.9
CTR - 166bhp/ton - 0-100 in 16.9

You've pulled that FRS 0-100 from Evo mag haven't you? It's wrong, that was a tweaked car, it won't do that as standard. Other mags have timed it in the mid-late 16s, what you'd expect it to be.


As for turbo vs. n/a drag race. Hmmm.... hard to say, it'd be very close. Although the turbo would nail it for 'in gear' times.

 

[wozzaa]

I reckon the turbo would win. More torque is going to pull it off the line quicker.

Turbos don't instantly come on boost.......

If you can drive properly and launch the car correctly it will be on boost before it leaves the line. Who races a car and launches it from low revs?

 

[Kneel]

Turbos don't instantly come on boost.......

If you can drive properly and launch the car correctly it will be on boost before it leaves the line. Who races a car and launches it from low revs?

Yup you can get some stupid launches just by holding the revs on boost and then setting off, believe me the powers there the second the wheels are moving. I am unsure of the outcome of a drag race though because the N/A will have a nice smooth power delivery yet the turbos can be a bit on/off...

 

[GordonD]

In a quarter mile race the only gear you use the whole powerband in is first. And in that case you are limited by how much traction you've got, so the extra torque of the turbo wouldn't gain you anything. Plus you don't come off the line at idle.

That said, the best quarter mile times I got in my 172 were NOT by picking up revs and dropping the clutch when the light turned green. I suspected it was because that guarantees wheelspin and so activates the traction control and cuts power.

 

[youngsyp]

read my reply a few posts up...that explains how/why.

I'm afraid it doesn't old chum.

Although I can understand where you're coming from, if you max out each gear, in any car, you'll be into the zone of most torque on the up shift so, the turbo car making more torque lower down the ropm range, is irrelevant.
The same can be said for power, once maxing out a gear, when you up shift, you should be square in the 'power band' again.

If you get a good launch, and control the wheel spin well off the line, the engine, whatever the induction type, will again be in the 'power band' all from the moment of launch.

Of course, getting a good launch is the hard bit so, that's why the driver will need to know both cars and how they behave, very well.

 

[youngsyp]

....................allways one isnt there.

That's "always one, isn't there" old bean.

 

[Neil G]

Turbo would also run out of steam at higher speeds

 

[stan*]

read my reply a few posts up...that explains how/why.

I'm afraid it doesn't old chum.

Although I can understand where you're coming from, if you max out each gear, in any car, you'll be into the zone of most torque on the up shift so, the turbo car making more torque lower down the ropm range, is irrelevant.
The same can be said for power, once maxing out a gear, when you up shift, you should be square in the 'power band' again.

If you get a good launch, and control the wheel spin well off the line, the engine, whatever the induction type, will again be in the 'power band' all from the moment of launch.

Of course, getting a good launch is the hard bit so, that's why the driver will need to know both cars and how they behave, very well.

Its a very hypothetical and subjective question...so I dont really know why im bothering ....but lol...

Given the gear ratios are the same, and the peak power is the same, and that the turbo will yield more power and torque at all lower rpms (by virtue of its operation), then its fair to say the turbo will have more acceleration as it will have more torque...regardless of whether uve just shifted or not, since the ratios are the same.

e.g. say peak power on both is 6000rpm (for arguments sake), when u shift up and the revs drop back down to say 4000rpm, the turbo will be producing more torque from 4000-6000 rpm....therefore it will accelerate harder through this band.

its a daft question really...theres far too many ifs and buts.

 

[nath17t]

Turbo would also run out of steam at higher speeds

depends how big your turbo is
and i think turbo wound win coz it would push the gears faster and comes on peak power sooner
i raced a mustang (new one) in my clio and left it for dead

 

[DAIR]

Hmmm So most of you think that the turbo would win!!!!

hmmmmmmmmm So should i get the Corsa VXR?

 

[Michael172]

hmmmmmmmmm So should i get the Corsa VXR?

Are you gay ?


There is your answer.

 

[DAIR]

hmmmmmmmmm So should i get the Corsa VXR?

Are you gay ?


There is your answer.

No