Spoolin

Quick question for you folks:


The other day I was test driving an Evo 9 and a Nissan 350z? Although their performance is comparable and I've seen them go at it stock and they are about the same speed, why is that the evo has a more "head in your seat feeling" or "gut wrenching" feeling. Because in reality the 350 is just as quick as the evo but it lack that feeling, can anyone explain to me why that is the case? and can I recreate that with a turbo tc? thanks

zer0

Thats what you call a "Turbo"... N/A will never hit as hard as a "Turbo"... Unless its a V8 with lots of torque.

Rabid_Lemming

I dunno zer0....if you have a fully built N/A engine, with a high compression ratio, it hits pretty hard. Granted it becomes a much more expensive endevour in anything under 6 cylinder vehicle, but the power is more instantaneous. The cost for parts is rough though, with some of our engines running as high as 7k built, with an 11:1 compression ratio. I get what you're saying with the Turbo aspect of it though...it kicks you back once it's fully spooled and in full boost, as opposed to a more consistent rate of acceleration from N/A

paul_dezod

06 GTO gave me that feeling.

zer0

I know what your saying. But Turbos make Torque, and Torque makes fun!! For a lot less $$$.

paul_dezod

Corky Bell

TanabeTC

well also with the evo 9 they have turbo lag... my buddy has a red mr and so at first you dont feel it push you back in the seat until the turbo is boostin... it was like that when i had my 1.8t jetta.. i mean obviously its not nearly as powerful but you can still feel it pull your head to the seat when it boosts... just a thought

Spoolin

if it is because of the evo's turbo that makes torque that gives you that feeling the Z have a fairly decent amount of torque too, so why doesn't it feel the same? I wanted to get the Z but I was a little bit disapointed...and I couldn't get the evo because my lady hates the looks of it...

engifineer

turbos are more spikey... that is why a similar amount of hp in a spikey turbo setup will not be as fast overall as the same power in an NA setup if it has a flatter power curve, but you will "feel" more of a pull since it is not as linear and smooth.

Spoolin

oohhhh, well that makes sense. Thanks engifineer! so you feel more pull due to the fluxuation of the torque curve..gotcha that helps alot!

Rabid_Lemming

Get the Z, and slap in a nice big old turbo!

It probably has a lot to do with perception. Consider this:

In the Z, you started to go WOT, and you heard the engine respond, at the same time, it's begun to push you back in to the seat, and at a more constant rate of g-forces.

In the Evo, you begin the WOT, and you heard the engine respond, but due to the greater complexity, between the boost spooling, and the air making it's way through all the piping, your expected response has not happened. Then once the lag is over, all of a sudden you have a greater power and torque output. The rate here takes a sharp spike in terms of the g-forces involved.

So while the numbers are close, the delivery is different. Of course I could be wrong in all this, but this is what I think is going on.


**edit** yeah what engineer said =)

rhythmnsmoke

^^I think that about sums it up....hehe

Also, did you remember to disable the VDC when you drove the Z?.....probably not. The VDC retards the engine, not allowing it to spin fully. This in turn slows the car down even though you are going WOT. A Z with a disabled VDC feels and responds a whole lot faster than a Z with the VDC engaged.


I speak for experience.

rhythmnsmoke

^^I think that about sums it up....hehe

Also, did you remember to disable the VDC when you drove the Z?.....probably not. The VDC retards the engine, not allowing it to spin fully. This in turn slows the car down even though you are going WOT. A Z with a disabled VDC feels and responds a whole lot faster than a Z with the VDC engaged.


I speak for experience.

FLIN-SCION

No one has brought up the AWD aspect... I believe that is the major difference. Of course AWD is going to give you that feeling of "push" because the traction is WAY better, when you can put the power to the ground you will be able to feel it!

engifineer

unless he is spinning the tires it will not make a difference. AWD robs more power to the ground, so if anything it will be worse.

rhythmnsmoke

That's only the case if he was launching the car from a stop, to which I don't think he was doing.

jetlounge

iTrader: (3)

what is the "head in the seat" feeling?

because i am thinking of something completely different...

captainlaziness

As stated before, the sudden "rush" is due to the difference in how the engines make power.
A N/A engine (typically) has a flatter power curve which results in a smoother acceleration.
A turbo engine (typically) has a peaky power curve, the turbo needs to spool up, this gives a turbo engine a sudden "rush" in acceleration.


It's that step in the turbo engine's powerband that makes it feel punchier compared to a similarly powered N/A engine.

FLIN-SCION

Not necessarily, yes the traction is going to be a lot more noticable on launch but even through the power band (especially when boost ramps up) the AWD is going to stick. Thats what I was referring to. 2wd vs. AWD = AWD always wins when it comes to traction.

engifineer

Again.. unless he LOST traction, it would make no difference at all. If the tires were not breaking loose, then they would both feel the same acceleration-wise.

And the explanation captain gave is pretty good. That is also why a good running NA, 300hp car can outrun a 300HP turbo setup. More area under the curve wins regardless of peak hp.