i agree with NA engines having a much more linear and broader torque curve. but i'm hearing all this talk of turbo lag, but i get full boost by 3200rpm. i'm in positive boost as low as 2200rpm. i have limited track experience but how often are your revs that low? i know when I drive around town, i use the same 'technique' as i would at the track, (ie. downshift defore turns, heel and toe), and i NEVER find myself stuttering from turbo lag.

anyway, I think alex_alex hit it on the head with his post, so there's no need to reiterate what he said.

 

But this predictability you mention really comes down to how good the driver is. Even on an autocross course, if you are in boost, you know exactly how your car will respond under throttle, that is to say, instaneously. Likewise, if you are off boost, you know exactly how your car will respond under throttle, and that is to say, sluggishly.

As long as you stay within the boost range, the response will always be instantaneous.

Further, the issue here is forced induction or not, so naturally, we must hold displacement constant.

If we are comparing an NA tuned 2.0L versus a turboed, the "lag" that you would feel on the turbo motor is not really that much slower necessarily than the same engine tuned NA would leave you.

Similarly, if you were comparing 5.0L's, a turboed motor that is this big would show much less lag than 2.0 turbo, but would probably not lag much more than an tuned NA at lower RPM's.

Of course, a 5.0 NA tuned would probably do much better on an autox (assuming equal handling and weight distrib) than a turbo 2.0L, but that is not the issue, and is not what was originally being compared.

 

ok,ok,jump all over my back! j/k

To be perfectly honest...a twinscrew supercharger is my favorite choice. Even though I really, really like my EVO 'powerband' my friends supercharged Integra GSR is probably the most streetable monster I've experience in my life! It pulls from 1200rpm all the way to 10,000rpm. Its a little monster!

Yes...a tuned NA is great, yada, yada, yada...but I just feel there are so many good FI systems are out there, there is one to suit every driving style.

Later,

jcnel.

 

NA has power throughout the rpm band ONLY when you start talking about larger displacement engines. The RX-8 and the s2000 are both NA, and neither of them are much better lag-wise than the EVO. I think there is more perception of lag in the evo b/c the change in speed once boost is so much more than the change in speed once VTEC hits.

As someone on here has stated on their profile, VTEC is like having all of the lag, but none of the turbo.

 

NA sounds better!! intake on FI makes the spooling/sucking sound, whereas NA makes a roaring sound...

 

In general, i would have to agree that a Tuned NA takes more work. But i would not agree that a tuned NA takes more SKILL. Tuning a turbo is just as complicated, as is illustrated by the numerous instances just on this website where a tuner as messed something up or tuned a car improperly. In some of these instances, the modified car is actually running SLOWER than stock.

Further, many admire NA tuning b/c it involves going into the engine, and rebuilding internals. But the purpose of rebuilding internals is to make them stronger and more able to withstand high stress levels. On a 2jz-gte, or a 4g63, however, the internals are most often left alone because they are already strong enough to withstand such pressure and stress.

Others admire tuning NA b/c building internals is much more complicated, and involves many more parts . . . but i would argue that turbo charging is no less complicated. In fact, you ask many people why they choose to go NA, and they'll tell you its b/c turbos have too many moving parts, which ultimately means more things can break and more things can go wrong.

 

But you don't necessarily need an open-air intake on an FI. Mine is still running the stock intake, and making a little less than a 100 more hp.

And you should take a listen to several of the more highly tuned stock NA cars, like the M3 and the Ferrari 360, and tell me what you think of the sound they make. Both of them, at WOT, have this unbearable and incredibly cheap raspy / tinny rattle / whine to them.

 

. never mind.... just being a smartass.... we need a "delete your post" button

 

post deleted, in response to engineerboy deleting his post. I appreciate the civility.

 

I am a road racer at heart (I have never auto-x'd so I can't comment). I was able to take my 2.0 SR powered 240 and dog out the back of a Z06 in the corners...ahem, we will forget about what happened in the straights. It's all about knowing YOUR car and being able to get the most out of it.

Lag is just the same from a 2.0 N/A running aggressive cams and high compression to a 2.0 T/C running a big turbo. A good driver will be able to minipulate the engine and car to stay in the power band. Once that skill is mastered you can run with any car.

I personally like F/I better for:
1. Tunability (if that's a word)
2. Flexability (you can change boost settings to meet track needs)
3. getting more power out of less engine (that's what I think is impressive)
4. Sleeper status (that Z06 had no clue what just ran up in his rearview mirror)
5. Topend (I love hitting the straights and just keep pulling away from the car behind me)

 

i drove a 360 modena today and loved every minute of it. if you don't like the sound that car makes then...well....i don't know what to say. Sure it doesn't spool up and take off at low RPM like an EVO does but I liked it a hell of lot none the less.

 

The sound you hear when you are actually driving it is incredible. The engine is right behind you, and thats all you hear. Stand behind the car and have someone take off for you, and you'll hear what i mean. The exhaust rattles pretty badly. I have seen this on 4 360 coupes, one spyder, and one stradale already. . .

 

i understand what you are talking about and ive heard it a whole lot because its my dads . It sounds almost like a 2-stroke at high rpm and i love the sound of 2-stroke motors (yamaha banshee)

 

Well all the cars you mentioned sound better at the auto-x alex.

I've been in (or driven) all of the lower end cars you named from the srt- through the M3 and Z06 but haven't had a chance for the higher end ones yet so I can't talk about the feel with 100% certianty but I know I like the way the z and M3 come on to power better than say... A wrx.

P.S. The sr-t feel faster because it is. If I had a dollar for everytime I saw a s2k owner that thought he could beat a srt-4 and got his *** handed to him... I'd have 4 or 5 dollars.

BTW, I'm not a fan of modding a low hp car all NA, it's too costly and there are too many trade offs (sound being the biggest - too loud IMO) I'm just saying that BMW, lamborghini, and ferarri are on to something here.

 

i would take the porsche carrera gt over any of those cars, sure you can up the ante of the impreza wrx and the lanevo, but surely enough if you can afford the modena or the carrera gt you can do the same to those cars and have it fi and what do you get? a wolf in sheeps clothing, and its elegantly pleasing to the eyes.

one such example is the e46 m3 modifed with a sc, now that is a god forbidden beast! it really depends on the lifestyle you pursue, as for me i'd rather show up in my carrera gt FI in a classy beverly hills restaurant rather then my impreza wrx, that would be my errands mobile =-)

till then its my everything car ;-)