Turbo lag?
 

N00b up in this ma...

I understand the concept of turbo-lag but I was never told specifics.

Is there a difference in throttle response with and without turbo?

Like, when people say turbo lag, are they referring to the time it takes for the turbo to kick in, or are they talking about the general responsiveness of the throttle? I'm having trouble articulating at 5am...sorry guys.

If it's the latter, I wonder if it's worth more power if I can't make quick decisions on the road regarding throttle input.

Depending on setup and configuration, turbo-lag can go from hardly noticeable to a large factor while driving the car.

I think of turbolag as the time it takes from I press the pedal until I get the steady-state torque I expect at that rpm. So, say you're at 4000 rpm and flooring it. Turbolag is the time it takes before everything is settled and the car is surging forward.

Now, there is a second effect that some call turbolag. The effect where the turbo is very inefficient at low revs, and as the revs climb you get a powerful surge as the turbo starts to work better.

I noticed that the throttle on the FR-S is ridiculously sensitive (but then, I came from driving sedans and SUVs). I can blip it and within milliseconds, feel the car rush forward.

I guess I'm referring to the second effect that you speak of, where the turbo kicks in as the rev climbs. At low revs, will the throttle response be the same as stock throttle response, I guess is the question.

Below the effective range of the turbo you will get less responsiveness due to the increased volume of piping and exhaust resistance. Also, you will be anticipating the surge when the turbo comes on, so it will FEEL even less responsive.

My old car had what felt like NO power below 4200rpm where everything came at once. It still had almost 200hp at 3000rpm, but when you go from 200 to 350hp within 1000rpm it feels like a kick in the butt.

The video shows this second effect. I press the accelerator just after I pass the bump, but if you watch the boost gauge (in the pillar pod) nothing much happens until I pass a certain rpm, where everything happen at once. I don't call this 'turbolag', that is just a product of the actual turbo size vs displacement and a host of other factors.

http://youtu.be/DzW1EgXYhXg?hd=1&t=10s

Pretty much what others have stated above. In my old car, Cobalt SS turbocharged, the factory turbo would spool up to 15 PSI by 2000 RPM (small turbo. Minimum lag) and would deliver 260TQ (@ the crank) to the wheels. Later on, I got a turbo upgrade which raised the boost from 15 PSI to 22 PSI, but I would not get 22 PSI until a higher PRM. My wife and I were driving side by side one day and she had her windows down and I decided to punch it and let the turbo kick in just for the hell of it. Well when we got home, she said I reminded her of the old cartoons, where the character's feet are moving, but the character them self is not and then the next thing you know, the character shoots forward. She said she heard my turbo spool, but did not see me moving. Next thing she knows, my car shoots forward like a bat out of hell. Great way to visualize turbo lag :lol:

Turbo lag refers to the lag time in between pressing the accelerator pedal and feeling the engine surge forward. Think of it as engine responsiveness. This is what people refer to as lag on the track because even at mid-high RPMS a turbo car can have this disconnect between foot and acceleration.

An NA or a SC car will not have this.

What you are referring to has been called turbo lag but really is just not being in the efficiency range of the turbo yet. Flooring the car at 1000 rpms and not getting the surge of power till 4000 rpms. On the race track you wont be dipping below 4000 rpms which means you will always be in the efficiency range. So in terms of performance driving, turbo lag is "waiting" for the boost (thus torque) to reach max while driving in the efficiency range.

Its

I for one like a little bit of lag, the anticipation of knowing in a few seconds my head will be smashed into my seat is a lot of fun haha.

Here's an old video which shows a visual demonstration of the kind of lag a really big turbo will produce. You can hear him mashing the throttle but he isn't moving. You then hear the turbo spool and audios.

http://m.youtube.com/#/watch?v=rmNy-...%3DrmNy-ajRV0U

How do you embed YouTube again on this forum?

I wanna know how much more responsive these new turbos are from Garrett (GTX) and BorgWarner (EFR). Can they be efficient and responsive enough to pull me away from wanting a supercharger? Having owned and driven a few turbocharged cars, I know I prefer the linear response of a roots-style blower, however if these new turbos are as good as they claim, maybe it can eliminate lag to the point that a supercharger almost seems obsolete?

*looks at the GTX2863R that he bought for his MR2 and wonders "could I put this in the BRZ instead?"*

full blown used the gtx28 in their stage 1 kit

Ohh that's real nice. Practically mirrors the stock powerband, just MOAR of it! And that's with a stock exhaust, which means there should be even better response when switching to a 3" TBE. Interdasting... So that's a nicely-matched turbo for this engine. The 2863R is a tad smaller than the 2867, but that's fine because I prefer response over outright power.

They did, 7 psi full 3" exhaust made 300 wheel

Ermahgerd... Now to get it to pass emissions with just one cat... hrm.

I went from the stock turbo on my Mazda 323 GT-R (IHI RHF6CB) in the youtube clip above to a GT2863. Stock it wouldn't spool until 4000rpm, now I can get 14PSi at 2k. No changes to cams or anything, just a turbo swap and a retune.