Calandrino
New member
Thanks Sean. that was a detailed, helpful link regarding the Trifecta tune.
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Acceleration Lag
- Thread starter Calandrino
- Start date
Swordsmith
242hp/252 ft-lbs BNR EFI
A turbo car will always have some lag; you step on the gas, the regular engine goes to work immediately, the increased exhaust starts the turbine spinning, the turbine pumps pressurized air into the engine which can now use more fuel, creating more exhaust pressure, turbine spins faster, and so forth. The lag is there because it takes time to get spinning up to speed (spooling) and then to generate the pressure. A good tune reduces this time, but can't eliminate it because these are mechanical processes that simply take some time to get up to full power.
A full second sounds like a pretty long time for that process to take, though. I've had the tune since very shortly after getting the car, I don't really remember how long lag was before, but... an actual second? Liking the tune even more than I did before, I guess!
You don't get NO acceleration while waiting for turbo, but you don't get the insane amounts of it that you do once the turbo kicks in.
Trifecta full tune also includes No Lift Shift (dunno if the budget one does) which allows you to keep the (torque demand... but pretend I said gas) pedal all the way on the floor while you punch the clutch in, shift, and out, this lets you retain boost instead of dumping it and starting over with every shift. That doesn't apply to auto transmissions though, I guess.
A full second sounds like a pretty long time for that process to take, though. I've had the tune since very shortly after getting the car, I don't really remember how long lag was before, but... an actual second? Liking the tune even more than I did before, I guess!
You don't get NO acceleration while waiting for turbo, but you don't get the insane amounts of it that you do once the turbo kicks in.
Trifecta full tune also includes No Lift Shift (dunno if the budget one does) which allows you to keep the (torque demand... but pretend I said gas) pedal all the way on the floor while you punch the clutch in, shift, and out, this lets you retain boost instead of dumping it and starting over with every shift. That doesn't apply to auto transmissions though, I guess.
ThatTmoGuy
New member
Budget tune does include NLS
Calandrino
New member
Swordsmith, what is your elevation and 0-60 time with your mods?
The elevation certainly doesn't help my lag time. I commute from ABQ to Santa fe for work, and Santa Fe is 7000ft (ABQ is 5000ft) elevation. The lag and overall performance are noticeably affected by the 2000ft elevation gain. This may explain why my lag time is so bad. I haven't timed it but it sure feels like a full second.
The elevation certainly doesn't help my lag time. I commute from ABQ to Santa fe for work, and Santa Fe is 7000ft (ABQ is 5000ft) elevation. The lag and overall performance are noticeably affected by the 2000ft elevation gain. This may explain why my lag time is so bad. I haven't timed it but it sure feels like a full second.
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ThatTmoGuy
New member
Well you went with the right motor with those kinds of elevations, Forced induction is the best way to gain power up there since the air is so thin.
CoHPhasor
Active member
True, but having experienced the lag, I'll tell you right now - What we experience isn't turbo lag.
It's literally like you haven't touched the throttle at all, almost to the point of a choke.
As people with manuals never complain of something like this it's an auto-specific problem.
(Plus lag on a turbo this small should be nigh imperceptible)
Calandrino said:
Absolutely not. I was being nice.
There really isn't a solid all-encompassing FAQ that breaks in newbs completely here so it isn't all your fault.
(Should I write one? Probably. Do I have the time? If you babysit my son for a few days I do.)
ThatTmoGuy
New member
Is my mod noob thread not good enough for you people?!?
key1cc
New member
It does feel like an eternity when you just plopped into oncoming traffic and you have your foot mashed to the floor and your are barely moving.
If a car is coming up behind me at 60 miles per hour..... thats 316,800 feet per hour or 88 feet per second if my math is right....
I find it better to accellerate normally rather than attempting to call on the turbo....then at least you are moving.
This only appears to be an issue however if I'm moving only a few miles per hour having just turned into traffic then I attempt to floor it.
I have 93 octane in the tank at the moment.
Key1
If a car is coming up behind me at 60 miles per hour..... thats 316,800 feet per hour or 88 feet per second if my math is right....
I find it better to accellerate normally rather than attempting to call on the turbo....then at least you are moving.
This only appears to be an issue however if I'm moving only a few miles per hour having just turned into traffic then I attempt to floor it.
I have 93 octane in the tank at the moment.
Key1
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ThatTmoGuy
New member
I'm starting to think this mostly a problem with the auto/slushbox, When i stab the go pedal it just goes.
Swordsmith
242hp/252 ft-lbs BNR EFI
Yeah I'm not getting a "nothing is happening" sensation, what I'm getting is gogogoOMGGOGOGOGOGO, a kick in the pants that happens distinctly after I floor it, instead of at the same time, but it's just in addition to the kick I got from flooring it in the first place. It's also not at all long after, I was playing with it this evening and I'd say somewhere between a quarter and a half second, probably closer to the quarter.
If I don't use NLS, I get this after every shift, with it, it just stays insane till I have to let up.
I also can't picture what you mean by "accelerate normally instead of calling on the Turbo". The only way I can not call on turbo is to keep a light foot and short shift. If you somehow got in and unplugged my turbo, I'd still get my best acceleration by putting the hammer down, I'd just be missing the extra push.
Rereading your description, it sounds like you're in too high a gear. Normally I will short shift, getting up into a high gear as fast as reasonably possible without lugging it, but if I want power, I keep the gears low and let the RPMs build up, there's a lot more power that way. If I'm in 6th and decide to pass, it can be painfully slow, and the turbo doesn't kick in fast either... but drop down to 4th and I've got a rocket at my fingertips.
I think maybe the "turbo lag" you are feeling is actually being in too high a gear, and lugging along until you're finally moving into the powerband for that gear.
Have you tried the auto/manual shift thing to see if you can force a downshift for more power in those situations?
If I don't use NLS, I get this after every shift, with it, it just stays insane till I have to let up.
I also can't picture what you mean by "accelerate normally instead of calling on the Turbo". The only way I can not call on turbo is to keep a light foot and short shift. If you somehow got in and unplugged my turbo, I'd still get my best acceleration by putting the hammer down, I'd just be missing the extra push.
Rereading your description, it sounds like you're in too high a gear. Normally I will short shift, getting up into a high gear as fast as reasonably possible without lugging it, but if I want power, I keep the gears low and let the RPMs build up, there's a lot more power that way. If I'm in 6th and decide to pass, it can be painfully slow, and the turbo doesn't kick in fast either... but drop down to 4th and I've got a rocket at my fingertips.
I think maybe the "turbo lag" you are feeling is actually being in too high a gear, and lugging along until you're finally moving into the powerband for that gear.
Have you tried the auto/manual shift thing to see if you can force a downshift for more power in those situations?
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key1cc
New member
I also went out this evening to really pay attention to what is occuring and you described it accurately. The rocket takes off some amount of time after you floor it....not at the same time. It is less than a second delay, but a delay nevertheless. With my GM outlook there is zero delay so I guess I just need to get used to this.
As far as "calling on the turbo", I was under the impression that the turbo does not really kick in unless you press the throttle sufficiently down enough to activate it. This can be seen on an ultra gauge as I just went out and did a test where I accellerated "normally" up to 50 miles per hour without the boost on the ultra gauge ever going above 3.5 psi. My typical driving style regularly takes boost above 17 psi without WOT. The video from GM in this link here
http://www.sonicownersforum.com/forum/t5011/
is where GM states that our engines act like a typical engine for crusing along but the turbo kicks in when you need the extra power.
Key1
As far as "calling on the turbo", I was under the impression that the turbo does not really kick in unless you press the throttle sufficiently down enough to activate it. This can be seen on an ultra gauge as I just went out and did a test where I accellerated "normally" up to 50 miles per hour without the boost on the ultra gauge ever going above 3.5 psi. My typical driving style regularly takes boost above 17 psi without WOT. The video from GM in this link here
http://www.sonicownersforum.com/forum/t5011/
is where GM states that our engines act like a typical engine for crusing along but the turbo kicks in when you need the extra power.
Key1
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key1cc
New member
It is only an issue when I'm just merging from a standstill so I am usually under 10 mph when I mash. My auto tranny wont let me anywhere near 6th gear or even 3rd gear for that matter at such a low speed...I think you accurately described it when you stated the rocket comes after the pedal mash, not at the same time. I was just not use to that.
Key1
ChrisJ
Active member
The Sonic I had with an auto was a 1.8, but I never noticed lag with that. Apparently the 1.4 auto is a different animal?
I can say with our two cars which are manuals the only time I notice lag is if I do something which would obviously cause it with a turbo. For example staying in 2nd gear at around 3k but only giving it a little throttle and then flooring it. You can easily tell when the turbo spools up and its a beautiful thing.
Other than that I've never noticed any issues so I agree with others when they say its transmission or computer related.
I can say with our two cars which are manuals the only time I notice lag is if I do something which would obviously cause it with a turbo. For example staying in 2nd gear at around 3k but only giving it a little throttle and then flooring it. You can easily tell when the turbo spools up and its a beautiful thing.
Other than that I've never noticed any issues so I agree with others when they say its transmission or computer related.
Preloader
The M32 Martyr
Fixed.
I use to go for 4th, now I grab for 3rd when I need to change my scenery, and time stands still for me.
ThatTmoGuy
New member
under ~70 I double clutch and grab third for that quick jump to ~90 till I grab 4th and I'm already gone!
ThatTmoGuy
New member
Match the downshift so you don't jerk it and break something.
Very informative, Read the description How to Heel and toe, rev match, and double clutch
Very informative, Read the description How to Heel and toe, rev match, and double clutch
ThatTmoGuy
New member
After two years of driving my old '86 Ranger and Rev matching is double clutching. It's a muscle memory that's hard to stop, Just like heel toe braking.
