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Turbo Lag

15K views 26 replies 15 participants last post by  NinerBikes  
#1 ·
Has anyone else noticed a lot of turbo lag, sometimes it takes a lot of pedal to get the truck to move then other times it snaps out like a new truck should. IDK
 
#6 ·
Why would any mfg set the throttle like this? You would have a hard time convincing me that its not turbo lag. With fly by wire there is a hesitation then smooth power is applied.This is not the case with my truck. My truck has nothing until it gets boost then snaps from a stop. If it was fueling it could be fixed with a flash, or if it was a fly by wire throttle issue I would believe it could be updated with a flash as well. Can't fix lag and that's why its still there. Seems to be better when the engine reaches temp and the turbo gets hot.
 
#11 ·
Mine is extremely sluggish when cold, but its very smooth when it's warmed up. I have no real complaints & I know not to try to pull out quickly if the truck is cold.
 
#14 ·
I've read this some where and it helped. The throttle response is programmable.

Sit in the truck turn on the ignition slowly apply the throttle to the floor and slowly back off to closed throttle then turn off the ignition.

Let us know it this improves the throttle.

I do this periodically when it starts irritating me and it either reprograms the truck or my brain.
 
#15 ·
So the fix would be drive it like you stole it for a while so the truck learns you right? LoL thanks for the info I will try the reprogram to see what happens.

As for the other threads I couldn't find anything on turbo lag by just typing that in the search. it was much easier to start a new thread
 
#16 ·
I don't notice it that much, if at all when the truck gets to operating temp. Wouldn't it be a very easy fix to just re-flash for better fueling? I'm glad its not lag then, it should be an easy fix? The whole drive it like you stole it does not make sense to me because I will not drive the truck like that everyday, and it will just relearn your normal driving habits.
 
G
#21 ·
If you are noticing this phenomena on your truck, you are expecting too much of it and driving it too hard on a cold motor. Show some mechanical sympathy and back out of it until all the vehicles systems are fully warmed up. It's programming that's designed to prevent you from wrecking the equipment before all the systems are up to full operating temperatures. They've had to dumb down the fueling parameters to accomodate the least common denominator among us, that still doesn't know that you need to take it really easy while warming up a diesel engine while driving when motor is still cold.

If you are driving this way and still notice it, modify your driving technique so that you DON'T notice it. Adapt YOUR driving patterns.
 
#24 ·
I believe that you are right on, Niner... Boost is also inhibited during warm-up. However, if you push the accelerator hard enough, you can override this engine protection feature, in case you require emergency power. That's the "rocket ship" lurch that people have mentioned.

Because of the variable geometry, these turbos have little to no lag. I would encourage anyone that has the sluggishness problem to try it with the engine fully warmed up. That may be a problem in colder climates.
 
#22 ·
for the diesel newbies:
1) I hope most of you know by now that in diesel engines the pedal controls fuel being injected, where as in gasoline engines pedal controls air coming in.
2) what contributes to "turbo lag" is the famous diesel smoke limitations plus EGR that oem apply due to emission standards. when engine is cold or you exhaust temperatures are cold you apply a lot of fuel but a lot of fuel means a lot of smoke so in order to reduce smoke EGR and other things are incorporated. One companies start to actually tune this engines properly there should be no more lag
 
G
#27 ·
for the diesel newbies:
1) I hope most of you know by now that in diesel engines the pedal controls fuel being injected, where as in gasoline engines pedal controls air coming in.
2) what contributes to "turbo lag" is the famous diesel smoke limitations plus EGR that oem apply due to emission standards. when engine is cold or you exhaust temperatures are cold you apply a lot of fuel but a lot of fuel means a lot of smoke so in order to reduce smoke EGR and other things are incorporated. One companies start to actually tune this engines properly there shouleed td be no more lag
Fueling is limited when cold for one reason... the pistons need time to warm up gently under load. Hammering the throttle will blast the pistons with excessive heat causing areas with not a lot of metal to expand too rapidly from the heat, while the piston boss area, where the pin is, has a lot of mass of metal to heat up. This variance in amount of material and heating it up quickly with heavy throttle applications, over time, will cause the pistons to crack, due to different thermal expansion characteristics. This was common knowledge on the early diesel MB Sprinter engines being driven too aggressively on a cold motor, by delivery outfits like Fed Ex and UPS drivers in very cold climates, the engines were failing with cracked pistons. Logs showed abusive driving practices on a cold motor.

Just another parameter tuners never take into account, longevity of anything they map, vs engine life. Clueless in all the parameters involved. Just programmer hacks.
 
G
#26 ·
Diesels, to warm up fully, need to be driven gently, accelerated on VERY gently, while cold, to warm up. They will not warm up just sitting there idling, they need a very mild load and some fuel consumption to warm up all that pig iron in them, as the blocks are big, and use a lot or metal, they are built super heavy duty, so there is a lot of mass and material to warm up.

Read your owners manual, follow what it says for cold weather operation and start up and driving procedures.