Turbo lag...what's your experience?

greiswig · **Posted:** Sun Oct 01, 2006 9:12 pm

You know, when I first got a Diesel Power module and installed it, the turbocharger seemed to spool up much quicker. But after awhile....

It's almost as though the computer learns what the module is doing, and undoes it. Now, my turbo lag is back. If I'm at an intersection that I need to cross quickly, I daren't risk it. I have to be able to anticipate a full second of lag after I depress the pedal before the engine kicks in and moves me. Seriously..."one one thousand" then it goes.

Having never had a turbocharged vehicle before, for all I know this is normal. You tell me.

DarbyWalters · **Posted:** Sun Oct 01, 2006 10:03 pm

It is not so much the "turbo Lag" but a fuel delivery parameter that DC uses to keep smoke (EPA) at a minimum at take off...that is what I have read a few other places. It stops the engine from dumping too much fuel and sending it out the tailpipe. I too think it is a safety concerns sometimes

greiswig · **Posted:** Mon Oct 02, 2006 12:33 am

DarbyWalters wrote:

It is not so much the "turbo Lag" but a fuel delivery parameter that DC uses to keep smoke (EPA) at a minimum at take off...that is what I have read a few other places. It stops the engine from dumping too much fuel and sending it out the tailpipe. I too think it is a safety concerns sometimes

Ah! That might explain why a fuel module would affect this directly. How lengthy a lag are you experiencing, Darby?

DarbyWalters · **Posted:** Mon Oct 02, 2006 1:13 am

Seems about the same as you and it is always when turning in front of traffic that I think about it... :shock:

The VW TDI's had the same kind of problem but they have a different program that can be defeated I think to get rid of this condition

RTStabler51 · **Posted:** Mon Oct 02, 2006 1:45 am

brake boost gets rid of turbo lag. :-)

Bonehead · **Posted:** Mon Oct 02, 2006 4:50 am

RTStabler51 wrote:

brake boost gets rid of turbo lag. :-)

......and tread off the tires to if you don't watch it

OzLtd · **Posted:** Mon Oct 02, 2006 5:51 am

RTStabler51 wrote:

brake boost gets rid of turbo lag. :-)

That is so true. I do this trick every now & then if i'm at an intersection & have to move quickly. I dont boost it up heaps like as if I were doing a 1/4 mile run, but just enough to get the car feeling like it wants to be let loose !! In the wet you dont even need to brake boost to spin the tyres, it'll bloody drift for god sakes!!!! :shock:

Having 245 MTR's on makes the problem much worse too !!

DarbyWalters · **Posted:** Mon Oct 02, 2006 6:18 am

Not on the Liberty...If it detects too much "brake and gas", it throws a code and puts you in "limp mode"...that will put you at risk in the intersection.

Jeger · **Posted:** Mon Oct 02, 2006 7:27 am

DarbyWalters wrote:

Not on the Liberty...If it detects too much "brake and gas", it throws a code and puts you in "limp mode"...that will put you at risk in the intersection.

I have not had that problem yet, just how much is too much? My CRD seems pretty happy to spin both rears for at least a few seconds. :roll:

I wound it up a little before crossing an intersection the other day, left two solid stripes clean across the intersection, even got a little sideways :shock:

ESP was in partially off mode.

DarbyWalters · **Posted:** Mon Oct 02, 2006 8:02 am

I don't know how much is too much, but there have been a few people who threw a code that read Gas and Brake Applied simotaneously...

RTStabler51 · **Posted:** Mon Oct 02, 2006 8:56 am

I haven't had that issue yet either. The CRD isn't ment to be a rocketship, I only do it in moderation at intersections I need to get through. There's been more than a few times where the turbo lag has almost resulted in a tbone!

jeep06 · **Posted:** Mon Oct 02, 2006 9:07 am

this set up we have resembles the Dodge/cummins engines, they won't launch very well stock because the MAP sensor won't let mass quanities of fuel be delivered until the MAP (Manifold Air Pressure) sensor sees x-amount of boost pressure.....hence no smoke on take off. But a good aftermarket go faster box will fool that boost signal since it connects to the map sensor harness and makes the ECM think you are already building boost. Haven't heard or read about any boxes for the CRD that connects to the map sensor yet. That would be sweet....

:)

midwest · **Joined:** Tue Apr 25, 2006 12:03 am **Posts:** 173

RTStabler51 wrote:

I haven't had that issue yet either. The CRD isn't ment to be a rocketship, I only do it in moderation at intersections I need to get through. There's been more than a few times where the turbo lag has almost resulted in a tbone!

If turbo lag is almost causing t-bone collisions, you are taking foolish chances on the road.

RTStabler51 · **Posted:** Mon Oct 02, 2006 2:44 pm

midwest wrote:

RTStabler51 wrote:

I haven't had that issue yet either. The CRD isn't ment to be a rocketship, I only do it in moderation at intersections I need to get through. There's been more than a few times where the turbo lag has almost resulted in a tbone!

If turbo lag is almost causing t-bone collisions, you are taking foolish chances on the road.

Thanks Dad!

aardvark4x4 · **Posted:** Mon Oct 02, 2006 2:52 pm

Because Jeep diesels are now 'fly by wire', i.e there is no throttle cable or other mechanical connection between the driver and fuel system, if the powertrain control module sees the throttle position sensor is off idle and the brake switch is on at the same time, it shuts down into limp mode in case the throttle position sensor has failed, potentially causing the engine to run out of control.

midwest · **Joined:** Tue Apr 25, 2006 12:03 am **Posts:** 173

RTStabler51 wrote:

midwest wrote:

RTStabler51 wrote:

I haven't had that issue yet either. The CRD isn't ment to be a rocketship, I only do it in moderation at intersections I need to get through. There's been more than a few times where the turbo lag has almost resulted in a tbone!

If turbo lag is almost causing t-bone collisions, you are taking foolish chances on the road.

Thanks Dad!

You can laugh all you want, I have investigated enough collisions to know it's not funny. Again, if this is truly a problem for you, think about your driving habits before you kill someone-it's no joke.

DarbyWalters · **Posted:** Mon Oct 02, 2006 5:39 pm

Guys and Gals,

People are just telling thier experience with lag and traffic. Not one person said they were trying to pull in front of on coming traffic with too little space/time to make it. They are saying that the "delay" makes them a little apprehensive.

It is like the old days of a carb loading up on you and bogging down.

greiswig · **Posted:** Mon Oct 02, 2006 5:53 pm

DarbyWalters wrote:

Guys and Gals,

People are just telling thier experience with lag and traffic. Not one person said they were trying to pull in front of on coming traffic with too little space/time to make it. They are saying that the "delay" makes them a little apprehensive.

It is like the old days of a carb loading up on you and bogging down.

True. My record and insurance company would show that I am a safe driver...hence my concern. You gauge how much of a gap you need between cars to merge or cross a street based partly on the performance of the vehicle. The safe driver of a Corvette will cross a street with a smaller gap between vehicles than would the safe driver of a Chevette. In this case, I've got a vehicle that exhibits very good pickup most of the time, but is unpredictable off the line. So I end up driving like I'm in the Chevette. I'd rather not have to do that. I'd rather have more predictable performance so that I don't make an error in judgment, and neither will anyone else driving my Jeep.

OzLtd · **Posted:** Mon Oct 02, 2006 7:44 pm

greiswig wrote:

DarbyWalters wrote:

Guys and Gals,

People are just telling thier experience with lag and traffic. Not one person said they were trying to pull in front of on coming traffic with too little space/time to make it. They are saying that the "delay" makes them a little apprehensive.

It is like the old days of a carb loading up on you and bogging down.

True. My record and insurance company would show that I am a safe driver...hence my concern. You gauge how much of a gap you need between cars to merge or cross a street based partly on the performance of the vehicle. The safe driver of a Corvette will cross a street with a smaller gap between vehicles than would the safe driver of a Chevette. In this case, I've got a vehicle that exhibits very good pickup most of the time, but is unpredictable off the line. So I end up driving like I'm in the Chevette. I'd rather not have to do that. I'd rather have more predictable performance so that I don't make an error in judgment, and neither will anyone else driving my Jeep.

Well said, and greiswig, I agree with you also. I'm into safe driving practises that dont impeed on others - I save that for the race track :wink:

DarbyWalters · **Posted:** Mon Oct 02, 2006 7:59 pm

OzLtd wrote:

Well said, and greiswig, I agree with you also. I'm into safe driving practises that dont impeed on others - I save that for the race track :wink:

Heck, you are safer on the race track than in traffic... :lol:

Turbo lag...what's your experience?

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