Lag or No Lag

[nachob]

Originally Posted by biglare

We can meet up if our schedules work out and you can take mine out for a rip!

Biglare, I thought of you but yours has a tune! On the other hand, yes I want to try your tune! You can drive mine and see how it feels side by side. Let's get together!

[Blue55]

Nachob, biglare. I'm in LA. Maybe if our schedules work we can all meet up. I've got a tune as well.

[firechicken99]

Originally Posted by Dackelone

That is EXACTLY the predicament we are in... when we get the latest SW update. Everything is a trade off. But I would MUCH rather have rattles WITH no lag and performance then no rattles with fairly decent lag.

I hated BMW's latest SW fix so much it was what pushed me to get a flash tune. Now I am happy.

haha yes!!!! Love how we need our own little "fix", to "fix", a "fix"

Even back when I had a 335, until I bought my procede the rattle was a little annoying, but once installed (and before tuning rattle out) I could've given a rats a$$ about "rattle" because the thing was so damn fast!! The 335 is definitely one of the most "detuned" cars I ever had my hands on. It was night and day. Glad the 1M fixed this from the getgo!

[nachob]

Originally Posted by ///M1

Well stated, I've highlighted a section in Bold as I have heard a number of people complain that after getting an aftermarket tune (running higher boost naturally) they felt an increase in lag.

On the last paragraph, FWIW, I felt a crisper throttle response after I installed the midpipe on both my 135i and now on the 1///M.

This is really important data but I wish someone would map the throttle position relative to the power on the chart.

My friend has a 50 year old carbureted Jaguar and it has instant throttle response.

I just want to reiterate, that, I LOVE THE CAR and I'm 100% good with it as it is, I was just concerned that maybe mine had a problem since so many reviewers kept saying the car had little to no lag.

Anyway ///M1, thanks for sharing the chart, it really shows the differences in the motors and clarifies some things.

[DCYT]

Hey Nachob,

Did your 2nd 1M also have this behavior? Or is it different.

I am checking out a car and it's doing exactly what you described.

Originally Posted by nachob

This is really important data but I wish someone would map the throttle position relative to the power on the chart.

My friend has a 50 year old carbureted Jaguar and it has instant throttle response.

I just want to reiterate, that, I LOVE THE CAR and I'm 100% good with it as it is, I was just concerned that maybe mine had a problem since so many reviewers kept saying the car had little to no lag.

Anyway ///M1, thanks for sharing the chart, it really shows the differences in the motors and clarifies some things.

[nachob]

Originally Posted by DCYT

Hey Nachob,

Did your 2nd 1M also have this behavior? Or is it different.

I am checking out a car and it's doing exactly what you described.

Lol yes 2nd 1M is the same. It has lag. I have driven a lot of turbo cars now. I am also more aware of it now because I have a 330i zhp as my daily. When I had first 1M it was my only car so it wasn't as obvious. Now I switch between both cars and the zhp is eager to rev. The 1m you have to press the throttle and it feels like when an NA car is cold. Nothing wrong just not eager until the surge then all is forgotten. It's funny how both 1Ms have different characters. My first one I recall being louder as do my friends. It also had a long and loud cold start. My 2nd 1M has a shorter lower RPM cold start. 2nd gear in my 1st 1M was finicky and more than once ground during shifting fast. My second 1M gear go is lovely, delicious, perfect. 2nd gear is great. My second 1M is Canadian but has exact same US EPA and California ARB equipment and verification. It even has cal ARB sticker like US version but something is slightly different. I believe they configure it like a cold weather version? It has heated seats standard and the cold start is slightly different but I can't validate it. I want to find out. Maybe they use differnt plugs in cold climate cars or engine tune is different but as far as lag is concerned, it feels the same.

[DCYT]

Alrite ... so all is good ..

My impression of it is upon tip in, it has the inline 6 response ... then a second later, the thrust comes and the car takes off ...

Just felt a little weird ....

Thanks for the confirmation!

[nachob]

Originally Posted by DCYT

Alrite ... so all is good ..

My impression of it is upon tip in, it has the inline 6 response ... then a second later, the thrust comes and the car takes off ...

Just felt a little weird ....

Thanks for the confirmation!

Yeah. It's all good. I also notice it
More when cold. It's less noticeable when car is at full temp

[kprocivic]

N54/55 has the least turbo lag I have ever experienced with any engine. Now the new 488 Ferrari I hear has none. It makes since to the oem turbos are so small they should spool up very fast.

[CarJunkie]

I find slightly less lag in M sport mode.

[nachob]

Originally Posted by CarJunkie

I find slightly less lag in M sport mode.

M mode is cool but ironically I found it too touchy on the autocross course. Yes, I forgot about that!

[DCYT]

BTW, I am asking about throttle lag and not turbo lag.

Throttle lag = nothing happens when I hit the gas. After 1 sec, feel engine respond...... Then turbo lag if any.

Turbo lag = The time between engine respond after stepping on gas, spin up turbo to build boost pressure and get thrust.

[nachob]

Originally Posted by DCYT

BTW, I am asking about throttle lag and not turbo lag.

Throttle lag = nothing happens when I hit the gas. After 1 sec, feel engine respond...... Then turbo lag if any.

Turbo lag = The time between engine respond after stepping on gas, spin up turbo to build boost pressure and get thrust.

throttle lag in 1M is because of turbos unless something is wrong with car. You can have throttle lag in a carbureted car if mixture too rich, plugs bad, vanos not working etc. but in this thread we are discussing a normal functioning 1M and the lag is from the turbochargers.

[DCYT]

Even at 3500 rpm +, I am still experiencing throttle lag where the car will wait a 1/2 second before it'll respond to my right foot.

I drove a N54 335 with cobb tune last night and it did the same thing

Think of it as a fluorescent light bulb on the other side of the world that has never been turned on. The time between you flick the light switch and the bulb emitting light is throttle lag. The time between the dim light bulb warming up to full brightness is turbo lag.

[nachob]

Originally Posted by DCYT

Even at 3500 rpm +, I am still experiencing throttle lag where the car will wait a 1/2 second before it'll respond to my right foot.

I drove a N54 335 with cobb tune last night and it did the same thing

Think of it as a fluorescent light bulb on the other side of the world that has never been turned on. The time between you flick the light switch and the bulb emitting light is throttle lag. The time between the dim light bulb warming up to full brightness is turbo lag.

It is possible that there is some other issue with your car then. Perhaps your plugs or injectors are not up to par. You could have some carbon buildup or VANOS is not operating correctly. You might even have early fuel pump issues but even at 3500 RPM, the N54 does not respond immediately to throttle inputs which is why I started the thread. I was trying to get a sense for how much is normal. It is more noticeable for me because I switch between a NA 330i which has an inline 6 and the 1M. But, I am also on my second 1M and driven more BMW turbo cars since then. It is normal. It feels as if there is a balloon between the throttle pedal and the throttle actuator. You press the pedal and the balloon squishes, then pushes the throttle plunger and you get power. This happens in all of the power band. Some less than others but never feels mechanically linked like the throttle in the NA car which feels instantaneous.

If you have higher miles, you might want to check that your wastegate is working correctly and that you don't have a leak in the system where it is not keeping enough pressure in the plumbing. There might be a leak, a crack in the charge pipe that lets boost escape etc. I would start there, then carbon build up. Then move on to techron injector cleaning and pay attention to cold start to see if car turns over a lot before starting which could be a fuel pump issue.

Best wishes.