skratch77

Just figured Id throw this out there but we all fear our cars blowing up in the winter because x tuner tuned it in the summer and is the reason we see blown up pistons in ice cold weather.

Iv been watching my fuel trims and they went from 4.7-5.5 in 50-70 weather to 7.8-8.4 in under 20 degree temps.

Does that mean my kleemann tune is adjusting and adding more fuel in colder weather?

I just hit the dyno and made north of 545whp and the A/F was 11.8 near redline and the temps were about 30d out.

im also only running 12 deg timing up top end and could be the reason my car hasnt blown up yet.

either way just asking if these cars fuel trims are adjusting to the temps and I dont know if it has anything to do with mickey mousing the o2 sensors to not throw codes with no cats and it leaves the car in a state where it cant compensate for denser air.

Im taking my 178 pulley off and going to stock boost since I have made my car impossible to drive in the cold anyways.

I have a video of 3rd gear of me going 180d sideways from just 3k rpms and the temps around 30 or so.There is no tire or lsd that can put the power down and its not worth me blowing up my car so the stock pulley will go back on real soon.

can someone look at there ltft and see if they move on the fly with throttle input.

mine will go from 8 to 5.7 with maybe 10% throttle and then 3.7 with 30% and then 1.4 with 100% wot but they are changing depending on the amount of throttle I give it.

If you have a butchard tune on your car to trick the check engine light from not coming on I would like to know if your ltft change on the fly with throttle input or if they just stay the same with part throttle and full throttle.

skratch77

Iv had one file on my car from kleemann and it went from 460whp to 480 to 503 to 530 and the final run with CAMS to 546 and I never retuned my car and just kept adding mods and the car would adapt to them on its own.

went from 168 pulley to 180(78 technically) and then added TB and then changed a few things for better cooling and everything I added mods the car picked up power and the A/F pretty much stayed the same.

AKnight55

What cams are you running?

skratch77

honeslty... who do you think lol

AKnight55

Kleemann?

Your car must be a beast now.. Lets see some 10 second runs come spring time!

skratch77

doing some serious cooling mods and thorwing stock pulley on her.

Ill be happy if I can run a mid 11 with stock boost pulley and I gave up on 10s at new england drag way.

My best 60ft there is 1.7 with brand new drag radials.the track sucks donkey dick for traction and there is no way any e55 is getting in the 10s there.

Jakpro1

12 up top? Thought Klees ran 16-17ish up top. More radical tuners ran it 19-20s and the engine blower tuners (some fly by nights in the old days) had 23+.

Yup 2 friggin 3 plus timing up top. No wonder motors toasted in the old days

urbamworm

Sounds like you need some bigger injectors in your car before you have a big problem. I don't understand why anyone would have all the mods in the book and not have upgraded injectors.

BBBSS

Long Term Fuel Trim changes slowly as the vehicle sees cold weather more and more as it expects it to be cold dense air that needs more fuel to run stoich. IAT and Oxygen sensors play a big part in how your car adjusts fueling for different temperatures. When your ECM is tuned they don't just tune for warm sunny days. There's TONS of charts and graphs that all need to be tweaked for various circumstances. IAT, RPM, Load, what the O2's are reporting, are knock sensors complaining, a whole bunch of things go into how your car determines how much fuel to inject per combustion event.

There's also Short Term Fuel Trim that allows it to dump more fuel if conditions are fit in its opinion. A good tune involves quite a number of parameters that all need to be adjusted properly to give you a well running motor in all the different conditions you may run into from below zero to well over 100 degrees and rain or dry, barometric pressure changes even have an effect that needs to be accounted for by that computer.

Mercedes built the brain, your tuner gives it the PHD it needs to deal with all the craziness we put it through. It's amazing how accurate these things are when tuned properly. This is why a good tuner is so important. Not everyone knows how to properly adjust for such an incredible amount of variables, plus you need good condition sensors to give the computer the info it needs to make its decisions.

Basically your computer will know how to deal with whatever weather is thrown at it with a good tune assuming all sensors are reporting correctly and your fuel system is up to doing what the computer asks it to do.

skratch77

well its alot safer than having 30 d advanced at 6000 rpms

Jim I see 22 max and it lowers going towards redline,but from 5k up its not alot of timing at all.

BBBSS

I'm assuming these things run open loop when warming up, then go closed loop at a certain temp once the O2's and other sensros come into normal operating ranges. Anyone know what temp the computers go closed loop? You don't want to run it hard at all before you get to this temp usually. Computer isn't getting all the input it wants and is in a limp mode of sorts and assuming what it thinks is safe to do. Usually runs pretty rich when in this state and not exactly ideal conditions especially if its real cold as these motors seem somewhat sensitive to it to be even passing someone quickly in my opinion.

skratch77

Here is the thing.some people are running cattless like me but have different ways of tricking the ecu to not throw a code.Maybe the state the ecu is in when the cats are shut off this way affects the way the ecu can adjust fueling with more dense air.

My ltfts change with throttle input on the fly depending on load and tps and when I go wot they stay solid near 0 but they are always changing with how I drive.

My 02 sensors are working and the catts have been turned off threw another eprom on the ecu.

urbamworm

A sensor that is shut off is just a downstream secondary o2 sensor that doesn't even matter. It is only there to monitor the catalytic converter efficiency for emissions. So if a tune shuts off the 2nd o2 sensor due to not having cats then it should make no difference for anything important to how the car runs since the primary o2 sensor is what is important for fueling adjustment.

BBBSS

Correct. Can someone tell me if the pre-cat O2's on these are wide bands? I'm gonna guess they are but this car is very new to me and I'm trying to take it all in.

shardul

iTrader: (1)

Plug and play stand alone FTW. Dont pm me because I am not selling one but I will have one on my car.

SterlingE55

Don't pm me bc im not selling one. Literally lol'd on that one. I'm excited to see it in action. I'll even pay admission...

urbamworm

Narrowband, pretty amazing ha? I ask myself why all the time. Makes no sense at all to have a $90,000 strictly performance driven car that runs with a narrowband when wideband come on cheap economy cars.

PTE

Anyone know what temp the computers go closed loop? You don't want to run it hard at all before you get to this temp usually.
Very close to 142* F , engine temp
Cheers _PTEngineering

chawkins2001

Angelo, when did you put the cams in the car, did you notice more top end, just to verify, you went with Kleeman??

Robert AMG

iTrader: (1)

- the upper O2 sensors only works for calibration, the downstream send only the efficiency of the cats.
- when you go wot the O2 sensors stop working then the graphs set by the manufacture or tuner works and they adjust with the major parameters like AIT, boost and Knock.
- i have see 55k engine blown with timing at 6 degrees, definitly there must be high ait and high knock and the ecu is retarding to it's max which he can but the knock is still and engine blow. if you have timing below 13-14 then there is something not good and the ecu is retarding.
-stock timing is at 13-14, you can increase it by tuning 4 -5 degree, anything below 13-14 or more then 18-19 is definitely dangerous.

those are my experience with those engines, maybe i am wrong, can someone with more experience please correct me.

skratch77

The ecu target shoots its a/f before 3200 rpms and is why my ltfts adjust on the fly depending on how much throttle i give it.i know exactly how the car works on reading the 02s.

What im asking is if you have a tune that wont throw a code for no cats being catless if the ecu is in a limp mode and is not adjusting a/f right with colder air.

Some files wont throw a check engine and leave the ecu in a state where it wont pass or fail readiness on the ecu.

Im curious if some can see if there ltfts change with light input before 3200 rpms.