[D's Bimmer]

I am driving along at 120kph around 2400rpm. If I try to go WOT in 6th gear the car bogs down. No codes or anything. Yet if I drop it down to 5th gear and then WOT no problem at all.

Is this because I am to low on the RPM's for a WOT in 6th gear? Or is there some else at work here?

[bahn]

Oh dont do that.... that gear is too high for WOT it's meant for overdrive. Your RPM's will be to low. This can cause overboost, bucking, pre-ignition and etc. Start WOT pulls from at least 2500+

[vespa]

A stock car shouldn't do that but it seems that the commonly available tunes mishandle low RPM and/or rapid pedal changes. The power loss you feel is the result of the DME detecting pre-ignition or detonation and reducing timing and boost to (hopefully) prevent damage.

[bbnks2]

Originally Posted by vespa

A stock car shouldn't do that but it seems that the commonly available tunes mishandle low RPM and/or rapid pedal changes. The power loss you feel is the result of the DME detecting pre-ignition or detonation and reducing timing and boost to (hopefully) prevent damage.

Who do you suggest for an n55 tune? Driveability definetly suffers when all a tuner cars about is highway pulls.

[prima_materia]

Yup, I made the mistake of hitting the gas while in 6th at a low rpm while on the expressway. For those few short seconds I thought that I'd completely ruined my car [bucking, sputtering, 4x4 cel]. Learned real quick not to do that.

[STR8-6IX]

NEVER do this. ever.. its not good for any type of motor, but its especially bad for turbo engines because the turbo is boosting, putting huge amounts of stress onto the engine without getting you anywhere.

sixth gear is an overdrive, thats why it wont let you do it. you should never apply more throttle then what the RPM's permit, ever. you wont go any faster but are simply wasting gas and putting wear onto the engine.

[Rotary Rasp]

I'm FBO e85... my car picks up speed real fast WOT in 6th above 60mph (3000rpm)

2400rpm is probably a little low to be flooring 6th.


Someone correct me if I'm wrong, but I believe the autos have a taller overdrive. (OP and I have MT)

[STR8-6IX]

Originally Posted by Rotary Rasp

I'm FBO e85... my car picks up speed real fast WOT in 6th above 60mph (3000rpm)

2400rpm is probably a little low to be flooring 6th.


Someone correct me if I'm wrong, but I believe the autos have a taller overdrive. (OP and I have MT)

anything below 5000RPM is too low to be flooring it.

throttle position should always be proportional to engine RPM. since you have an MT, this is easier to do and especially important in your situation.

[Welcome to NBA Jam]

Originally Posted by PrimaMateria

Yup, I made the mistake of hitting the gas while in 6th at a low rpm while on the expressway. For those few short seconds I thought that I'd completely ruined my car [bucking, sputtering, 4x4 cel]. Learned real quick not to do that.

Only do it if you're testing your clutch life, and only for a few seconds

The N55 seems to be happiest at WOT starting in the 2500 RPM range. It's got so much torque!

[DaZuc]

Basically lugging the engine in 6th @2k

Drop it down 2 gears my friend

[vespa]

Originally Posted by STR8-6IX

NEVER do this. ever.. its not good for any type of motor

I think you meant any type of carbureted motor. Fuel injected engines can be floored anytime, anywhere. Unless of course they are improperly tuned.

The computer has a complete table of safe tested air, fuel, and timing targets for every load and RPM from below idle to above redline. When you floor the pedal you're not forcing the engine to do anything, you're simply asking the computer to select the maximum known power configuration for the current conditions. Of course you can eventually overheat the engine by requesting high power for long periods of time, but that's not the issue here.

[Bours]

it happene to me too ! i floored it in 6th at 65 mph on a 3 lanes freeway.....

half engine and loss of power and 4x4 in the dash !

couldnt accelerate no more had to go between cars and pull on the side !

pretty scary id say

[FireBlaze]

MHD reports that pressing down 50-60% of the throttle results in 90% of actual throttle. I'm sure we've all been "lugging" the engine especially with our advertised low RPM torque.

[STR8-6IX]

Originally Posted by FireBlaze

MHD reports that pressing down 50-60% of the throttle results in 90% of actual throttle. I'm sure we've all been "lugging" the engine especially with our advertised low RPM torque.

lugging the throttle is so bad for your engine

[Rotary Rasp]

I was driving my car today and I realized that I misspoke, 60mph in 6th = 2000rpm on the 6MT.

Even at 2000rpm, the car pulls smooth. By 70-75mph(2500rpm), I'm boosting around 13psi and it feels/sounds healthy and pulls hard.

If you guys are getting a CEL, you need to take a look at your tune.

[Jeff@TopGearSolutions]

That's too much load and heat. Excessive strain on all components of the engine. If you need to accelerate rapidly, down shift to the appropriate gear. At 60, 3rd or 4th would work.

Although a vehicle may not exhibit "trouble" going WOT in 6th, I can assure you the engine is not happy with it.

[bahn]

Look up LSPI

[Torgus]

Not that I do it often but I can floor it in 6th just fine. There is no reason to do so but it causes no issues for me. If I needed to pass usually I would downshift.

Have a look at your tune or something else is off hardware wise.

[Bours]

Originally Posted by Jeff@TopGearSolutions

That's too much load and heat. Excessive strain on all components of the engine. If you need to accelerate rapidly, down shift to the appropriate gear. At 60, 3rd or 4th would work.

Although a vehicle may not exhibit "trouble" going WOT in 6th, I can assure you the engine is not happy with it.

i have alpina flash and it goes to 6th gear at like 50mph in D mode loll

is it bad for my engine for DD or its only at WOT that its putting stress on engine ??

[Jeff@TopGearSolutions]

Originally Posted by Bours

i have alpina flash and it goes to 6th gear at like 50mph in D mode loll

is it bad for my engine for DD or its only at WOT that its putting stress on engine ??

We are referring to WOT. I have Alpina too. You'll notice an Automatic car will downshift at a certain load for obvious reasons, it's much easier on the engine internals and more efficient to get in the right gear.

[ANMVQ]

I did this once also, and also have Alpina but I drive in manaul 99% of the time. I was in 6th and just pushed the pedal and OPPS. LOL Still getting used to being back in a FI car.

[vespa]

Originally Posted by bahn

Look up LSPI

Interesting. Apparently LSPI is a recently discovered high boost / low RPM phenomena that is linked to oil and carbon in the combustion chamber and is not well understood or well managed by ECUs. Sounds like a good explanation of the OP's concern.