[335i E92]

Evening all...

Took the car our for a blast tonight to clear it's throat as done a lot of town driving recently.

Motors running really well and pulling strong in every gear. However after quite a few full wot runs (on v quiet dual carriage way) I noticed that when shifting quickly from 2nd to 3rd it would die for a second or two.

This has happened before a couple of times in the exact same situation. Am I witnessing heat soak here or maybe I have held on to the previous gear too long an hit the limiter which has carried through to the next gear for a second or two?

On the occasions it's done it previously I've backed off for a few miles n let the temp get down to below 110 tried another blast n it was fine again.

Anyone experienced this? Am I outlining my need for an upgraded intercooler? Is there something wrong with the car? Or maybe I just held the previous gear for 2 long?

As I said the car afterwards ran perfectly so I'm pretty sure it's not a turbo, fuel pump or diverter valve related issue.

Anyone experienced this after some spirited driving or have any ideas??

Cheers

H

[zltm089]

sounds like you got a manual gearbox? i've noticed heat soaked a few times....but not that often...

[335i E92]

Sorry, yeah I have stick shift. Tbh it's only ever happened a handful of times and after some hard driving. I would have thought heat soak would be a slight loss of power and nit like someone had just pulled the rug from
underneath you.

Maybe I just pushed it too hard and it was telling me to stop being a douche bag.

[zltm089]

when i had my peugeot, i used to rev it until the red line....over reved a few times and experienced what you described...the rev limiter kicked in and loss power instantly...

I would never do this on other cars that I own!!!...

I tend to shift quickly ( quick press of the clutch and right foot "featherring" on the gas pedal) and at around 6k rpm....there shouldn't be any loss of power that way and no damage to the engine....

[335i E92]

Originally Posted by zltm089

when i had my peugeot, i used to rev it until the red line....over reved a few times and experienced what you described...the rev limiter kicked in and loss power instantly...

I would never do this on other cars that I own!!!...

I tend to shift quickly ( quick press of the clutch and right foot "featherring" on the gas pedal) and at around 6k rpm....there shouldn't be any loss of power that way and no damage to the engine....

My car 95% of the time gets treated better than the mrs, 5k oil services & never push it when cold. I don't purposely redline the car it's just that sometimes when your having a play it's easy to get carried away & tbh the way the car pulls with the evolve remap you're at the top of the revs before you know it.

I'll just have to be more conscious in future of changing up a tad quicker. Im pretty sure it's nothing else as the car is running 100%.

[m1bjr]

They all do that sir, bogging down.

Basically its just turbo lag, you just dumped all the boost by lifting off the power fully.
It will take a half second to rebuild, you just dont notice it when slow shifting.
The autos can hold a little boost (as does the Procede and JB3/4 map option for manuals) between shifts to help eliminate this.

I see you have a remap, so the problem is more pronounced as you are trying to build a few psi more than stock too, which takes longer - so the lag is bigger.

Also don't rev a 335i to redline, there is no point.
Set to shift at 5,600rpm or so as after that its all dropping off quickly to the redline.

[335iLondon]

Originally Posted by m1bjr

They all do that sir, bogging down.


Also don't rev a 335i to redline, there is no point.
Set to shift at 5,600rpm or so as after that its all dropping off quickly to the redline.

Agreed, but depends on the map characteristics.
I hold the revs longer after having my DMS remap.
Peaks at 6.5k

[335i E92]

Originally Posted by 335iLondon

Agreed, but depends on the map characteristics.
I hold the revs longer after having my DMS remap.
Peaks at 6.5k

+1

Before my Evolve map it used to die a death just over 5k but now it stays strong and peaks at 6.5k which is why I’m probably hanging on to each gear a little longer than previous resulting in the occasional power loss when hitting the higher rev range and then changing up too quickly.

[neil@JuicedUpTuning]

Originally Posted by m1bjr

They all do that sir, bogging down.

Basically its just turbo lag, you just dumped all the boost by lifting off the power fully.
It will take a half second to rebuild, you just dont notice it when slow shifting.
The autos can hold a little boost (as does the Procede and JB3/4 map option for manuals) between shifts to help eliminate this.

I see you have a remap, so the problem is more pronounced as you are trying to build a few psi more than stock too, which takes longer - so the lag is bigger.

Also don't rev a 335i to redline, there is no point.
Set to shift at 5,600rpm or so as after that its all dropping off quickly to the redline.

Plus you could have done a data log with the JB4 and sent it in for analysis

For what its worth you can run a JB4 ontop of a flash in most cases. You simply get min you flash power or the JB4 provides more power. No reported problems. You get logging and guage hi-jacking for boost, IAT on your dash gauages for quick reference.