New Member
May 14, 2018
Hi everyone.

Before the statement of "use the search function" starts, please note that i have used it, and google, and every other avenue, but all i get is MSD80/81 results, and some other threads. but nothing significant to what im trying to find out.

I have an '09 E92 335i N54 DCT. (South African car). it is currently equipped with JB4, MHD Pump BEF, gutted stock Cats and an upgraded Charge Pipe with Forge DV set.
the Wastegate arms have been replaced as well as the Turbos reconditioned.
I am getting slight Turbo Siren, but nothing crazy, and have just fixed a boost leak at the Intercooler to Charge Pipe connection. and made a bracket to hold on the Rear turbo inlet pipe as it had come off.
My issue is that car feels gutless, i cant even get the Traction Control light top flash anymore, an it used to flash at the slightest heavy throttle input.
my throttle is also extremely unresponsive, and very laggy.
My DCT shifts are not bad, but not smooth like they should be
whereas about 2months back, the car was very strong, and had decent response.

i drove a friends '09 Z4 35i N54 DCT, mods were, Charge Pipe, Intercooler, stock Cats and Stage1 MHD OTS map.
the difference was night and day, his car had instantaneous throttle response, it was extremely strong, and lit up the TC light like a christmas tree all the time.
Hi DCT gearbox is ridiculously smooth even in Sports+ mode, and engages brilliantly.
His ROM is INA0S.

I know INA0S is the 335is revision ROM, but i just want to find out if the INA0S is the reason for the great throttle response, and smooth DCT Shifts.

I have read that there is a possibility to update the ROM on IJE0S cars to the INA0S version, but how, can i take it to the dealer, or is it specialist work? ive already contacted my dealer, and they dont know what im talking about, and im not sure exactly what to ask of them.

look forward to learning a bit more here, and hopefully i can get steered in the right direction. Id live to Update to INA0S, as ive heard great things.

thank you in advance everyone.


Apr 19, 2017
I have the IJ version and no issues at all with power or throttle. Stage 2 plus mhd and Fbo with upgraded vacuum hoses.


Aug 11, 2017
If INA0S is an updated rom for your car, could flash it with MHD or WinKFP pretty easily. If INA0S isn't part of the update path, could still do it, but would need a copy of a stock bin to flash...like pulled from your friend's car.

The real diff between your car and his is JB4 vs. flash only. With enough work, JB4+BEF can be "ok" on DCT, but if you tried JB4 and then flash only back to back, you'll likely notice the difference in DCT shifts immediately.
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Oct 28, 2017
Monroe CT
Contact Terry with a log he will get you setup perfect he has great customer support and knows his hardware better than anyone.


Jan 7, 2017
Remember: Maintenance before mods. I’d make sure to check your fuel injectors, walnut blast / clean intake, coils and plugs, etc., LPFP and HPFP pressures (do logs!) before looking to change the engine software.
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Apr 19, 2017
Remember: Maintenance before mods. I’d make sure to check your fuel injectors, walnut blast / clean intake, coils and plugs, etc., LPFP and HPFP pressures (do logs!) before looking to change the engine software.
I would not recommend altering engine ROM.


New Member
Jul 26, 2018
jb4 and DCT does not run well together, the torque requests from the dme to the dct not correct anymore because of jb4 piggy back


New Member
May 14, 2018
Hi everyone.
My biggest apologies, i didnt even return here to check the responses, as i assumed the subscription was activated, so i was only responding to my N54 tech thread.

let me respond to what was given above.

I have been in touch with Terry, however, this was due to other issues, in getting the car running correctly, which is fine now, but was not related to querying the INA0S ROM. i was chatting to him directly via FB Messenger, and he pointed me in the direction of Jake Yamona, but id need specialised hardware cabling to do it apparantly, (ICOM), which i dont have. so for now, this is on hold, as its not an urgency, i just read that there would be differences, just not sure what they are still.

I have the following mods:
Stock D0wnp1pes (gutted them)
secondary [email protected] delete
Upgrade Charge Pipe
JB4 Map5

I have new Coils (Bosch), new Plugs (Bosch OEM).
Will post logs below in CSV format, as this shows my HPFP and LPFP are in range and look good.

Noted regarding the decision against the ROM update. I am currently having no issues on the IJE0S, i just merely have an interest, and its for personal knowledge to know the difference.

Please see the logs attached, i know we have spoken before via PM, and you recommended going Flash Only. i have contacted BQ Tuning, and have had a response to having my vehicle Custom Tuned.
However will get this done, bvut want to wait to till i have all the relevant hardware installed (currently waiting to pull the trigger on a 7.5" Race Cooler.

I know the attached is JB4 logs, these are WOT logs, things look good, however Map 2 shows timing flatlines, i believe this is due to me only having 95 Octane fuel (equivelent to 91RON in the USA)

Thank you for that info, my personal research has led me to that exact thought, and has me considering removing the BEF and JB4, and flashing a Stage 2 MHD OTS map for the time being, would you agree with this?
I do not want to cause the DCT Gearbox unnecessary damage or issues that i can avoid.

Thank you in advance to everyone that responded here.
The car is currently running very well now, Boost meets target, with a slight overboost, but nothing alarming,
my WGDC meets FF (i dialed this in)
AFR seems on point, but i think i need to get clarification.
I have also attached the JB4 window graph. incase it means anything to you all :)
Map 2: