Stacking Cobb & JB4

[one30five]

I've been reading so much that ive started t forget some of the first bits of information I started gathering earlier...

Someone set me straight please.

I'm N55 Jb4 iso FBO. and have DCT

I ordered a Cobb mainly because of advice, and a fundamental understanding that flashing DME will allow DCT to take accurate (more so than from piggyback) load data which in turn means the DCT is using better clamping force on clutch... <- whether or not that is articulated correctly, flashing DME is superior to piggy back when it comes to DCT working properly with higher HP and torque.

Through my reading n the forums (here and n54tech) I saw someone say "you can't run cobb flash once your Jb4 is iso" MAYBE it said cobb "maps"

anyway, i'm looking for some clarity on how stacking the two works. AND if i'll be able to achieve what I described regarding the DCT? I'm probably overthinking this.

I already know that jb4 is going to control boost. I like that. I want to retain that feature and most of the others. NOt to mention back end support from BMS, who is testing a pure stage 1 now. I guess what im saying is that the way I perceived the post about ISO making it not possible to run cobb flash, was that I would essentially have bought a cobb for sake of loading a BMS back end flash?

Like I said - someone set me straight on this please

[Donny Rino1]

On a side note dinan now has a piggy back ecu for the m5, guess Terry is doing something right lol

[one30five]

lol. not trying to be a jerk, but what does that even matter (relative to my question)

[jsmonet]

eh, it's their way of getting around not having the keys for those ecus

[BEAR-AvHistory]

Ran one of the first 335is JB4/ISO + Cobb setups with the BMS flash. Specific flash was developed by Terry for the 335is/DCT. Worked very well 12.1/116 with 96.5 octane, Conti 245/275 DW tires otherwise stock car.

Best one on the system was a 335is with a pump gas + E85 mix. Pure stock with RFT he did 11.8/117. These are N54 twin turbo engines.

The IS flash will not run on a base 335i with the JB4/ISO + Cobb. They run a different flash package.

[one30five]

I don't think I articulated my question properly. I'm not asking about a TCU flash or backend flash designed for DCT cars. Im just wanting clarification on how the stacked tunes work in conjunction with each other - or if they even do after ISO modification to JB4 board

Let me put it this way...

With JB4 ISO for n55 can I still get a stacked cobb to read accurate "load" data. I believe that the TCU determines clamping force on either boost or torque numbers. but not the boost or torque (or whatever it is) that JB4 is creating. It is taking stock info. Essentially TCU thinks 8lbs of boost, when its actually 15. Or it thinks 300 ft lbs of torque when its 350....

From what I understand cobb rectifies that issue - but how? and will it do it when stacked with an Jb4 iso as opposed to intergrated?

[froop]

Boost when stacking is usually determined by whichever is targeting higher but the DME sees what it us targeting I believe.

E.g. If the DME is targeting 8 and the JB4 targets 15 you will get 15 but the DME sees 8. If the DME targets 14 and the JB4 targets 15, you'll get 15 but the DME sees 14, less of a disparity.

[one30five]

that makes sense. so would I run a OTS aggressive map, and JB4 on map 5? and will that even work if my jb4 board is ISO-modified?

[Nugget]

Originally Posted by one30five

that makes sense. so would I run a OTS aggressive map, and JB4 on map 5? and will that even work if my jb4 board is ISO-modified?

I would only run the flash provided by Terry if you are stacking. Not an OTS map.
What do you want to achieve by stacking?

[one30five]

Originally Posted by Nugget

What do you want to achieve by stacking?

I started experiencing the "slipping" or what I think is a confused DCT when running higher boost. I've received advice from several reputable sources that the 7sp DCT determines appropriate clamping force by taking info from DME. maybe that info is boost, but I've heard the term load table.

Since piggyback tunes work by "tricking DME" intercepting and changing signals to/from DME, the information the DCT is taking (to determine clamping force) is very innacurate.

I thought that flashing DME with a flash tune (Cobb) would help close the gap between what power is being made, and what power the DME is reporting. which IN MY MIND, would help the transmission work more efficienctly/ effectively

SO I thought that stacking would allow JB4 to control boost and keep me arounf the 16.5-17 psi I see on logs while the Cobb would flash the DME for 15 psi, thus making the inaccuracy only 1.5 - 2psi, vs an inaccuracy of 8 or more (I think stock max boost is 8psi?)

I know that at least one part of my understanding of this is flawed (wrong)

Does that make sense Nugget? I want to flash the DME to boost as close to what Jb4 would boost, while allowing the JB4 to still do its thing.

[Nugget]

I switched to Cobb for the same reason.
But what do you want the JB4 to do that you can't do flash only?
Meth control, gauges, map switching?

[one30five]

I'm under the impression that Jb4 can get more boost? is that true? or can protunes match>

I just bought pure turbo stage1 . and I wanted to run as much e85 as possible. so I figured the BMS back end would come in handy since it is essentially N55 big(er) turbo specific

[Nugget]

Pro tunes can match.
I've run up to 21psi Cobb only, to run more than that (but you won't be with a Stage 1) you may need to upgrade the MAP sensor.

[froop]

Originally Posted by one30five

that makes sense. so would I run a OTS aggressive map, and JB4 on map 5? and will that even work if my jb4 board is ISO-modified?

Nah it doesn't work like that exactly. You would need to decide what is controlling what and adjust accordingly, e.g. Boost, AFR, timing, fueling, etc etc

With a JB4 I believe you would need to use map 6 which is used for custom mapping.

On my Procede/Cobb setup, I basically use the Cobb OTS E30 maps with some map adjustments because I'm running E50. On the Procede I zero out AFR and timing maps and adjust fueling levels so it's the Cobb that is controlling those primarily. The procede is controlling primarily boost and meth.

[one30five]

Originally Posted by Nugget

Pro tunes can match.
I've run up to 21psi Cobb only, to run more than that (but you won't be with a Stage 1) you may need to upgrade the MAP sensor.

yep. 3.5 bar MAP sensor for anything over 21 psi.

I really appreciate the help. what it boils down to is that I had some misconceptions on my part. That, and I've never flash tuned, so i'm a noob when it comes to that.

Nugget - I know you use PTF for your tune, or had. Are you happy with the results? do you recommend?

[Nugget]

Originally Posted by one30five

yep. 3.5 bar MAP sensor for anything over 21 psi.

I really appreciate the help. what it boils down to is that I had some misconceptions on my part. That, and I've never flash tuned, so i'm a noob when it comes to that.

Nugget - I know you use PTF for your tune, or had. Are you happy with the results? do you recommend?

They can be very busy but I believe right now they have the best grasp of flash tuning N55s. So yes I would recommend PTF.

[Wolfie1]

Originally Posted by Nugget

I would only run the flash provided by Terry if you are stacking. Not an OTS map.
What do you want to achieve by stacking?

Ugh sorry guys for keep on bringing up old threads but I am doing the pure turbo stage 2 upgrade. I am going to be stacking the Cobb with the JB4 and then eventually get a protune.

My question is: is Terry still providing people with this flash tune?? And if so how can I get ahold of him? Is he at BMS??

Thanks guys

Edit: NVM guys gotta love google. Figured it out. From my research Terry and BMS no longer supports Cobb BEF but has switch to MHD. Which seems like a way better options than the Cobb