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Discussion Starter · #1 ·
Very exciting to let you guys know, this morning the first trial on a R35 using just an accessPORT successfully saw real controlled boost via the ecu, RPM based boost control. No boost controller in sight.

For the last month or so, to help take the work load away from the Cobb GT-R team (Trey, JoeGR, Turtle), GTC main tech man Thistle had been busy with the raw GT-R rom files. The wastegate duty table axis now uses RPM instead of airlow, which was the reason behind the boost spikes. This now allows proper independent control of overboost situations by rpm. Now wastegate duty follows the map by RPM.

More testing to be done, but an otherwise standard car with significant traction problems in the dry, although this was on the initial map which gave 20 PSI midrange and 17 PSI at 6000 RPM and will be detuned in the midrange as the car is otherwise stock. The important point is that now we can detune the midrange and keep the high RPM boost up

Next up Knock in datalogs


If you thought the AP was good, its about to go to next level thanks to the tireless efforts of the team who never stop striving to improve.

All being well GTC will shortly be offering custom tunes with the new features included. I have told a number of people to hold off buying custom tunes from us until this was implented and we were happy, and also to save boost controller $$$
 

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That's fantastic news Ben! That's a real breakthrough!
Jack @Boost Logic had to retune, and (imo), significantly detune mine, to combat those damn dreaded boost spikes. Is this something all Cobb Pro tuners will have available to them (ie, us Yanks)?
 

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Discussion Starter · #4 ·
That's fantastic news Ben! That's a real breakthrough!
Jack @Boost Logic had to retune, and (imo), significantly detune mine, to combat those damn dreaded boost spikes. Is this something all Cobb Pro tuners will have available to them (ie, us Yanks)?
ye big breakthrough which was started and finished pretty quickly
we all hate those dam spikes in Nissans system. So lucky no one did an engine in the early days.

Yup will be available though all protuners, who will soon have access to accesstuner pro 2.0 after tests.
 

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Maps from last week has this new feature? Yes I mean mine map :)
 

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Sweet, now I can go to Surgeline tuning and we can re-dyno tune my car. Tim from Surgeline (Cobb affiliate), told me an engineer in Europe was working on it for Cobb. Didn't know it was thistle for sure but I was wondering. Great job thistle!!!!
 

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Wow, that's great to hear. still havent gotten one because i havent broken the car in and have to make sure my mechanic wont be sticking it to me if i have it on the car. Glad I waited so far.
 

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Fantastic! I just ordered a boost controller, too. I'll hold off on the install until this becomes more mainstream. Thanks for the dedicated work on this.
 

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im not a tuner so i dunno this ecu stuff, but wanted to ask some questions, sorry if they look uneducated, i know only a little, and i have only done a greddy emanagement setup on an older car along time ago on a non supported ecu.

did the limitation on air come from the 23psi limit from the maf, hence this being a work around??
if that limitation was removed would it work by airflow and not need RPM based?

if thats all not a bother what about that 23psi limit? what will this rpm based ecu gain from removing that limitation?
 

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This is unrelated to boost pressure or airflow limits.

This is a method to accurately control the wastegate to get your desired boost curve without spiking.

On a completely standard car I have 17.5 PSI at 5500 RPM tapering to 14.5 PSI at 7000 RPM. This is usually actuators/EBC territory.

I have done only two flashes on the new system, will do a third to fine tune and then collect/post some nice logs I hope.
 

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Discussion Starter · #15 ·
Loads graphs and data to follow to prove it does what it says on tin, inc full throttle gear changes


V2 map holding 1 bar at 7,000rpm. totally stock car
 

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Not dyno'd, just tested on my commute


Previously about 0.2 bar less at the top end, limited further by spiking on flat foot short shift or 1-2/2-3 redline changes.

It is certainly consuming more air and fuel, so it is hopefully likely to add power.
 

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Um, can someone please explain what this all means in layman's terms for the mechanically challenged amongst us?
 

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Um, can someone please explain what this all means in layman's terms for the mechanically challenged amongst us?
Easy....
More power at the top end, without the boost spike on full throttle upshifts in the middle.
No more $$$ for boost controllers and actuators as now a tune can deliver the same result


What Thistle needs to do now is get a version to Australia for testing - as after all Bart Simpson showed us that toilets flush the other way down under - lets hope the boost control isnt inverse. In other words I really need to test it on our car (can also supply boost error/target dyno graphing)
 
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