Nice vid guys. I always learn something watching your vids even though I've been working in the industry for 15 years now.... And I own a R32 GTR 😊. Appreciate your content.
Good video, thank you. I have an important question. From my experience with the BMW S50 engines, is that the MAP pressure readings are representative of load. In these engines the ITBs are connected with a common vacuum rail so the pressure readings are more like in a single throttle setup. Is the engine in this video lacking such a common vacuum rail? This is also the case for other BMW-M engines with ITBs like the S54 CSL and S65 which uses MAP sensors from stock.
Even when running alpha N, where possible it's advisable to incorporate a MAP signal so the ECU can performa background compensation for MAP. This should be done from a balance bar that takes a feed from behind each throttle to give a stable average MAP value. You would think then that we could simply use this MAP signal for a conventional SD fuel table but unfortunately it isn't quite that simple as MAP alone isn't a good indicator of airflow with ITBs.
Oh and one thing not covered here, and kind of in response to Andy's question. Often ITB engines have a really crap (unstable) MAP signal. So tuning low loads and cruise on the MAP sensor is an exercise in tearing your hair out
Actually you can get a MAP signal that's nice and stable by taking a line off each throttle body and running them to a small reservoir. That still won't give you good results if you try tuning using MAP alone though.
@@hpa101 I use the efi-hardware kit for this this (it's really well made,) on my GTiR. With the 4 cylinder, it's still a little too 'jumpy' for my liking. No doubt on a 6/8/10/12 where there are more cylinder pulses it would event out even more.
@@manitoublack This guy managed to do it by running 4 signals through a processor, not sure about the details, but he often comments on HPA videos. ru-vid.com/show-UCd4tiSGPjtd7OHRtPjQ9DHQ
thank you very much ! i m new to this tunig word and your video help me to understand how to set up my ecu to work correct with my set up ! only one qustion i have : (bmw m50nv itbs, ecu master emu black ) i dont have 4d table in ecu master as option but i do have "map vs rpm correction " is it that what shoud i use to correct the my ve table at 100kpa + ? and should i consider value of 100 to be 100% of the ve table (97 = -3 ) ?
Hi guys @hpacademy Quick question: you mention that you don’t need to use alpha-n for the ignition table as only the fuel delivery is influenced by the individual throttle bodies (which makes sense) Is this true for NA applications as well? I have both tables with tps on the load axis atm and just wondering if switching the ignition table back to MAP would be benificial. 13b engine, megasquirt ecu. Thanks!!
Hello Andre, I heard in your webinar that you were dealing with the Fcon Vpro Hks setup, I would be grateful if you would do a short course or an introductory lesson on the operation of the Vpro ECU, if of course it is advisable and will help broaden the horizons of a beginner tuner!
Thanks mate, yes this lesson is from our Gold Archive. Which is a set of 250 lessons, we produce one more every week. You can become a Gold member for $19bucks a month, or get 3 months access free with every course you purchase :) - Ben
As I understand it some ECUs offer a "MAP window" feature, where the user can choose a sampling window during the cycle (720 degrees). This is then set to start sometime after intake valve opening and end time after intake valve closing, and a minimum MAP value during that window is used to calculate fueling. Any experience with this?
In the speed density system the MAP is taken in the plenum chamber and after the single throttle plate. In this example for the main fuel delivery table you are using TPS as the load axis because there is no common plenum chamber but in the lambda target table you are using MAP as the load axis to allow for changing turbo boost pressure. Is this MAP taken after the throttle plates or is it taken between the turbo and the throttle plates. If it is taken after the throttle plates are there hoses coming from all 6 inlet ports to some form of surge chamber to even out the strong pressure pulses that you would get from a single port only.
Can solve the high boost rich problem more elegantly by tuning in in VE mode. Using a TPSxMAP with MAP measured in pressure ratio between IMAP and eMAP? To the best of my knowledge Link don't offer this option. Regardless excellent tutorial 👍
Pressure ratio would be the preferred load axis input, however that creates two separate issues. First up it's quite involved and reasonably costly to add an EMAP sensor (at least once the turbo system is already complete and running). You also need to be able to filter or dampen the signal adequately to make it useable without adding latency to it - Not difficult but it's often ignored. Secondly (and probably the more pressing issue) is that a lot of aftermarket ECUs don't offer pressure ratio as a load axis option.
I wish it was but sadly nope. In all honesty unless you're already done with the project I wouldn't recommend adding ITBs to a 2JZ. It's unlikely you'll see any real advantage from doing so and even in the RB world most people chasing high power will revert to a plenum and single throttle. If you're doing it for the sake of being different then have at it, however if you're expecting a massive transformation in terms of response you may be disappointed.
@@hpa101 with the current situation nz is in, I'm just doing things for fun. I do have a goal. Nothing more than 500HP. 300hp is more than enough to drive to the south island and see what those b roads are all about.
It's a little easier to use a RWD car on a rolling road dyno vs AWD or FWD. The load is the exactly the same, the engine doesn't care what it's driving it's doing the same things at the same load cells regardless. You can even tune the engine on a dyno by itself if you wish - Taz.
So what if we don’t have an on board wideband in the ecu and only using the dynos, do we just use the tps for base fueling then can use the 4d table for boost?
You don't need an onboard wideband to tune but you will need a wideband - either a portable one that you can log the output from, or one connected to the dyno. Without that you have no way of knowing the AFR.
I’m aware of that I meant using the dynos wideband instead of having one wired into the ecu. The primary fuel base table will be the same but what secondary table is used for boost. Cheers
Many aftermarket standalone ECUs don't actually offer the option of a MAF sensor so you may have no option. There's nothing wrong with using a properly sized MAF though in an application that's compatible with one. A MAF or in the case of the RB26, twin MAFs also adds to the complexity of the intake system.
ITB's are only marginally valuable on a NA engine. On a Turbo engine ITB's are completely useless, therefore, DON'T USE THEM. You can still run a MAF with a Turbo and ITB's. ITB's can be made to work with a Speed/Density setup by creating a vacuum/pressure reservoir that connects all intake ports after the TB's, but this is a pain in the butt way to do it that requires a lot of cut-and-try experimentation, for ZERO GAIN. If you're installing a Turbo on an ITB engine, REMOVE THE THROTTLE BLADES AND SEAL THE THROTTLE SHAFT HOLES, OR, GET A PLENUM STYLE MANIFOLD. The power difference is zero to none, and your tuning headaches will be greatly reduced. The best setup is to put a huge TB on the inlet of the compressor, and a MAF ahead of the TB, this eliminates the need for a BOV and reduces Turbo Lag at mid to high rpm, and to a lesser extent, reduces Inlet Air, and Compressor Housing, Temps. If you are considering using Alfa-N tuning, then you already have an after-market ECU, which means you can run a standard GM MAF which is good to over 1000 HP and very easy to tune. The GM MAF is specified to be mounted in a 4 inch tube, you probably can't come close to using all that flow potential. This setup also allows you to run a small percentage of your Water/Alcohol Injection at the Compressor Inlet without fear of running it through your inter-cooler, because the inter-cooler will be running under vacuum ~95% of the time. In fact, with a properly engineered Water/Alcohol Injection System, you can probably get rid of the inter-cooler and all those expensive pipes, it only depends on how extreme you are going. . .
Unfortunately making a blanket statement like you've done is both misleading and inaccurate - There's unfortunately not a lot of absolutes in the world of performance engines. There can be some significant advantages to ITBs on N/A engines in terms of power which we've proven on the dyno multiple times in both the Honda K20 and B16/18 as just two examples. It's not always a case of chasing power either, and Nissan chose to use ITBs on both the GTiR's SR20DET and the R32-34's RB26 for improved transient response. ITBs WILL NOT give good results using a MAP-based load input, regardless of using a vacuum balance reservoir (the RB26 even includes a balance bar in stock form). You can make the engine run perfectly at WOT but you won't be able to get accurate or consistent control of the AFR at part throttle. This goes for an N/A engine but is even more evident in a turbo application. I spent a good portion of the early years of my career with my own turbo ITB engine running an ECU that could not use a TPS load axis so I have plenty of experience here and I'm very aware of the limitations. I'd also disagree that tuning an ITB turbo engine creates headaches. If you follow the techniques in this webinar it's incredibly simple. Putting a huge throttle body on the inlet of the compressor (turbo?) is a terrible idea as your effective 'plenum' volume is now massive, incorporating all the intercooler plumbing and your intercooler. This will create more tuning headaches than properly tuning ITBs with 4D mapping ever will, particularly when it comes to idle control. 'Huge' is also not the way to specify a suitable TB size and bigger is most certainly not better when it comes to the throttle butterfly. To address your last point, while a properly calibrated MAF has its place, it's not the answer to every problem. The first issue is that many of the current crop of aftermarket ECUs don't even allow for a MAF input. Secondly a MAF is a poor choice for some engine combinations, particularly those running aggressive cam profiles with a lot of overlap since this creates reversion at idle which plays havoc with the MAF signal - Andre
![TPS + MAP Tuning | Turbocharging with ITBs - Alpha N [GOLD WEBINAR LESSON]](/img/logo.svg){kind=logo}
