BOOTMOD3 BM3 ECU TUNE FOR TOYOTA SUPRA

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satindragon

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It varies, but most of the dyno charts I've seen show a 45 - 55whp increase over stock. with similar torque. With a catted downpipe I saw a +81 whp and +114 wtq. Other than cost, there's pretty much 0 downside to running a catted downpipe (like the one from AA).

Car sounds great in sport mode yet is still quiet when in comfort. Perfect in my opinion.
 

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It varies, but most of the dyno charts I've seen show a 45 - 55whp increase over stock. with similar torque. With a catted downpipe I saw a +81 whp and +114 wtq. Other than cost, there's pretty much 0 downside to running a catted downpipe (like the one from AA).

Car sounds great in sport mode yet is still quiet when in comfort. Perfect in my opinion.
I am just worried about an off the shelf tune, I haven’t got any tuners I trust in my area.
 

satindragon

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The OTS tunes are typically pretty safe. They don't make the same power numbers as custom tunes because they're designed to be conservative. Every engine is slightly different so without putting the car on a dyno or reviewing logged road pulls, a responsible tuner is going leave a fair amount of margin.

A car with a good DME tune is in many ways safer to run hard than a car with just a JB4 on a stock ECU. The stock ECU tends to target a leaner Lamda/AFR than most aftermarket flash tunes.

Here's an example of a 5th gear pull on JB4's map 3 which targets 6psi more boost over stock. The engine is seeing 16.6 psi of boost at this point in the run. The 2 parameters to pay attention to are the AFR and Trims. In JB4 parlance a fuel trim value of 25 means the ECU isn't making a change to the short term fuel trims in order to hit the Lamda/AFR target. A value of 50 would mean the ECU is attempting to add up to 33% more fuel whereas a value of 0 means it's trying to remove up to 33% fuel. Seeing a value of 0 or 50 for any length of time is a bad thing.

In this log we see the trim is up to 42 in order to meet the stock AFR target of 14.4. We're not at the limits of the short term fuel trim but the Lamda/AFR target is still on the lean side for my taste. It's better for fuel economy and emissions as well as likely being a bit easier on the catalytic converter though.

map 3 jb4.jpeg


Now for a log of the same car doing another 5th gear pull, running a flash tune along with JB4 in map 6. I'm targeting 2 psi more of boost on top of what the flash tune is requesting from the turbo. This results in the engine seeing the same 16.6 psi of boost just like the previous run. The first thing to note is the flash tune is targeting a richer AFR of 12.4 which coupled with a tad more timing is why the engine makes more power.

The short term fuel trim is sitting at 30 which is also very nice. This leaves much more head room for the ECU to make fueling adjustments to meet the lamda/afr target.

All this is to say that even an OTS flash tune is going to do a lot towards making the car safer to run hard. It also will give you more headroom should you decide to run an add-on like JB4 for easier control over changing boost.

IMG_BC7D1A790DA4-1.jpeg


EDIT: Additional markup on screenshots
 
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