Switching between E85 and pump on chrome?

**Greg E** · 11-12-2014, 11:29 AM

You don't want to use knock as a boost controller.

Matt, you have the beta ROM for switchable maps. What's the story with testing it?

**mjannusch** · 11-12-2014, 12:27 PM

I ran it with a rigged-up switch, and it did what it was supposed to. I wasn't able to change fuels, but the boost tables worked as expected for me. I made the fuel and timing tables identical and just changed the target load and base WG duty cycles to see if it would change boost and it did. Next step is to put some tweaks into the fuel and timing maps and make sure it actually switches maps if I flip the switch. After that, I'll try the injector scaling and dump in gasoline instead of E85.

At the moment, there's a foot of snow on the ground so no more testing unless the conditions improve.

**mjannusch** · 11-12-2014, 12:30 PM

Originally Posted by Greg E

You don't want to use knock as a boost controller.

Well yeah, but when you put in shitty gas you shouldn't be going WOT all the time either.

You should see some background knock which will lower the octane value and dial back your timing, richen up the fuel, and reduce the boost. Then that gets factored in at WOT as well.

But yeah...

**Greg E** · 11-12-2014, 01:45 PM

That ROM worked perfect for me but gave jesters issues with logging for some reason. Have to investigate that further.

Glad to hear it worked perfect for you. When you do get the chance to test, verify the fuel and timing tables switch by setting the tour mode maps to some funky value. You can log the fuel map look up by itself in EVOScan to see if the value changes.

**Lobo2112** · 11-19-2014, 03:55 PM

I'm going to be running a 98 SL ecu with a separate EBC... so its not gonna work so well on the whole "reducing boost" automatically part. I was planning on having 1 of my 2 boost settings on the EBC be essentially wastegate pressure and hopefully using this feature to switch to a second tune set up for 91 (87???) octane, no meth, and wastegate boost... vs my expected norm of 93 + meth + ??? boost. The idea of going on a road trip through the boonies, not being able to find premium gas or methanol, and having to put low quality gas in the car without any compensation for it pretty much terrifies me. I most certainly don't want to be redo-ing this build over something like that in a couple years.

**Greg E** · 11-19-2014, 05:55 PM

All you guys who cheaped out and didn't buy a true 98/99 VR4 ECU or a Brett or Adam ECU are going to be pissed off if I release the next version of chrome because the SL ECUs don't have the hardware to support the switchable maps.

**mjannusch** · 11-19-2014, 06:43 PM

Yeah, that's a bummer...

**NOMIEZVR4** · 11-19-2014, 10:05 PM

Originally Posted by Greg E

All you guys who cheaped out and didn't buy a true 98/99 VR4 ECU or a Brett or Adam ECU are going to be pissed off if I release the next version of chrome because the SL ECUs don't have the hardware to support the switchable maps.

Didn't cheap out just jumped on the bandwagon quick before Adams/Brett's ECU's became mainstream. Worse case scenario, those of us with SL ecu's can get them converted.