Scion tC Forums banner

VVT-i controller?

2321 Views 12 Replies 9 Participants Last post by  ElementRacingTRD
There is a thread over at scionlife about this... anybody know anything about it?

"I did a search already but didnt find anything so I thought I would post it. I was reading in one of the tuner magazines today but forgot which one and in it they had a controller that works for both VTEC and VVTI. They tested out the controller on a celica GT-S and it gained from what i remember was about 17 hp and 10 lb tq. The msrp was about 480. Has anybody else seen this yet and do you think it would work with the TC? I wouldnt mind getting it if it did."

There is a group buy going on for $325
1 - 13 of 13 Posts
are you talking about the PFC that is availabe for the celica?
I'm talking about whatever is being talked about in the thread I linked to.
Originally posted by Zygote55@May 13 2005, 09:41 PM
I am starting a group buy on the new power enterprise cam-con.
That was taken from Scion Life. I would definitely buy it.
i got banned from scionlife

i can't see the thread
See less See more
basically the more engine parts you have, the more hp you can gain from this[/b]
Those scionlife guys are so sophisticated!
Originally posted by mach5@May 14 2005, 05:22 PM
i got banned from scionlife

i can't see the thread
How did you do that - Marty and me tried - they didn't ban us
See less See more
the gts has VVTL-i...vvti-i with lift. it has a secondary lobe on the camshaft that it switches over to at a ceratin rpm, similar to vtec. VVT-i alone is variable timing, it simply advances or retards the intake cam (and soon exhaust cam with toyotas new Dual VVT-i
). This movement of the intake cam is based on rpm and load andis constantly moving, it doesnt "switch over like VTEC and a controller like the one being discussed would show no benefit.
See less See more
Originally posted by zoltiz+May 14 2005, 05:01 PM-->QUOTE (zoltiz @ May 14 2005, 05:01 PM)
@May 14 2005, 05:22 PM
i got banned from scionlife 

i can't see the thread
How did you do that - Marty and me tried - they didn't ban us
i'm just that good
tell a girl that i will straighten her out with my pipe in her ass
tell someone to go end themselves
call the whole site a joke
etc etc

it all added up to a good ole bannin
See less See more
I read through the English documentation on the install and tuning. It gives you control over VVTi and basically fools the computer into thinking you have more or less air than you actually do, it's not really an enrichment scheme per se, it's a work around that is common to most piggyback fuel controllers that don't directly control the injectors (S-AFC, etc.)

Personally, I wouldn't waste my money on this. I'd spend the money necessary to put in an F-Con V to get direct control over the engine and have the self-tuning features the F-Con has. One of the biggest problems with tuning Toyota engine control with piggybacks is TCCS's ability to modify the fuel maps based on data provided by the O2 sensor. Since the 2AZ has a wideband, I'm sure this is even more challenging.

Here's what happens: you adjust for a richer mixture, the wideband detects a rich condition, and adjusts the fuel maps to bring it back to what it was told is normal at the factory. Your rich adjustment just went away, so you go back to the piggyback and dial in more rich. TCCS sees it again; and again, adjusts it back to what it wants. This continues until you exceed the 20% built into the ECM, and your piggyback is attempting to make adjustments outside the ECM's ability to change. Game over. Engine is in poor tune, and you have to reset everything to zero and start all over again. LOTS of Supra tuners learned this the hard way.

Tuning Toyco engine management with piggybacks is very challenging with only rpm and airflow inputs. You need to know a LOT more about what is going on to fool the ECM and have it stick. That's part of why most serious aftermarket tuners ditch the OEM ECM and go for AEM, MoTeC, Autronic, Haltech, or some other aftermarket device. It's just too difficult to tweak the OEM setup with piggybacks.

This doesn't mean it's impossible to do, it's just harder. HOWEVER, the tC ECM does have the ability to be modified using an external device. I don't know the details of this, nor do I have the $8k to buy the tools to do this, but I suspect this is how Scionspeed is modifying the ECM to work with their turbokits. I could be wrong, but my understanding is they don't depend on piggybacks. FWIW, the GReddy eManage is also a piggyback with highly advanced capabilities, the F-Con V can also be a piggyback or a standalone. Both of them are far beyond the ability of this device, and offer a MUCH more comprehensive solution to the tuning problems brought on by aftermarket FI.

Here's the link to their documentation.
See less See more
why do i always enjoy reading Lance's and ZEROmotorsports's posts. This is why i love being a member of this forum.
See less See more
very enlightening post
1 - 13 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.