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The mkiv Supra Owners Club

VVTI DBW standalone ECU's


MarkR

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I have a VVTI 98 supra that I've now gone single on. We're using a Solaris ECU.

 

Ryan came over to map it and then realised that the ECU had gone into lockdown mode as it wasn't connected to a normal ECU. After a few hours of trying to sort it out and numerous phone calls etc, we left the Pedal Postition sensor disconnected and connected the TPS, but turned it 45 degrees so that the locked down position (half closed) was now fully closed, and moved the throttle cable to allow the cable to open the butterfly fully. We had a few other issues that prevented mapping that day which are now sorted and a basic map was left on the ECU.

 

What has everyone else with standalone ECU's and VVTI done with their throttle bodies. I'm not happy with the 45degree solution and feel that there must be another way.

 

The MOTEC guys apparently sorted it out but are keeping the solution close to their chests. It's a bit frustrating with all the secrets floating about and no one willing to help so any clues would be great.

 

Thanks chaps.

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No he didn't. Steve's car had already had something else done to it before he got to it. We actually had a non-vvti TB handy but the holes don't match up. It's mean getting an adapter plate made up or replacing the intake manifold too. Also, the DBW controls the idling whereas the non-vvti has other arrangements.

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I have an omex ECU and apparently that couldn't run the vvti as designed ie. gradual changing of the valve pitch, but rather either full on or off if that makes sense.

 

I also lost the FBW in the process as well. I guess this means that before the turbo kicks in at 3800 revs, I haven't much power as I could have, but as I tend to drop down for any attack, I don't experience issues as I prefer to drive around 6 mpg :eyebrows:

 

My only problems arise on idle. I was told this could be rectified with a larger throttle valve but as my knowledge is limited to just opening the bonnet and topping up fluids, I have decided to live with it. This does mean that as I come to a stop I have to be concious to let the revs die down to around a 1000 before putting the clutch in as if I do it earlier, the revs dip to such an extreme that it stalls.

 

The lesson I guess is if you are going to buy a Supe that you intend turning into a single, then don't buy a vvti tiptronic until the gurus have worked out all the solutions!

 

Sorry I can't offer any more help.

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Thanks for that. I don't want to lose the DBW (unless I get a great big veilside intake ;) ) I'd prefer to get it right and then everyone else can learn from it. I don't understand the pro's keeping these things a secret. It's a community of knowledge and it would be great to share solutions to problems. I realise that these guys have a living to make, but this is how the sport progresses. I welcome the guru's input and will gladly have them around to sort it out.

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IIRC the VVTi TPS has two sensors that are linked (somehow) to control the throttle body gubbins. The pair report the physical postiion of the acellerator pedal slightly differently and thus the signals are used by theECU slightly differently to try and introduce a degree of noise/interference immunity: the summary is that an unexpected combination of signals would normally inform the ECU that something has potentially become corrupt along the way and the driver might not actually be requesting WOT, for example.

 

Anwywayy when Ryan fitted the Solaris to my single turbo VVTi, he reported that one of these sensors was bust, so programmed it to just use one as a replacement wasnt' entiely necessary and certainly would have been costly.

 

That's IIRC - if Ryan can't remember then I'll be of little use as he's the man, I'm just recalling what he said to me at teh time of fitting. He might have forgotten the sensor issue.

 

I don't think anything else is different on my throttle body, but am happy to go take pics if you want?

Nothing of the OEM or other ECU remains in my car, so installation is certainly possible without those items. Although my stock boost indicator (the limited use 'yes/no' display) no longer works.

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IIRC the VVTi TPS has two sensors that are linked (somehow) to control the throttle body gubbins. The pair report the physical postiion of the acellerator pedal slightly differently and thus the signals are used by theECU slightly differently to try and introduce a degree of noise/interference immunity: the summary is that an unexpected combination of signals would normally inform the ECU that something has potentially become corrupt along the way and the driver might not actually be requesting WOT, for example.

 

Anwywayy when Ryan fitted the Solaris to my single turbo VVTi, he reported that one of these sensors was bust, so programmed it to just use one as a replacement wasnt' entiely necessary and certainly would have been costly.

 

That's IIRC - if Ryan can't remember then I'll be of little use as he's the man, I'm just recalling what he said to me at teh time of fitting. He might have forgotten the sensor issue.

 

I don't think anything else is different on my throttle body, but am happy to go take pics if you want?

Nothing of the OEM or other ECU remains in my car, so installation is certainly possible without those items. Although my stock boost indicator (the limited use 'yes/no' display) no longer works.

 

Your memory is good. On the left hand side (as facing the engine bay) and connected to the throttle cable is one sensor (the pedal position sensor) and on the other side connected to a myriad of cogs and motors is the TPS. Ryan said he didn't use the PPS as it's not required but does use the TPS.

 

Had yours been mapped before Ryan had a go on it by someone else or another standalone ECU? There has to be a mod that stops the failsafe from stopping full throttle.

 

Pics would be so welcome, especially ones as from the pic above.

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Had yours been mapped before Ryan had a go on it by someone else or another standalone ECU? There has to be a mod that stops the failsafe from stopping full throttle.

Yeah, the car was already single turbo when I bought it, using a MoTeC ECU that Ryanjust didn't get on with and I was finding frustrating: mostly because it was not closed loop but I wasnt' keen on working around its other niggles/shortcomings so took the leap into Solaris' world. So I don't know what was done to the car before I got it I'm afraid, or by whom: Jake might know, as he owned it before me, but again it was already single turbo when he bought it.

 

Pics would be so welcome, especially ones as from the pic above.

OK matey I'll try to get some done tomorrow if I get in before it gets dark: you/Ryan are more than welcome to come prod it if you want to take a direct look.

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Did the Motec boys not end up up following the Vpro boys and piggybacked in the end?

I don't think so because if they did - specifically if they did on my supra - then Ryan would know what he did to go from that setup to the Solaris as a standalone setup, because that's what he did on mine.

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Kopite is another VVTi single who may know?

 

He also did the DBW delete if memory serves..

 

He also ditched the VVTi in the end :D

 

Ignore me then. I only mentioned it because the 2 VVTi's I have seen with Motecs have been piggybacked - It was a fair while ago mind you.

 

Ignore my previous posts grammar.

 

Was one of these Chris Webley's Mig?

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The VVTI is not such a big issue. Ryan can do that as far as I know and I'm sure Steve will back me up on that.

 

It's the mods to the throttle body that I'm interested in. I know Chris Wilson was looking into this a few years ago as I've seen a few threads that he started/participated in querying similar issues. One of Ryan's connections said he moved the butterfly by changing it on the spline but we ripped the TB to pieces and could not find a way of modding it without breaking the plastic retainers. The PPS side is impossible to change, and the TPS side has more cogs than you can shake a stick at.

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