Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 probably no good but.. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 I dunno half a bl00dy job! LOL had other things on our minds rather than a photo build Quote Link to comment Share on other sites More sharing options...
Wez Posted July 5, 2005 Share Posted July 5, 2005 Does the VVTI head fit on a non VVTI block, are the inlet and exhaust ports the same and how is the VVTI system controlled. If we had more information on the control mechanism then new releases of the AEM software may be able to support it, AEM already support VVTI on other models. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 Wez I believe Arnout is in the process of doing this. Quote Link to comment Share on other sites More sharing options...
Digsy Posted July 5, 2005 Share Posted July 5, 2005 Do you have a pic of the valve as well? I'd like to see how many ports it has. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 only the one previously posted Quote Link to comment Share on other sites More sharing options...
Digsy Posted July 5, 2005 Share Posted July 5, 2005 Well, just to further the controversy, I'm wasn't 100% convinced that it is an infinitely variable system, but I'm as convinced as I can be, looking at the pics. My scepticism lay in the age and the design of the system. Off the shelf infinitely variable systems are relatively new and all the recent ones have been vane-type - and the current VVTL-i system certainly employs the latter design to do the "VVT" part. The cam pulley on the VVT-i Supra is a helical spline design. You can see this simply by looking at the cam pulley itself. You can see the helical splines on the outside of the VVT unit body (see attached pic). Toyota used at least two variations on the VVT-i theme: An early helical spline design and a later vane type. Also, according to this article they have also in the past used a simple one-shot, helical spline VVT mechanism on the 4AGE engine. Plus all the helical spline systems that I knew of (with the exception of BMW's VANOS) were one-shot types. Therefore I was all ready to conclude that the Supra mechanism was such a device. The key is in the design of the camshaft nose. One-shot devices use a single pressure feed and a drain path. Oil pressure is fed via a valve and ports (either in the head or a cam cap) into the camshaft. Sometimes the head is groooved and the camshaft is ported, or -as with the Supra- it is the other way around. When the oilway is pressurised the oil is fed through the cam nose into the VVT pulley onto one side of a piston, and the piston moves. The helical splines turn the axial movement into an angular movement between the pulley and the camshaft and this creates the timing adjustment. There is a constant leak path through the piston seals and this is returned to the cylinder head via a second pathway in the camshaft, which drains into an empty space in the cylinder head. When the oil pressure is removed, the piston returns to its rest position under spring pressure. Variable devices have two pressure feeds (sometimes termed A and B on the control valve drawings): One feed acts on each side of the piston. The valve constantly switches between the two (using the cam position sensor for feedback) to keep the cam timing at the desired position. Since the Supra VVT-i engine clearly hs two hydraulic feeds, which could be either "A" and "B" or "pressure" and "drain", we need some more details to fully confirm whether it is one-shot or fully variable. The clincher would be the control valve. A one-shot system would be three-way, with an oil feed and a drain, either of which could be connected to the camshaft. A fully variable system requires a four-way valve with an oil feed, drain, and "A" and "B" ports. When "A" is connected to the oil feed "B" is connected to the drain, and vice-versa. Without seeing inside the valve it is impossible to know for certain, but other details hint at a fully variable system too: If the second port on the camshaft was a drain, there would be no need to route it back through the cam cap and into the valve body. It could simply break out of the camshaft behind the cam cap and drain into the cylinder head. Lastly, fully variable systems always have oil flowing through either port A or port B - therefore the cam bearing always has an oil supply through leakage and does not need a dedicated oil feed for lubrication. A one-shot system shuts off the oil flow when it is not operating and so the cam bearing needs a second oil feed for lube. I think I can see these feeds on the near edge of the second and third cam bearings, but I cannot see a lube feed on the first. A pic of the valve (or - lordy - the hydraulic circuit) would clinch it. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 A pic of the valve (or - lordy - the hydraulic circuit) would clinch it. If you think we are gonna strip the car down again............... LOL Borrow Alex's for the weekend Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 5, 2005 Share Posted July 5, 2005 Isn't it nice when someone who knows what they are talking about shows up -Ian Quote Link to comment Share on other sites More sharing options...
Guest Usmann A Posted July 5, 2005 Share Posted July 5, 2005 Still doesnt explain to me why they are 3 pulses off the cam hall sensor? I know piddly all off Vvti supras, but thanks darren, that post just kinda confirmed what I thought how a helical Vvti system works .. and I learnt something new today.... Quote Link to comment Share on other sites More sharing options...
Alex Posted July 5, 2005 Share Posted July 5, 2005 Darren, if you can use my car to find out then you're welcome to. Terry, will getting to the bit darren needs to see require any new gaskets etc? (My cam cover gaskets are crappy anyway) Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 Darren, if you can use my car to find out then you're welcome to. Terry, will getting to the bit darren needs to see require any new gaskets etc? (My cam cover gaskets are crappy anyway) Excellent:thumbs: Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 so this now begs the question, the VVTi cars running motec ecu's, have they spent the time to control the VVTi properly... Quote Link to comment Share on other sites More sharing options...
TRD3000GT Posted July 5, 2005 Share Posted July 5, 2005 so this now begs the question, the VVTi cars running motec ecu's, have they spent the time to control the VVTi properly... I take it this question is aimed at me as Im the only Supta VVTI running a Motec... There was a French Motec specialist who setup the VVTI part of my Motec ECU. The whole process took 4 whole days 8-5 pm...to complete and for Motec Australia to accept. Motec Australia rejected his first 2 efforts saying they knew it could be done better. I have not had ANY problems with the car since I had it back and it seems to tick over very nicely. I am confident in the work because I saw the ammount of time and effort that was put in to it but thats as far as I can go. I have no idea of the quality of the work if Im honest. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 No not solely at your car Chris as you werent the first Supra VVTi with an M800 in this country. I am sure the car works fine, it whether its working to an optimum that I am querying. Quote Link to comment Share on other sites More sharing options...
TRD3000GT Posted July 5, 2005 Share Posted July 5, 2005 No not solely at your car Chris as you werent the first Supra VVTi with an M800 in this country. I am sure the car works fine, it whether its working to an optimum that I am querying. I would not know... Is there any way to find out? Also as far as Im aware My car is the ONLY VVTI single turbo supra running a Motec M800.. Motec confirmed this as it was the first VVTI map they had done. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 only seeing the map. I assume you can access it? Quote Link to comment Share on other sites More sharing options...
Wez Posted July 5, 2005 Share Posted July 5, 2005 How does the motec control the VVTI or does nobody know? Does it work on just RPM or RPM vs LOAD etc? How is the VVTI modulated, does it require frequency changes or simple voltage differences, i have no idea so would be interesting if someone has more info on this. Quote Link to comment Share on other sites More sharing options...
TRD3000GT Posted July 5, 2005 Share Posted July 5, 2005 only seeing the map. I assume you can access it? I have no idea... This is when I will bow out gracefully. If you think you can find out and want to see Im game.. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted July 5, 2005 Share Posted July 5, 2005 guesstimate voltage Wez Quote Link to comment Share on other sites More sharing options...
TRD3000GT Posted July 5, 2005 Share Posted July 5, 2005 guesstimate voltage Wez So how do I know if I can access the MAP's and know if its running to the optimum? Quote Link to comment Share on other sites More sharing options...
Wez Posted July 5, 2005 Share Posted July 5, 2005 You should be able to download the software from here :- http://software.motec.com.au/release/ and then download the map from your car to your laptop/computer, if you have not done anything like this before might be worth taking extra care as you really do not want to trash your map. Quote Link to comment Share on other sites More sharing options...
Alex Posted July 5, 2005 Share Posted July 5, 2005 I would not know... Is there any way to find out? Also as far as Im aware My car is the ONLY VVTI single turbo supra running a Motec M800.. Motec confirmed this as it was the first VVTI map they had done. Whilst this page says eManage I know it went MoTeC before you...however whether or not the VVTi is working as intended is another matter. Quote Link to comment Share on other sites More sharing options...
TRD3000GT Posted July 5, 2005 Share Posted July 5, 2005 You should be able to download the software from here :- http://software.motec.com.au/release/ and then download the map from your car to your laptop/computer, if you have not done anything like this before might be worth taking extra care as you really do not want to trash your map. Looks FUN but sounds dangerous! How do I plug the lap top in ? Quote Link to comment Share on other sites More sharing options...
Wez Posted July 5, 2005 Share Posted July 5, 2005 Hmmmm, did they not leave you a link cable, hold on let me check if its a normal serial cable. Quote Link to comment Share on other sites More sharing options...
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