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The mkiv Supra Owners Club

SRD1XXX : VVTi vs non-VVTi comparison


Luxluc

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I remember back in the day people would move away from the vvti heads for the none vvti . not sure why but im sure modern ecus are a factor

 

As you say, it was because the ECUs in the past were unable to control the VVTI system due to a lack of outputs on the actual ECUs. Now, we have the likes of Syvecs which can control the movements of the entire solar system, let alone our VVTI cars!

 

Great comparison video OP, thank you for sharing! :thumbs:

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Since you changed the intake plenum as well, installed a heavier modified VVTi head and added 0.2 bar of boost it's comparing apples with pears unfortunately. Would have been nice to see the effect of VVTi only. The best way to do it would be to tune & dyno it with VVTi "disabled" (intake can at constant angle) and repeat the same with VVTi enabled & properly tuned I think.

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I don't think the additional head modifications would have made such a substantial difference in spool... also going from a Greddy plenum to a Hypertune plenum wouldn't have a substantial effect like going going from a stock intake to an aftermarket one. As for the additional boost, that would not have the effect of aiding spool. Having said that, I agree with the notion that the test isn't 100% controlled but it does at least give us a rough idea as to the advantages the VVTI system has over the non-VVTI.

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Since you changed the intake plenum as well, installed a heavier modified VVTi head and added 0.2 bar of boost it's comparing apples with pears unfortunately. Would have been nice to see the effect of VVTi only. The best way to do it would be to tune & dyno it with VVTi "disabled" (intake can at constant angle) and repeat the same with VVTi enabled & properly tuned I think.

 

When Luke's new setup was on the dyno for the first time, Lee did a test of pump fuel 1.4 bar with vvti on versus off. I'll grab the dyno graph comparison next week and upload it.

Suffice to say the overall trend of vvti making more power and torque and coming in sooner was still true.

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Since you changed the intake plenum as well, installed a heavier modified VVTi head and added 0.2 bar of boost it's comparing apples with pears unfortunately. Would have been nice to see the effect of VVTi only. The best way to do it would be to tune & dyno it with VVTi "disabled" (intake can at constant angle) and repeat the same with VVTi enabled & properly tuned I think.

 

Just disregard my thread.

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Here is a dyno comparison at 1.4 bar on pump fuel on Luc's new setup. First run (red) with VVTI disabled, second run (blue) with VVTI enabled. Hope that answers your concerns phobos.

 

http://www.mkivsupra.net/vbb/attachment.php?attachmentid=234228&stc=1&d=1577971504

 

Sweet!

 

I don't think the additional head modifications would have made such a substantial difference in spool... also going from a Greddy plenum to a Hypertune plenum wouldn't have a substantial effect like going going from a stock intake to an aftermarket one. As for the additional boost, that would not have the effect of aiding spool. Having said that, I agree with the notion that the test isn't 100% controlled but it does at least give us a rough idea as to the advantages the VVTI system has over the non-VVTI.

 

Some of the mods might be even counterproductive to spool and the effect of VVTi only might even be larger without them. I'm by no means saying that I don't like the final result, I'm just saying that the comparison is not showing the effect of VVTI only.

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