csa Posted January 8, 2008 Share Posted January 8, 2008 now, what's the deal with the VVTI. People here in Denmark tends to hesitate when the talk comes to tuning the VVTI. is it any more difficult to map than the non vvti? is there any limitations to single/big twin power output? is the parts different and more expensive? ..in short...whats the fuss about? Quote Link to comment Share on other sites More sharing options...
Guigsy Posted January 8, 2008 Share Posted January 8, 2008 well the stock ECU is more complex (16 bit oposed to 8?) so any replacement system would be harder to map i guess? but ill leave that to someone in the know Quote Link to comment Share on other sites More sharing options...
Alex Posted January 8, 2008 Share Posted January 8, 2008 VVTI's are more complex. With complexity comes cost through extra mapping of the Drive-By-Wire and VVTi functions etc. A piggyback ECU IMO is simply not enough, you need to use a full standalone (with or without the stock ECU running normal functions like AirCon and even the VVTI). Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 8, 2008 Share Posted January 8, 2008 Surly they would be no more difficult than say a Honda V-TEC, do the maps have any more resolution than non VVTI? is it a genuine constantly variable by load set up? or just switched at certain RPM? Quote Link to comment Share on other sites More sharing options...
Alex Posted January 8, 2008 Share Posted January 8, 2008 It's PWM and infinately variable, so I doubt they just turn it on and off Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 8, 2008 Share Posted January 8, 2008 It's a lot more complex to map, if you want to keep drive by wire and VVTi, and tuning parts and general tech info are harder to come by. A radically modded MKIV of any engine version will be simailarly complex, but you will probably bin VVTi and drive by wire at the higher levels of tuning. Quote Link to comment Share on other sites More sharing options...
csa Posted January 8, 2008 Author Share Posted January 8, 2008 is there any power limitations to the VVTi? Quote Link to comment Share on other sites More sharing options...
Jake Posted January 8, 2008 Share Posted January 8, 2008 If the cost of mapping the VVTi worries you then just don't use it. If the (in the scheme of things) small cost of getting the VVTi mapped is a deal breaker then modding Supras probably isn't for you. Why restrict yourself to older model Supras for the sake of say £200-£300 extra mapping fees? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 8, 2008 Share Posted January 8, 2008 is there any power limitations to the VVTi? Bizarre question! Of course there are, like any engine. Quote Link to comment Share on other sites More sharing options...
Scott Posted January 8, 2008 Share Posted January 8, 2008 I think he meant VVTi in comparison to non-VVTi with regards to limitations. In other words, do they both hit the same power barriers that need to be overcame or can one shoot a bit further than the other. Just ask as i am curious too Scott =op Quote Link to comment Share on other sites More sharing options...
csa Posted January 8, 2008 Author Share Posted January 8, 2008 Quote Link to comment Share on other sites More sharing options...
Alex Posted January 9, 2008 Share Posted January 9, 2008 I think he meant VVTi in comparison to non-VVTi with regards to limitations. In other words, do they both hit the same power barriers that need to be overcame or can one shoot a bit further than the other. Just ask as i am curious too Scott =op No they are the same engine, just the head is more complex. HKS do a replacement VVTi intake cam in the Valcon kit. The VVTi should infact be capable of more midrange than the non VVTi...so a STOCK VVTi setup is able to deliver more power across the rev range than a STOCK non-VVTi. Quote Link to comment Share on other sites More sharing options...
Mike B Posted January 9, 2008 Share Posted January 9, 2008 Jake; didn't you get yours mapped recently as a full install, including vvti map on the new ecu? Chris Webley has his mapped too but they binned the FBW but kept vvti IIRC. There is another on the board that uses a copy of the map that mine was created with. FBW trottle is good for det detection; if mine is not happy it will just pull the throttle, I've seen it do exactly this on the dyno. Keeps your engine healthy and will ultimately save it if you have a big problem, Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted January 9, 2008 Share Posted January 9, 2008 FBW trottle is good for det detection; if mine is not happy it will just pull the throttle, I've seen it do exactly this on the dyno. Keeps your engine healthy and will ultimately save it if you have a big problem, Bit belt and braces, don't really see the point, as ECU will immediately pull ign timing if dets detected. Quote Link to comment Share on other sites More sharing options...
Ian C Posted January 9, 2008 Share Posted January 9, 2008 Actually it's a brilliant feature, Tricky Much better than just pulling timing as it limits boost as well. I've seen it in action, saving someone's car from, ahem, themselves (they know who they are) -Ian Quote Link to comment Share on other sites More sharing options...
Alex Posted January 9, 2008 Share Posted January 9, 2008 Actually it's a brilliant feature, Tricky Much better than just pulling timing as it limits boost as well. I've seen it in action, saving someone's car from, ahem, themselves (they know who they are) -Ian Quote Link to comment Share on other sites More sharing options...
Mike B Posted January 9, 2008 Share Posted January 9, 2008 It pulls ignition too in stock for so I believe, but when it pulls throttle it feels like a 30% engine cut.. and then you know somethings wrong. On the dyno it just chops the top of the power curve and tries to feed it back in along a line of maximum tolerance. Quote Link to comment Share on other sites More sharing options...
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