Cereal_Killer Posted June 19, 2009 Report Share Posted June 19, 2009 Last week I had my truck up on the dyno and got the tune a lot better, the AFR is right where I'm commanding it and its running good. Today I compared my tune to the stock tune and my VE table is about 10% lower than the stock one. I dont understand how that can be, my motor is a hell of a lot hotter than a stock motor so how can it be less efficient? Quote Link to comment Share on other sites More sharing options...
thorne Posted June 19, 2009 Report Share Posted June 19, 2009 I wish I could answer but I'm still used to how you tune subies. I'm learning about Chevy stuff which is all VE based but I don't know enough. I'm interested to see possible answers and explanations. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted June 19, 2009 Report Share Posted June 19, 2009 10% lower on which ve table? Quote Link to comment Share on other sites More sharing options...
Cordell Posted June 19, 2009 Report Share Posted June 19, 2009 Who cares? Seriously, as long as you're getting whats commanded, it will shift a few other tables slightly, but that's why you tune VEs first. I'm not experienced enough to know what causes stuff like that, but between cylinder volume and IFR might not be spot on. I'm not sure I'd worry about it, hopefully one of the more experienced guys chimes in and maybe I'll learn something too. Quote Link to comment Share on other sites More sharing options...
Cereal_Killer Posted June 19, 2009 Author Report Share Posted June 19, 2009 Both Idle and off idle, actually my idle VE is almost 30% lower than the stock idle VE. Idle AFR is 14.5, fluctuates a little though but idles good at 850, right where commanded. edit, now that I think about it my IFR might be a little lower than actual, I have fuel pressure set 2psi higher than stock but never changed the IFR in the tune, how do I figure IFR? Quote Link to comment Share on other sites More sharing options...
Rob1647545496 Posted June 19, 2009 Report Share Posted June 19, 2009 Last week I had my truck up on the dyno and got the tune a lot better, the AFR is right where I'm commanding it and its running good. Today I compared my tune to the stock tune and my VE table is about 10% lower than the stock one. I dont understand how that can be, my motor is a hell of a lot hotter than a stock motor so how can it be less efficient? is it 10% lower all the way across the board or just in the lower RPM range is the vehicle cammed? Quote Link to comment Share on other sites More sharing options...
Guest Hal Posted June 19, 2009 Report Share Posted June 19, 2009 Call 614-778-8984. Brian will tell you all you need to know. Quote Link to comment Share on other sites More sharing options...
Cereal_Killer Posted June 19, 2009 Author Report Share Posted June 19, 2009 I was working with Brian, thats whos dyno I had it on. Yes Rob, I have a cam. In some places its over 10% different. How can I post a spread sheet file? Quote Link to comment Share on other sites More sharing options...
Rob1647545496 Posted June 19, 2009 Report Share Posted June 19, 2009 with a bigger cam the VE table should be smaller in the lower RPM ranges but more then stock up top. Quote Link to comment Share on other sites More sharing options...
Cereal_Killer Posted June 20, 2009 Author Report Share Posted June 20, 2009 Its lower throughout, if you post or PM me your email I will send you a spreadsheet of the 2 tables, stock vs mine. Anyone that cares to take a look I will send them to you. Quote Link to comment Share on other sites More sharing options...
Billiumss Posted June 20, 2009 Report Share Posted June 20, 2009 When you add a cam to a engine, its not as efficent at low rpms thus having a lower VE number. Higher WOT rpms you will notice a good increase in your VE numbers. Quote Link to comment Share on other sites More sharing options...
6 Speed S4 Posted June 20, 2009 Report Share Posted June 20, 2009 Are you running stock heads? Ported stock heads? aftermarket? What size cam is this? Quote Link to comment Share on other sites More sharing options...
Cereal_Killer Posted June 20, 2009 Author Report Share Posted June 20, 2009 Its all in my signature, the cam specs are with the 1.6RR's I'm running, the heads are port matched only but have other machining done to use screw in studs, guide plates and the springs recommended for my cam. I've looked back at my tune and the IFR's are correct for my fuel pressure, only thing I'm not sure about is the injector offset, does fuel pressure change offset? Quote Link to comment Share on other sites More sharing options...
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