The Ford engineers had a wealth of test data to base their tune on. It seems just as risky to accept an aftermarket tune from vendors who undoubtedly do not even come close to Ford in their level of understanding. Seems no different to me than the balancer modification? For you guys who assert Ford knows best on the balancer, do you feel the same way about their tune and if not, how do you explain this incongruity?
Well, you know what they say. Opinions are like assholes, everyone has one. Might as well throw mine in. Having read the entire thread, I'll chime in on a few points:
1. Although we've been on the edge, I think it is great that we can have this discussion/debate on this kind of forum without once seeing it resort to name calling and personal attacks. That's why this is a good place - comprised of good people.... don't let it slide!
2. Regarding the engine tunes and why the aftermarket can (seemingly) do as well as Ford: The first point is that Ford Racing and Ford are not one in the same and the GT Tune is coming from Ford Racing. No doubt, the Ford Racing engineers are very smart and there is much collaboration with Ford - but still, they are two different environments. But this is, perhaps, a minor point. At the risk of oversimplifying, an aftermarket tune really has 3 major objectives: a) Safe A/F ratio; b) safe timing; c) driveability (transitions, idle, tip-in, etc). All of these objectives must be achieved for various altitudes, temperatures, boost conditions, etc. The major point here is that the ability to monitor these parameters as well as to know what ECU table changes are local and which are global and how they interact is a learned skill - and practiced/refined over a lot of time (years) by the prestigous tuners that are commonly referenced on this forum. I submit that one of the largest variables amoung tuners is their individual definition of "safe". I suspect that Ford Racing, for example, might tend to be one of the more conservative. The net is that I would have no qualms about installing a Heffner, Shadowman, Torrie, etc. tune in my car. Now, if we turn the tables just a bit and say that we have to create the highest output tune AND meet ALL of the constraints/parameters of the OEM.... things like, emissions to the nth degree under EVERY operation condition, corporate engine longevity stds, WOT test for several hours, etc. - then I will say I would trust the OEM to do that better than anyone else. If no other reason, they uniquely have the gazillion dollars of equipment to do this properly as well as the wealth of historical experience.
3. Regarding the harminic balancer: My opinion is that Ford did a truely remarkable job in creating the GT and of the components in a very short time. As we know, the final engine that we have was not finished until reatively late in the game. I have EVERY confidence that Ford has given us a balancer that is perfectly fit for this application - and for the lifetime of the car. For this, I have no doubts. Where I may agree with Luke is that perhaps there are tweaks and improvements that can be made. Theoretically (ignorance is bliss - just ask me), it may be possible to make a balancer that is both lighter while simultaneosly meeting all of the other parameters that the balancer has to do. The question is... who has the gazillion $ of equipment, access to multiple identical GT engines, and a wealth of knowledge to test/evaluate this. For me, I would only trust Ford. OK, so what motivation is there to discard the OEM balancer anyway? This is my last point.
4. Why discard the OEM balancer in favor of ANY other balancer? Because it is "bad"? Nope, I don't believe this. For the gains in HP and rev ability because of lighter weight? Nope, the risk rewards equation just doesn't work for me i.e., the potential gains are modest compared to the uncertainty (not to mention the time, effort, and cost to change.) To have the ability to spin the OEM SC faster and produce more boost with less risk of belt slippage with a smaller upper pulley only? I say no again. First, and most importantly, the limiting factor of producing more "good boost" with the OEM blower is NOT a function of getting to a pulley just above where belt slippage occurs. Rather, there is an efficiency point of the OEM SC that CAN be achieved and exceeded with an upper pulley ONLY. You have only to look at what Kenne Bell achieved by doing exactly this. Simply stated, if you want to run a very small upper pulley - you have just to do what Kenne Bell did and that is to shim power steering pump away from its mount to make up for the belt slack. This is a simple solution - far easier and less expensive than a lower balancer change. You will exceed blower efficiency BEFORE you have belt slippage with a upper pulley only swap.
Finally, I do not make any assertions that the IW or any other balancer is either better or worse than the OEM balancer. I just do not have enough data available (i.e. exhaustive testing on our exact engines) to know that an aftermarket IS as good or better. JMO, ICBW
That said the more I think about the more I really do want to know the answer and what you guys think. You state the Ford tune is not as attractive because you cannot customize it. Why would one want to customize it? The Ford engineers had a wealth of test data to base their tune on. It seems just as risky to accept an aftermarket tune from vendors who undoubtedly do not even come close to Ford in their level of understanding. Seems no different to me than the balancer modification? For you guys who assert Ford knows best on the balancer, do you feel the same way about their tune and if not, how do you explain this incongruity?
