Quote:
Originally Posted by Luni
When toyota dumped TVIS they compensated for it.
Gen3 head has larger intake runners and smaller head ports. The air velocity increases as it enters the head and thats how they do it on the gen3.
Gen2 head has smaller intake runners and larger head ports. Its a proven fact the gen2 head outflows the gen3 head by a small margin. Toyota increased the velocity of the air going in with tvis to increase torque.
The gen3 also has different timing curves to help out with torque/spool as well. I havent seemed to lose spool on my gen2 engine by running gen3 electronics.
If I was going to build an engine, Id prolly start with a gen2 since I have one. I still disagree that it isnt worth pulling a "perfectly" good gen2 for a good gen3. Id trade mine for a gen3 in a heartbeat.
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I take your point, but don't entirely agree with it. The Gen3 intake runners, regardless of flow velocity, which in itself, will only get you so far up the CFM scale, don't have the flow capacity of the combined primary/secondary runners of the Gen2..shame the rest of the manifold design wasn't as effective. And lets face it, I don't think too many USDM's have effective T-Vis's..no reflection on Toyota.
The addition of a longer duration cam with higher lift was no doubt a compensating factor for the smaller intake runners.
I really think too much is attributed to the Gen3 engine, as a result of better electronics & MAP based system, along with all the other upgrades, least of which being bigger injectors & higher flow turbo.
The Gen2 has been hamstrung for so long with an L-tronic ECU & AFM, with all the issues of fuel dumping & lack of resolution. I still haven't seen a stock MAF based Gen2 capable of 300whp on pump gas, even with ROM tuned ECU's..and we all know any Gen2 is capable of far, far better.
Nobody can tell me that a mildly upgraded block & head with 2 manifolds attached is better than another one..simply because one has a Gen3 part number.
As I said, stock vs stock..definetely! but only because the Gen3 has all the goodies the Gen2 needs to overcome some inherent problems, that were no doubt put there for a reason..at least in some instances.
Anyhow..we're just starting this whole thing up again
