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Originally posted by toylover
I understand how it all works, and I know that cams don't necessarily raise the redline and that the 5SFE cam is a super mild grind. What I was asking was, is there a point in doing cams and not raising the redline.
Lemme try and rephrase, the 5SFE has an oversquare bore:stroke ratio which means that it will make roughly the same amount or more torque than HP. In addition, the head flows very poorly, not because Toyota did a shitty job, but because they had economy in mind opposed to performance like the true Twincam engines. Even the intake manifold has super long runners, again for low-end. So basically what I'm asking is, is it worth modding the 5SFE at all unless you address the major obstacles standing in the way of performance?
Its an economy engine, trying to give it the characteristics of a high-reving, sporting 4 banger seems like a real bitch and more expensive than its worth.
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I tend to agree... if you've ever seen dyno runs of built 5SFE's... they're pretty modest. The point is, camshafts will make power with good tuning. It's not necessary to raise the redline, or modifiy anything, although mods like that will fully utilize the camshafts, it's not abosolutely necessary. The 5SFE block, like you say, is an oversquared design with a very very mild valvetrain, so revving on the stock internals is not gonna be very safe or a realistic option... but again, like I said above, it all depends on the cam profile. You can run a mild profile and make power like I mentioned. I was trying to explain, the stock 5SFE quits making power dramatically after 5000 rpms. A pair of cams can dramatically alter the powerband shift it a little higher at least until its redline/fuelcut. Camshafts do not necessarily change the engine's characteristics. The dynos I've seen of n/a modified 5SFE's still made a LOT of low-end to mid-range torque and STILL lost power on the top. It all depends on the cam profile being run. As far as it building a 5SFE... I personally wouldn't, cause I don't like that engine all too much, but if the owner wants to go ahead and do it, I'll pass on the bit of info I know... I personally believe you can make more power out of a 7AFE than a 5SFE...
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I was told not to touch the cams unless I want to mess with the ECU. You'll lose idle quality with cam. Cams are so expensive, I don't know if a really mild cam worth the trouble at all.
You mod the engine to match its design spec.
5S-FE is a torque engine, not a high reving high HP engine. Keep it like that. Do mods that'll keep its power band and rpm. Don't try to rev it high and free flow everything too much. P&P will do wonder with it but don't open exhaust port too much or at all. Turbo it will be nice, 2.2L high torque engine.
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All depends on the cam profile. We're talking about a pretty mild cam profile here, so the idle is not gonna be too loopy, nor will the ecu need to be altered (piggybacked)... nor will there be any significant torque losses throughout the entire powerband. Again I'll say, it all depends on the camshaft profile.
