@chap79 your current setup is identical to mine (2" & 31s and I assume everything else stock). what EGTs do you see? Would be interesting to see how the 31s EGT compare to
@kgrove's 33s, assuming also stock everything else. And how did you approach your EGR delete? Just blanking plates or is there more to it?
@kgrove I doubt I will run past 32s, currently on 31s. 33s seems a little too large for my liking on this car. How did you also delete your EGR? I see online there's kits with blanking plates & gaskets. Do i need any other hosing etc? I also intend to install a EGT gauge so will need the plate with a threaded hole.
While collecting EGT data points is helpful, I'd caution against reading too much into any one single set of EGT measurements. There are a lot of other variables between the two cars that could impact EGT - clogged injectors, worn piston rings, sludge in the intake manifold, etc.
I used an EGR kit for my delete - removed the pipe and valve system, rerouted the vacuum tubes on the throttle body VSV, and blanked off the two manifold openings where the EGR pipe had attached. The blank on the exhaust side had NPT threads for an EGT probe. The extra coolant hose running behind the engine for a rear heater makes getting the EGT probe into the EGR blank a bit of a pain (would be easier on a Prado lacking the rear heater option). Getting the EGR pipe off the studs was a royal pain in the a$$. I ended up having to saw my EGR pipe in half so I could remove the exhaust and intake fittings separately as I could not create enough space to remove the pipe off the studs on both sides at the same time.
That said... I'd have two cautions regarding how I did it:
1) Knowing what I know now, I'm questioning whether I should have deleted my EGR in the first place. I read reasonable sounding info supporting both sides, but the more scientifically supported arguments suggest the EGR system reduces EGT rather than increase it. It sounds counterintuitive that mixing hot exhaust into the intake air could reduce EGT, but the rationale is that the spent exhaust is inert and reduces the combustion potential in the cylinder, and therefore the explosion isn't as powerful and EGT is reduced. Since the advent of EGR systems was to reduce NOX by reducing combustion temperatures, it makes sense that disabling the EGR system may increase your EGT. The flip side argument is that if the explosion is cooler and less intense, you'll have to throttle up more to compensate for reduced performance, so your EGT might end up in the same spot either way, especially in real world situations where you're trying to climb a hill at a given speed. Both arguments have a logic, so the only way I could become convinced of which works would be to install an EGT probe on the exhaust manifold and test EGTs under the same condition, once with the EGR fully functioning and once after blocking the VSV that opens the EGR butterfly to effectively disable the EGR system. Without that test, I lean toward a functioning EGR system as being better to keep EGT down as it seems more supported to me, but I'm not going to die trying to capture that hill.
2) If you did want to delete your EGR system, I would lean towards leaving the EGR pipe in place and instead disable the vacuum tube that opens the EGR valve on the intake. I think this would effectively accomplish the same thing in stopping hot air from entering the intake system, but this method is WAY easier to accomplish and can be easily reversed if you change your mind (or the authorities change it for you).
Or if you decide to keep your EGR system functioning, install a catch can so that hopefully your intake manifold stays cleaner.
For my 10 blade - I just replaced the fan as my viscous coupling seemed fine. I do suspect my 10 blade may have hurt my fuel economy a touch. I can't prove that... just a suspicion.
Here is the Prado I sold a couple weeks ago (not the one I'm driving today with the EGT gauge). I included it because it's the same paint scheme, similar lift, same OEM wheels. The wheels don't have spacers like yours, but the 12.5s without spacers probably extend outboard to about the same place as 10.5 with spacers. Looks are entirely subjective so it doesn't matter which I like, but this should give you a pretty accurate idea what yours would look like with 33x10.5 plus spacers.
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The 33s definitely fills up the well nicely. My only concern is the performance (or lack of) going up to 33s, and given the stock is wheel is only 15x7, many tyre options for 32s or 33s do not recommend fitting below 8 or 8.5. I take it you have no issues fitting on OEM? What about when airing down?
