kpr

Yeah im saying when you get to a point in cam size, no matter the size of the exhaust side on turbo is gonna be a bad day, in terms of boost threshold. rotarys are inefficient as shit so produce a lot of exhaust gas for the the power they make. so small exhaust side always a bad day

same thing that happens with an na engine. big cams, the exhaust gasses will want to go back into the cylinders at low airspeeds . on a na engine with good headers and exhaust can get away with a lot more. Now with a turbo jammed on the exhaust side, you have basically taken away any opportunity to make that work good. hence why turbo cams are always smaller than na stuff. unless its just living at high rpm. so yeah with the egr going on. you make less power and have less energy to spool the turbo. to make things more confusing, dialing the same cams in to have more overlap will actually make things better not worse. if you advance the shit out of the intake cam (increasing overlap) engine will make more bottom end power and spool the turbo sooner. The short runner intake manifolds everyone loves these days actually make it worse also

bit of a extreme case, but shows it well green is stock cams 232deg in/ex blue: 284in / 278ex these are na cams so pretty aggressive for turbo black: 284in / 232ex sounds like a missmatch but retains low end and gains up top can see how the 284/278 comes on 1000rpm later. (bottom lines are boost) probably using the 278 for a inlet and something around 250-260 exhaust would work decent on this engine Im just saying for example a G series garret vs an old GT series garret, the the G series will blow the gt series out of the water. can basically go down a frame size and make the same power with a far better spool up. So replacing the factory rb20 turbo with say a g25 will spool similar and probably make double the power - just a rough example not suggesting its what to go with.

End of the day long as you are buying the latest tech, sized correctly cant really go wrong. compared to the older stuff. As for camshaft selection if you are worried about boost threshold, going too big especially on the exhaust cam will make it super lazy.

pretty sure neo and the earlier non neo run the same vct. both are just on/off It doesn't really do much on the 25's/ 30's ive tuned. pretty much is in advanced position most of the time. as run out of revs to utilize it, on your average setup on a 20 bottom end with decent size cams would be more of an advantage to extend the top end without killing it everywhere else. few places do a kit to change them to adjustable so can easily adjust the start/end point. Going to a fully variable setup likely a major if possible. having a head that has just on/off setup factory. doesnt make it any easier to go full variable. most likely harder.

pretty much the same any other china rod. they are fine, all of them have measured up good. and none have came out the side of the block at 10krpm yet. but i wouldn't be expecting a high end rod. I assume its the same factory that make most of them and you can get what ever you like printed on the side of them

maxchina will do custom rods. i had to buy 12 as minimum order. from memory it worked out to be mid 700's for set of 4 inc shipping costs. this was probably 3-4 years ago also

Exhaust ports Relationship between the intake and exhaust

yeah diff overkill, same as kp. but its not gonna break. It is the early hilux stuff, which have a lighter case and head. so isnt stupid amounts heavier than a t series

guess will have to find out the hard way haha

Has a hilux diff with trd lsd. Had a w57 in it when was turbo, last thing i done on the car was rebuild that box and still have it. but yeah have a j160 lined up for it. Likely run a link extreme, since the lower models need an external box to run e throttle. by the time mess around with that better off just to get the extreme I do like the built in pdm of the haltech r series. but otherwise rather a link. You can keep your speeduinos haha. I just spent awhile on one, fighting trigger issues ended up swapping to a link. everything just works, tune and done

diameter of the headers and whats after them has a big impact on how soon the engine starts making any decent power. especially when there is a big set of cams involved. a lot of people running big cams will just think thats when the cam "comes on". Things like vvti and vtec help a decent amount, since can manipulate the valve opening/closing events. but a good setup is a big benefit, with or without them. Those numbers in the that drawing look pretty good, i wouldn't expect to gain anything on any 4age upping those pipe sizes. The big headers that are on the starlet at the moment, run a 38 od out of the head and do pretty much the same thing as what im currently building, cone up to 44.5mm for the rest of the way. When i first built them, they were 44.5 the whole way. they made no more top end power and lost a stack of midrange. compared to 38mm headers of the same design. I then changed that part out of the head and they picked up top end power but midrange loss was still there. engine was probably only making 130kw at the time. but was pretty interesting how the bigger tubes done nothing for it anywhere, and the little bit out of the head made all the difference

Yeah. I probably could just build another manifold for the cable itbs and test this setup in the starlet. it would be a good test, to throw the high port head on the bottom in starlet, with all the bolt ons and same cams. the only difference being the high port and smaller valves. may happen yet. kinda depends how long getting the trueno operational takes. It doesn't have a gearbox, driveshaft or ecu. plus lots of small things

made these today. 2-1 collectors, merge and transition to round all in one, with diverging cone. probably dont need a cone here, but it works in other places, so why not They took just as long to make as getting the whole bit above tacked together Think I said most of this in the discussion thread; they will be 4-2-1 with the primary length being similar to all my 4-1's. will put a flange just after these collectors. so can try anything from merging to 2-1 directly after the 4-2 merge. to stupid long. made tapered die on the lathe to shape the outlet, welded them with the die in place and they held there shape pretty good Look like this before shaping and welding after, cut to length

primary's are 38.1mm tube. so 35mm id. out of the port its 32mm and actually tapers down to 31mm before the cone out to 35mm. sounds small, but have made 160kw on same sizes. They are actually going to be 4-2-1 . once get the 4-2 section merged together. will design a flange that will go just after the merge. Then can test a bunch of different length 2-1 sections. Im kinda going against proper science and trying a few things at once. Ideally i should test the high port head with the starlet exhaust side. but that wont fit the trueno. and the starlet ecu wont run the e -throttles. Have tested couple of very different merge collectors on my big headers, with zero change in power. How small they merge down to and whats directly after, can make a big difference though. especially in the bottom end.