Roman

Yeah! Must something like that. Says in toyota stuff that it's done for sake of more torque. Also some of the above stuff is incorrect because I just read its got a 12mm offset not 11. D'oh. Will be the same but more exaggerated I guess. Also, gash expansion is an interesting typo to make

Here's some afternoon diagrams to go with the morning graphs @yoeddynz So while I was trying to figure out the VVTI situation, I was trying to think if the crank being offset in the block helps give piston clearance for vvti (piston accellerates away from TDC faster?) The crank sits 11mm further towards intake side of the engine, relative to the centreline of the bore. I just finished some of the drawings to take some measurements from to try understand whats going on with this. So there's some weird shit that goes on as the piston accellerates at different rates depending on if its coming down or going up. (when rotated clockwise) When the crank is laying flat at 90 or 270 deg, the piston is a different distance up the bore for each. On the way up, it's 6.962mm higher by that time, than the way back down. Then also, the crank angle at which the rod is perpendicular to the crank, happens at an earlier time on the combustion stroke than compression stroke. It happens at 21 degrees above horizontal instead of 12.44 degrees. Maybe there's a better gas expansion ratio at this point, of the gas expanding relative to the combustion chamber volume expanding. So more force can apply on the crank. Or something else dunno. Either way it's weird shit. Also some weird shit happens around 90 deg of crank travel on the combustion stroke. Where the rate of accel does weird stuff. I'm guessing this is also something to do with having the piston exert more force on the crank at that position.

KPR's 10k rpm comments are in reference to... well... doing 10,000rpm I have no idea what would be the next weakest link. These rods come with ARP bolts and they state they are 9k capable / 600hp rated. It's all just guesses at this stage, there isnt a well established group of people revving Prius engines to 9k haha. It seems Thailand has the most love for turd polishing 1NZ motors. But the language barrier makes things tricky. And yeah the thing with porting the head is that you can increase flow but if you are already at 100% VE then you're not magically going to stuff 30% more air into the engine. But the thing is, fuel table generally indicates where the most airflow happens which relates to peak torque. So even when this starts to nose dive, you're still gaining horsepower. This is fuel map from an old tune on beams motor: The big hump of peak VE is at around 6500-7000rpm then drops off pretty sharply - but still makes best power past that point. (Weird wobbly shit on the graph is thanks to MAP as load source and possibly weird exhaust related harmonics with massive ports) Then look at the prius one If someone showed this to me without the rpm scale, I'd be thinking "Where's the other half of your fuel map? It's not what I would have expected at all.

Nah it will be fine* *until it isnt

I'm in a Facebook group chat about Toyota stuff. Obviously these people have no idea who they are dealing with

Speak of the devil Disregard low end grunt, acquire 9000rpm

Haha yes, I agree. Also it's been enjoyable driving it with the airbox on at night time, because I'm not doorting some poor rural persons kids awake from 3km away haha. So I'm not at all keen on a loud exhaust. Can hopefully keep it reasonably quiet. With my Carina I was surprised how rowdy it wasnt with only straight through mufflers. I'd originally flanged the rear one so I could swap for a chambered muffler to keep it streetable. But didnt need to in the end. See how it goes.

I'm onboard with KPR's school of thought / observations, that beyond the extractors and a short segment after that, the rest of the exhaust is just gas transport. Nothing to do with tuned length, velocity, etc helps. Even on his near stock 20v, removing the exhaust after extractors gave gains. So yes this will get a 3" pipe at some point, haha. Adding a restriction or back pressure never helps. With the porting vs exhaust situation. If you look at the big dick swing K motors with custom heads etc, and they will hugely favor the intake side valves, even at the expense of crappy positioning for exhaust side. So I think porting will help to some extent even if I have a stink exhaust, IF it's allowing a higher amount of fresh air to be captured at higher rpm. I found a chart from someone who ported a 1NZ head. So the maximum lift cams you can get for a 1NZ are 9.5mm lift, that equates to 0.37" on the chart. So if you look at what an unported intake side flows at 9.5mm as is, its about 160cfm. With ported intake side, you now reach 160cfm at about .25" or .26" which is about 6.6mm lift. So instead of having that peak flow value at the impossibly fractionally small amount of time that the cam sits at full lift, you've now broadened it, and this goes all the way down the chain embiggening the flow capability of your cam at all lift values. Which is valuable in this case because I cant actually get any cams bigger than 264 deg 9.5mm lift. On the other hand, it's still possible that this is going to achieve nothing until I've sorted the exhaust. But that's fine too, because exhaust will definitely happen, just not yet.

The next most logical thing to do on this car, power wise, is leave it alone and just drive it the exhaust. However I'm a bit road blocked on that currently, for a variety of reasons. So I've been having a think about leaving it alone and just driving it what else I can do for free/low budget. So its time to just drive it give a head a tickle up and see if it makes any difference. The following is best guesses with no actual testing or proof. So take with a grain of salt. The "bad" news about porting a 1NZFE head seems to be that most of the tutorials that I've seen, work to address problems that dont exist with a 1NZFE haha. Because a modern factory casting/machining/port design are quite good to begin with. If they were shit, I probably wouldnt be seeing 8500rpm already. The intake port side is very steep and has an awesomely shaped short side radius. The valves are decent size for displacement, and the bowl area can be tidied up a bit but isnt the worst thing I've ever seen. There are some casting marks to tidy up but they're not incredibly dreadful. I am thinking the areas that will show tangible improvements on a 1NZ head are: -Deshrouding the intake valves, on the combustion chamber face. So removing the slight lip that exists from the machining process. This should hopefully give better flow when the valve just comes up off the seat. So I guess it's kinda like having a slightly longer duration cam for "free" as your useful airflow starts at an earlier amount of lift. However need to be careful to minimize the amount of material lost, or compression ratio starts to drop. So I dont think I will do the exhaust side, as there's less benefit when the flow direction is reversed. (For a turbo motor I'd do the whole lot as losing a smidge of CR isnt detrimental in the same way) I'm thinking that this will either be marginal to the point of being completely pointless, or possibly the most important change of all. Then in the intake port, smoothing out the transition from the machined bowl area into the cast area. And reducing the size of the injector boss protrusion. Then also narrow up the divider a bit, but maintain a rounded nose on it. I'm not sold on the idea of knife edging. I doubt there are going to be any massive gains here. Maybe nothing at all. But even the tiniest improvement cylinder filling at 8000+ rpm equals potentially a tangible difference. Either way it's something fun to learn about and it's "free" in that all it really costs is a whole lot of time. Haha. This is a junk head (RIP 2NZFE) which I've been practicing on so far, I managed to cut right through the injector boss seat from inside the port... But now I know how far I can go without issues. Will be fun to see if it makes any difference once I've done a proper head. But it's heaps of work. Definitely earning those 1.5 horsepower gains haha.

Yeah that's worthwhile! It's amazing how all that stuff can add up, and you have a supposedly light engine drowning in accessories weight.

Good effort! The more I look at the yellow car, and the more I've looked at that other thread and seeing these IRL. The more I'm convinced you probably own the least dented one on the planet

They must be ramen the air in

Assuming some of the shorter ones will be on extensions, and since this is kinda like horse racing I'd say: 1. It's Ramen men, hallelujah 2. big straight blue lagoon 3. big white badonkadonk 4. green swirly boiz 5. smaller than average, white, but an arse like a jack hammer 6. blue screw drivers If we could get all of the dyno plots overlayed and slowly increasing rpm then get someone to narrate over the top like a horse race please

second place is the first loser (to noodles)

In reference to the start of this discussion, which was my car heat soaking (or at least, the IAT sensor heat soaking) at the drags. It's a very simple thing to replicate. Because I can just go for a drive with lots of airflow, do a full throttle run. Then leave the car to sit idling for a significant period until the IAT gets high again (with IAT sensor set to observational only, not changing tune) Then do another full throttle run straight away. Then monitor the percentage of difference in Lambda value of the two runs, and the two idle speed conditions. This will show what the "Real" heat soak value is at each end of the spectrum. Thinking about things a little more though. Since my motor has very high compression, I think it's likely that the heat of compression is probably considerable. So the IAT being 20 or 35 deg probably doesnt make too much difference. From a knock perspective, perhaps IAT isnt that relevant. If that is the case, then it's just adjusting the fuel trim by a % that's needed, based on observational result. Calculations are good for giving a starting point, but observation gives you the sum of all variables, some of which you cant calculate for. From my drag runs, with goal AFR of 12.8:1. In the third gear runs I was just slightly richer of this target. In the first gear runs with heat soaked IAT sensor, I was sitting around 13.2:1 So a definite indicator that the air coming in was cooler than IAT was reporting, so skewing the airmass result. TL;DR: Unplug IAT next time hahaha

Arent you double dipping by multiplying the axis by both MAP value and VE?

Yeah to had to swap in the guts from a later model speedo to make it work. Was from an st202 celica or something like that. The odo came with it, and I lost my trip meters. The tacho worked just with the addition of a resistor, from memory.

On a non cross flow head though! Heat soak city

Hey, IF you run your tacho as an output from the ECU, then instead of allocating it as being just a tacho, you can make it a GP PWM table. Then you can output a frequency and/or pulsewidth that corresponds to each rpm point on a table, so you can get it 100% accurate even if the zero point of the needle of your swapped in unit doesnt line up. You can do the same with a speedo too, I did this to both on my Carina because neither of them were accurate at various points on the gauges.

It's like that! Not sure if it's something to do with alloy block, but compared to other motors I've had, it seems to gain and then lose engine temp really quickly. Or maybe the thermostat is just a bit sluggy. It's still got the normal 1NZFXE thermostat in there that the motor came with. I'm not sure if they make it "slow" on purpose perhaps. Compared to the regular engines. Or maybe it's because this electric waterpump is only rated to move water around to suit a 75hp engine haha.

Painful bill, but man that dash looks incredible!

Yeah I dont know what's going on with the sensor, I've used this same sensor previously and it's been insanely quick to react. Like almost instant with throttle. But the last few I've used have seemed sluggy. Maybe that have a glass coated thermistor and the other ones were exposed. Maybe I shouldnt buy aliexpress IAT sensors, who knows. hahaha. Yeah ideally I'd just be able to clamp the IAT reading to ambient air and ignore the heat soak from staging. As its 100% fake news. For next drags I might setup the IAT sensor as a general purpose one instead so it wont affect the tune. The IAT sensor is down near the pod filter on the back side of the intake tube. Towards the end of the day I turned the radiator fan on full time to keep some airflow going. On the launch and burnouts man there were some big smacking sounds coming from engine bay hahaha. A few times I thought an axle might have popped out. I think pod filter hits the bumper, but also sounds like the engine mounts hit limit of their travel or something. Currently standard rubber in the mounts with shore A 60 polyurethane filling the gaps. I think maybe I need to do some full poly mounts, and maybe go shore 80 for the rear one.

This is what I was up against with the IAT situation, just looking at some logs. IAT approaching 70 degrees while staging! So because I've mostly tuned this during colder conditions, I've been on the conservative side of things for high IAT for knock related reasons. I've never seen IAT anywhere near this, usually because car keeps moving while I'm doing anything fun. So I think I need to better shield the intake from engine bay heat, but also there's not necessarily much I can do about it if the car is just sitting there for minutes at a time. I'm only running about 25 deg max advance, but it's pulling out 7 deg in first gear because of heat. So I'll try get to a nightwars next time, assuming they start up again at some point.

Made it to the drags! Man it was overcast but steaming hot today, during staging I was getting 60 degree IAT, then down to about 40 by the end of the run. Was like a sauna in the car with the windows up and no fan or anything haha. Anyway, my best overall time was 14.74 @ 94.6 mph with a 2.572 60 foot. I had my fastest trap speed earlier in the day when it was cooler, did a 95.58mph. Which was funny, although I was slower quarter time, I ended up trapping faster than the V8 SS Ute that was in the other lane Was an awesome day, so much fun! Only issue was the alternator detentioning itself a bit. Clutch got a bit soggy after some burnouts. Despite everyone telling me that I shouldnt run a standard clutch, well guess what? Yeah they were right. So basically, yeah, my launches suck. Definitely need to abandon 185 wide front tyres if I'm going to further my drag racing career haha. I reckon there's a few more MPH in it with a better exhaust, as I'm still running the standard pea shooter system. Will work on things some more and head back! Hopefully they will run night speed again, so I can get some cooler IATs. Maybe need to look at better partitioning and heat shielding the intake from the engine bay air.

And that good taper too