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Roman

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Everything posted by Roman

  1. 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.
  2. 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.
  3. The reason I made my tippy ones previously. Is that if theoretically the idea of a really big bellmouth works, then it's going to work less well on the middle ones where you've chopped off so much of the sides. Or, it's going to scavenge air out of the adjacent cylidners which seems just as bad. Yet as we found out, it didnt help anyway. Will be interesting to see how these go! Can peach cans please become the baseline test
  4. Congrats on first shake down! One thing to consider is that even if power were the same, your power to weight ratio has improved on account of the weight loss. And less weight in the heftiest part of the car, so there are handling gains too. Also the peripheral benefits you mentioned at the start, like excellent aftermarket support means there's heaps of scope for development. I'm stoked to see it running, look forward to seeing further developments! I reckon you can easily wring a bit more out of the motor with some tweaks. The best part and most fun part is definitely yet to come. Thanks for your efforts to document the actual changes etc, I think this is legitimately the first time I've seen an attempt at a fair comparison.
  5. Going through results from this, gains super arent huge, but it's something. However I'm now happy that the VVTI situation is as good as resolved, as I've got a good working range while still keeping the full high comp. Now I will be able to see full benefits from a good exhaust. So that's next on the list. Coilovers and some slam would be cool, but out of budget for the next long while. EDIT: I refined the tune a bit, and yeah its picked up some midrange, can pretty easily see the difference compared to last! Feels great, I'm happy with it. Glad to have this bit ticked off the list. Based on some of the stuff that KPR has done, it would be interesting to see if that big steep increase at 4k rpm improves with a better exhaust. There's drags on at Meremere this sunday, if the stars align I might get there.
  6. Yeah all of the prius electric stuff happens in the gearbox, and apparently they are heavy as hell. So the 5 speed earns its keep for fun factor and keeping the weight down. Sooo because I was annoyed that it still looked like it wanted more advance. The rolling pin idea that @Spencer posted was great, and I probably should have done this. But I retimed the chain so it was only 1 tooth back, and yep in this position valves hit pistons. So I made a fairly ghetto stopper that jams between the housing and the existing stopper pin. It looks like it could fall out but it cant (famous last words...) I had a few issues getting vvti working again at first, I found that my stopper was *slightly* slightly slightly too long compared to the depth of housing. So it was creating a tiny gap to the lid so the oil could pour out with less resistance - so not enough to move the cam or disengage the pin. Fixed that, and have just been for a hoon to see how new angles look. Results are awesome, there's now a distinct cross over where various angles are better than the other. So a max of 37.3 deg with the stopper in place. Awesome! So that's 17.3 deg advance over normal cam timing's home position. So I could still potentially have another 20+ deg over that, with piston cutouts - but it doenst look like it's going to be necessary. As I've got a cross over point from max advance at around 5500rpm. Still going through the results to make a new VVTI map, but its looking promising.
  7. After I got my VVTI angles sorted, and the fuel map dialled in, everything seemed good - but it wasnt... Airflow was obviously up, fuel was right, why was it feeling sluggy and shit? I thought I might be imagining things, because everything looked good in ECU. But did some virtual dyno'ing to check. Confirmed I seem to have lost about 15hp pretty much everywhere. Did some basic troubleshooting, nothing seemed amiss with spark, etc. I thought maybe the tyres were getting flat so pumped them up. The motor also smells oily, but no visible leaks anywhere? Then I had a thought... ohhh.... I check the dipstick - yep I'd managed to overfill the engine with oil probably by about 2 litres haha. I forget these tiny engines take hardly any oil. I thought it would have been underfilled with the amount I put in, so didnt check because I am an idiot. Must have been absolutely beating the piss out of the crank to lose that much hp from windage. But now it's running good again after draining it. I might see if I can advance it 1 more tooth on the chain without hitting anything, but this will likely be reaaalll close. The fuel map currently looks like this, could definitely rev out some more if I put on my brave pants stupid hat
  8. Not much new to show, it's mostly the same right now but a bit quieter with the airbox on. Need some events to go to!
  9. Basically it wants to be pinged to max advance right until nearly redline, which at first I thought was cool but then makes me realize it just wants even more advance but cant have it. So still no way around needing those other pistons. But still, really happy with this for a "Free" stopgap fix! This is a before and after VE map (fuel table adjustment) from adjusting to best cam position.
  10. First results! So at zero degrees advance now, it's real smooth to drive and idles real nice but it totally eats shit at full throttle haha. At cruising speed/rpm it's pulling 25% fuel out! Further investigation needed, but I think this is gonna mean I've unlocked some prius spec economy when the cams in that position. (Reduced pumping losses / dethrottling will actually work for once) So at full throttle, usual test of incrementing the cam. No MAF this time, so just looking at lambda results to see if it runs leaner (more air, so needs more fuel) Results are distinct! Approximately the 30 degree line (Yellow line) is the previous home position of the cam. Now with 45 degrees advance (red line) its gained shitloads. So it looks like some amount of gains right up to 8k rpm which is awesome! And I might have filled in that big hole in the fuel map around 4500rpm. Will do some more finer tuning around the 25-45ish range, but pretty stoked!
  11. Ahh yeah so this cam has a locking pin that holds the cam at base position until there's oil pressure that can fill the gear. Otherwise the came rocks back and forth as the spring tension acts on the lobe. So I retarded the cam 3 teeth, and much to my frustration it still didnt reach full travel. This didnt make any sense because if I put it back 4 teeth, I'd be back to where it starts at home position. So I pulled the chain back off, and testing it loose - the cam doesnt move the full way anyway! So looking in more detail. It turns out there's a stopper pin that limits its advance. Like so: (This is at maximum advance) So this is great news, it meant I might not need a whole 3 teeth of cam retard. I tried it with only 2 teeth reaches the stopper pin with no piston to valve issues! Awesome. So now just got to finish chucking it all back together and do some testing. Hopefully see something useful from it. Will be interesting to see how it idles and drives with weird home cam position.
  12. Yeah I've thought about that - but I'd need 4 of them machined exactly the same, and I'm not sure how I'd secure them in position. If I have to take the cam gear off and cam out, then it's easier to just retime the chain. So will give that a go first
  13. Car has been running great. Just frustrating that all of the events to attend are getting shut down. Since it's been running good with no problems, obviously the thing to do is pull it apart again. As I want to investigate how much VVTI movement I can get with the current situation. From memory the valves clanged into the pistons at around 18 degrees advance. Counting the teeth on the cam gear, it's got 36 teeth so 10 degree divisions. So I cant quite use 2 teeth worth of advance, which is a pity. So I'd need to retard the cam gear by 3 teeth, and use only 10 deg advance over the current position. But then I gain 3 teeth worth of cam retard too, over just a fixed position. So at home position the cam would be open for quite a long period during compression stroke - Doing what the standard prius motor does. Hah. So I might get some better fuel economy out of it. Since the valve angle is quite steep I dont think there's any possibility of clanging intake valves into exhaust valves, but I will check on my spare head. I wonder if this will act weird with ITB setup. As there's less room to push the gas back into the intake. It's a wanker to do all this because, of stupid chain drive and sealed front cover. As well as that I've nanged on the front pulley with about 50 litres of loctite. Hopefully the starter motor can get it off. At TDC-ish It can advance about this far before it hits
  14. Nearly finished. The sillyness is quite pleasing
  15. It's actually modelled after a screw driver handle thank you very much
  16. The round pipe at the bottom has an area of 2123mm2 The six slots have a combined open area of 5058mm2 So hopefully not too much pumping loss. Probably could have made them skinnier or shorter. In hindsight I think the wave will lose too much pressure travelling past the slots. But it will be interesting to see what length pipe it behaves like. Easy to make, first one is about 1/3rd done already. They are designed to be printed upside down so it doesnt need any supports. I dont think they will win any awards for outright power etc, just an extreme test case for trying to catch and reverse a wave with a capped end. So might see some weird peaks and troughs in the powerband perhaps.
  17. Here's my submission for TORNADO SUPER SWIRL SUPER DUPER INTAKE Rather than swirl being the main idea though, it's more that it's a side feed runner so the end can stay capped. So maybe we'll get a stronger reflected wave perhaps? Will it work? Probably not! Will it be awful? Maybe not! This is why it's fun. Will try come up with something else as well.
  18. I think this is where people see water spiraling down the bath plug hole and then assume that this is good flow. Or it wouldnt be @kpr's first run in with a tornado enthusiast hahahaha I might print some more junk for this
  19. I cant wait to see how demoralized he gets when the peach cans win again
  20. I love reading detailed stuff like this, really makes me feel like ive achieved something for the day when I obviously havent. Keep it up please
  21. So whats the plan, big block motor in with the LSD box, into the best chassis?
  22. Another cool thing about rampable fans. Instead of instantly on/off and shock loading your closed loop idle. You can gently ramp in the extra alternator load using a timer or whatever and it will help keep engine speed steady without a jolt.
  23. Currently got shore A 60 filled mounts and its pretty rattly. Could perhaps do the rear one in 70 or 80.
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