kpr

Any suggestions for a AC DC Tig, around the 200amp mark. willing to spend up to about 3k for a decent machine. Currently have and old 160amp mitech ac/dc/plasma. its getting pretty tired and need more power for ali welding.

Spent another day machining stuff. Finished tapered tubes. Machined more off the back of trumpets, as was pointless weight. Made some bosses to make a new vac chamber which sits on the under side of the throttles. Cant use plastic bmw one (in bottom picture) since have moved the throttles closer together

Got another throttle body adapter plate made in ali this time, thanks to @Stu . Plus some more throttles, which still need more mods, but done enough for test fitting. Been working through some clearance issues. chopped up and shortened water outlet as fouls on the front throttle, it welded horrible because old cast ali, but should be good enough. alternator is in the way, think have a solution sorted with a smaller alt and modding the bottom water pipe so it sits closer to the block. Blah, pictures:

conclusion: bmw throttles make no more power. injectors in bmw throttle instead of head, no change. have revised throttle linkage setup. still not as good as the setup on the 20v throttles, but a whole lot better But have gone with this setup as it heat soaks less. both the throttles and the fuel rail are isolated from the head, with a thermal gasket and 25mm bit of plastic. should be bit more consistent, since hot air and fuel suck Also found that cylinder 1 was running a touch leaner than the rest, after checking afr per cylinder. so have added a fuel trim to add a bit more fuel on cyl 1,

Made a start on the plenum I tested the trumpets on the starlet. red line is straight pipe the same length as the bellmouths (blue). Pretty much no difference till airflow demand is high. after that the bellmouths win. Down on power about 10kw to what starlet makes due to runner length. Some goose put a massive suspension tower in the way, so stuck with this length on the hilux

just using short silicone hose on my na setup, works fine. will do the same on this missing the hose clamps in this pic

If you like a sloppy mess

Why are the starlet itb's in this thread? Because the the inlet manifold on the hilux sucks. Not power wise, it seems to work good. but it vibrates, cracks and the big plenum doesn't work with what im trying to do. stalls out easy and any kind of cam setup other than factory, even cam timing changes on stock cams makes it a whole lot worse. wont idle on all cylinders and stalls real easy. not ideal for 4wding itb's will solve the big plenum issue, also will be able to isolate the plenum from the engine with some short silicone joiners. to solve any vibration issues. So had those bellmouths in above picture from another project, recycling; extended them by welding some thick wall tube onto the bottom machined a taper into them to suit the 52mm throttles and slightly adjusted the bellmouth so has bit more of an elliptical shape. machined some of the excess off them. could have taken whole lot more off but was over it by this stage. will probably test them on the starlet before welding them into plenum

@Truenotch Filter vs no filter. cant remember which one is which, but yeh zero loss @Roman red is my normal cam timing. blue is the inlet cam retarded 8 degrees. had a play with the exhaust cam. advanced it 5 deg, then another 5deg. pretty much no change other than a few bumps here and there. maybe slightly better all round with my normal setup, but seems pretty numb to changes. my normal settings im maxed out on both cams, any further pistons will eat valves i do have a vibration issue with either a wheel or wack axle that screws with the dyno and gives inconsistent results, right up top at around 180k i need to fix. / start running it up in a lower gear.

from the cam timing testing ive done (need to revisit on dyno) can get pretty aggressive on the overlap, inlet advance and exhaust retard. gain a stack of power everywhere usable under peak, with minimal if any loss in peak power . side effect being power drops fairly fast after peak as can see in my dyno sheets. going the other way it will try hold onto that peak power for another 500rpm or so. Inlet had most effect. exhaust done similar but maybe only half or less effect so yeh pretty much nothing new there ^ . if you have vvti /vvt you can have your cake and eat it too. many years ago i attempted to retrofit a vvt pulley off a 20v onto a 16v, its possible but gave up on the idea.

I heard muttering in the pits that the resonant frequency of the 20v's effects the timing gear, resulting in inaccurate time slips. the smoke theory does make more sense

while we are on the subject, remember that time at meremere a NA 16v beat a turbo 20v. @Stu

all good its not spam, pretty interesting, always looking for new ideas to try. will have a better read though those pages later. heres that chart overlayed. i started the overlay at 30kw at 3000rpm same as flywheel power, as assume wouldn't be loosing 16kw down there.. looks about right since smallports naturally spit out more midrange than the other 4age versions

@Truenotch Those chambers look interesting. haven't tried anything like that on the runners. but definitely going to put it in my list of things to try. Have something similar after the collector to my exhaust. black part being 2.5" collector. red the cone and green 3" exhaust can see the cones on both extractors here @Rhyscar I have a short merge for the 44.5's with same 2.5" collector. it didn't seem to have any effect. but was pre dyno, so possible was some very minor differences. will likely revisit the megaphone setup also. should be gains to be had, but not expecting a lot like on the intake side. Its running somewhere between 12.5 and 13:1 compression. was going to go for more on latest build but cheaped out on new pistons. could skim a little more off the head. but would likely have a negative effect. as its all pretty tight and would have to adjust cam timing to gain piston to valve clearance. Found a dyno run to overlay from here https://motoiq.com/extreme-engine-tech-technosquares-monster-naturally-aspirated-toyota-4ag-part-3/ 1800cc engine, another interesting point is they are only running 285cc injectors, im using 540's at 60% = 324cc worth fuel. guessing they could be running high fuel pressure otherwise would be 100% duty for that power Looks pretty good vs this one considering down 200cc

maybe worth a try. but im more leaning towards 44.5 is just too big. the step made more power, so tempted to try that on the 38mm's. the stepped section will be getting pretty small and may cause a restriction though. no real specific area in the rev range im aiming for, what ever it likes really. Tbh goal already achieved was looking for 150kw with good midrange power. but why not carry on.. i know i could easily make 155kw+ with the parts i already have hanging around. but would only be good for wank factor or a circuit /drag car. as would take a big hit in the low/midrange. would be interested to overlay my power curve onto other 4ages making the same power.

Think i tried it at some stage and wasn't any difference. will try a back to back next time its on the dyno. from memory its the biggest one 435x190x115. which i assume is od. trumpets are about 75mm long. so should have 25mm clearance. You mean the dip at 4500 ish from the big extractors? they aren't too far off the same length as small. I did cut the big ones shorter not long after building them, and wasn't really much if any change. although was probably only 50mm or so. also, the big ones didn't actually make any more power than the small ones up top, until i added the stepped section. once i'm finished messing around with the intake, will try some more exhaust stuff.

noisy version of above

yeh, cams in this have over 5mm/4mm - in/ex lift at tdc. Chances are it wouldn't even idle on a single throttle setup

Bouns graph: the shopped line is done years ago when had stock cams in the car. was done on same brand dyno, but in 3rd gear not 4th, which would have shown maybe another 5kw. still, it shows with right setup don't have lose low down power with big cams.

measurements are the orange pipe length, not total runner. can see the peak move up in rpm range as cut pipe down. afr was no where near perfect in any of the runs but close enough not to have a massive effect on power. Red: 200mm run from above chart , blue: removed the black bellmouth part, making runner about 80mm shorter over the 200mm one green: with only the silicone 45 deg joiner pink: ali pipe from my normal intake minus the 78mm trumpets/bellmouths. forgot rpm scale in this one.. Blue : ali pipe only as above Green: throttle bodies only red: normal setup

Was actually keen to make some kind of extractor style intake, with the bellmouths / filter sitting in the big gap beside radiator.

POWER DUCT. all the hype. none of the powa

Tried more stuff, ended up back in the same place. Including this: -50kw was trying to find the first reflective wave. chased it along the rpm range cutting the pipe down 200mm at a time., but just found negative results. half way thru noticed the silicone joiners wern't playing the game and doing some crazy stuff. possibly giving some wack results. but pretty sure i seen what i needed to see. seems the loss in the super long pipe with bends in it offsets anything that would be gained from the reflective wave. Got the bmw throttles on there now running the big injectors further back in the throttle bodies. makes exactly same power throughout the curve as with the 47mm 20v throttles and injectors in the head. But soon as you mess with this: drop the top trumpets off and goodbye 10 -15kw everywhere. so yeh that setup seems to be on point green: current setup. with small extractors red: old engine big extractors blue: old engine small extractors And.. road test, not having the hole at 4500rpm plus bit more up top, shit hustles of the mark through 1st and 2nd gear. throttle bit too touchy for my liking though, need to revise the linkage setup.

Sounds faulty to me. Especially if the presure is jumping around. Almost sounds as though there is something sticking inside and it has to build up more than the preset pressure before it bypasses. Shouldn't matter if vac line is on or off. I ran one the same back in the day. Had to keep an eye on the base fuel pressure as would drop over time. Others had same problem. I try to use factory regs when possible now.

Got them back on. Need bit more testing, but looking like same results all the way through..