kpr
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Posts posted by kpr
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Tried some different angle megaphones. nothing really happened up top. but below 5500rpm some various wigglyness happened
5 degree - blue
6 degree - red
9.5 degree - green
straight - pink
full exhaust - black
full exhaust seemed to be down a touch up top on the rest. the stand out was the 5 degree. not because it made any more power. but because it was the nicest curve in low revs.
The flat megaphone i made on full exhaust sounds terrible when cruising. kinda expected it to do this, as have had the same problem before. seems to be an issue with the pipe not being able to hold its shape like a round pipe would. Also it was made to the equivalent of 7 degree round megaphone, going by inlet and outlet area. no idea if this would be the right way to do it, or if there is any way it would act the same as a round pipe.
Have built a new one that should be 5 degree equivalent. Added a divider straight down the middle, to stop it flexing. unsure if will have any effect on the wizardry
Yep the rest of the exhaust still has all the metals. stainless, mild and aluminum
seems to have stopped making the horrible noise on a short test drive. haven't dyno'd it yet. will be happy if acts similar to the 5 degree in blue graph.
The headers currently have this diverging cone setup on them pre the above stuff. probably should have be testing from the choke point back.
but have a good results with this setup in the past, seems to get you most of the way there when combo'd with the right muffler.
Also over crawling under the car.
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Ive done 2 with that same extrusion and injectors. both in drill press. pretty sure i done the same thing as @RXFORD suggested for the finish. no idea what drill size i used. just used a countersink tool for the entry taper. probably isnt the ideal angle but fine unless you hamfist it
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Other thing that seems to happen, is it moves the power curve around, by altering the effective intake length. can see the peaks and dips get pulled down in rpm with the injectors moved out. Im sure high end race car people know about this. But if average joe moves injectors on an intake that's slightly the wrong length. could be decent gains from this alone.
So yeah, if the stars align and combo of things work together. probably looks to be big gains. If take all those factors out probably still little gains.
If 1-2hp to be had. high end race car engine = yes
make intake 30mm longer and the power curves start to line up
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Thats a finger follower setup is it not. lighter than bucket setup. for all the rpms
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The one on left worked bit better. but bad example of what would actually work best. as both kinda sucked for the application. too much duration.
Can only go so much duration till it turns your engine into a turd. im running a 304/300 (262/258 at 1mm) combo. the 318/320 takes a massive hit in the bottom end for only little numbers up top
Yep, kinda in the cam manufacturers hands on that one. too aggressive will just start breaking stuff.
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would be interesting to see the whole curve on them. if the kelfords open the valve faster to the first mm. do they continue on accelerating the valve faster, getting to higher lift faster?
This is an interesting pic that shows the numbers shown, only tell a small part of the story. left is a 318/11mm right is a 320/10.8mm pretty much same on paper with the advertised measurements. not so much when looking at them.
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other than more stress on the valvetrain, more jam without any of the side effects of longer duration cam. so still runs like a nana car.
but yeh not much of an upgrade if want to make decent power-
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doubt the 1nz cams were 264 @ 1mm. thats pretty massive. would be in the 300's @ 0.1mm. but yeah depends on the cam manufacturer what the "advertised" is measured at. sometime 0.1mm or 0.3mm on jap stuff. so possibly the 264's where at 0.3mm.
But yeah, still can be vastly different that's why the 1mm numbers are a bit more relevant. the 4gr cams must have a slow ramp to keep the valve train happy. for them to be only 207/205 @ 1mm and 263/262 at 0.1mm. other cams in the 260's will be 220-230 at 1mm.
short version get them big cams @Roman-
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A friend got me a deal on a strata advance tig. pretty happy with it so far
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megasquirt lyfe.
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easier just to oversize standard throttles, pretty much nothing to loose if your intake is a bit oversized. lots to lose if undersized. if under size intake enough to make gains off the bottom = cork in top end.
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So, i tried a whole bunch of different angle reverse cones, on my test pipe. the part that goes back down smaller to the muffler
18, 23 and 33 degrees included angle
basically didnt do anything
orange full exhaust. all others test pipe
So yeah the orange run with full exhaust. its magically fixed itself and doesn't drop off up top anymore. not sure why, the connection to the big headers is pretty janky atm, so possible exhaust leak. or maybe the way it was on dyno wasnt right. was making 169kw uncorrected, so beat the crap out of it to get oil temps up till it cracked 170kw
Atlantic engine = red
My junker = blueThe vvti is helping out here quite a bit. its amazing/cheating
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sure, I work pretty slow and generally charge out 23 hours per day. Not to mention the minimum charge out fee
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Ok, so the green line is the last time i tried the big headers. which happens to be the setup i ran a 13.5 1/4 on. And i thought the 146kw was about the most i was going to get out of it back then. not make over that number across a 3000rpm window
Red is the atlantic car
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Was slightly intimidating pulling 10k after having the 7a in there, that was lucky to do 7500rpm
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so I tried the big headers i made ages ago, now engine is making more power.
kinda same deal as last time. more up top, and a decent hit in bottom end
so did some testing with some new exhaust setups after headers. then built something that would actually fit on the car
made the below abortion, to replace the existing abortion
for reference inlet and the outlet after the reso/muffler is 3" tube.
Black is the big headers with the megaphone pipe. blue is small headers with the old pipe as in above graph. bit wiggly under 4k. but aint care about that. pretty good gains through midrange. has picked up the bottom end to match the what the old setup did. the megaphone pipe makes it fall over a bit sooner, but over all better. some fine tuning of the angle would likely help
Im running a different collector on the big headers now. but yeh otherwise as below,
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those max fab reso's dont cut down the noise much. get another straight through with biggest barrel you can fit (more absorption material) to go at the back along with the reso up front.
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ac/dc tig, 200amp or more, budget around 3k. Any stand out machines these days? or chose your chinese shade of colour ?
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might be able to change that idler pulley to an eccentric type one, to get belt adjustment
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as above, will be fine long as has airflow through it. big reason for cooling issues is air either goes around radiator, or has no where to get out the other side
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with the right exhaust setup, should be able to run the high cam way down at 4500 - 5000rpm and gain stacks of mid range.
cam specroman 1nz 266/266? deg
2zzge high cam 292/276 deg
7age 284/278 deg
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toyota hemi, basically ultimate turd polishing. along with low weight, close ratio box and well setup cars. probably some exotic fuel. Even though only 2 valve, the bigger bore than stroke allows bigger valves to fit in same capacity. one of those engines that have plenty of scope to modify but nothing special in factory config.
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2zz- 82mm bore 85mm stroke
3tc - 85mm bore 78 mm stroke
3tc = race car engine
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trailing coils are just a basic single coil as far is i know. so long as igniter can supply enough current, should be able to use them in what every configuration you like.
fc/fd leading coil is a wasted spark. the trailing coils are direct fire.
Stu's 1985 4age EP71 track car discussion
in Project Discussion
Posted
5e block with all the rod ratio i hope.