kpr

So if im maxing out a turbo for what its capable of producing in my case a standard Rb25 turbo at 212kw, is it likely that the standard internal wastegate wont be up to it? I only ask as the computer & engine i have now was dynod for that figure, the only difference was that he had an external wastegate of the exaust. Im keen on going back to internal wastegate to keep things simple and get a better turbo in with less play at the same time. Cheers boe shit answer. but try it and see. if it doesn't work it isn't that bigger deal to put an external gate on afterwards. you could always hit the waste gate hole with a die grinder, before you put it on to improve chances of it working.

hah, for the 85 man. kp stays na!

gotta make one for my turbo manifold soon. will take some pics of how i make em.

as in how to make them, or angles etc?

was wondering how long before someone asked.. theres a slot between the 2 plenums, from one end to the other, idea is to fill the main plenum evenly, so you get even cylinder distribution. area of the slot is slighly bigger than throttle body area. so it doesn't cause a restriction. Truenotch: hah then you'd spend the rest of your days, telling your engineer to stop being a lazy cunt. todays achievement was, remounting the turbo back in the same place i had it 2 months ago! might start on the exhaust manifold this week. was going to make it out of thin wall tube to keep weight down. but really dont wanna be rebuilding it if it breaks

actually done some work on this today, finished the inlet manifold. some pics from ages ago i was too lazy to post: inlet manifold under construction & mocking up turbo,still haven't decided if im gonna leave it in this location yet. comments and mockery most welcome

nar, unless plug is too cold they will foul up, when just cruising about. shouldn't have any issues with 7's. if plugs are too hot can cause detonation or pre ignition, so when running more boost using a colder plug is good idea

when the internal gate sucks basically. boost issues. unstable boost, boost creep, etc. although half the time is not the actual gate thats the problem. its usually bad boost control device that causes unstable boost. or actuator is faulty or not up to the task. if none of the above is the problem. and boost is creeping up with revs. you can port the internal gate to get more flow. which may fix issues. getting an actuator with more travel to open the flapper futher can help also external gate is the easy way out, but your pretty much guaranteed it will work. unless its undersized, or installed wrong of course. possible small gains could be had by going to external gate. as your removing turbulence from around the exhaust wheel. end of the day all your doing is bleeding off exhaust pressure, so turbo doesnt spin as fast.

+1 for check gap, since thats what you've changed. can gap down to .6mm without any issues. wont need to go that far. if at all with 13psi. but try .8 if you're going to gap them down. stock is probably 1.1mm or something around there. edit: yeh you've gone colder, higher number is colder in ngk range.. check gaps against old plugs

shit is hardly rocket science. but can be made to sound like it as up there. think more specific questions are required, else to many tangents to go off on.

nice setup. pretty impressive power too, what was the difference between your old and new motor?

hmm yeh, never had my battery in boot setup checked. wof and cert, they never bother with it

agreed. altho best to have one in there. also sounds more gay without one when the air escapes back thru turbo compressor surge is different again and a whole lot worse for turbo. when turbo supplys too much air for engine so compressor wheel tries to stall while the engines trying to spin the exhaust side the other way still. snap

you can get a exide orbital for around 250 if you go to the right place( this was few years back tho) they the same deal as the optima ones. they are pretty sweet,

as above, most internal gates will work sweet. some will become shit and cause boost issues when you wind up the boost. external gate will give better control. when running high boost. alot of the bigger turbos have no internal gate. anything bigger the t3 size usually doesn't running an external off the back off the turbo from the stock wastegate port is gonna restrict you to the internal gate hole size , unless hes die grinded the shit out of it. cant remember what the ex housing on a rb25 turbo looks like, but unless it has 2 separate outlets for ex wheel and wastegate. it wont work off back of turbo anyway.

turbo stuff is pretty easy. compared to n/a ive been playing with turbo stuff for awhile. i can say its alot easyer to just throw some parts together and have it work fairly good. unlike n/a. have seen some pretty horrible turbo setups work not bad. i didnt read all that stuff above, but heres my understanding on how wastegates etc work, things that will effect wastegate size, power, boost level. exhaust housing size. but generaly you can just bang your standard 38mm size wastegate on most smaller engine setups, and will work fine. only when your making big power. or on large engines you'l need to go bigger. will be running a 38mm gate on my ae85, which will be around 200kw at wheels. allsorts of was to raise boost. bleed valve is usually just an air leak in the line to the actuator or bottom port on an external gate. so it just drops the pressure in the line to the waste gate so it opens later. pretty unreliable unstable way of doing it but cheap. if going with a fixed boost level the best way to do it is to use a stronger spring in the external gate. you can do similar thing with actuators, either swap to a stronger actuator or can add an external spring to it. may look hori but works a hell of alot better than a bleed if you add pressure to the top side of an external gate it will stop the gate opening. thats what they are doing in those pictures, with the regulator, your basicly adding to the spring pressure. add a few psi to the top port of the gate and it will add onto the spring pressure, hello more boost. electronic controllers basicly do the same thing but a better job than the manual stuff. bov's most people run them before thottle. so flow doesnt have to go backwards. but at the end of the day it doesnt really matter too much. you can run without them but can get a bit hard on the turbo im stick of typing now,

toda stuff seems to run pretty big primary's & secondaries, if those measurements are id. the 4age and b16 etc have same measurements on them as well. im only running 38.1 stainless on mine which is about 35-36mm id. thats alot more area

helmholtz is the pressure waves your tuning the length of the pipes to. its used alot in intake tuning helmholtz resonator, generally the first straight through muffler is helmholtz resonator design. google it, its pretty techo shit beyond what i can explain. high rpm stuff seems to use sharper collector angles,

yeh pity there's compromise in a street car, with those pesky mufflers and must exit here rules. / ears bleeding. im saying from what ive found, after it has exited the extractors and the correct length and size collector. going huge from there on doesn't really matter, too small does. so best to go too big rather than too small. making it quiet and flow well is a cunt pretty much.

keen to try make some 4-2-1's again. seems to be what everyones doing at the moment. the old 4-2-1's i had on the kp. actually worked pretty good. but were tuned for wrong rpm for my cams and looked shit have read a little about stepped headers . spose to be good for high rpm use. must be some drawbacks though as dont see them used alot. n/a is pretty tricky, pretty much gotta try stuff and see what works

yeh same deal here, thats why i was running a 2" system to start with. but smaller exhaust for better torque, velocity scavaging etc, seems to be bs in my case at least. just been comparing the tune we used on the dyno with 2" exhaust, to the current tune. ive added 45% more fuel at 5000rpm! tapers down to not much at high rpm and low rpm, but have added fuel everywhere. have done other mods as well, but exhaust changes are responsible for most gains. huge midrange gain from changing to the bigger exhaust. pitty it scrapes like shit on everything as it is, otherwise i'd be tempted to try bigger.

I think I recall exactly the same on mine. There was a thick layer of white deposit there (mild steel construction). After that point in the exhaust my system megaphoe went out to 4.5 inches and had some swirl arrangment inside it.I will see if I have a photo but basically the thing was more than a total waste of money as I spent a year an several thousand dollars trying to make the engine go properly due to my hgesitation in chopping off something that someone else charged be a bunch of cash to make. The emperor's new clothes.......... cut out the megaphone today. now it has a section of 2.25" (300-400mm) welded to collector. then steps up to 2.5" for the rest of the exhaust. afr has stayed the same. but it accelerates faster. no loss of power down low. thinking i might try 2.5" all the way . least im going in the right direction now anyway, slowly!

have one in kp. no issues. other than it come with a shit cap and shit drain valve thing

hah, yeh might start to mold itself around the exhaust. how about a fiberglass one? may hold up to the heat a bit better. thinking i might use my current perspex one(or parts of it) as mold for a fiberglass one. as unsure if its going to fit with my new manifold setup. you could allways do the same if its starts to go out of shape with the heat.

yeh was just normal stuff far as i know, mate gave it to me. its pretty easy to shape. heat it with heat gun, then bend using a straight edge. just don't over heat it else it starts to bubble. i used superglue to stick it together. then ran a bead of silicone around the joins. theres probably a better way to stick it together, but hasnt broken. only issue ive had is its got a few small cracks in it. but possibly happened due to it hitting on the brake booster. biff it in a tin of gas and see what it does maybe? Unclejake: stick with the big exhaust i recon, i gained nothing but happy times going bigger. tune the exhaust to size & length then dump into biggest exhaust possible (within reason) maybe worth a go.