Brock-Lee Posted June 9, 2009 Share Posted June 9, 2009 lofl, I got confused by my own explanation. The internal wastegate bleeds of pressure from before the turbine wheel so the turbo stops making more boost. What chris' turbo has had done is they removed the internal wastegate and have just put an external gate on that stock wastegate port. so its still bleeding excess pressure off, its just further away. Link to comment Share on other sites More sharing options...
forced Posted June 9, 2009 Share Posted June 9, 2009 I think you mean that the wastegate flap is welded up. If you're using the original WG port with an external then all you're doing is trying to fix a problem in the wrong way because the internal port will always flow sufficient so long as everything around it allows it to happen. Which also sounds like a really good way to bugger up a good turbo. As for low boost and no BOV, I had an old fairlady Z here at one stage, Early 80s, 2L V6 Turbo, no intercooler and no BOV. My mate's got an 86 Supra 2l straight 6 TT, again no BOV from the factory (can't find it anyway?)Most earlyish turbo jappers ran low boost. As far as the positioning of the BOV goes, the idea is to keep the air flowing in the same direction to keep the turbo spinning. You don't want some of the air in the pipe reversing when the BOV opens when the throttle closes. Steve Link to comment Share on other sites More sharing options...
thegreatestben Posted June 9, 2009 Share Posted June 9, 2009 1ggte's dont' have any form of "bov" the 7MGTE's and 1JZGTE's do though. Link to comment Share on other sites More sharing options...
My name is Russell Posted June 9, 2009 Author Share Posted June 9, 2009 I think you mean that the wastegate flap is welded up. nope Brock-Lee is 100% on the mark well explained Link to comment Share on other sites More sharing options...
kpr Posted June 9, 2009 Share Posted June 9, 2009 when the internal gate sucks basically. 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 Your turbo you have will be fine with internal wastegate, if it had one! What boost is that engine tuned for? Your turbos let down will be its comp wheel which shouldn't be boosted over around 12-14psi. Im not sure what model RB25 turbo you have but if you choose to sell and buy another RB turbo I would wait around and try get a 300zx T25. From what I know they are the same specs as the RB series(unsure which RB turbo or if there is a differance) turbos but with a steel wheel which will allow you to boost over 14psi if thats what you wish. But if your engine is tuned at 200+kw at treads now at say, 7psi, then you still have plenty of room to play. If you buy another turbo and choose to run internalk gate HKS make an aftermarket actuator for that turbo. I think this is just the equivilant of a stronger spring in an external gate. Now a question: Has anyone had experiance with mounting a wastegate directly off the rear housing? I,e making a new hole and welding a flange on. I know its cast. Gaz i would have thought it was shaft speed that would stuff them. for example, the shaft speed when installed on a rb25 on 12psi would be alot faster, than if it was running 12psi on a smaller/ engine that flows less air. both are running 12psi, but turbo will be required to spin faster to make that much boost on the rb25. will be making more power also. have seen a few setup on t3's, with external waste gate mounted off the internal waste gate port. both seemed to work without any issues. the housing was ported out. and was older style t3 housing with the removable internal wastegate setup (side bolts off and just leaves a hole) i acquired said turbo, but chose to run the wastegate off the manifold instead, on my setup think the 300zx turbo your talking about is actually a t3. steel exhaust wheel, and 60 trim compressor wheel(biggest t3 wheel). alot of older nissans have t3's that will interchange but have smaller compressor wheels and exhaust housings than the 300zx one. Link to comment Share on other sites More sharing options...
Ke36 Posted June 9, 2009 Share Posted June 9, 2009 heres another way to do it like what gaz was talking about however i agree with what steve says (i cant believe i just fucking said that ) as far as what brock was talking about with the other wastegate, if the internal is not doing the job properly then putting an external further away through the same hole is unlikely to fix the problem as your still trying to flow x amount of air through the same diameter hole, which doesnt fix the issue Link to comment Share on other sites More sharing options...
kpr Posted June 9, 2009 Share Posted June 9, 2009 will flow more tho. as hole doesn't have waste gate flapper in front of it anymore. most actuators dont open all that far.. but yeh agree, kinda stupid mounting it there unless you grind the hole out to correct size. Link to comment Share on other sites More sharing options...
Gaz Posted June 9, 2009 Share Posted June 9, 2009 Yeap Ke36 thats what I want to do. Did it work well? Is it your setup? Merrits to it? So that may be another option Chris. Chris's turbo at the moment has no flapper on standard wastegate hole. Its not welded its just open. The WG was placed off the dumppipe on a flange. Gaz Link to comment Share on other sites More sharing options...
ProZac Posted June 9, 2009 Share Posted June 9, 2009 21st Century Performance, by Julian Edgar Amazon: 1 new from $266.68 2 used from $173.59 Sounds like it would be good. Might look in library. Wow, thats really expensive, glad i picked my copy up for a tenner. Library is definately a good bet for that one. Link to comment Share on other sites More sharing options...
thegreatestben Posted June 9, 2009 Share Posted June 9, 2009 Rotating housings on turbos, Specifically inlet housing - Do you just loosen the big Snap ring and turn it? I want to point the intake outlet upward as much as possible. No problems turning it or does it have to be at a certain angle? Link to comment Share on other sites More sharing options...
eke_zetec_RWD Posted June 9, 2009 Share Posted June 9, 2009 most likely has a dowl to locate it in the factory position if its held on with a circlip. so new hole needs drilling. dnt be tempted to remove dowl and just leave it. once did this and felt tite ect but it did spin! Link to comment Share on other sites More sharing options...
Honda Ass Dragger Posted June 10, 2009 Share Posted June 10, 2009 Yeap Ke36 thats what I want to do. Did it work well? Is it your setup? Merrits to it? So that may be another option Chris.Chris's turbo at the moment has no flapper on standard wastegate hole. Its not welded its just open. The WG was placed off the dumppipe on a flange. Gaz IMO KISS Keep it simple stupid You will be able to find all the bits required to convert you turbo back to be internall gates for alot less than the cost of going external, by either modifying your exhuast manifold or doing as other have suggest attaching an external to the exstiting internal hole agin I will agree with forced that this will not fix the problem. Id jsut get it working well with the stock internal, get a nice pump pipe made up, and buy a decent ebc not a cheap one i mean a good one as it make a huge differnce as for blow off valve there lots of arguments to having one or not having one, id say go with 1 get it mounted as close to your throttle body as possible, if you don't like the nose get it plumbed back into the intake tract or get a filer for it. don't go doing unessicary modifaction if there not required you know the motor is good for 200kw, going back to an internal gate is not going to change this figure at all Plus 200kw is enuff to have fun to start out with, once you ready for more then get serious buy yourself a gt3077r until then be happy with what you have because IMO its friggin great looking set up as for getting the internal wastegate parts shouldnt be to hard to find an exhuast housing from a blown r33 turbo will have all the required bits for cheap, everyone these days is removing them to go with a crappy chinese stanless manifold and china turbo and waste gate, so they can have huge lag, suffer from heaps of exhuast leaks sticking waste gates, and stupid external sounds Link to comment Share on other sites More sharing options...
Mr.Mk1 Posted June 10, 2009 Share Posted June 10, 2009 ebc? Link to comment Share on other sites More sharing options...
Simon Posted June 10, 2009 Share Posted June 10, 2009 ebc? Guessing electronic boost controller? Link to comment Share on other sites More sharing options...
Honda Ass Dragger Posted June 10, 2009 Share Posted June 10, 2009 ebc? Electronic Boost Controller Greddy Profect B FTW Link to comment Share on other sites More sharing options...
Ke36 Posted June 10, 2009 Share Posted June 10, 2009 Yeap Ke36 thats what I want to do. Did it work well? Is it your setup? Merrits to it? So that may be another option Chris.Chris's turbo at the moment has no flapper on standard wastegate hole. Its not welded its just open. The WG was placed off the dumppipe on a flange. Gaz sorry man not my setup so unsure, was built buy a mitsi guy (who knows his stuff) the only issue with a setup like this though is the welding, you cant cheap skate or take shortcuts on it or it will crack the reason guys do it this way is it keeps the flow for the air you are bleeding off at the best angle alot of people think there wastegate isnt working etc and they need a bigger one due to crappy mounting on a manifold and the air having to do a rediculous 90+ deg turn to bleed off through the gate which is never going to work well this way the flow is much better so it will be more effective thegreatestben as eke said you just take circlip off and remake a dowel aligning hole for it, drill or i just notched my comp cover with a file and slam it back on Link to comment Share on other sites More sharing options...
Mick Doohan Posted June 10, 2009 Share Posted June 10, 2009 would depend on of if your primary concern was having better flow/ not turbulent gas to the turbo .......the wastegate flow will not help you make power and having turbulence and a hot spot in your housing at that point couldn't possible be good for the housing ... there are far better ways to do it and that is why its not normally done like that ... in saying that laminar flow effects come into play as well just my thought's Link to comment Share on other sites More sharing options...
ProZac Posted June 11, 2009 Share Posted June 11, 2009 Easier (but not strictly correct) to think about the exhaust side as purely pressure. X amount of pressure makes the turbine spin a certain speed. The wastegate reduces this pressure, making the turbine spin slower, controlling the boost. If the wastegate isnt big enough, and cant reduce the pressure enough, the turbine spins faster and faster, creating more and more exhaust gas (pressure), and the problem snowballs. Only reason to not use an internal gate is if the turbo doesn't have one (common on aftermatket stuff), or the fitted one isnt big enough, also quite common when 'upping the boost'. I suppose another reason is that aftermarket external wastegates usually have more precise control, as they dont have a long actuator arm or anything, making boost control easier overall. Cant see any real disadvantages to the way ke36 has had it done, still a hole in the right place to let some gas out. Just a pain if you want to change turbos! Still want to go for a skid in your car though man Link to comment Share on other sites More sharing options...
Mick Doohan Posted June 11, 2009 Share Posted June 11, 2009 you are correct .. once you are over 500 degree's the gas flow becomes laminar .. and therefore exhibits different flow characteristics its the reason why even the crappiest manifold work generally the quality and flow of your manifold only shows up with spool time speeking of turbo's heard sams car last night on full song .. sounds amazing Link to comment Share on other sites More sharing options...
forced Posted June 11, 2009 Share Posted June 11, 2009 you are correct .. once you are over 500 degree's the gas flow becomes laminar .. and therefore exhibits different flow characteristics its the reason why even the crappiest manifold work generally the quality and flow of your manifold only shows up with spool time Well that's a new one.... totally original. The only exhaust that will ever be close to laminar is the one that's 100% silent and that one hasn't been built yet. Steve Link to comment Share on other sites More sharing options...
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