Guest rasheedn Posted November 25, 2014 Share Posted November 25, 2014 Hi Guys, I have a JDM engine (vvti) and running it with a stand alone ecu I took out the Exhaust Gas Control valve and created 2 new downpipes for each turbo I cant seem to control boost 1. i either get 1 bar of boost if i keep the Intake Air control valve closed 2. if i open the IACV i get maximum boost 3. On the front turbo there are 3 ports A. Boost source B. Wastegate port 1 C. Wastegate port 2 I kept port A (boost source) connected to port 1 as per OEM and port 2 to a boost solenoid. Nothing happens cant seem to control boost 4. On the 2nd turbo. I cant see shit as the engine is in a bmw e36 Can anyone else with all this mess? My idea is to keep the IACV port open all the time (by giving it a boost line or by actually opening it and removing the valve) and the 2nd turbo to connect the wastegate to the front one and control them both together 5. another question is regarding the 2 vacuum lines that go back with the other towards the 2nd turbo and go around to the back of the engine towards a white pressure tank. What does this do? and can i disable it? Ideally i want to remove all the metal lines and just connect each wastegate to boost and boost solenoid and control the damn boost any help would be really appreciated. I did look online and i noticed everyone just controls boost by the 1st turbo this is not working for me, dont know why Quote Link to comment Share on other sites More sharing options...
Ian C Posted November 25, 2014 Share Posted November 25, 2014 I assume you're trying to run the two turbos in parallel rather than sequential? If not, you're on a loser by altering pretty much anything. If you are, that's fine but the stock wastegate system only flows enough exhaust gas if the rest of the setup is fairly stock, i.e. you have all the restrictions in the exhaust system in place. Normally the exhaust gas goes through the EGCV then two CATs. Decatting means you need to put a restrictor ring in place to control the boost or it'll overboost. You haven't really specified what the boost problem is though, it reads a bit like you either get 1bar or "maximum", but we don't know what "maximum" is, or what it is you're trying to do that's failing. Raise the boost? Lower it? Get it to a specific value? Have you plumbed in all the VSVs and control systems? The IACV lets boost out of the second turbo so keeping it closed is a bad idea - all your boost is off turbo #1 and anything over about 0.6bar is too much, it'll be overspeeding and overheating the air charge. Sounds like you have runaway boost issues which implies the stock wastegate system is overwhelmed by a freer-flowing exhaust setup. The pressure tank is simply there to control the sequential system VSVs when off boost, so if you've gone parallel there isn't any need for it any more. Quote Link to comment Share on other sites More sharing options...
Guest rasheedn Posted November 27, 2014 Share Posted November 27, 2014 Hi, Thanks for the quick reply and help I am running the turbos in parallel I do not have any CATs in the system I built a free flowing downpipe for each turbo . so all the Exhaust Gas control valve stuff is out and i have a free flowing exhaust system If i plug the IACV and give it boost then the car over boosts to more than 1.2 BAR (i have my limiter set) I want to remove all the stock metal lines and disable the pressure tank I also want to keep the IACV open all the time so the car is a true parallel turbo Control the boost!! this is the tricky part. Are both turbo wastegates the same ? (both open and close at the same pressure) I have seen people blocking one port of the wastegate and running the other to a boost solenoid with a boost source on the other solenoid port (solenoid port a boost, solenoid port b wastegate) or getting boost source to port 1 of the wastegate and port 2 of the wastegate to a boost controller what is the correct way of doing all this mess! Quote Link to comment Share on other sites More sharing options...
Ric Posted November 27, 2014 Share Posted November 27, 2014 (edited) If the car has no cats it will overboost to well over the safe operating limit 1.2bar. This is why people install Restrictor rings in the exhaust. to limit the boost to 1/1.2bar You can't lower boost with a boost controller, only raise. Nice downpipe idea though, if it works out could be a nice earner. Edited November 27, 2014 by Ric (see edit history) Quote Link to comment Share on other sites More sharing options...
Guest rasheedn Posted November 27, 2014 Share Posted November 27, 2014 seen this ?? http://www.supraforums.com/forum/showthread.php?576272-JDM-TT-Supra-amp-Restrictor-ring-overboost-BULL-HIT Quote Link to comment Share on other sites More sharing options...
Ric Posted November 27, 2014 Share Posted November 27, 2014 (edited) seen this ?? http://www.supraforums.com/forum/showthread.php?576272-JDM-TT-Supra-amp-Restrictor-ring-overboost-BULL-HIT The fact that you are seeing over 1.2bar sorta proves that thread useless. You've removed one of the most restrictive things of the twin system, the cats and the downpipe. Lets not forget, the USDM turbos are usually steel, like the UK spec's here. AFAIK Edited November 27, 2014 by Ric (see edit history) Quote Link to comment Share on other sites More sharing options...
supra_ufo Posted November 27, 2014 Share Posted November 27, 2014 also when the weather is cold it will overboost even more? Quote Link to comment Share on other sites More sharing options...
Guest rasheedn Posted November 27, 2014 Share Posted November 27, 2014 lol you are right this does not make any sense tho so if i open the wastegate fully. would it still boost more than 1.2 bar ? if so then the car should overboost right now more than the 1 bar i am boosting now with the iacv closed no? Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 27, 2014 Share Posted November 27, 2014 FYI the second turbo waste gate is not actually plumbed as a wate gate on the stock turbo manifold , what it does is let the gas from turbo 1 to spin turbo 2 also as ian said keeping the iacv closed and having the so called second wastegate open will be making the 2nd turbo spin and make preasure with no place to vent it unless the iacv is creaping open as iirc its only held closed by spring tention which may add to you boost issue . But as said the stock turbo 1 wastegate is not man enough to control boost above stock levels Quote Link to comment Share on other sites More sharing options...
Guest rasheedn Posted November 27, 2014 Share Posted November 27, 2014 i have a downpipe for each turbo so they turbos do not affect each other exhaust wise i dont think anyone has tried to do what im doing this could be interesting sunday i will remove the iacv and see how it acts i will also remove the pressure tank also will check the 2nd turbo wastegate (what pressure it opens and closes and compare to turbo 1) Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 27, 2014 Share Posted November 27, 2014 I can see the picture now im at home, looks like a good idea would surtainly help spool and boost but the turbos are still old and not very good compaired to todays standard, As you have both wastegates used as wastegates you might actually be able to control the boost best of luck with it Here is a thread you will love to read through will help you massively http://www.mkivsupra.net/vbb/showthread.php?298965-Kevin-s-Compound-Sequential-Twin-Turbo-Design Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 28, 2014 Share Posted November 28, 2014 The stock wastegates (and I use the term loosely for the rear turbo) do not have the capability oif flowing enough volume of bypass gasses to control boost with your (nicely executed) changes. Big problem with no easy remedy I can think of offhand. Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted November 28, 2014 Share Posted November 28, 2014 The stock wastegates (and I use the term loosely for the rear turbo) do not have the capability oif flowing enough volume of bypass gasses to control boost with your (nicely executed) changes. Big problem with no easy remedy I can think of offhand. There is one. Port the wastegate opening. We did this on several sets of turbos that where converted to hybrids and it works fine The wastegate on the second turbo is not a wastegate in your configuration. Close it down completely and bring turbo #1 to a turbo specialist for a modification of the wastegate port. Quote Link to comment Share on other sites More sharing options...
Guest rasheedn Posted November 28, 2014 Share Posted November 28, 2014 damn... doesnt sound promising any idea how much boost i would get if i keep both wastegates fully open ?? i would rather do a single turbo conversion than waste more time porting wastegates and all this shit! Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted November 28, 2014 Share Posted November 28, 2014 I'm repeating myself: The Second Wastegate is not working nor lowering the boost when the Setup is working in Parallel mode!! It is a bypass to lower the boost for the first turbo when the system is in sequential mode! In clear words: In your case if you close it or open it up it won't make any difference at all! The only chance to lower the boost on your system without causing restrictions is to port the Wastegate on the first turbo. Nothing else will help! It is no big deal nor costs the world to port it. The OEM flap can still close it if ported sensibly and will work a treat lowering the boost. If you keep everything the way it is you will boost to around 1.5-1.65 bar depending on outside conditions if the Turbos are healthy. Quote Link to comment Share on other sites More sharing options...
np89 Posted November 28, 2014 Share Posted November 28, 2014 could you not remove the factory actuator system entirely and then attach two adjustable actuators (say HKS) to each turbo and run them both as two independant turbos? That should allow you to control the boost effectively, whilst simplifying the system, assuming each turbo is a std internally gated setup? Quote Link to comment Share on other sites More sharing options...
mellonman Posted November 28, 2014 Share Posted November 28, 2014 I'm repeating myself: The Second Wastegate is not working nor lowering the boost when the Setup is working in Parallel mode!! It is a bypass to lower the boost for the first turbo when the system is in sequential mode! In clear words: In your case if you close it or open it up it won't make any difference at all! The only chance to lower the boost on your system without causing restrictions is to port the Wastegate on the first turbo. Nothing else will help! It is no big deal nor costs the world to port it. The OEM flap can still close it if ported sensibly and will work a treat lowering the boost. If you keep everything the way it is you will boost to around 1.5-1.65 bar depending on outside conditions if the Turbos are healthy. Are you sure about that ? I will have to double check if i still have my old 2 second turbo in the shed , but the way he has got rid of the stock sequential turbo housing mainfold/down pipe part , it may work as a wastegate , Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 28, 2014 Share Posted November 28, 2014 It will work as a wastegate for the rear turbo. he'd have to ensure both actuator capsules opened the same amount at the same boost pressure, and that the lever arm ratio on the flap valves was the same. It's not something I have looked into. Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted November 28, 2014 Share Posted November 28, 2014 Are you sure about that ? I will have to double check if i still have my old 2 second turbo in the shed , but the way he has got rid of the stock sequential turbo housing mainfold/down pipe part , it may work as a wastegate , Yes i am sure about that. I've attached a picture of the second Turbo Outlet. As you can see the Wastegate entrance is after the Turbine wheel and then exits to the Downpipe. It will work as a Wastegate Type Control in sequential mode because the Exhaust gas can bypass the EGCV flap in the downpipe but in Parallel mode it won't do anything else. Only advantage in opening it would be more flow possible through the System in TTC but in this constellation with the two big Downpipes for each turbo that won't make any real difference. Quote Link to comment Share on other sites More sharing options...
Guest rasheedn Posted November 28, 2014 Share Posted November 28, 2014 thanks for taking the time and posting a picture to show a clearer idea 1. if i port wastegate area on turbo 1 and do nothing on turbo 2, wont turbo 2 overboost anyways ??or overspin ? 2. do u think its doable to port turbo 2 wastegate flap area trying to decide what to do with this crazyness Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted November 28, 2014 Share Posted November 28, 2014 1. No it won't the wastegate on turbo 1 is the only one which can alter the Pressure/Turbo speed on your setup and both turbos will have the same Speed 2. You can port it but there wont be any difference if the flap area on turbo two is bigger. It has no effect on Turbo Speed/Pressure on your setup. The only one that matters is the front Turbo #1 Wastegate. Quote Link to comment Share on other sites More sharing options...
Guest rasheedn Posted December 2, 2014 Share Posted December 2, 2014 an update i connected the IACV to a boost source front wastegate 1 port to boost from the turbo , 2nd port to my mac boost solenoid left the rear turbo as it is didnt bother doing anything with its vacuum lines boost solenoid port 1 to wastegate , port 2 to a boost source i am getting 1.2 bar boost flat out BUT 99 injector duty cycle!! so now i will install some PTE 1000 cc injectors i have lying around with HKS fuel rails wastegate DC is 50% so far i think i can increase a bit more and see what happens Quote Link to comment Share on other sites More sharing options...
mellonman Posted December 2, 2014 Share Posted December 2, 2014 an update i connected the IACV to a boost source front wastegate 1 port to boost from the turbo , 2nd port to my mac boost solenoid left the rear turbo as it is didnt bother doing anything with its vacuum lines boost solenoid port 1 to wastegate , port 2 to a boost source i am getting 1.2 bar boost flat out BUT 99 injector duty cycle!! so now i will install some PTE 1000 cc injectors i have lying around with HKS fuel rails wastegate DC is 50% so far i think i can increase a bit more and see what happens what ecu are you running ? the stock ecu does set injectors to 100% at high boost high rpm, also 1000cc on stock turbos is over kill massively , i have 630cc on my single turbo running 80% @ 524 bhp and 510ftlb as an idea , do you have an afr gauge which would give you a good indication if injectors are actually needing to go flat out Quote Link to comment Share on other sites More sharing options...
Guest rasheedn Posted December 3, 2014 Share Posted December 3, 2014 i am running a link G4 extreme ecu i know the 1000cc are a massive overkill but i got them for a realllllyyy good price and i will go single turbo at some point with e85 so i think 1000 will be good in the future here's a log i have a bit of knock and i think its because of the injectors Quote Link to comment Share on other sites More sharing options...
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