Mach 5 Posted January 14, 2011 Report Share Posted January 14, 2011 Im having a problem controlling boost after my 3inch downpipe upgrade. basically boost will go to where its set and then slowly creep to as high as 20psi. I was considering porting the wastegate hole but I dont know how much material can be removed or if there was any other option. I have leak checked all lines and everything is ok. wastegate actuator is basically new. any ideas greatly appreciated! thanks -Jarek Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted January 14, 2011 Report Share Posted January 14, 2011 Im having a problem controlling boost after my 3inch downpipe upgrade. basically boost will go to where its set and then slowly creep to as high as 20psi. I was considering porting the wastegate hole but I dont know how much material can be removed or if there was any other option. I have leak checked all lines and everything is ok. wastegate actuator is basically new. any ideas greatly appreciated! thanks -Jarek My first thought was that maybe your turbo was too large, but it's not: http://www.squirrelpf.com/turbocalc/graph.php?version=4&pr0=1&pr1=1.07&pr2=1.52&pr3=1.98&pr4=1.98&pr5=1.98&pr6=1.98&pr7=1.98&airflow0=3.4&airflow1=7.3&airflow2=15.1&airflow3=25.7&airflow4=30.5&airflow5=33&airflow6=36&airflow7=37&product_id=37 It get's close to the surge line, but not close enough to worry about. So I would be looking at the wastegate as the problem. Quote Link to comment Share on other sites More sharing options...
GOT2B GM Posted January 14, 2011 Report Share Posted January 14, 2011 http://forums.neons.org/viewtopic.php?f=22&t=163327&view=previous Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted January 14, 2011 Report Share Posted January 14, 2011 It's an internal wastegate right? Is it adjustable? If it's adjusted too tight, then it won't open the wastegate all the way. Too loose and it won't close all the way (won't build boost). Quote Link to comment Share on other sites More sharing options...
Mach 5 Posted January 14, 2011 Author Report Share Posted January 14, 2011 ok Im going to try removing the actuator and drive it. Hopefully it wont really build boost so I can say its an actuator. I found a link somewhere that said I an port the wastegate hole a little bigger but I dont know how much that will help. oh and it is an internally regulated turbo. -jarek Quote Link to comment Share on other sites More sharing options...
GOT2B GM Posted January 14, 2011 Report Share Posted January 14, 2011 I'm gonna say you removed enough back pressure that the turbo isn't as limited flow wise anymore. So now turbo is spinning faster / moving more air, your wastegate port needs to be bigger to allow enough exhaust to bypass the turbine wheel to slow it down. To me if the issue didn't arise until after the 3" DP, then its not actuator issue. I'm gonna say port WG port. Quote Link to comment Share on other sites More sharing options...
kuntzie Posted January 14, 2011 Report Share Posted January 14, 2011 when i open my cutout i gain a few psi minimal, gained like 5 when i went from 2.5- 3" exhaust, had to adjust the boost controller you have to adjust the the wastegate actuator threads, im confident your not outflowing the wastegate hole Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted January 14, 2011 Report Share Posted January 14, 2011 could it be that the velocity dropped so much with your new DP that it cant draw the gasses from the WG when it opens because its easier to go through the wheel? one garrett engineer claimed that a progressive 7 to 11 inch thinner pipe section right off the turbo to keep velocity up for a split second. when I read that, I ordered a special flange made from CNC machined steel 3/4" plate. the flapper does not need to open all the way, it just needs exhaust to move faster away from the turbine housing. those hot gasses crease out sideways, not straight back. the flapper cant open "all the way" because those springs need to be tight, so you don't need a giant cavity for it to "swing" open . no, it barely opens. a low profile flange for the flapper thats barely enough space for it to crack open is the key. concentrated hot gas can follow direction better, and change direction at will. I am not saying increase backpressure though, just velocity. make the first bend out of 2" thick walled MB SS and it will outflow stock. the stock cast DP housing sucks because it bottlenecks. I am sure if porting the exhaust housing helped any, that garrett would have done just that. instead one of the engineers just came out and stated the obvious. Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted January 14, 2011 Report Share Posted January 14, 2011 you have to adjust the the wastegate actuator threads ^^^ This Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted January 14, 2011 Report Share Posted January 14, 2011 loosen the wastegate too much though and it will leak and boost gets all fluttery. you want it to pop off and stay shut mostly so the fuel can be tuned. keep the stock WG solenoid on there so that the boost and actuator can be tuned via tunerpro 5. Quote Link to comment Share on other sites More sharing options...
Mach 5 Posted January 14, 2011 Author Report Share Posted January 14, 2011 well I dont have the option of the factory wastegate solenoid as its an NA car thats turboed. I have been using a Hallman manual boost controller with the cockpit upgrade oh and I just got home.. test drove the car with the wastegate wide open actuator fully disconnected, it boosts about 5psi at 3000rpm and around 20psi in 3rd at 4800rpm. so its definitely a case of the wastegate being too small for this turbo. I dont know if porting it is going to do any good. Jeff wasn't yours a 2871? this is a gt series 3071 so I think the different compressor housing may affect it. idk just throwing it out there. trying all possibilities -Jarek Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted January 15, 2011 Report Share Posted January 15, 2011 what is the WG wide open actuator fully disconnected mean? the threaded rod has the clip off and the wastegate is wide open? Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted January 15, 2011 Report Share Posted January 15, 2011 I have a hard time believing that a factory wastegate is too small. I mean, it came with the turbo right? I can't believe garrett would put out a turbo with a wastegate that's too small. Quote Link to comment Share on other sites More sharing options...
kuntzie Posted January 15, 2011 Report Share Posted January 15, 2011 ya im not talking about the wastedgate that comes on a turbo car from factory.. and its going to be your lines going to your boost controller, you failed to mention you were running a MBC Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted January 15, 2011 Report Share Posted January 15, 2011 if you could pin a boost solenoid into the ecm you could datalog WG duty cycle. then it would let you know exactly what position your WG flap is in exactly as boost ramps up. take advantage of one of the more useful utilities 8F has to offer. I added a WB to the red 90's wiring harness, and I would not be scared to add a EBS in the 88 when the time comes. since it runs on 8F. Quote Link to comment Share on other sites More sharing options...
Mach 5 Posted January 15, 2011 Author Report Share Posted January 15, 2011 the actuator is not connected to the wastegate at all and it is wide open so the turbo is bypassed. the turbo I would think at most should only spool 3-4psi on its own that its.. but theoretically not be making any pressure because the valve is open. but Im making pressure an d lots of it way high up in the rpm band. Its not bleeding off the pressure like its suppose to. I cant seem to figure out why. It is a Garrett turbo from atp I think atp modifies garrett turboes for their own needs..idk Ive been finding more and more links on this being an issue with only this turbo and not the 2871. personally I like the manual boost controller but because Im the kind of person that believes in the fewer parts something has the less of a chance for failure.. "I have a hard time believing that a factory wastegate is too small. I mean, it came with the turbo right? I can't believe garrett would put out a turbo with a wastegate that's too small." - I would like to believe the same exact thing but idk -Jarek Quote Link to comment Share on other sites More sharing options...
Mach 5 Posted January 15, 2011 Author Report Share Posted January 15, 2011 what is the WG wide open actuator fully disconnected mean? the threaded rod has the clip off and the wastegate is wide open? Yes. That is what I mean. so it shouldnt be boosting right now. I really do appreciate everyones thoughts on this topic here and when we do figure out the root cause it will help the next guy with the issue. -Jarek Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted January 15, 2011 Report Share Posted January 15, 2011 correct me if I am wrong, but you can run a MBC and still datalog WGDC. Quote Link to comment Share on other sites More sharing options...
Jonpro03 Posted January 15, 2011 Report Share Posted January 15, 2011 :think: :shrug: Quote Link to comment Share on other sites More sharing options...
kuntzie Posted January 15, 2011 Report Share Posted January 15, 2011 (edited) i can completely take off my wategate (external- 36mm) and my car will STILL make boost, check your vac lines and piping, on te turbo there my be a vac nippe you left open to atmosphere also, my gt2861 did the same thing at one time Edited January 15, 2011 by kuntzie Quote Link to comment Share on other sites More sharing options...
Mach 5 Posted January 16, 2011 Author Report Share Posted January 16, 2011 ok well I made a video I will put up the link when its done uploading. all of the lines are secure and not leaking, wastegate open still making 20psi. its very laggy but it will do it. I could see possibly 5psi at most 10psi with the wastegate open but 20 is just rediculous. I found a bunch of threads on Nissan and Evolution forums with this exact issue so I guess kits not just me. -Jarek Quote Link to comment Share on other sites More sharing options...
Mach 5 Posted January 16, 2011 Author Report Share Posted January 16, 2011 ok here is the video.. http://www.youtube.com/watch?v=0UxsPQGxHxI Quote Link to comment Share on other sites More sharing options...
GOT2B GM Posted January 16, 2011 Report Share Posted January 16, 2011 You're winter driving that? Quote Link to comment Share on other sites More sharing options...
Mach 5 Posted January 16, 2011 Author Report Share Posted January 16, 2011 my Bonneville broke so I have to. Need money for axles, radiator, and a MAF -causing check engine light and random stalls no start. otherwise it would be different. Quote Link to comment Share on other sites More sharing options...
kuntzie Posted January 16, 2011 Report Share Posted January 16, 2011 :47 Quote Link to comment Share on other sites More sharing options...
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