wrngwae Posted September 3, 2010 Report Share Posted September 3, 2010 (edited) hey guys, trying to pick some brains here. I was planning on going to the race track today after work but everyone bailed out on me. which is a good thing. i was trying to tune in for it. and well i got my boost up to 19psi and was adjusting my manual boost controller in for the last psi i was gonna go,,,i was shooting for 20psi. but it started going down,,,,,down,,,,down.... with every adjustment. im currently at 15psi and can go up no further????? it blew past 20 the first time i put my manual boost controller on to dial it in awhile back so i know it will pin my 20 psi guage.(i did it on accident once along time ago)....so a little help please. I did 1. put pressure to all my joints with soapy water and my air compressor,,,,,,no leaks..... 2. checked my waist gate actuator arm,,,still on and needs a tug to get on the pin.... 3. removed heat shields on turbo,,,,,no cracks anywhere on the snail or header..... 4. minimal shaft play in the compressor side.... btw its a big 16g in a stock housing. Is it possible that the waist gate its self inst sealing right now? it will build to 15psi nice and steady than that is it? it runs real good no knocking, pinging, rattles or anything odd. i run the right NGK plugs. timing is correct. new vac advance. new wires. so it is not something a newb would miss. Thanks for the help all! Edited September 4, 2010 by wrngwae Link to comment Share on other sites More sharing options...
Skullzaflare Posted September 3, 2010 Report Share Posted September 3, 2010 (edited) ive tried 3 MBC with no luck. itd hit 15psi and drop to 10 is that what yours is doing from 19 to 15? or did you try turning it up to 20 a few turns then it went from 19 to 15? Edited September 3, 2010 by Skullzaflare Link to comment Share on other sites More sharing options...
wrngwae Posted September 3, 2010 Author Report Share Posted September 3, 2010 (edited) thanks for the input. i but im sure its not the MBC. i completely removed it and plugged the port on the waist gate for full port....and......15psi max and steady with no dropping under load. just a thought,,,,,,plugged down pipe?????? restricting the flow? Edited September 4, 2010 by wrngwae Link to comment Share on other sites More sharing options...
wrngwae Posted September 4, 2010 Author Report Share Posted September 4, 2010 (edited) ok,,,,tore down the turbo tonight and found 3 cracks at the waiste gate on the snail or exhaust housing.thought i had the smoking gun. grab another stock housing. do some porting for it to fit. and bam right back to 15psi.......nice and steady,,,,,what in the heck........... im stumped. maybe a leak down is in order on the motor??? i have done all the pipes.. Edited September 4, 2010 by wrngwae Link to comment Share on other sites More sharing options...
wrngwae Posted September 4, 2010 Author Report Share Posted September 4, 2010 what,, no one has AN IDEA... maybe should post about a new shifter that is dry????? maybe i could get a response. no one here but B.S.er's lol come on...im stumped. hell beat me up too just give me some ideas.....i will look Link to comment Share on other sites More sharing options...
Indiana Posted September 4, 2010 Report Share Posted September 4, 2010 How far were you going when you were driving, how fast for how long etc. If your intercooler is heat soaked your boost pressure will drop given the same MBC setting. It can limit to an extent how much boost you are able to make. If you drive normally for a few miles and let the intercooler and motor cool back off does it do the same thing again or will it boost higher? Where is the MBC located? If it gets too hot it could weaken the spring in it. Link to comment Share on other sites More sharing options...
wrngwae Posted September 4, 2010 Author Report Share Posted September 4, 2010 thanks for the reply John. it is my D.D. i drove home from work Thursday and started turning up boost a little at a time with a few short runs down the road and back. I run it daily at 15psi. as i was raising the boost pressure with the MBC I got close to 19psi than on that run it went down to 17psi. i thought i turned it the wrong way, but i didn't. So I gave her another turn and no result. so i disconnected it all together and plugged the vac/boost line. but it was still stuck at 15psi? so that is when i stopped trying an started looking for problems. my piping has no leeks, i fount those cracks on the seat of the waste gate. and the turbo sees fine too. my inner cooler is kinda beat up since it is a D.D. but not too bad i wouldn't think. but i will get the comb out and clean her up. now it will every now and then hit 17psi but rare. i drove her last-night after i found those cracks and it hit 17 but only once?that was with a warm motor and 2nd gear up hill at about 4500 rpms. af/ratio rich. Link to comment Share on other sites More sharing options...
Indiana Posted September 4, 2010 Report Share Posted September 4, 2010 The higher boost might have been just from boost spike while upshifting. You just saw that briefly then it came back down to 15? What turbo is that you are using? Link to comment Share on other sites More sharing options...
cyberquest Posted September 4, 2010 Report Share Posted September 4, 2010 you do understand the car needs to see LOAD to reach max boost pressure. your not gonna hit 20psi in 1st and 2nd gear cause its not under as much load, you wont see that max boost till 3rd and 4th. Link to comment Share on other sites More sharing options...
wrngwae Posted September 4, 2010 Author Report Share Posted September 4, 2010 hey john, no boost spike it would hit that way before i thought of shifting. and it is a big 16g. in a stock modded housing. and bryen, even it 5th rolling about 55/60ish hit it goes up to 15 and stops like it hits a wall....but rpms still increasing..... Link to comment Share on other sites More sharing options...
cyberquest Posted September 4, 2010 Report Share Posted September 4, 2010 you would wire the wastegate arm shut to see what happens? be very careful though, if you see it hit 20 let off the gas cause it will keep climbin. but that could verify if its wastegate related. just a weird thought here but you mentioned pegging the 20psi gauge, you sure it didnt mess up the gauge? Link to comment Share on other sites More sharing options...
wrngwae Posted September 4, 2010 Author Report Share Posted September 4, 2010 i did try it without the vac/boost line off the accuator with the same result and i have a bov if it gets crazy i let off it goes down.... and the accuator needs a little tug to get it to the pin so that shouldnt be it. But,,,,,,,,,,,,,,,,,,,,,,,,,,i didnt think about the gauge,,,i will pull the one off the raider and see it is the same one lol..brb Link to comment Share on other sites More sharing options...
wrngwae Posted September 4, 2010 Author Report Share Posted September 4, 2010 it is not the gauge. i will do a compression and leak down test and let you know. may even gut some catalytic converter. Link to comment Share on other sites More sharing options...
wrngwae Posted September 5, 2010 Author Report Share Posted September 5, 2010 ok,,,,, well i out my turbo. and found a piece missing out the back on the O ring seal area on the compressor housing area. And there was a piece of O ring missing....so,,,,,there is the smoking gun right.... so i brake out the welder, carbide and the angle sander and fix it up post haste. grab a O ring out of an old rebuild kit. and reassemble. ITS THE SAME GOSH DIDLY ARN DARN #^$%*$&^*%()ING THING. but only not it has a little stumble around 10psi...i think i need to open the pocket book for Forced performance.....oh yea. btw compression was 110 across all 4. Link to comment Share on other sites More sharing options...
Indiana Posted September 5, 2010 Report Share Posted September 5, 2010 So this is a TD05H shaft in a ground out stock turbine housing? Maybe when the turbine housing was ground out, especially if you did that yourself, that is the problem. The gap around the turbine blades may just be too great and that's all you will get no matter what you do to it. Link to comment Share on other sites More sharing options...
wrngwae Posted September 5, 2010 Author Report Share Posted September 5, 2010 that is a possible. i took my time and test fit it several times to ensure proper fitment. but it did build more before with the other housing. i did some reading last nite and was informed that the max boost out of a bid 16g was 22psi is that correct? my turbo is a 2nd hand one with minimal shaft play. but that dosent mean its not tired correct. i my just get a bearing kit and try that befor i spend 300 to 400+ on a rebuild from gpop or F.P. unless there is a resident turbo specialist here.... Link to comment Share on other sites More sharing options...
Skullzaflare Posted September 5, 2010 Report Share Posted September 5, 2010 may sound like a dumb question, but did you check and see if maybe the gasket is leaking between the head and manifold? oe between the manifold and turbo? Link to comment Share on other sites More sharing options...
wrngwae Posted September 5, 2010 Author Report Share Posted September 5, 2010 i have replaced the header due to cracking (do they do that lol) at number one cyl and could hear the leak. but i cannot guarantee its not leaking there but would it have the same popping sound? oh and i also replaced the mainford to hot side of the turbo before as well that made it sound like a damn jet plane,,,,cool but ineffective lol. i will look though and report. Link to comment Share on other sites More sharing options...
Indiana Posted September 5, 2010 Report Share Posted September 5, 2010 You can port out the manifold too that helps a great deal. S16G run 30psi on DSMs and EVOs all day long so I don't know where you read that part unless it was in here. No problems running well past that on cars here either. Turbo kit is simple, hardest part is cleaning off all the turbine shaft. If you have access to a media blaster that cleans the parts easy. You'll have to polish the shaft back up after that, rag wheel on bench grinder and some compound and then for the oil seal groove string w/compound on it while spinning the shaft in a drill press works. This on a motor with stock sized intake/exhaust valves? Its been so long but maybe with those and that turbo that's about the limit I can't say. Link to comment Share on other sites More sharing options...
wrngwae Posted September 5, 2010 Author Report Share Posted September 5, 2010 yea, no leaks and the manifold to hot side of turbo gasket all good. i have a nonjetvalve head and i am unsure of the valve size. but there are no marks where the compressor was rubbing the housing???? and i read about the 22psi off some other B.S. forum i take it. i just dont get it????? good compression, good pipes, sealed turbo, good actuator,it has got to be the damn exhaust,,,it hast to. i really dont want to gut the cat but,,,,,i think i have no choice......im doing it,,,,,,,,,i may fail emissions but screw it...i have got to figure this thing out.....oh, on a side note....i tried to tune with 2 secondary injectors and i ran like dog doo. but i was stuck driving it for 70ish miles and it was so rich it never seen the bounce of the seek for optimal fuel efficiency from my a/f gauge like i did b4 maybe all that fuel plugged the cat?????? Link to comment Share on other sites More sharing options...
StarquestRescue Posted September 5, 2010 Report Share Posted September 5, 2010 (edited) it has got to be the damn exhaust,,,it hast to. i really dont want to gut the cat but,,,,,i think i have no choice......im doing it,,,,,,,,,i may fail emissions but screw it...i have got to figure this thing out.....oh, on a side note....i tried to tune with 2 secondary injectors and i ran like dog doo. but i was stuck driving it for 70ish miles and it was so rich it never seen the bounce of the seek for optimal fuel efficiency from my a/f gauge like i did b4 maybe all that fuel plugged the cat??????Have you changed the plugs since then? If you just have an unmodified factory pre cat you could get one all ready gutted from some one one here. Edited September 5, 2010 by StarquestRescue Link to comment Share on other sites More sharing options...
wrngwae Posted September 6, 2010 Author Report Share Posted September 6, 2010 (edited) yea, i checked the plugs with the compression test and the leak down.....the plugs were fine but,,,i can get another set no biggie...i will order them from jegs... does someone have a modded downpipe or something?????paypal ready!!!i know bryen aka cyberquest had one but other than that idk... Edited September 6, 2010 by wrngwae Link to comment Share on other sites More sharing options...
wrngwae Posted September 7, 2010 Author Report Share Posted September 7, 2010 ok, all, update. i got some pvc and and a shrader valve. and put some O2 to the complete setup. well, there is a leak at the intake manifold at the bottom of #4 cyl.... so its looking like an intake manifold gasket. it was leaking on the bottom so i thought the noise was the blow thru the exhaust valves depending on the cam position. so im going to swap it and see from there...........ugh im tired lol. Link to comment Share on other sites More sharing options...
87B71Brad Posted September 7, 2010 Report Share Posted September 7, 2010 I dunno if its too late but my 87 dd 16g turbo went out and I didn't have enough money to buy a new turbine shaft so I used the one off of my blowed up 18g. Heres the catch there both td05h but the shaft I used happened to go back in the turbine housing while boosting and it sheered all the fins down where there is just one size. The size of the inducer..or exducer..cant remember. The smaller one!! So I put it back together and its boosts pretty good acually...lol But it wont go over 15lbs I screwed my MBC all the way in after driving it a week to work and I figure thats why...I'm acually amazed it makes 15lbs. Soo I bet if the clearence between the turbine wheel is too big on urs than its going to act sorta the same way. Did you mic the housing a after enlarging it?? Hope it helps... Link to comment Share on other sites More sharing options...
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