First I want to thank all the people who have been trying to help me solve my problem.I have been battling a high boost/knock problem since I have installed a Dutt neck stock intercooler, I can't get the boost lower than 18lbs, when I do a 3rd gear WOT run I get knock.On the ScanMaster o2's are 757- knock 4.9 both occurred at 76mph,when I saw the knock I got out of the throttle.My TT chip is set at the default 128 for all of the parameters,the max boost for my chip is 16-18lbs running 93oct.I e-mailed Eric and he recommended I try to add 5% more fuel in the chip and if that didn't work he thought that my new adjustable waste gate actuator might be the problem, but it was verified by Jack Cotton that it was indeed a standard boost actuator.So Jack recommended I remove the metal orifice inside the "Y" fitting located at the factory boost line set up,in the hopes to reduce my boost,but I still can't get it lower than 18lbs with the rod on the actuator adjusted all the out with no tension on the DP puck arm.I understand that the Dutt neck will increase the boost by a couple of lbs, but I think I should be able to lower the boost using the waste gate actuator since it is supposed to be adjustable from 12-22lbs.Has any one ever had a problem like this,if so what is the next step,I am trying to get this problem solved before the snow starts to fly.Any help is greatly appreciated.Thanks,ikle.
Tuning Gurus step inside
- Thread starter ikle
- Start date
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
I see you have an ATR 3" down pipe. I have one of those too. I had problems with the wastegate puck pivot sticking. Is yours moving freely when the adjustable control rod is disconnected from it? The pivot should be loose and free to move easily throughout it's entire range of motion. If not. then it will need some fixin' using some parts from RJC.
Eric's recommendation to add fuel is a good one! Do it.
You can also try running the wastegate "tuner style", which means connecting a single hose from the nipple on the compressor cover directly to the nipple on the wastegate diaphragm. This setup removes the stock control solenoid from the wastegate system. You'll get maximum pressure applied to the wastegate diaphragm and the lowest possible boost will result.
Eric's recommendation to add fuel is a good one! Do it.
You can also try running the wastegate "tuner style", which means connecting a single hose from the nipple on the compressor cover directly to the nipple on the wastegate diaphragm. This setup removes the stock control solenoid from the wastegate system. You'll get maximum pressure applied to the wastegate diaphragm and the lowest possible boost will result.
BEATAV8,
Thanks for the reply,the waste gate puck does move freely with the rod disconnected,:frown:I was kind a hoping it was binding but it wasn't.Please bare with me a little I am trying to understand why this is happening because when I had a GT6131 bb turbo with a standard adjustable waste gate actuator,70mm TB and plenum and a PTE stretch intercooler on this car I never had a problem with lowering the boost under 18lbs. Correct me if I am wrong but isn't the boost determined by how much exhaust is directed through the exhaust housing of the turbo?This is done by how much distance the DP puck is a way from the exhaust housing port hole,the closer to the exhaust port hole the more boost right?Isn't there two ways this is done,1) how short the waste gate rod is, which in turn regulates the movement(travel) of the rod, the shorter rod the less travel it has the more boost,2) how heavy the spring is in the waste gate actuator,the heavier the spring the higher the boost right? So when I went back to a stock set up(turbo,intercooler,TB and plenum) I was able to run 15lbs of boost,then I install a Dutt neck stock intercooler and 18lbs is as low as I can get.I even got out my stock actuator, cut and threaded the rod, put on the adjustable end,set it to the exact same length as the stock and 18lbs is all I got.Doesn't make sense,isn't the boost for a stock GN set at about 12lbs from the factory so if I use the stock factory actuator,stock turbo with the Dutt neck stock intercooler shouldn't my boost start around 15lbs?
There are many of GN's out there with this set up running 15-16lbs of boost with no issues.I am not doubting you but getting rid of the stock Y hose set up and running a tuner style set up, one hose from the actuator to the turbo compressor,wont the boost fluctuate because the computer can't bleed off any air to control the boost? I am new to these cars and that's why I am turning to more knowledgeable persons, like yourself,for the answers to my problem.Thanks,ikle.
Thanks for the reply,the waste gate puck does move freely with the rod disconnected,:frown:I was kind a hoping it was binding but it wasn't.Please bare with me a little I am trying to understand why this is happening because when I had a GT6131 bb turbo with a standard adjustable waste gate actuator,70mm TB and plenum and a PTE stretch intercooler on this car I never had a problem with lowering the boost under 18lbs. Correct me if I am wrong but isn't the boost determined by how much exhaust is directed through the exhaust housing of the turbo?This is done by how much distance the DP puck is a way from the exhaust housing port hole,the closer to the exhaust port hole the more boost right?Isn't there two ways this is done,1) how short the waste gate rod is, which in turn regulates the movement(travel) of the rod, the shorter rod the less travel it has the more boost,2) how heavy the spring is in the waste gate actuator,the heavier the spring the higher the boost right? So when I went back to a stock set up(turbo,intercooler,TB and plenum) I was able to run 15lbs of boost,then I install a Dutt neck stock intercooler and 18lbs is as low as I can get.I even got out my stock actuator, cut and threaded the rod, put on the adjustable end,set it to the exact same length as the stock and 18lbs is all I got.Doesn't make sense,isn't the boost for a stock GN set at about 12lbs from the factory so if I use the stock factory actuator,stock turbo with the Dutt neck stock intercooler shouldn't my boost start around 15lbs?
There are many of GN's out there with this set up running 15-16lbs of boost with no issues.I am not doubting you but getting rid of the stock Y hose set up and running a tuner style set up, one hose from the actuator to the turbo compressor,wont the boost fluctuate because the computer can't bleed off any air to control the boost? I am new to these cars and that's why I am turning to more knowledgeable persons, like yourself,for the answers to my problem.Thanks,ikle.slimtastic
yea dude...I rock
- Joined
- Aug 9, 2002
do me a little test and unhook your stock wastegate rod from the swing arm then go wide open throttle. if you still get a ton of boost then you will need "more wastegate"
ive never been able to control boost with a internal wastgate on a big turbo, which is really strange for your stock turbo
how are you reading your boost? stock equipment or a boostgauge?
ive never been able to control boost with a internal wastgate on a big turbo, which is really strange for your stock turbo
how are you reading your boost? stock equipment or a boostgauge?
jasjamz
THS Racer
- Joined
- Sep 30, 2004
Huh??? If he does that the car shouldn't make any boost. If it does then the puck is sticking closed or close to it. No need for more wastegate. I have the ATR dp also. I had it repaired for the sticking issue years ago.
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
Yes you are correct, more energy to the turbine = more boost. Preload on the wastegate is also an important item. As you shorten the wastegate rod you are increasing the spring preload. Shortening the rod does reduce the available travel but more importantly it increases that preload, requiring more pressure in the control line to make the wastegate crack open.
The duttweiler neck has a bit less restriction. So it makes some sense that you have a bit more boost after installing it. The wastegate control line is connected to the turbo compressor cover, so it's still seeing roughly the same pressure as it was before the new neck was installed.
It's entirely possible that you may need to adjust the wastegate rod to be just a bit longer than stock. Can you loosen it to the point where it has very little preload on the puck/pivot assembly? You don't want to make it too long, or the wastegate will be open all the time! But you can set it so that it's fully closed and has a light preload on it.
The other important part is that factory boost control solenoid. It works by bleeding off pressure in the control line. That means it reduces pressure which would be working on the wastegate diaphragm to push the wastegate open.
If you minimize the spring preload by making the rod longer and also maximize the pressure in the control line by running "tuner style" (removing the factory bleed style boost control solenoid from the system), you should be able to get the boost down to 15 or 16.
If none of this works, the last resort would be to pull the turbo off the car, separate the turbine housing from the turbocharger, and use a die grinder to enlarge the diameter of the wastegate hole in the turbine housing. If you enlarge the hole, the wastegate will be able to bypass a larger volume of exhaust gas, providing less energy to the turbine. You may have noticed on your 3" downpipe that the ATR wastegate puck diameter is huge compared to a stocker. That's because large wastegate holes are a common necessity on bigger turbos and high power applications.
True, so lets make sure its not a wastegate issue. if it does make boost we can safety wire the wastegate open so we know this is not a issue and try again
i did this myself tonight, looking for a creep issue. i'm running a 6765 billit turbo, have the new extra large puck from rjc and the hole ported to 1/16 of the edge. and with it wired completly open , i still got about 5-6 lbs of boost.
NOW WHAT, and how much will this cost.
Thanks guys for all the replies,BEATAV8,there is absolutely no preload on the puck swing arm assembly,I don't have to pull on it at all to put it on the swing arm assembly.So what you guy's are saying is the next step is 1) to remove the waste gate rod from the swing arm assembly and do a WOT blast, if it makes boost then 2) I should wire the swing arm open(pull the swing arm assembly towards the pass fender, right?)and do another WOT blast if it is doesn't make any boost then its a DP issue not a waste gate issue.If it doesn't make boost by just removing the waste gate rod from the swing arm its then a waste gate issue.Then I should 3) hook up the waste gate rod to the swing arm and run one hose from the nipple on the actuator to the nipple on the compressor side of the turbo eliminating the factory boost solenoid.Then for some reason if that doesn't work 4) I would need to enlarge the exhaust housing port to allow less exhaust gases into the exhaust side turbine creating less boost,correct?Thanks again for all your help,hopefully we can figure this issue out so I can really enjoy this car this coming spring,ikle.
slimtastic
yea dude...I rock
- Joined
- Aug 9, 2002
negative. ive found that on super large/efficiant turbos, a internal "stock style wastegate" wont control any boost effectivly while keeping to a lower boost for street applications.... its not because of the wastegate hole size as much as its because of the "angle of attack" to the wastegate hole itself
when running a big turbo ,a 90 degree hole in the side of a turbo wont flow alot of exhaust through it when the velocity is super high and the backpressure is low.
if he wires the wastegate puck completely open and manages to make boost then he will need a external wastegate with a good "angle of attack". if the boost made with an open WG is low (5-6lbs) you could prolly just get away with enlarging the WG hole and making easier access for the incoming exhaust. but big boost creep wont get solved with a larger WG hole
jasjamz
THS Racer
- Joined
- Sep 30, 2004
His sig says Stock turbo. His previous post indicate the wastegate and intercooler changes. Do you know of something different or do you consider the stock turbo huge? If the arm is sticking it could happen at different times usually caused by heat variations.
slimtastic
yea dude...I rock
- Joined
- Aug 9, 2002
in my origional post i said "which is strange for a stock turbo"
irreguardless, if he wires thepuck off the seat, goes wot and still build alot of boost then that tells us his wg is insufficiant. if it kills all boost production then its prolly a sticking puck or a vacume routing problem
We Have Boost
Thanks guys for all the help,Well today I removed the waste gate rod from the DP swing arm and went WOT and it made boost which was very surprising to me, but at the same time relieving because now I am getting somewhere.So I took it back home and wired the waste gate swing arm open (towards the pass side fender) and went for another ride.Surprisingly it made boost, a lot of boost (17-18lbs),it started making boost at about 3,800- 4,000 rpm's and I got off the throttle at about 4,700 rpm's, when it started to show knock on my ScanMaster, o2's where 808 and I had 1.6 degrees of knock retard, they both happened at 48 mph.Can anyone believe that a stock turbo is doing this,Why?I did replace the DP to turbo gasket with a copper gasket from G-Body parts for a integrated waste gate.What are your guys thoughts,whats next?Thanks again for all the help,ikle.
Thanks guys for all the help,Well today I removed the waste gate rod from the DP swing arm and went WOT and it made boost which was very surprising to me, but at the same time relieving because now I am getting somewhere.So I took it back home and wired the waste gate swing arm open (towards the pass side fender) and went for another ride.Surprisingly it made boost, a lot of boost (17-18lbs),it started making boost at about 3,800- 4,000 rpm's and I got off the throttle at about 4,700 rpm's, when it started to show knock on my ScanMaster, o2's where 808 and I had 1.6 degrees of knock retard, they both happened at 48 mph.Can anyone believe that a stock turbo is doing this,Why?
I did replace the DP to turbo gasket with a copper gasket from G-Body parts for a integrated waste gate.What are your guys thoughts,whats next?Thanks again for all the help,ikle.
jasjamz
THS Racer
- Joined
- Sep 30, 2004
Read your first post again, you didn't tell him to wire it open. ATR pipes had that problem and mine was one of them. Carbon build up would cause them to get sticky over time. You could work them free but they would slowly get clogged and stuck again. On these forums some people will do what they read and nothing more which can cause confusion. Now, as for him needing "more wastegate" with a stock turbo...very doubtful. More looking needs to be done before changing parts is all I'm saying.
Thanks guys for all the help,Well today I removed the waste gate rod from the DP swing arm and went WOT and it made boost which was very surprising to me, but at the same time relieving because now I am getting somewhere.So I took it back home and wired the waste gate swing arm open (towards the pass side fender) and went for another ride.Surprisingly it made boost, a lot of boost (17-18lbs),it started making boost at about 3,800- 4,000 rpm's and I got off the throttle at about 4,700 rpm's, when it started to show knock on my ScanMaster, o2's where 808 and I had 1.6 degrees of knock retard, they both happened at 48 mph.Can anyone believe that a stock turbo is doing this,Why?
Pull the gasket out look for carbon marks to see if the gasket is partially blocking the hole. Try it without the gasket and the arm wired open. If the hole in the gasket is off center to the wastegate hole on the turbo, it creates a restriction thus making boost!
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
slimtastic
yea dude...I rock
- Joined
- Aug 9, 2002
how sure are we that this it is a stock turbo?
sounds like if nothings in the way of the puck or opening and when the swing arm is completely disconnected the car still "rockets" to boost.....it might need more wastegate :biggrin:
measure the wastegate hole in the side of the turbo housing, how big is it?
sounds like if nothings in the way of the puck or opening and when the swing arm is completely disconnected the car still "rockets" to boost.....it might need more wastegate :biggrin:
measure the wastegate hole in the side of the turbo housing, how big is it?
Slimtastic,this turbo was on the car when I bought it from the original owner and from talking to him about what he did to the car he said it was completely original(stock).Everything from the air box to the chip was stock,the turbo even had the stock inlet bell with a hose going to the pass side valve cover.He also said that "these cars are fast enough and there was no need to modify anything",I had to tell him I was just going to restore the car in order to purchase the car from him,so I think it is an original stock turbo.Is there anything on the turbo that will confirm it is indeed a stock turbo?Thanks for your reply,ikle.
