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Big Turbo Discussion Thread #2
- Thread starter GTR_Killer
- Start date
NATURAL_BORN_BT
New member
US fuel is WAY better than canadian! We have a big mustang shop downtown and They cant run 93 oct tune with our 94 oct on blown and turbo mustang only the 91 oct tune!!
jettaglx91
Go Kart Champion
Take a picture of a gas pump
jettaglx91
Go Kart Champion
Not sure if anyone has ever run into this but I have a weird overboost issue on this car. Using maestro I have all kinda of stuff turned way down. Target filling under 200kpa, wastegate duty under 50, but no matter what I do it will run about 15psi till like 4500ish then starts creeping up to like 24 by redline.
What is really odd is that is typical of an external wastegate car that cant flow enough exhaust so it doesnt make any sense since this is just a normal GT3071. Anyone ever ran into anything that sounds remotely similar? Only thing I was thinking was possibly a bad N75.
What is really odd is that is typical of an external wastegate car that cant flow enough exhaust so it doesnt make any sense since this is just a normal GT3071. Anyone ever ran into anything that sounds remotely similar? Only thing I was thinking was possibly a bad N75.
wndwsdwngti860
Upsidedown
NATURAL_BORN_BT
New member
Last edited:
jettaglx91
Go Kart Champion
do you have a picture closer then 10 feet away? smh
seriously though the point is to see the label if your rating is (R+M)/2 or if its RON
It's same way as us and it better than our 93, it's been tested. I have used it in the past.
Right off their site -
http://retail.petro-canada.ca/en/independent/2056.aspx
The octane number written on the gas pump is Anti-Knock Index (AKI)
Ultra 94 - with ethanol
RON 101.5
MON 88
to me it sounds like wastegate or the spring. i guess it could be the n75 but idk why that would be rpm dependent if it was just the valve itself.
Not sure if anyone remembers, but last April I had some oil pressure issues. At cruise, everything was fine, but at idle and stop/go situations in hot weather it was low enough that it would trigger the oil light. I changed the main and rod bearings, which the old ones looked absolutely fine, and the oil pressure was slightly higher (not great), but high enough that the light never came back on all last year. Just an FYI, never ever had a drivability/running issue because of this.
Fast forward, to around December/January. Head was off the do springs and fix a broken exhaust stud. Upon reassembly I picked the screen out of the cam bearing bridge. I figured it was easier to get rid of it than blow out for the 3rd time.
Last month, in this northeast heat wave we've been having, oil pressure light came on coming home from work in stop and go traffic. WTF.
I got to thinking, others have removed that screen without an issue, but with the screen in it must have been causing just enough of a restriction to get the oil pressure above the sensor threshold. Where else could I be losing pressure? Main and rod bearings are changed, head was off and looked fine....wait a second...the FUCKING BALANCE SHAFTS. The block I used to swap in was from a 2010 and had a 2009 build date. The earlier motors are the ones more susceptible to balance shaft issues.
So, Sunday I tore this thing apart. BOOM, front balance shaft had one of the ports completely blown apart and another was mushroomed out. Parts came Monday night. Back together last night. Drove it to work today. Pressure is finally where it is supposed to be. 25psi at HOT idle (as opposed to anywhere from 9-14 before) and 45psi at 2k RPM (spec is >2.7 bar at 2k RPM = 39psi).
So pissed I didn't think of this earlier, but at least now pretty much every single thing on/in this motor is new. I've found countless threads where people have these oil pressure issues and just end up swapping in a new motor, so I figured I'd just write a book about my findings. Also noticed the new balance shafts do not have reliefs cut in them inside the enclosed bearings or on the back end where it sits in the block.
Fast forward, to around December/January. Head was off the do springs and fix a broken exhaust stud. Upon reassembly I picked the screen out of the cam bearing bridge. I figured it was easier to get rid of it than blow out for the 3rd time.
Last month, in this northeast heat wave we've been having, oil pressure light came on coming home from work in stop and go traffic. WTF.
I got to thinking, others have removed that screen without an issue, but with the screen in it must have been causing just enough of a restriction to get the oil pressure above the sensor threshold. Where else could I be losing pressure? Main and rod bearings are changed, head was off and looked fine....wait a second...the FUCKING BALANCE SHAFTS. The block I used to swap in was from a 2010 and had a 2009 build date. The earlier motors are the ones more susceptible to balance shaft issues.
So, Sunday I tore this thing apart. BOOM, front balance shaft had one of the ports completely blown apart and another was mushroomed out. Parts came Monday night. Back together last night. Drove it to work today. Pressure is finally where it is supposed to be. 25psi at HOT idle (as opposed to anywhere from 9-14 before) and 45psi at 2k RPM (spec is >2.7 bar at 2k RPM = 39psi).
So pissed I didn't think of this earlier, but at least now pretty much every single thing on/in this motor is new. I've found countless threads where people have these oil pressure issues and just end up swapping in a new motor, so I figured I'd just write a book about my findings. Also noticed the new balance shafts do not have reliefs cut in them inside the enclosed bearings or on the back end where it sits in the block.
Cadubya
Autocross Newbie
Not sure if anyone remembers, but last April I had some oil pressure issues. At cruise, everything was fine, but at idle and stop/go situations in hot weather it was low enough that it would trigger the oil light. I changed the main and rod bearings, which the old ones looked absolutely fine, and the oil pressure was slightly higher (not great), but high enough that the light never came back on all last year. Just an FYI, never ever had a drivability/running issue because of this.
Fast forward, to around December/January. Head was off the do springs and fix a broken exhaust stud. Upon reassembly I picked the screen out of the cam bearing bridge. I figured it was easier to get rid of it than blow out for the 3rd time.
Last month, in this northeast heat wave we've been having, oil pressure light came on coming home from work in stop and go traffic. WTF.
I got to thinking, others have removed that screen without an issue, but with the screen in it must have been causing just enough of a restriction to get the oil pressure above the sensor threshold. Where else could I be losing pressure? Main and rod bearings are changed, head was off and looked fine....wait a second...the FUCKING BALANCE SHAFTS. The block I used to swap in was from a 2010 and had a 2009 build date. The earlier motors are the ones more susceptible to balance shaft issues.
So, Sunday I tore this thing apart. BOOM, front balance shaft had one of the ports completely blown apart and another was mushroomed out. Parts came Monday night. Back together last night. Drove it to work today. Pressure is finally where it is supposed to be. 25psi at HOT idle (as opposed to anywhere from 9-14 before) and 45psi at 2k RPM (spec is >2.7 bar at 2k RPM = 39psi).
So pissed I didn't think of this earlier, but at least now pretty much every single thing on/in this motor is new. I've found countless threads where people have these oil pressure issues and just end up swapping in a new motor, so I figured I'd just write a book about my findings. Also noticed the new balance shafts do not have reliefs cut in them inside the enclosed bearings or on the back end where it sits in the block.
Wait so the port was clogged? Or damaged?
Look at the first picture. Something got in there and busted the port open. That is just supposed to be one small hole. The whole inside was scored and damaged as well.
Charles@NGP
Ready to race!
I had a similar failure with the front balance shaft on my CC's engine. Found metal shavings from it stuck in the pickup tube. The shaft was definitely worn and would not spin freely.
I just ended up building the motor for my big turbo setup since it was already torn down.
I had a similar failure with the front balance shaft on my CC's engine. Found metal shavings from it stuck in the pickup tube. The shaft was definitely worn and would not spin freely.
I just ended up building the motor for my big turbo setup since it was already torn down.
Well, I bought this shortblock used with rods already in it. I pulled the pan's and checked the bearings before I installed it and they looked fine. When I started having these issues I changed all of the main and rod bearings. And then finally just changed the balance shafts.
Mine did spin freely, but you could feel a rough spot. Another thing to note and I'm glad you posted a picture.. The most updated shafts don't have the reliefs cut in the back like you see in your picture. It's one complete circle.
How did you know yours was failing? That's another funny thing.. my pan has been off a billion times since this started and it has always been clean as a whistle. Absolutely nothing in it. I swapped pumps at some point too. But all is good now. 40 miles or so on it now and it's going well!