The Diesel Garage banner

1 - 11 of 11 Posts

·
Junior Member
Joined
·
171 Posts
Discussion Starter #1
whati s maximum back pressure sensor psi??? idle i can see 14-15psi but full throttle up to 80-90 (275 spartan) is this too much?? will a 4'' down pipe and 5'' straight makes a big difference in place of stock down pipe + 4'' straight pipe. i just got my head gasket done on my truck$$$ what do you think???

Thank
 

·
Junior Member
Joined
·
19 Posts
80psi is really high but I have seen the same numbers. Only fix is a waste-gate kit from elite, or dirty diesels kit if you can get one. The down pipe won't help since back pressure is between the heads and the turbo and down pipe is after the turbos. Cab off job is up for you again I think, but maybe someone with more info will chime in.
 

·
Member
Joined
·
263 Posts
whati s maximum back pressure sensor psi??? idle i can see 14-15psi but full throttle up to 80-90 (275 spartan) is this too much?? will a 4'' down pipe and 5'' straight makes a big difference in place of stock down pipe + 4'' straight pipe. i just got my head gasket done on my truck$$$ what do you think???

Thank
Something isnt right, those numbers are WAY too high
 

·
Junior Member
Joined
·
171 Posts
Discussion Starter #5
could it (elite waste gate) be installed without removing the cab??? what is safe pressure??? i do have egr delete plate but they are not installed yet, will it help reduce backpressure???

Thank
 

·
Justifiably Confused
Joined
·
67 Posts
Backpressure

80-90 is waaay high. I just did Elite studs and gaskets due to puking which I believe that backpressure had a lot to do with. After doing the motor work and before doing the Elite wastegate kit I refused to put my foot into the throttle purely because of backpressure.

I have recently finished my cab on install of the wastegate and EGR delete kit, which I was aslo able to do without removing the turbos. My backpressure is limited to 65 and probably equally as imporatnt the EGR deletion also eliminated one of the circuits in the coolant system making the water pump less taxed. It was widely believed that another contributing factor to puking was the additional cooling circuit of the EGR system making hot spots on other areas of the coolant system. The delete system, which ever product used, is definatelty worth the install.
 

·
Junior Member
Joined
·
21 Posts
14-15psi at idle? Take a look at what the back pressure reads when the ignition is ON but the motor is not running. I'm assuming you maybe reading the pressure in PSIA and not PSIG. Which would account for the higher than normal numbers.
 

·
Senior Member
Joined
·
1,415 Posts
yes they do read PSIA even taking that into account these trucks are really high drive pressures. you want as close to 1:1 as you can get.
 

·
BLING BLING
Joined
·
636 Posts
My back pressure numbers are the same as the OP. Im right about 70 psi at about 32 pounds of boost which is about half throttle. This is with the 310. I havent even put it to the floor in a long time because of this. I puke coolant all the time if I get half throttle or more. Pretty sure gaskets are in my near future. haha.
 

·
Member
Joined
·
191 Posts
from what I have seen the worst backpressures are at the half throttle range, I can see 75 or so on the 210 tune, but you have to remember to take 14 off if your at sea level, those numbers are including baro pressure.
 

·
Member
Joined
·
52 Posts
Hey, the highest I see is about 55-60 with the 275v3 at any throttle. 275 v4 was in the 75-80 range at part throttle and wasn't hardly moving. Scared me so I went back to 275 v3, lots less strain.
 
1 - 11 of 11 Posts
Top