bigeking
Arlington, Texas
Senior Member
Joined: 01/14/2008
View Profile
Good Sam RV Club Member
 Offline
|
Could someone tell me which reading is the most helpful----pre-turbo or after turbo.
Everett & Jayne
2008 GMC Duramax-Allison Extended Cab Dually Locking 3:73 rear end
Line-x bedliner Pullrite hitch Retrax Bed Cover---2008 Nu Wa DA 339RSB
Life is'nt about how you survived the storm...
It's about how you dance in the rain!
|
Dale_S
Saugus, CA
Senior Member
Joined: 05/23/2007
View Profile
Offline
|
Pre-Turbo is the preferred.
|
Oswald38
3rd Rock
Senior Member
Joined: 12/04/2007
View Profile
Offline
|
I agree but it depends so I sure would get to one of the diesel forums in a hurry even though there are some smart cats here. I like the dieselstop.com
|
Dieselgem
Northeast
Senior Member
Joined: 04/07/2005
View Profile
Good Sam RV Club Member
|
Pre-turbo is what you want to read.
08-KZ Escalade 41'CKS Escalade
2008 F450 Super Duty Truck
2003 FLSTS
2003 FLSTC (Wife's)
|
JIMNLIN
out here
Senior Member
Joined: 09/14/2003
View Profile
|
pre turbo for watching my Cummins EGTs.
Jim
"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers
'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 gvwr two slides
|
|
|
KeninAZ
Prescott, AZ
Senior Member
Joined: 06/22/2002
View Profile
|
Pre-turbo
You want to know the temp of the air going in.
|
Charlie Q
Brusly, Louisiana
Senior Member
Joined: 12/28/2004
View Profile
Offline
|
Pre-turbo. The reason being, if the exhaust going in gets too hot, it could damage the turbo.
'03 Chevy CC/SB,D/A,4X4, Airlift Bags, Bilsteins, Reese 18K slider, Predator programmer.
'06 Mobile Scout 31 BWFS
Yamaha 3000ISEB, Hard wired rearview camera from Rvcams.com
|
goodcruisin
Greenwood, IN
Senior Member
Joined: 04/17/2007
View Profile
Offline
|
Concur...Pre-Turbo. Monitoring EGT (Exhaust Gas Tempurature) is what you want to do. The pyrometer is placed in the exhaust manifold, in front of the turbo, to allow you to monitor how hot the air going into the turbo is. If it's too hot you'll melt the turbo fins. Monitoring after the turbo does little good as the turbo is sucking in ambient air, where it experiences a rise in tempurature due to being compressed by the turbo, then it's sent through the intercooler where it goes into the engine at a reduced temp. Generally speaking max EGT you want to see is 1250. See this article on Diesel engines which shows the max EGT for each of the most common engines.
John (USN Ret) & Debbie
Tux (APBT/Dalmation)
'96 Monaco Windsor 36' DP 8.3 Cummins
Ready Brake & Demco Excali-bar
'02 F250 V10 w/ Banks Power Pack
'03 Ford Explorer
'04 Volvo S80 AWD
'05 Acura TL
240" Dragster 540 BBC
26' trailer
14' Boat w/9.9 Merc
|
Jaseds
NE TN.
Senior Member
Joined: 08/16/2007
View Profile
Offline
|
Best place is after turbo,reason being if the pyrometer probe should break off ,say good bye to your turbo. Only difference will be the reading showing couple hundred degrees less whenplaced inthe exhaust pipe right behind turbo.The older engines used to have them at the turbo but most all semis are after nowadays if equipped.
 Have A Nice Day
|
chuck4788
West of the Middle
Senior Member
Joined: 05/10/2006
View Profile
Offline
|
I agree that the best position is before the turbo because that location will provide the fastest response and will indicate what is happening in the combustion process. After turbo will show lower readings because the tubine sucks a lot of heat out of the exhaust gas, and the heat absorbed by the turbine is always changing depending on the boost created. The engine builders prefer after turbo because the risk of loosing the probe is less because of the lower temperatures, and any resulting debris won't damage the turbine. The gear heads like it pre-turbo because it provides a better indication of the combustion process. Two other points:
Specs on most of the newer engines do not include pre-turbo EGT, only post.
Hewitt Industries claims their probes are suitable for pre-turbo installations.
Chuck
02 Beaver
505hp C12 Cat
Trailblazer toad
|
|
|
