domano Report post Posted February 26, 2022 Curious those with the ISB 6.7 340hp Cummins what’s the maximum Turbo PSI they are receiving. My maximum is around 17, and Freightliner is telling me they feel that’s a little low. I’ve noticed recently that climbing mountains, I’m just not getting the power I used to have. Share this post Link to post Share on other sites
wildebill308 Report post Posted February 26, 2022 (edited) Haven't had a 6.7 but my 5.9 would run 35+. What does Freightliner think the problem is? Have you checked the CAC for leaks or all the clamps on the airline/ducks in and out of the turbo? Bill Edited February 26, 2022 by wildebill308 Share this post Link to post Share on other sites
domano Report post Posted February 27, 2022 On the waiting list to get it into Freightliner…. Was hoping someone here with the same engine can tell me their PSI…. I can’t find anything online with regards to a suitable range (ie. if typically it should be 30-35 and I’m running at 17, then I know I have a problem, but if 19-20 is typical, then it’s probably okay)… just trying to get feedback here if anyone knows. Share this post Link to post Share on other sites
mikekohut Report post Posted February 27, 2022 When I was running with an ISB, I believe the turbo pressure was about 22. Share this post Link to post Share on other sites
wildebill308 Report post Posted February 27, 2022 14 hours ago, domano said: On the waiting list to get it into Freightliner…. Was hoping someone here with the same engine can tell me their PSI…. I can’t find anything online with regards to a suitable range (ie. if typically it should be 30-35 and I’m running at 17, then I know I have a problem, but if 19-20 is typical, then it’s probably okay)… just trying to get feedback here if anyone knows. Why don't you call a couple of your local Cummins dealers and ask them? Bill Share this post Link to post Share on other sites
hermanmullins Report post Posted February 27, 2022 domano, My first thought was, "have you ever had your Turbo serviced? It sounds to me like you may have a sticking Waste Gate Valve. It would also help to know the year of you RV and make. Herman Share this post Link to post Share on other sites
domano Report post Posted February 28, 2022 2017 Newmar Ventana LE 3709 340hp Cummins 6.7 ISB. Never had it (turbo) serviced. I’ll call Cummins tomorrow and ask then about what PSI I should expect on, say, a 6% grade rolling at 65mph. Right now I drop to about 30 before getting over the mountain. Share this post Link to post Share on other sites
wildebill308 Report post Posted February 28, 2022 Are you manually downshifting to keep your rpm up? Bill Share this post Link to post Share on other sites
jleamont Report post Posted March 2, 2022 On 2/28/2022 at 9:47 AM, wildebill308 said: Are you manually downshifting to keep your rpm up? Bill Bingo, when I manually drop a gear pulling a hill I get more boost vs allowing it to shift on its own. Share this post Link to post Share on other sites
manholt Report post Posted March 7, 2022 Same here....I think we all do that. Also runs cooler! Share this post Link to post Share on other sites
akadeadeye Report post Posted March 7, 2022 How do you check turbo psi? Don Share this post Link to post Share on other sites
hermanmullins Report post Posted March 7, 2022 Don, my coach have a gauge on the dash. Under a pull it will go up to 24 Inches. Herman Share this post Link to post Share on other sites
manholt Report post Posted March 8, 2022 Yup, gauge in dash! Don, you should have it on your dash also....Never had a DP that didn't. Share this post Link to post Share on other sites
jleamont Report post Posted March 11, 2022 On 3/8/2022 at 9:54 AM, manholt said: Yup, gauge in dash! Don, you should have it on your dash also....Never had a DP that didn't. Doug’s Allegro Bus NOPE! Share this post Link to post Share on other sites
manholt Report post Posted March 11, 2022 Joe, that was a POS from day one! Share this post Link to post Share on other sites
wildebill308 Report post Posted March 11, 2022 I didn't have on my Bounder but added one and a EGT gage. Bill Share this post Link to post Share on other sites
elkhartjim Report post Posted March 11, 2022 If its a FTL Chassis, its on the Light Bar Control Unit. Turbo Pressure, Tranny Temp, Engine Temp, Etc, Etc. No exhaust gas temp, darn it. The gauge measures in PSI. Share this post Link to post Share on other sites
