Running 1 psi on the freeway with bigger turbo
#1
Running 1 psi on the freeway with bigger turbo
I put a 64/14-71 on my 2006 last week. I used to run 5-6 psi on the freeway at 70mph, now I am running 1-2 psi with the larger turbo. Have others gotten the same results? Is your fuel mileage suffering from this? It seems to run good and spool up quickly, just wondering how this affects everything. Thanks
#2
It's common to see reduced boost while cruising with a bigger turbo, but that sounds a little too low. Is there any haze while you're cruising? Have you done a thorough leak check on the manifold at the head and turbo flange?
What's your max boost look like?
What's your max boost look like?
#3
that sounds normal to me too as that's what my 64 did. At 70 running with low rpm's the drive pressure is very low so you're not going to be building a lot of boost.
The joys of owning a larger turbo :-)
The joys of owning a larger turbo :-)
#5
Banned
Join Date: Dec 2005
Location: Twin Falls, Idaho
Posts: 5,194
Likes: 0
Received 0 Likes
on
0 Posts
#7
Registered User
I see around 4 psi at 75+mph crusing with my SPS66. I does depend on how sensitive your gauge is on the low and high end. My autometer gauge does not really start moving accurately until I see around 4psi on the TST Remote.
Trending Topics
#10
Registered User
Join Date: Oct 2004
Location: Whidbey Island, WA
Posts: 217
Likes: 0
Received 0 Likes
on
0 Posts
I put a 64/14-71 on my 2006 last week. I used to run 5-6 psi on the freeway at 70mph, now I am running 1-2 psi with the larger turbo. Have others gotten the same results? Is your fuel mileage suffering from this? It seems to run good and spool up quickly, just wondering how this affects everything. Thanks
#12
Registered User
Join Date: May 2007
Location: Woodland Hills, CA
Posts: 216
Likes: 0
Received 0 Likes
on
0 Posts
#14
Registered User
Join Date: Apr 2003
Location: Cummins Technical Center, IN
Posts: 6,564
Likes: 0
Received 6 Likes
on
5 Posts
It's part of life with a bigger turbo-- lower cruising boost means higher average EGTs.
jh
#15
Registered User
Join Date: Apr 2004
Location: Sturgis SD
Posts: 1,609
Likes: 0
Received 0 Likes
on
0 Posts
I just got back from a 400 mile trip last night. TST 1, X2 milage max, at 65-70 I got 20.4 mpg. 75-80 was about 18.2. This is with a new 66 with only 100 miles on it when I started! On mine the bigger turbo didnt hurt my milage. My exhaust temps for most of the way were around 600-650 and boost was 2-5 psi.