Login Register

1998 S70 GLT How much boost should I be seeing?

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

Post Reply
ferocity02
Posts: 166
Joined: 25 October 2014
Year and Model: 1998 S70 GLT
Location: Califfornia
Been thanked: 14 times

1998 S70 GLT How much boost should I be seeing?

Post by ferocity02 »

For fun, I hooked up a boost gauge to the vacuum tree on my 98 S70 GLT. At WOT below 4k RPM the most boost I see is 6-7psi. I would go over 4k RPM but it's the wife's ride and don't want the sh*tstorm that would come with breaking it.

Is this an acceptable amount of boost?

Is the boost adjustable? Can it be adjusted without tuning? Seems like the air-fuel ratio would be pretty far off if the boost was increased. I'm guessing these cars run in open-loop under WOT since the O2 sensors are narrowband?

User avatar
rspi
Posts: 7303
Joined: 5 November 2011
Year and Model: 850 T-5R Wagon
Location: Cincinnati OH
Has thanked: 34 times
Been thanked: 72 times
Contact:

Post by rspi »

That is correct boost for that low pressure turbo car.
'95 855 T-5R M, Panther - 22/28 mpg, 546,000 miles
'95 955 T-5R Yellow Wagon, Lemonade, 180,000 miles
--------------------
Volvo's of past: '87 740 GLE, '79 262C Bertone, '78 264, 960's, '98 S70 GLT, '95 850 T-5R YellowVolvo Repair Videos

User avatar
bmdubya1198
Posts: 6338
Joined: 30 December 2014
Year and Model: 2K V70R M56
Location: Charlotte, NC
Has thanked: 304 times
Been thanked: 517 times

Post by bmdubya1198 »

After reading around, I'd be VERY careful about adjusting boost. As in, I wouldn't do it. Get a tune before you do anything messing with the boost. You'll blow out the head gasket.
00 V70R Venetian Red/Charcoal M56 Swapped 214k
07 XC90 V8 AWD Sport Titanium Grey/Black 220k
92 245 White/Beige 249k
91 944 Turbo 175k
…and a bunch of other stuff
Sold-
03 S60 2.4T
00 S70 GLT
98 V70 GLT
93 944
98 S90
95 850 GLT
01 S60 2.4T
05 S60R M66
08 S40 2.4i
88 744 Turbo M46

Post Reply
  • Similar Topics
    Replies
    Views
    Last post