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98 V70 AWD, no boost reading

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

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benpineapple
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Re: 98 V70 AWD, no boost reading

Post by benpineapple »

Alright, I have a good reason for reviving this thread. The V70 has been doing great, recently joined the 200K club. Today while stuck on a backed up freeway, I figured I'd plug in the ole OBD2 reader, see what it had to say (spent two hours bumper to bumper, I got VERY bored); it was giving me a boost readout. The boost readout actually made sense, I think. Once out of the freeway mess, I was able to see some proper stats. It peaked at about 12psi when I'd punch the throttle, stayed at about -10psi when coasting, and between -4 and 0 psi when in cruise-control.

I'm thinking either A: the OBD Fusion app makers released an update that is able to calculate it somehow, or B: the MAP sensor randomly started working.

I might hold off on buying that manual gauge after all...
2006 V50 T5 [190,xxxM]
2013 XC90 FWD [80,xxxM]

2001 V70 X/C AWD [sold at 120xxxM],1998 V70 AWD [RIP at 249,255M], 1990 240 [SOLD at 220xxxM]

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abscate
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Post by abscate »

I think it is reading an extrapolated boost pressure from rpm and MAF air flow. This should be pretty accurate though.

I did some playing with my speed and boost on a long Adirondack Northway trip and found the mileage at 60 mph with no boost soars to the 30 mpg level. That extra 10-15 mph costs a good 4-5 mpg in efficiency
Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 XC90-in-Red
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benpineapple
Posts: 313
Joined: 3 November 2015
Year and Model: '06 V50 T5, '13 XC90
Location: MI
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Post by benpineapple »

abscate wrote:I think it is reading an extrapolated boost pressure from rpm and MAF air flow. This should be pretty accurate though.

I did some playing with my speed and boost on a long Adirondack Northway trip and found the mileage at 60 mph with no boost soars to the 30 mpg level. That extra 10-15 mph costs a good 4-5 mpg in efficiency
Whoa! That's huge! Which Volvo was that on (I see quite a few in the signature haha)? I'm definitely going to take it nice and slow next time I go on a long road trip.

I'm assuming you're talking about a drive up I-87? Adding 4-5mpg on a trip like that, wow, props.
2006 V50 T5 [190,xxxM]
2013 XC90 FWD [80,xxxM]

2001 V70 X/C AWD [sold at 120xxxM],1998 V70 AWD [RIP at 249,255M], 1990 240 [SOLD at 220xxxM]

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abscate
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Joined: 17 February 2013
Year and Model: 99: V70s S70s,05 V70
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Post by abscate »

That was on the 1999 T5 - the P2 isn't boosted....but it is a stick

:D :D :D :D :D

My memory wasnt as good as I thought - here are the numbers I reported on the T5 in OCT 2015

The high pressure turbo really eats gas once the boost comes on. My 1999 on highway

70 mph 25 mpg
60 mph.27 mpg
50 mph. 31 mpg

Prii never fit anywhere for me. I would never drive one on a freeway due to poor crash protection, they suck in winter, and around town I ride my bike.
Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 XC90-in-Red
Link to Maintenance record thread

benpineapple
Posts: 313
Joined: 3 November 2015
Year and Model: '06 V50 T5, '13 XC90
Location: MI
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Post by benpineapple »

abscate wrote:70 mph 25 mpg
60 mph.27 mpg
50 mph. 31 mpg

Prii never fit anywhere for me. I would never drive one on a freeway due to poor crash protection, they suck in winter, and around town I ride my bike.
Wow, those MPG #s are good to know. I wish I had the patience to go slower than 70-75 on the freeway.

Haha Priis have no place anywhere.
2006 V50 T5 [190,xxxM]
2013 XC90 FWD [80,xxxM]

2001 V70 X/C AWD [sold at 120xxxM],1998 V70 AWD [RIP at 249,255M], 1990 240 [SOLD at 220xxxM]

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abscate
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Posts: 35273
Joined: 17 February 2013
Year and Model: 99: V70s S70s,05 V70
Location: Port Jefferson Long Island NY
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Post by abscate »

I might try to turn my wastage actuator back to delay boost to help my 60 mph number up to 30mph - that would be cool.

Since I have a manual, I can always get the revs for the asking, anyhow.
Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 XC90-in-Red
Link to Maintenance record thread

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