The Volvo 850 Turbo
Here’s my 1994 Volvo 850 Turbo. The photo makes the paint look better than it is.
The Goal Of A
Have A Fun Daily Drive, That Was Cost Effective
When I purchased the car it was not making boost, but the sell as all hyped about how much power the car had. I seller said the car was his wife’s, but based on some his comments he was a car flipper – like his insistence the car had 178K miles on it, when the odometer didn’t work, and the title noted 178K the prior year. He was bragging the he was impressed with the power -- on that specific day, as if he had never driven it before. I asked if it has had any check engine lights, he said yes, and they that a sensor was changed. But, late I realized the check engine light neve illuminated. That fact led me to believe that the bulb had been removed. I forgot to check the bulb when I had the dash off…but next time I have it off I will look into it.
Getting Started
My first mission was to change the timing belt and coolant system. Volvo 850s and 70s are known for coolant system issues. So, I changed all of it, including the bulkhead connector and the heater core.
The second think I did was to change the PCV system, which is another weak point in the these models
Thirdly, the control arms and strut top mount were shot, so I replace those so that the car could drive in a straight line without my need to saw at the wheel…like I was drunk.
Then I need to find out why the car was not producing boost, since it ran well. The reasons boiled down to multiple leaking vacuum lines. I went through and replace all of them. So the car then made around 7psi of boost.
The Modifications
Then the fun began. I start to up the boost with some mods:
Improving Boost
1.) Japan turbo manifold from a new model Volvo Turbo. This manifold is known to flow better than the stock 850 manifold
2.) Volvo 16T turbo
3.) 3” down pipe, that I custom-made
4.) 3” exhaust to let the turbo breath better (high flow cat)
Here is the Grassrootsist-thing about this. The mods that I listed cost me less than $200.
While I was doing those mods, I add a boost gauge and a wide-band O2 sensor to keep track of the engine’s health and performance.
Comparing boost performance with the new mods, there was a good improvement in boost production and spool up.
Spool up after 16T turbo upgrade
5.) I make a manual boost controller to build more boost. The target boost level was 14psi. Stock is said to be 7-8psi for the 1994 850 @222hp. So, this is about doubling the boost pressure. I know that mathematically that should be close to 400hp, but I know that efficiencies and other aspects of power production won’t equate like that.
Here’s a look at how the mods impacted boost performance:
Boost Mods Compared
The I 5 Sounds
The sound the 5 cylinder makes is interesting and unique…I would say a cross between am I4, I6 and a H4:
I5 850 Volvo Sounds
On the Road Sounds
After that exhaust, I make a dual exit pipe because I thought it was more aggressive looking. I like that staid appearance of the Volvo, with the sporty looking exhaust
Solid Motor Mounts
The stock rubber mounts were torn apart, so I trying to fill them with silicone, which worked for a while but didn’t last. So, I make a solid mounts for the top mount.
Intake Modifications
I noticed that the car seemed to be choked a bit at WOT, so I want to improve the ability for the turbo to suck in the air it needed. Here’s what I did for that, but one thing I failed to mention in the video is that I added in an air straightener in order to keep air velocities up with the larger 3” intake. I will build a shroud around the filter to stop the hot air from entering the intake.
Now I can hear the turbo spool up and the recirculation valve…recirculating.
Custom Intake Modification
Wheel Spacers
I installed wheel space on the back to help the look of the track. The stock wheels were tuck way inboard. The rear track was narrower than the front, so wheel spaces evened things out.
