Installing a turbo

Sivuy · Post by **Sivuy** » 13 Feb 2025, 00:47

Hi all,
I recently acquired a 98 S70 Base model with 126K on the clock. Engine strong and well maintained. Ijust installed front sturts, hubs, control arms, sway bar links. I am debating whether it is practical or advisable to add a turbo. Any thoughts??? Thanks in advamce.

Post by **abscate** » 13 Feb 2025, 04:12

It is not.

The compression on the NA engine is different , so an engine swap and redo if the management system is needed to make the change.

Post by **Clemens** » 13 Feb 2025, 06:07

There has never been a reported NA to Turbo conversion on any Volvo forum, if I remeber correctly, there are alot of issues. It surely is possible somehow, but alot of work and electronics tinkering would be needed.
Besided the mechanical differences of the NA and Turbo motor, the electronics simply don't match.

dikidera · Post by **dikidera** » 13 Feb 2025, 06:23

If you commit to the project and are willing to experiment, yes you can. The Subaru guys have been doing this for years.
Only because of the higher compression, you will not be able to run much boost.

The first step for installing the turbo is the PCV system, it needs to be overhauled to the turbo variants of those years. The next step is for mechanical ignition timing to be placed at 0. Or if electronics, the timing maps must be zeroed out. Next is exhaust manifold and turbo need to be obtained from a turbo variant of those years.

Of that era, B5244T was the one with higher compression though still lower than the NA variants. In this case, it was 9:1 compression and had a power output of 193hp.

If users here take note, the much newer B5204T8 engines have the NA compression(although thicker cylinders) are not GDI and still rock a turbo. And from base 180hp they can be boosted up to 235hp. Though again, thicker cylinder walls and likely different pistons and rings.

The main concern when turboing a NA variant engine is not whether the rods will hold, but if the piston ring gap will be enough to allow for the expansion. Piston rings must never butt ends. Piston ring gaps have never been explicitly mentioned by Volvo.

The only way it works well is if:
Pistons rings of turbo and NA variants are the same.
Pistons for NA have the same material as those of turbo variants.
While I did mention rods will likely hold, there is nevertheless a small possibility that they wont. Depends really how different they are compared to Turbo rods.

Post by **Sveedy** » 13 Feb 2025, 08:11

If it was something really doable, someone would have really done it.

dikidera · Post by **dikidera** » 13 Feb 2025, 08:20

Sveedy wrote: ↑13 Feb 2025, 08:11 If it was something really doable, someone would have really done it.

Not with the attitude around here(and other volvo forums) on this topic.

Post by **Sveedy** » 13 Feb 2025, 08:32

Historically, this is where the skeptic says " Please demonstrate ". If you could do that, then attitudes would change.

dikidera · Post by **dikidera** » 13 Feb 2025, 08:49

I mean I know it's an entirely different beast, but

But when someone wants to do it, they do it.

Post by **scot850** » 13 Feb 2025, 19:08

As the saying goes, " anything is possible if you throw enough money and time at it!"

Can you make a 25 year old NA car a turbo? Sure. But at what cost in time and money? It is way cheaper to buy a turbo car and improve on that. That way you already have the electrics, harnesses and turbo ECU in place.

Should all this stop someone from doing a project like this? Of course not, and I hope they do as it may well teach us an easy way to do this. Just like making an AWD P80 a FWD car instead.

Good luck!

Neil.