What turbo should I choose?

[dikidera]

Hopefully in the near future provided there are no other issues, I will install a turbo on my NA S60. Many things can occur to prevent me from doing so. But I still want to have a plan of attack.

I think the TD04HL-13G will be the best fit, however I am still uncertain. My goal is to run actual boost of 3-4 PSI at the intake manifold if possible. But some of my calculations say it can't be run like this.

If we do some rough calculations, at 3 psi I should theoretically have close to 200hp at the crank. My plan however is to start with just 1 PSI in order to tune the car and see where the problems are. E.g fuel, knock, VVT advance and error codes.

However, my rough calculations say that 14.7 + 1 psi of boost = 15.7 psi, 15.7psi/14.7psi = 1.06 pressure ratio, which I am not certain any turbo is capable of, according to compressor maps. And even at 3 psi boost, this is still 1.2 pressure ratio. This calculation does not take into account any pressure drop from compressor outlet to intake manifold. If there is a pressure drop then maybe I am entering the islands of efficiency afterall.

My research has shown that the early 850 turbo models had 6 psi of boost? If so, could the same turbo be used for less than that?

[BlackBart]

Just an idea……

IMG_5666.jpeg (189.81 KiB) Viewed 493 times

[dikidera]

That turbo is big enough to roll on its own down the road xD

They see me rollin' they hatin'.

On a serious sidenote I was alerted to the potential for the rings on my pistons, being naturally aspirated and all that, that is possible my ring gap is too small, and then because of a turbo and thermal expansion, the ring gap becomes zero, the ring expands into the cylinders, scoring it.

Looking at the part numbers, on my B5244SG motor, the rings are also installed into P3 chassis replacement for the turbo motors. Yes, those motors with the high oil consumption.
However VIDA does not show me when they started using these specific rings for my motor. Often times there was a previous older part number which they update over the years and they dont show the previous ones.

VIDA also does not show ring gap. If I know my piston rings have enough gap, that is also another worry off my shoulders.

[Krons]

Hopefully in the near future provided there are no other issues, I will install a turbo on my NA S60. Many things can occur to prevent me from doing so. But I still want to have a plan of attack.

dikidera curious if you’ve considered looking for a clean S60 2.5T? I know low mile ones are getting harder to find. Recently had a 99k mile one come up and regret not jumping on it. $6k seemed a little high but such an outstanding platform.

That said, I can understand if part of the goal is just tackling the challenge to make it all work. Your plan of starting with low boost and working your way up seems solid.

[dikidera]

There are many S60s for sale over here, but too expensive especially facelift ones. At least the cost upfront is higher since you need the cash immediately. But slapping a turbo requires very little upfront, except in the rare case where a failure occurs. Just for comparison, the cheapest 2.4t/2.5t you can buy is over 5000 dollars without including cost of transfer, and general maintenance.


Prices aside, there is one aspect I had overlooked initially and that was the piston ring gap of the NA engines vs Turbo. According to VIDA, some of the NA piston rings are installed on the Turbo engines with no special ring gap specs.
VIDA does not have information on ring gaps, and online sources claim the original turbo rings had very little gap, whereas more is better there for thermal expansion.

It's my only concern, if piston rings expand too much and the ends touch, it is game over for the engine.

[BlackBart]

On a serious sidenote I was alerted to the potential for the rings on my pistons, being naturally aspirated and all that, that is possible my ring gap is too small, and then because of a turbo and thermal expansion, the ring gap becomes zero, the ring expands into the cylinders, scoring it.

Is the combustion chamber temp that much higher? Because of the additional pressure?

Can you verify and do a little ring filing?

[dikidera]

Possibly yes. It seems that in turbo builds, the rule of thumb is at least .025'' of gap and sometimes more, the more boost you want to run in order to allow for thermal expansion of the rings. Whether this applies to Volvo only those that have rebuilt engines will know.

With that being said, I only have one single source saying that the OEM rings have a small gap, of about .014'' or thereabout for the turbo engines and that is how they were factory fitted to the B5254T2 engines. , these same rings are a replacement for NA engines.

This would imply that Volvo run essentially NA piston ring gaps, since they have no gap specs, unless someone says otherwise.

[vtl]

Get a turbo engine.

[jonesg]

Get a turbo engine.

thats what i would do.

[dikidera]

That was my plan about 2 years ago or so, you guys may recall I even got the 2.5t wiring harness + Bosch ECM and even a 2.5t head(with dual vvt). But after a while of searching I had not found a 2.3t block and finding a 2.4t or 2.5t which may or may not have been cracked was out of the question and then of course whether they had taper or not.

Come on guys, NA-T is more fun. The Subaru guys do it, the Miata guys do it.