adding turbos to a 3.2

[Trakrat]

I did a few searches on here but come up empty.

Has anyone ever setup a twin turbo on a 3.2? Anyone know of some links on a TT build?

I came across some article a few weeks back (in Panorama or Excellence I think)... about someone who did a twin turbo setup on a 3.2 and wondering if anyone here had done the same??


I'm not looking at doing this yet... but I might in a few years after I get my current resto/build finished.

[Rodsrsr]

I don't see the benefit of that on a 3.2 which is probably why you wont see many threads on it. More piping, more weight, more complications, and more cost for exactly what gain?

[Jack Stands]

I seem to remember that someone was making a supercharger for the 3.2 (or perhaps the SC) back in the day. Might be an easier install if you’re committed to the modification.

[Sboxin]

You might call Chris at TuboKraft in Mesa, AZ
A few years ago I was able to drive one of his Turbo Boxsters - amazing torque

Turbo Kraft Porsche Parts and Custom Builds | Porsche Service Arizona

Regards,

[Rodsrsr]

The OP is asking about TWIN turbos.

[Tippy]

Originally Posted by Rodsrsr

I don't see the benefit of that on a 3.2 which is probably why you wont see many threads on it. More piping, more weight, more complications, and more cost for exactly what gain?

Twins spool far sooner (turbine wheel much closer to exhaust valve) than large singles and in general, provide more CFM

[Canada Kev]

Plus, the turbos would necessarily be much smaller and thus spool quicker. Unless one was planning sequential turbos which would indeed be silly to add to a 3.2.

[Tippy]

Originally Posted by Canada Kev

....... sequential turbos which would indeed be silly to add to a 3.2.

Sequential yes, but compound turbos would be awesome!!!!

I have my old HX40 sitting on the shelf, and it's crossed my mind to stuff it full of the Borg S366 boost!!!

[Tremelune]

Why would two half-sized turbos, each connected to half the motor's exhaust outlets, spool up faster than a single turbo connected to all of them?

[Canada Kev]

Mass and inertia. Think of how the original 930s were with that huge lag compared to more modern smaller engines with small turbos and their very low lag. Mind you, modern turbines have come a long way, but physics is physics. Or even old cars like a 959: small 2.8L engine and small turbos and as I understand not horrible lag, but still pretty high pressures.

[Tremelune]

Given the same amount of airflow, a larger turbo will take more to spin up than a small turbo, but in a twin turbo setup, aren't you using half the airflow per turbo (one for each three-cylinder bank)?

What's the size threshold at which two small turbos will be at desired boost faster than a single larger turbo, given the same total exhaust airflow and same pressure at the intake manifold(s)?

[Raceboy]

With two turbos you are not mixing up exhaust pulses. Twin scroll turbines serve the same purpose but many single turbo systems use regular single scroll turbine and that has noticeably worse transient response and boost treshold under otherwise equal conditions.

[Tippy]

Originally Posted by Tremelune

Why would two half-sized turbos, each connected to half the motor's exhaust outlets, spool up faster than a single turbo connected to all of them?

All about exhaust pulse energy. The turbine wheel is getting hit with hotter air closer to the exhaust valve.

The longer the distance, the slower the spool as the volume of air is compressing and getting colder the further away from the turbo.

[tdw28210]

I'd talk to Bisimoto Engineering.

Porsche 930 IROC Twin Turbo – Bisimoto Engineering

Not sure if it is a 3.2 but is definitely twin-spooled.

['76 911S 3.0]

Originally Posted by tdw28210

I'd talk to Bisimoto Engineering.

Porsche 930 IROC Twin Turbo – Bisimoto Engineering

Not sure if it is a 3.2 but is definitely twin-spooled.

That thing has a 996 watercooled engine in it

[Fly911]

Ruf did exactly this with their 1987 Yellow Bird, with great success. There is plenty of pictures and documentation on how Ruf built and set up their twin turbo based on the 911 Carrera 3.2L.

[Trakrat]

Originally Posted by Fly911

Ruf did exactly this with their 1987 Yellow Bird, with great success. There is plenty of pictures and documentation on how Ruf built and set up their twin turbo based on the 911 Carrera 3.2L.

I had thought RUF did a little more than just slapping some turbos on it.... I had thought everything was custom designed and built specifically for their engine (turbos and all) and they even bored the engine out.


I was just curious if there was a tested setup with a couple turbos and engine management that someone had tested.

I've 'heard' that these 3.2 engines are capable of making 700+hp... but I'm not sure what all that involves.

[Rodsrsr]

I guess my point was that there is a cost per benefit, even a cost per HP. Whats the car going to used for, professional competition or street fun? I'm running a Precision single turbo on my 3.2 with stock compression and I can tell you there is very minimal lag and it spooks up quite nicely. Would a twin turbo setup deliver more performance? Maybe it would, but for a street car its fixing a problem that doesn't exist. Additionally it wouldn't make sense to build an over the top twin turbo monster and connect it to a stock 915 gearbox. I know the OP didnt say this was his plan but I think more information is really needed before deciding definitively which direction to take with the build. Dont build a motor around whats best, rather whats best for the specific need. A well tuned single turbo on a stock compression 3.2 is more than enough for most street applications, unless one plans on joining street outlaws.

[FstTarga]

Single or twins all I can say is it’s a damn good time. I’d go with a smaller turbine than what I did if going single however, I have some good lag

[Canada Kev]

Originally Posted by Trakrat

I had thought RUF did a little more than just slapping some turbos on it.... I had thought everything was custom designed and built specifically for their engine (turbos and all) and they even bored the engine out.


I was just curious if there was a tested setup with a couple turbos and engine management that someone had tested.

I've 'heard' that these 3.2 engines are capable of making 700+hp... but I'm not sure what all that involves.

It was Ruf. Of course they engineered the hell out of it. Built a special turbo tranny with an extra gear, and who knows all the other stuff. It was a 3.4 litre engine, but those pistons and barrels were likely available from Mahle. I read somewhere that the suspension wasn't even all that special. It was factory torsions and upgraded sways, or upgraded torsions and factory sways, one of those options. But I digress...

The engine itself? I have no idea, but it was likely a wee bit more than just slapping on a couple turbos and calling it good.