Most aftermarket turbos aren't water-cooled, so can I safely disconnect the coolant lines from the stock sequentials? A turbo specialist at an import drag event here is San Antonio told me that having the lines connected didn't do anything for the turbos and that all it was actually doing was heating up the engine coolant even more. What do you guys know on this subject?

 

you can either heat up the coolant which has a big radiator to dissapate the heat, or you can heat up the oil which has a little oil cooler, or 2, to dissapate heat. sounds like a no brainer to me.

 

disconnect it. Saves your turbine's...but not THAT much.

 

I wouldn't even consider disconnecting the coolant lines to the turbos!!

 

Why? Oil does most of the cooling. I did this with my FC turbines. Ran the lines to each other. I boosted ~13 psi for over 2 years...on the ORIGINAL turbine and it finally went out at 135000 kilometers...

 

Jake, are you crazy?

I always recommend draining all the oil and coolant out as well, all it does is get dirty and eventually heat up the atmosphere.

 

speculation, speculation, speculation.

Good Idea to disconnect coolant lines? NO.

Bad Idea to disconnect coolant lines? NO.

The coolant goes into the center cartridge to cool down the oil that also goes into the center cartridge, which cools down the turbine. If you disconnect the coolant, your coolant will heat up less. How much more, I can't say since when I did mine, I didn't have an accurate water temp gauge.

It can be done. It has been done. Anyone else want to add personal experience on this subject?

 

It would be interesting to talk with the engineers who decided to route coolant to the turbos in the first place.

But then again, what do they know? They probably did it just to have another place for coolant to leak.

Let's see, spinning at - oh - around 100,000 rpm........
produces heat.........heat kills everything......let's make it hotter by disconnecting coolant lines! Yeah, that's the ticket - it will IMPROVE preformance if we do that!

Great idea.

No, I'm not an engineer. I just repair and recertify airplane engines, and yes, every once in a while a turbo airplane engine. I don't know **** about rotaries though. Obviously. I am just speculating.......

 

This is an interesting subject.. On all the FD's I've worked on, ALL the hoses to the turbos have either gone, or were more than ready... I see the logic in disconnecting them, but also see how those lines would most likely help cool those twins. They should be moving some heat, or the lines go out just due to the location.

 

All I'm saying is, if a big single snail can run without coolant, what is so different about disconnecting the sequentials?

 

I'd like to hear a few more opinions before I do this. As it stands right now, I'm going to remove the lines.

 

As with most posts on this thread, this is pure speculation, but here's my guess...

Turbos that were designed to run without coolant don't have coolant passages. Because the housing is relatively small and thin, some air cooling around the center housing may keep it from being too hot. If you remove the coolant from a turbo that was designed for it, you might overheat the bearings. They will be insulated by the air pockets where the coolant used to flow, so you won't get much air cooling. I am not sure how much air cooling really happens, but if it is significant, removing the coolant may be a problem.

Also, unlike a single turbo with a small center section with ample room for air flow, the stock turbos are plugged into that huge mass of cast iron. That seems like it might result in very high bearing temps. If it was my car, I wouldn't try it.

My Turbo II turbo lasted to 125K miles. 135 KM (84K miles) does not seem like a strong testament to turbo longevity to me. My 93 turbos were very tired but still functional at 92K miles.

-Max

 

I have an idea, the engineers at mazda probably know more than us?

 

Ok Crazy Jake, remove them. If you do please have the courage to write back in a few thousand miles about how the turbos are working.

It is really an absurd idea to remove the coolant from the stock turbos. The hoses are cheap and last 50K min. Stock turbos that are water cooled (everything from the late 80's on) don't really have a problem with coking the bearings like the earlier turbos did, water cooling is probably a significant factor in the reduced failures.

The oil flow rate is lower than the water, water transfers heat much better than oil. End result is your turbos will run hotter and so will your oil.

Jeff
Removing tires and brakes to save weight...

 

You can get your radiator temps even lower if you disconnect the coolant lines to the engine!

turbojeff: perople forget how awful turbos were for reliability before watercooled centers were common. i wouldn't consider running a turbo that wasn't water cooled.