ceramic CT26 boost limit...

I was all set to remap my engine at 16psi enough of you guys do it so it must be safe right? except you do it on US spec steel wheeled turbo's...

anyone have any idea of what the ceramic unit can safely handle? and how much different is it's efficiency range? should i be drastically re-assessing my 16psi goal?

I would never use any CT26 beyond 15 psi.

What's you reasoning for that Jeff?

I love my engine :)

The physical size of the exhaust housing of the CT26 can only flow so much air. Beyond 15 psi you are going to be creating monster backpressure inside the turbine which is going to increase your EGTs and eventually lead to detonation would could pop your engine.

The "extra" power you get beyond 15 psi is not enough to justify the risk. You just are not going to see the big jumps in power you would with a larger turbo designed to flow that kind of air volumn.

^ive seen themn hit 19psi...granted the deuce that it was on caught fire, he felt a diffrence in power...im pretty sure hes on this site

I never said they "couldn't" hit more than 15 psi.

Just because something can be done, does not mean it should be.

yeah i've seen a ceramic hitting 26psi.... but it was leeking oil into the intercooler so it def didn't like it!

i know the steel turbine will handle about 15-16 pretty well and it's within their efficiency "island" but i'm wondering what the ceramic wheel can handle before it spits out the back in a puff of black smoke. (i've seen that happen on a GTR) Can i safetly run 15 or 16 on the ceramic wheel?

yeah i've seen a ceramic hitting 26psi

That's not physically possible - AFAIK.

well that's what his guage was reading (maybe it was a prob wit the guage) was during a tarmac rally and it wasn't meant to be that high. I had to try not to laugh.

i guess it's down to 2 things only then. u either want power over safety, or safety over power.

i guess it's down to 2 things only then. u either want power over safety, or safety over power.


not really... above 15psi you aren't flowing air efficiently. you'll see a bell curve drop in power increase...

TRD2000: I can see the ct26 hitting 26 psi but because of the lb/min flow limit I would imagine it would either hit peak hp around 4500-5000 rpm or overspeed in that area. As for the oil leaking into the intercooler, I would imagine that to be related to the turbo's oil drain being restricted. More boost should help hold the oil out of the intake/exhaust tracts.

Oil in the intercooler is perfectly normal. Generally it is coming from the PCV (positive crank case vent).

EmmArTooGuy, if the CT26's compressor could make 26 psi ... how could the exhaust said ever flow that much air?

Answer: it can't.

I'm with you on this too. I had no idea what the limiting factor would be, but I imagined that you'ld reach a flow limit somewhere. That would be your peak hp rpm and then it would just be about a flat power curve or a descending curve. I'm not saying 26 psi all the way to redline.

So let me ask you this, how hard is it to cause the ct26 to sling itself apart? I'm thinking of doing somthing like a torque monster rather than a high rev engine.

The CT26 pushed hard would blow the engine up before it would blow up ... again, I don't think you could even spike itto 26 psi. The exhaust side can not flow that much air.