Turbo matching for ported Renesis
 

After blowing my first engine with help from ProStreet (pox be upon them), I've been working with Rick's Rotary, Vishnu and now Full Function (praise be upon them).

The XEDE EMS is great. Technically and functionally, it is an arguably superior alternative to the Interceptor-X, but Shiv (Vishnu) isn't too keen on taking on the risks of tuning high-compression turbocharged rotaries. Given the state of my bank account after replacing my Renesis, I can't say I blame him!

We've proven that a ported Renesis can flow a LOT more than the 18g can keep up with (I now know what a turbo sounds like when it's overspun), so I'm planning to upgrade the turbo as soon as I can afford it.

Sean at Full Function has some very sound ideas on what turbo to use, but I'd also like to leverage the wisdom of this group.

What I'm looking for is a ball-bearing turbo that can flow a lot more without being too laggy, yet also fit where the 18g is without too much time and cost. I'd be willing to take a BFH to the floorpan, but need to avoid high fabrication costs.

Use the BFH to make room for a GT35R. I've been studying the maps lately and this is the one turbo that can flow enough for the pressure ratios I want to do (2-2.2) - although there is PLENTY of headroom for more boost. Its modern and highly efficient. From what I've heard the ball bearings result in very quick spool-up. This turbo is the choice of lots of the SRT4 guys who have almost the same flow requirements as we do - albeit at lower pressure ratio. GT35R is the clear choice.

Don't know why you get me with that, but every time you do :rollingla

Is a 20g that much larger dimensionally? It would seem to me, and take it with a complete grain of salt, that you are looking at something in the T4/62-1 or similar lbs/min capacity. Really, though, that's just speculation. I'd wait for some of the real gurus on the forum to weigh in.

20g wheel in this housing would be worthless.

Because it still couldn't flow enough, or because the housing would impede efficiency of the airflow?

While we're at it, please recommend web-based resources for learning everything about turbochargers...the more technical the better, as long as there is a gentle intro.

It still couldn't flow enough. From what I can tell the TD06 frame would be sufficient for most PRs for our displacement - except for the insane redline of the rotary. From studying the closest maps I could find, it can flow enough until about 6kRPM or so - which would be fine for most piston engines with similar flow requirements. But this is probably why us GReddy owners start to loose boost at that RPM.

In fact, when I look at how my boost falls-off with RPM, it follows the choke line of the TD06 maps almost exactly. That's confirmation enough for me that that's the reason for the boost falling off so badly. The problem is exacerbated for people in high elevations like me (6000ft) since the PR must be higher for the same power output.

I think this one is damn good

http://www.stealth316.com/2-3s-compflowmaps.htm

I'm also hoping that a bigger turbo might make me a bit less pingy in the midrange, since the air won't be as hot (more dense) for a given psi. Or, to state it a different way, I can get a higher mass flow rate.

Maximum Boost, is a good layman's terms read also.

60-1 hifi. .81 or .84 hot side.

^ That would be my recommendation as well. I just love 60-1's on rotaries.

^^^^
I think we have a forum member with that turbo on his ported RX-8, don't we?

:boink:

Sapphonica, Any idea on how much bigger your exhaust ports are now that they are ported?

we're on the same page a lot of the time :)