First, I want to mention that this was not a healthy motor. Compression was low to begin with and was consistently going down during normal break in. I am not sure what the issue is but it is definitely happening on both rotors and is effecting compression on all rotor faces equally every time compression goes down. Since an engine pull was enviable, I decided to at least get some dyno numbers before shutting the car down for a possible rebuild.

Even though this is probably not the best example due to low compression, I thought it would be worth sharing since there seems to be very little results with the 66mm 9180 SXE. The dyno sheet is a 91-octane pump gas @ 14psi along with a E85 @ 28psi run. Compression during the pump gas run was low 80’s on all faces and lower then that on the E85 pull. EGTs were maxed out in the very low 1700-degree range on the 28psi pulls.

The engine is a ½” studded large street port with Rx Parts seals.

Relevant mods are as follows:

• Glease Man Big R 2” runner manifold
• 2 x Turbo Smart Gen 5 40mm WG’s recirculated back into the exhaust
• Borg Warner 66mm 9180 SXE with 1.0 A/R
• 4” Down Pipe
• 4” exhaust with 3 mufflers. (12” and 16” Burns Stainless with Vibrant exit muffler)
• Elite Rotary Shop full intake
• Custom ducted v-mount with 12 x 24 x 4 Garrett bar plate IC core
• FFE Mag Trigger
• ID 1000 primaries
• 4 x ID 2000 secondaries
• Walbro 450 lift pump
• Surge tank with 2 x Bosch 044’s
• AEM Infinity

 

thanks for the post and info on one of my two favorite SX-E turbos. it appears you pretty much got what it can give as i have it at 655 based on the efficiency plot and 670 based on stall rpm.

there isn't necessarily a direct correlation between the compression numbers generated at 250 rpm and max power. the year before i switched to Mazda i remember being at the Runoffs/Road Atlanta on the false grid for the GT-3 National Championship race. Cris Dembs. was on the pole and at the 5 minute bomb couldn't fire the motor. they poured oil down the Weber carb, it fired and he won the race. in his case although he lacked sufficient compression to start he still was able to make max power.

there's a lot to like re your engine compartment and of course it does perform.

the single item that does bother me is your air filter placement. as we all know IAT matters big time. that's why we spend lots of money on intercoolers... and they do work. i log IAT with a thermocouple. (four readings per second and accurate plus/minus 3 degrees F.) i also have a similar thermocouple just after the turbo before the intercooler so i know how much heat is removed from the charge air... my Pettit Cool Charge 3 removes 130 degrees around 20 psi boost. given the fact that 80 pounds of air can be going through the IC in one minute that is one HUGE amount of heat that has to go somewhere.

one of the challenges of our single turbo setups is how to find ambient to get away from the oven that is the exhaust side of the IC.

air intake placement is one of the reasons for my system design and it is by no means perfect. the aluminum panel between the IC end tank and air filter does a 90 jog over the coolant hose and another downward to tab into the fan shroud allowing the rectangular space alongside the radiator to be in contact with the air filter. pretty lame but better than being directly in the exhaust stream of the IC.




Maybe Matt Gold can come to the rescue. Matt designed an absolutely amazing very complex AI tank that is a work of art. complex because it needed to be.






same situation here. we need a structure/duct to feed ambient air to our intake along with a filter enclosure. it would pay big dividends and would probably drop intake air temps 30+ degrees. this item is the missing link in the intake chain. Matt, where are you?

 

PSA
Matt is busy finalizing the next evolution in FD headlights and will be available to address your concern presently.

 

Good work on the S366SXE, very clean setup...

 

Thanks for the comment Howard. I certainly see your point and the AI tank you referenced is by far the cleanest and most well thought out solution for the FD out there but I am not sure it is my biggest issue. Air temps at there highest point under boost were 122 degrees. I would consider this pretty acceptable at 28 psi on a very warm AZ day. Once I have a motor that can make it to another half mile event AI will be at the top of the list.

 

Thanks for posting this. Do you mind sharing some more details on the porting? When you say large, I'm guessing you mean as big as possible without the leading edge of the side seal falling into the port? Did you raise and/or lower the exhaust port?

 

Final intake temp isn't your only concern, every 10degC lower temp at turbo inlet is 3% more power from the turbo.

 

"Air temps at there highest point under boost were 122 degrees."

i do agree that 122 is O K at 28 psi.

the question is: is your data lagged?

this is an important consideration as low IATs are the foundation for a healthy motor. any reporting lag will generate lower than actual temps.

SX-E charge air temperature rockets from approx 100 F to over 350 F in just a few seconds. any reporting lag from a sensor and your readings could be low.

when i determined to get the real data i was aware of some sort of faster sensors but i knew from my EGT experience that a Thermocouple was the gold standard. given the extremely fast temp rise a warp speed sensor was needed to get the real data.

warp speed as in four readings per second. accurate within +/- .4 tenths of one percent error over the entire range. (that is just less than one F degree at 122).

i do know there are sensors faster than our original items and would be interested if there is speed and accuracy data available. perhaps you are getting your data from a thermocouple?

for those interested, i buy my AIR thermocouples from The Sensor Connection in Michigan. nice stuff, all made in the USA.

the part number for the "Air" temp thermocouple is:

EGT-AP-072-0181-55-N was $53 last time i purchased. i run two... one just out of the turbo before the IC and one in the stock location on my OE UIM.



you will need a thermocouple amp. i generally get them from EGT Technologies.



as it may appear i am seriously interested in low IATs and that is one of the reasons i run 100% methanol as AI injectant. i run between 900 and 1500 ccs and it lowers my IATs between 30 and 50 F as well as cleaning my internals, providing additional base fuel and eliminating detonation. 93 pump, meth, 585 rwhp at 24.9 psi with zero knock. my UIM after a run is cold to the touch.


THANKS for sharing your excellent results on one of my favorite turbos and you do have a really nice setup.

 

^Maybe splitting hairs here, but any reason you went w the AP-series 1/8" tip vs the IP-series 1/4" tip (slightly faster response, and rated more durable)?

Are you still using the Exhaust Gas Technologies probes for reading your EGTs? If so, how have they held up over time?

 

Here's the thermocouple amplifier I chose, in part, due to its CAN bus capabilities for data transmission. I also liked the female mini jack ports for direct plug-in from the sensors.
http://www.sptronics.com/TC201

Note: Most higher-end ECUs likely won't need this component since they can usually process data directly from two thermocouples.

 

thanks for the sptronics info. i prefer the Exhaust Gas Technologies amp as it is more compact and i just need the conversion.

yes, i am still using Exhaust Gas Technologies (EGT) probes and they have worked fine. should i have to replace one or both i will switch to The Sensor Connection.

 

Definitely food for thought! I really cannot argue given my last two motor builds have had issues.

 

This is the exact porting the motor has. https://www.rotaryengine.com/services/raceport.html