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surprised you went for the straight-thru XR-1 Sportsman rather than XR-1 Multi-core.
been trying to get someone at Borla to tell me what differentiates the standard multicore from the rotary version, but only receiving crickets. Maybe someone here knows?
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While trying to figure out if I have room to add a Burns Stainless muffler to the exhaust, I realized I've never captured the car's entire underside. So with a 2400lb yellow Sword of Damocles hanging from a blue lift 'fingers' over my prone body...
CYM Underside - Mar 2023
never bought one from Burns, but always Coast Engineering. I had thought they were the source for them that everyone else sells, but seem to have a low internet presence post Covid.
the one thing I’ll warn you about is the rivet nut fasters that secure the outer shell casing and allow repacking them. They’ll seize and/or booger up in short order if left as-is, not being up to combination of high heat and moisture. You definitely need to have them swimming in high nickel content anti-seize or you won’t be happy later. The standard auto parts store crappy copper anti-seize won’t cut it. Pay the price and order the good stuff from McMaster-Carr and use it pretty much everywhere you can get away with it on any threaded or close mating parts.
Packing is another issue between what actually dampens sound vs what can take the heat. There was a ceramic fiber string wool product I was buying from Germany that did both well, but last time I checked it was becoming hard to find here. I’ll have to look around.
In fact, just remembered I have a round 3” in/out x 6” OD x 16” body if that will fit your need. LMK. edit2: probably only a 12” long body now that I think of it.
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@Howard Coleman has me... well, a lot of us... thinking about water and corn. For my ethanol-based system, I've been considering the benefits and drawbacks of AI. I have a good handle on the octane benefits, but I specifically wanted to understand the Heat of Evaporation cooling impact of different setups. I constrained my look at two systems. In neither system did I account for the fuel-injected gasoline;s contribution to cooling in order to make the comparison more specific to common setups:
A simplified version of my system: ID1300XDS / ID2000 injectors at 80% duty cycle with a 4-bar/58-psi base fuel pressure (5760 cc/min est.)
Straight 1000cc/min AI system (water, methanol, or 'bug juice")
Heat of Evaporation - BTU cooling contribution of AI and Exx blends
So at my fuel system's e50 (without any AI), I'm within 17% of "bug juice" cooling and 50% more than straight methanol. I'd have to run close to e85 to have similar cooling to 1000cc of water. I suspect I will stay my course.
As always, I hope someone finds and points out any errors I may have made. ADD is a bitch!!
Last edited by Carlos Iglesias; 03-29-23 at 03:07 PM.
Reason: ADD is a bitch
Is that to say you're continuing without WI, because it won't help an E50 car much, or you're adding it because nothing cools like water? Sorry to be dense.
Is that to say you're continuing without WI, because it won't help an E50 car much, or you're adding it because nothing cools like water? Sorry to be dense.
Nothing dense about it, Peter. I wanted to state facts and I tried not to advocate one solution. I did the analysis for myself (and concluded MY choice) but also wanted to make the data available so others could draw their own conclusions. So to your question, it was intentionally ambiguous about "the best" choice.
Ultimately, I refer to my favorite Jewish dude from Chicago: There is no free lunch; all systems have compromises. For turbo rotaries in this case, the primary factors are:
Performance
short-term - anti-detonation, HP
long-term - engine durability, HP
Complexity (design, tuning, and operation)
Cost (fixed and variable)
Charge cooling crosses all of these. So it's a "witch's brew" of picking the right mix of each ingredient for each setup.
I'll admit that from a design perspective, I've been (perhaps) irrationally averse to adding another major component to the EFI system. This is even though I have a fair understanding of the benefits (including cooling impact from above). I just happen to weigh the factors differently than others in my particular "brew." You know, like beans in chili is common, but in Texas, it's heretical! Or the insanity of not offering sweet tea. But I digress. Anyways maybe my choices are due to my relative lack of concern over losing an engine. Maybe it's laziness actually adding a WI project and the time it completes with upgrading the transmission, installing a PDM, and swapping out the Aim MXL for a Motec C127 dash. Indeed, it's always a witch's brew of choices. So my current flavor continues (for now) without AI.
As a small aside, I think if/when I install WI it will be just that: water only. It will be excluded from tuning for power; 100% for safety and durability.
Last edited by Carlos Iglesias; 03-30-23 at 11:47 AM.
Reason: ADD is a bitch
this is a good point.
1. fewer failure points is better.
2. if you used more than water do you need different premix? how does it play with E50?
3. you should ask your tuner if you even need it, he would know better than anyone.
I did mean to ask how you accounted for the difference in your calculations of injecting E-fuel at the port/intake runner compared to further up the the flow path just before and/or after the throttle body with AI?
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j9fd3s -
1. Concur
2. A whole 'nuther can of worm I haven't put on my plate.
3. While I think my tuner certainly knows what I need from a tuning perspective, I doubt he would know if I need it from a durability/builder's perspective. He's a one-trick pony (tuning), not unlike Secretetriat. But perhaps I'll ask anyways... maybe he's also a fine rotary rodeo horse.
TeamRX8 - thanks for the excellent question. Long story made short... I didn't account for where the injection happened. Here is my thinking with assumption(s):
I constrained the look to the cooling effect, so I didn't consider the air mass increase that might be contributed to upstream vs. downstream injection. This conveniently eliminated atomization, phase transitions, and location variables.
The decrease in the air-fuel charge temp (i.e., BTU) during combustion and immediately after is what I wanted to know. I assumed that the critical operating environment is the actual combustion chamber during the bang and the onset of the power stroke until the trailing apex seal passes the Leading sparkplug. In other words, from ignition to sweeping past the Leading plug. The combustion temps decrease determines the cooling performance (e.g., anti-knock, engine durability).
I won’t refute those words in your own thread, but if you have any interest to know my true thoughts then you know how to reach me to discuss it face to face, if you so choose.
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I won’t refute those words in your own thread, but if you have any interest to know my true thoughts then you know how to reach me to discuss it face to face, if you so choose.
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My skin is thick and my knowledge is faulty. Both are getting worse with age.
A lot of assumptions on my part, so I'm thankful for any and all corrections and insights. If you're good with it, I'd love your feedback here for others to also perhaps learn from... or maybe just over lunch sometime soon. Either is welcomed.
Just wanted to throw in some input on the "witches brew". First off, your build is absolutely gorgeous attention to detail is of OEM class.
I did some very basic premix testing myself and I just wanted to add it here if anyone comes across this in the future.
I have had concerns in my own build that the W/M injection is washing the oil film off of the housing causing accelerated wear. This was determined after opening my motor after 1100 miles and seeing more wear than expected on my brand new series 6 housings.
I first tried the elementary idea of putting premix in my w/m:
Needless to say that didn't work (obviously). Water and oil do not mix even if you get the nicest synthetic you want lol.
I did do a test of the redline mixed in some standard 93 pump gasoline which mixed as expected with no settling/separation after 72 hours.
For now I have resorted to a 3oz to 1 gallon premix ratio or 50:1. I have selected this premix level based off of chainsaws/dirtbikes (not kidding). The car smells a little premixy but I would rather burn more premix than risk accelerated housing wear as I do not really have a way of pre-mixing my injection system.
Have you thought about this with your Water injection? Do you have any concerns about "over" spraying the engine?
Lastly, Please let me know if you would like me to remove this posting as I know you have a very detailed thread here and I do not want to fill it with useless information.
Thank you,
Michael
Last edited by Michael Mansour; 04-10-23 at 09:45 PM.
Reason: Add Detail
Just wanted to throw in some input on the "witches brew"...
Lastly, Please let me know if you would like me to remove this posting as I know you have a very detailed thread here and I do not want to fill it with useless information.
Thank you,
Michael
Howdy Michael and thanks post... which is far from "useless information." For that matter, it's particularly helpful since I continue to grapple with the decision to incorporate WI. I appreciate all perspectives and insights. Please keep 'em coming.
To your question, adding a combination of solvents (e.g., ethanol, methanol, and/or water) into the intake charge exponentially complications understand the effects (as mentioned in post #513 above). Before I proceed, I will need to better understand the film-washing effect. Suspect this will take some time so as to no "overspray the engine".
Last edited by Carlos Iglesias; 04-11-23 at 04:54 AM.
"I specifically wanted to understand the Heat of Evaporation cooling impact of different setups."
happy to oblige. here's a piece of a recent log from a couple of days ago. the temperature data is generated by thermocouples so it is real rather than fantasy.
i picked the last data point before an armadillo ran across the road and the TPS slacked off. ( actually would have liked to flatten the armadillo as they dig up my yard but also like my splitter and nose). so 7440, 15.4 psi. right at 500 rwhp.
note the three plots in the second graph. they are temp out of the turbo before the intercooler, IAT at the OE location and the third is the AI pressure.
temp thru the turbo (G40-1150) rises from 150 F to 273.6 F at 7440. this is slightly better (lower) than my EFR 9180. note the IAT at the OE location is 90.7 F. if you look at the bottom graph, my Math Channel, the subtraction is done for you, 184.9 F removed from the turbo output.
how much of that number is from the intercooler and how much from the AI?
a really good intercooler can remove 67% of the temp diff between the ambient and heated turbo output. when we refer to ambient we are not using the outside air temp. we use the temp at the air filter. mine is 105 F. if your air filter is anywhere near your intercooler add at least 20 F.
doing the math to solve for my IAT without my meth AI:
273.6 -X/273..6- 105 = .67
X= 160.7 F
without my AI and assuming my IC is 67% efficient my IAT would have been 160.7 F...
160.7 - 90.7 = 70F
my meth AI dropped my IAT 70 F
my IC dropped temps 114.9 F
this is at less than 16 psi. things will look more interesting at 30.
i am running two M15 traditional nozzles which is the reason my AI pressure is low. i figure i am doing around 600 cc into the motor. i can turn up delivery by changing the settings but am happy at present.
there’s no doubt that methanol cools the charge, but immagonna break out the pointy spear again and question how “real” it is without actual temp sensors at the appropriate positions.
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03-14-23, 02:47 PM
