any updates bump ...?

 

The last engine I built died from corner seal spring failure and the knock sensor I was using did not even detect any appreciable knock. but on teardown the corner seals were flattened from overheating, or knock. temps were normal, rebuild was just starting to climb in compression at 600 miles or so and I was on the way back from the land transportation office after an inspection.

 

I wonder what the weekend will bring …

https://www.theusmileracing.com

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i was planning a fairly extensive update after this weekend as i expected to be running the Texas Mile. loading up for the two day trip Tuesday night i managed to sever a fuel line. gas everywhere so i am lucky the car didn't get toasted. watching the TM on youtube live, now, is like watching the love of your life marry someone else. there is always April. my fuel was 75% VP X85L and 25% Q16. it will get burned in Texas come April.

 

I'm running an E85 tune in my Audi 1.8t. Being Wisconsin, I began having starting issues around 50 degrees Fahrenheit. I switched to E30 from the "Winner" gas chain and it now starts perfect at -20, improved fuel economy, no knock, and no loss in power.

I'm running a factory turbo and factory MAP sensor, so not "heavily modified". I have still doubled my torque from 3k to 5k rpm.

Thank you for your e85 posts, as I often consider converting my nearly stock FD.

Dave

 

one thing not typically discussed here is to use 1/2 oz. per gallon e-fuel top lube (in addition to any premix lube for rotary engines).

this will help the injectors to run smoother and inhibit corrosion in the fuel system/sticking injectors.
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Thank you for the heads up!

My FD is waiting for a ride down to Cam following an engine fire. Once he assesses the situation, I will discuss having E85 upgrades performed.

I too have had a fear of running e85 in my FD simply due to the corrosion I've seen in snowmobile and motorcycle fuel systems sitting with e10 in the off season. As always, there is a way to prevent damage.

Thanks again team rx8!

Dave

 

i'm really not sure if this is the place to put this, but i've run into the same thing on my car, and have gone down the rabbit hole a little
3500hz sounds like this, be careful with the volume!
its a higher pitched noise than i was expecting.
weirdly the ear is built to work better around that frequency range. the graph is kind of the reverse of what we usually see, its frequency vs db, so the ~4000hz range it takes fewer DB to hear something. (although you might physically feel 20hz)


anyways, imo, i think the odds of being able to hear any detonation above say 20mph (or part throttle) is pretty unlikely.

the other thing i did was to put a screwdriver on the knock sensor and put my ear on that, and its noisy! my knock sensor is picking up noise that is actually there
part B, noise transmits too, so like the loose exhaust hanger i had sounded like it was inside the car

third and lastly there are a bunch of different knock sensors. https://www.opticatonline.com/search?pt=5108&b=BFPZ

again not sure this goes here, but here it goes

 

" i've run into the same thing on my car, and have gone down the rabbit hole a little"

the rabbit hole is not fun.

in addition to analysing 4 intercooler cores i spent the entire 2021, which includes 223 logged runs, attempting to effect my knock readings. nothing i did changed them, including swapping in a brand new shortblock. approx 70 of the runs are on the new motor and it continues to gain compression. just before my Texas Mile abort i did a run with my Texas MIle fuel.... 75% VP X85L and 25% VP Q16. 31 psi with my 9180. pretty much the same knock readings as 93 pump and water meth AI. 40 to 60 on my Link G4X Extreme. no way was i getting real knock with that rocket fuel.

i have resolved to just accept this number as normal and focus on other things. what really irritates me is if i actually had a knock condition i would have learned something as to what specific remedies might be best. oh well. i am going back to 30, from 40%, E for 2022 road tuning.

they just announced the 2022 Texas Mile Schedule and April 1-3 is the date for the spring event.

my current challenge is to pull off a proper dyno session. most of the dynos are 100 plus miles south which isn't an issue in itself. the major pain is i will need to drain my fuel tank at the dyno site and fill it with my race fuel. prior to getting on the rollers. i guess it isn't too big a deal, primarily a pain.

the other item for 2022 is i am seriously considering swapping my 9180 for a Garrett G35-1050.

the 9180 77% efficiency island is only 8 lbs wide (54.5-62.5) at 30 psi while the G35-1050 is EIGHTEEN pounds wide (63.5-81.5)

similar at 20 psi boost. i also like the more stout turbine wheel even if it is a bit heavier. .

 

you would think with those different fuels, if it was detonation one of them would have made a difference, at least.

on my car it has two components, it does actually seem to knock under load (i'm on the base map), but the problem area is just with RPM. i'm using a PFC, but knock at idle is 0, but if i rev it to 3000rpm knock is in the 50's (the light turns on a 60). i've pulled the belt off for no change, swapped my Aluminum pulleys for the stock ones (this actually helped a bit). i can put it in gear with the clutch in for no change, so its something on or in the engine, although what it is i haven't a clue. not a lot of possibilities left.

frustrating!

 

my PFC would generate 40/50 knock just motoring but under boost the knock would drop to around 10. if it didn't drop then i had real knock. i found the original knock system combined with the PFC/Datalogit to be helpful.

 

that is exactly where i want to be

 

Short back story : I took a 70,000 mile stock internal, unopened S5 6 port NA and recently turbocharged and switched to running a Haltech 1500 (Entire fuel system E compatible and Flex sensor installed) The first few hundred miles on cold starts I could literally see black residue leaving the mufflers on startup. It was quite odd to watch.. This has since cleared up as I assume the ethanol was acting as a cleaning agent.

First we finished the 93 tune and recently wrapped up the E85 compensation map and I have been running E85 (E70%) is the most i've seen from the pump here in Mid Florida for Approx 1000 miles since running ONLY ethanol.

I have also been running 1oz / gallon switching back and fourth between Klotz SUPER Techniplate OR Bio Rotary Premix.

By the MSDS sheet the BIO Rotary premix has a higher lubricity percentage. But I am mixing both brands at 1oz / Gal.

I am not pulling super high horsepower, have not dynoed the car but I am running 10psi consistently. The engine runs strong all the way to redline and hot starts in a breeze. I will report back after several more months of running Ethanol and 1 oz of premix!

-M

 

so turns out i have two problems! the engine is noisy, not sure why at ~3000rpm its ~45knocks. i put a screw driver on the knock sensor and my ear on that, and its loud, not sure why
problem 2 turned out to be wait for it, detonation/preignition. easy fix, pull 2 degrees, and added fuel, and its fine (new ECU)

the only thing i've learned from racing for ~15 years is that the hard part is figuring out what the problem actually is. once you do that the solution is usually easy.