A safe way to approach Timing Advance with Lemmiwinks
 

Im currently homebrew converting a Upsolute E5 (100octane) K03 tuned 2.7T engine to E85. Getting fueling sorted and so on at the moment, but will be looking at Timing Advance (using Unisettings actually, but same as LW). Ive read the threads on E85, Tuning E85 (ie aiming for 6 - 12degrees advance) and the thread where pushing Timing too far ends up with a blown engine (again on E85).

Afaik, the danger here is Block 20 shows 0 retard on E85, always (from reading here and looking briefly at it when driving). So.. whats the smart way (without paying a tuner!) to do this?

Is anyone running E85 on a B5 S4

Can't say there are tons but there are enough. Most are custom full tunes IIRC.

Knock sensor voltage and keeping an eye on correction factors, I haven't heard about CFs always being a 0 on E85, I believe it can be scaled differently due to different software as well.

Its something to do with E85 no knocking at all, the danger is you put too much pressure on the engine itself. The octane rating of the fuel prevents knocks which means you are dont have that extra info to see what happening.

Right then, here is some quick runs I did in the rain just now, 3rd gear WOT to just around 70mph. The second chart is missing Cylinders 5&6, forgot to log them in addition to 1-4. CFs on both runs peaked at 1.5, over 99% of the logged CFs remained 0, so not much info there.

http://i55.photobucket.com/albums/g1...ckVoltages.jpghttp://i55.photobucket.com/albums/g1...ckVoltages.jpg


Still unsure on how to interpret Knock Voltages. KVs Ive seen here tend to be much higher and apparently differ from tuner to tuner anyway. +3 Timing didnt seem to make much change to KVs (or feeling when driving either).

[dust balls roll across screen..]

Upped the timing to 6.75degrees, KVs (Block26) peak at 15.6v and CF (Block20) remain at 0 with one blip at 1.5. According to http://homepage.mac.com/edyjun1/S4/l...ng%20Notes.htm (which makes no mention of E85, its generic info) I should be "aiming" for KV of about 24v, which would imply I have loads of room..

IDC peaks (once) at 90%. This is with 5.3FPR, 36lb Bluetops and stock fuel pump till the replacement arrives. No tweaks to primary fueling, need to fine tune startup however.


Im going to increase it to +9degrees Timing for the next run.

I don't know how many people have tried going E85 without a tuner. I always assumed it would kick our seals asses.

anyway. keep the info comming.

Ill be the guinea pig, pig being appropaite for an Allroad too. :)
When I remove the stock pump Ill have a look inside, it will have put up a year of mixed ethanol blends, from 5% to 100%, usually around 20%. Not bad for a pump with 156k miles on it.

stock fuel pump with a base pressure of 5.3BAR? Brave man IMO...

How much boost are you running? I would advise you to replace your FP with an 044 or something similar that will be able to handle the high pressures you're asking from it and will flow @ these pressures. I know you have a pump on the way, but I would even suggest you wait for it.

5.3BAR = ~77psi + 20psi boost = 97psi rail pressure... I wouldn't trust the stock pump to keep that up.