with the evo and e85, its pretty easy to hit mbt before encountering any knock, so timing has to be set by watching power. is the rb26 the same?

 

Good to know.
What sort of timing where u running with ur rb26? And when on e85 did u advance the entire map or just above max torque?

 

yup, actually I've never seen an instance where any engine would knock prior to MBT on E98, my more limited experience with E85 has been the same..
without being too specific out of respect for car's new owner, easily 10 degrees more than the typical evo map - peak torque benefited from the most advance.

Marshall

 

I will be on the dyno after i finish a full tank of e85 and have a fresh tank.
I will be watching power and torque very closely. Im keen to advance in the
midrange to get a fatter curve then see what gains i can get up top from 5500 to 8000.
I went to get my 1st tank but it was out of order. Hopefully tonight

 

We just got done doing an RB26 with twin 2530, tomei poncams (264s), stock head that made 441whp at 20psi on 110 octane leaded running timing like we outlined (this for sure). It was for roadracing so we didnt push it as far as we could but it still made really good power, power band was almost perfectly flat from 6500-8200.

aaron

 

I just got back from my 1st drive on e85.
I ran the 98 extremely low before fuelling up.
From 1st start up afrs were 16.9 at idle up from 14.3(98)
quick change of injector size got
it down to 14.7.
Had my fiance drive around while i tweaked a few areas to 15.5-16 light throttle cruise.
So far fuel economy is very close to my 98 tune. I have only given it a few hits to log WOT afrs. Been setting them at 12.2 and so far
without touching ign timing response is up and top end is on par with 98.
Will hit the dyno next week hopefully

 

ok, new to e-85, and started reading up, seems like I may be in the "danger zone"... Ive been running 10* @ peak tq w/ 23 psi, 11.5 afr (BBK-B). From what Ive just read, thats much higher than most tune for, or is this reasonable w/ this boost level? Car pulls hard, just not looking to purchase a new motor just yet.

Guess I should start dialing it in, w/ less * and more boost...
Only lost 7 hp going from 11.9 afr to 11.5.

 

23 psi is pretty low, but yeah, too much timing at that boost level. Maybe somewhere in the range of 4-7 degrees is more reasonable. Tossing out a wide range because I don't have my timing map in front of me. Bottom line is that E85 is generally tuned by power and not knock.

 

Thanks for poppin in. Im gonna try and bump boost up to 26 psi flat, and drop timing @ peak to 4* ramping up 2* each rpm point w/ 16* @ 7k, and 17* @ 7500.

car felt pretty freekin good tho @ 23 psi and 10* @ peak... lol

 

projectskyline, are you running that much timing on the stock ix turbo? what mods to do you have? sry to bump an old thread.

 

Hi, load=300 mine as 25* @ 8250 rpm
with 32psi hitting 330 load @8100rpm

your map seams agressive but correct

 

I just switched to E85 and am still dialing in a tune. I too am experiencing knock before MBT, but it's not consistent. In some cases, I can continue to add timing, despite knock on the previous run, and I will continue to gain power. Is that ok?

 

What AFR are you running, what is the timing, boost psi, and what RPM are you seeing knock at? Post up a log or Evoscan chart so we can help you to diagnose cause.

 

I have since dialed it all in, thanks.

 

Any comments about my ignition map. Im hitting ~11000load, so there is ~10degrees of advance.