back from the dead (again)

How about idle timing? I just got my 13B-RE running in my FB and while zeroing in the timing (running a E6K) I noticed it ran a lot smoother at 0 deg than at 20 deg BTDC. (900 rpm)
Also when you guys say you run X amount of split in the 0-2000rpm map do you have all ranges set to X amount or are you saying the most split is X? The map I have here has about 18 deg split at ~25in mercury and tapers down to 3 deg at 0 in mercury. Is that common?
Thanks, reading this thread now that I actually have a E6K makes a lot more sence to me
-Cam

 

anyone? Or did all the knowledgeable guys go on vacation?

 

Cam

Idle timming because of the very low speed of which things happen usually responds realy well to timing values in the range of -5 deg to 5 deg.

Some engines & IGN set ups have very narrow windows which hwen combined with a certain idle AF ratio will make the engine quite "happy" (stable combustion) with no or very little "vissible" cobustion residue visible from the tail pipe.

If you change the idle ign either side of it's ideal very much you will notice "smoke" at idle which is a sign that all is not burning eficiently (not oil smoke but fuel smoke).

It's a trial and error thing to suit your car, especially if its got a proper street port. I run about 11.2:1 a/f ratio and timing value around 2 deg ATDC with T&L together (no option for me to run split) and that works good on my engine for idle speed around 1100rpm

 

Thank you very much! Thats what I wanted to hear! While reading this thread I was thinking to myself "WTF, people are saying run mid 20's up to 3k rpm in vacuum, but stock is set to 5 AFTER top dead center at idle" That probably explains why mine likes so much less than 20 btdc I'll have to kick the idle timing down and live with the louder exhaust note, at least it will idle better though

I think mine must have a vary narrow window to tune at idle. If I adjust fuel any more than 0.10ms in any dirrection it lets me know about it.

I have smoke at idle but thats for another reason... oil is deciding to creep past the turbine seal. I have a .060" restrictor in it now but I think I'm going to be forced to go to a .050" or maybe a .045". To make sure it wasn't the drain line I ran the engine with the drain run into a quart container. It still leaked by the turbine seal. It was passing nearly .3 gpm of oil at idle (45-50 psi before restrictor) so i think I'm safe to put a smaller restrictor in it.

Another question if you have time. With timing locked at idle I noticed that it "jumps" around maybe + - 2 deg, is this common with engines that use a CAS? Maybe some electrical interference in my system that is causing this? Or slop in the gears??

 

Thank you for bringing this up.Can this happen with a stock ecu? i have a stock ecu with afc and 20b pump, rb turboback and intake..i have the fuel smoke,lots of white thick smoke i know it not coolant only happens on idle even after a long hard drive, its a 1990 turbo rx7.im planning to get stand alone but would like to fix this problem first

Thanks

 

bump

 

OK I have read and reread this thread. It's a great thread, but why in all of the maps on the forum, and elsewhere I might add, is NONE of the advice followed as far as I can tell.

 

Too late to edit but I wanted to elaborate on my statement above. Re: the split map, no one that I can see runs 15 split up to 2K(P05) and then 8 thereafter. That would be easy to do. Is it recommended? Also mentioned was running in the 30's on the leading for low rpms, yet most if not all the maps start in the 20's (if that) at low rpm. I am looking for a way to increase response and power off boost.

 

Where are you looking? I mean what maps?

 

any of the ignition maps posted on the forum, and any maps on the datalogit site.

 

Can you elaborate on this?

 

Well, if you fire the trailings before the leadings, you're essentially trying to run the motor in reverse....

 

this thread should be made a sticky...great job guys...Ive got ignition to do and then its back on the dyno for me. this thread has my mind racing...


j

 

I vote to make this a sticky too. I've learned more about timeing in this one thread than I have in months. Now off to play with the AEM

 

Concur w. stickie. Who should I contact?

 

Bringing this back up to see if we can get an answer as to if this is recommended.

 

Damn this is an old thread

 

Old but interesting!

 

It would be more interesting if someone answered the question.

 

yes answer the question. This thread is great reading...helping me learn some tuning

 

wow this is a great tread about timming thanks for the shared info!!

 

One thing that isn't discussed is exhaust gas temps. RETed said, in a nutshell, that one should calibrate your EGT guage on the dyno with a wideband to know what is "normal" as different EGT guages will read differently on the same car and vice versa.

I am seeing EGT's at about 1000C at WOT on the dyno in 4th, 15 degrees leading adv., 7 degrees split with an a/f ratio of 11:1 or thereabouts. Wondering if I should be reducing my leading or increasing my split to lower EGT's (or will that just raise them?).

 

good info guys!

 

indeed.

 

Hi,
Can anyone shed some light over this? I reckon you are running too much advance and too little split.

John
88 GT-R