ignition timing

[saint]

hi guys

got the boost issue on the hybrid turbo finally sorted. the issue i found was the stock ebcs, and finding an adequate restrictor pill. switched over to a 3port and worked great. flowing around 285-290 g/s at 1.4 bar/2.2 load. the gt 28 works so well in holding boost compared to the k04.

my next item to pick up is the ignition timing. which tables do i use, and by how much timing do i go? i added 5 degress yesterday to max timing table, at 4500-6500 rpm, and 3 degress in the base tables, but still flowed the same g/s, with 0 knock, as i am running 50/50 water/meth injection. how would u know if u set the correct timing?

[Kevin]

From my general understanding is that u would advance ignition timing after max torque. Timing increases as the rpm increases and decreases as the load increases. U need to check if u are making more power when the timing is changed. If not, then u need to stop advancing.


Smackin a GTI while on my iPhone using Tapatalk

[saint]

how would u know if u are making more power, ie: flowing more grams per second or the load tapering is at a higher value ie, instead of lowering to 1.75 now drops to 1.85, as an example?

also my 3.5 bar bosch sensor just arrived, what are the scalers and offset values. mathematically i worked out A- 75, B- 1 and offset (-12.5). another guy on the speedforum is using A-312.5, B- 0.24 and offset (-12.5). both workout on the equation, but which to use.

http://www.bmotorsports.com/shop/produc ... ts_id/1772

here is the link for the sensor

[mps6dave]

adding timing to the max table wont gain you anything,you need to add in the other tables (base norm and extended) in open and closed loop.and go up in 0.5* not 5*

[saint]

thanks dave for your reply.

ok will do that to open and closed loop tables, but does the car not wanna adv timing till it reaches max, and if max is set below open and closed loop will that be the limiting factor? at the moment from 4500 till 6500 rpm i have 0 knock, due to the meth working so well. what is the max i should adv timing, cuz from what i know is if it goes beyond a certain value like 15 degress after tdc then u start to lose power.

[mituc]

I think that above 6300-6500rpm you can go up to like 18 degrees if you don't see any knock. But don't take my word for it, just increase the timing values with like 0.7 or 1 degrees and see what you get.

[saint]

how would u know if the timing had made a difference other than a dyno, i.e: engine load or maf? taking my car on Tuesday for its first dyno, quite excited. but without any timing added. then after this week, will install the 3.5 bar bosch map sensor, then slowly add timing, but is there a max timing where if i add anymore i loss power, or it is just a feel and check when the powerloss comes in?

[mituc]

Usually power remains the same if you add timing past 19 degrees. As far as I remember from what I've read on MSF the power remains the same up until 23-24 degrees and then starts dropping because the spark ignition occurs too soon and the explosion wave decreases in intensity by the time the piston reaches the optimal position.

Timing makes a lot of difference. By example, with 330-340g/s of air you can make 320-330whp with 10 degrees of timing above 6200rpm or 400whp with 18-19 degrees of timing. That's at the same air flow, therefore the same boost and load (the calculated engine load does not depend on timing). And I bet anyone can tell the difference between 330whp and 400whp, you don't need a dyno for that. I could feel a clear difference for 1 degree of timing which doesn't add too much power really, at least not at the timing values I'm at (11.5-12 deg around red line), so I'm sure you will be able to feel the difference as well.

[EastCoastSpeed]

Usually power remains the same if you add timing past 19 degrees. As far as I remember from what I've read on MSF the power remains the same up until 23-24 degrees and then starts dropping because the spark ignition occurs too soon and the explosion wave decreases in intensity by the time the piston reaches the optimal position.

Timing makes a lot of difference. By example, with 330-340g/s of air you can make 320-330whp with 10 degrees of timing above 6200rpm or 400whp with 18-19 degrees of timing. That's at the same air flow, therefore the same boost and load (the calculated engine load does not depend on timing). And I bet anyone can tell the difference between 330whp and 400whp, you don't need a dyno for that. I could feel a clear difference for 1 degree of timing which doesn't add too much power really, at least not at the timing values I'm at (11.5-12 deg around red line), so I'm sure you will be able to feel the difference as well.

On what fueling were you targeting 11.5-12* degrees at redline? I’m tuning for ethanol now on E30 and currently have my timing at 12* degrees at redline. However I seen on another forum someone else was tuning for a bnrs4 for E30 and you said on ethanol blends it’s fairly normal to see people have 2.0 load tapering off redline and 16* degrees. I’m running stock turbo currently though I do have a BNRs3 I may throw on it. My last ms3 I made 330whp 380wtq on E30 FBO but this one doesn’t have an aftermarket intercooler like the last one. So far my power has been consistent with my 93 power so I’m not sure if I just need more timing or what. I’ve been adding where tq drops off mainly so from like 4500ish on around 4* so far. Though I think I’ve added some down low as well. Fuel trims are on point, MAF was rescaled is still near perfect within 5%. I’m targeting an .80 or 11.76 now because an .78-.79 was taking more ID duty cycle than I wanted. Any help is greatly appreciated! Thank you!

[mituc]

On what fueling were you targeting 11.5-12* degrees at redline? I’m tuning for ethanol now on E30 and currently have my timing at 12* degrees at redline.

I was obviously speaking of pump gas. With E30 you can run quite a bit leaner and add a ton more timing. If "redline" for you means 6500rpm then you're too low on timing at that RPM on E30 even if you were on 20PSI of boost. You can get away with that timing at 20PSI of boost even on 95RON/91OCT pump gas at red line (6500rpm).