VEMS Ign. Table, how much advance ?

[th.b.w.]

Hi,

in my Album is an Ign. Table that i run now for one week.

Who know how many ign. advance is possible and what is the limit for knock at map 270 and 300 ...


I run now at map 270~ 20° and map 300~ 19°, is it to much ?
Fuel is 98 super plus in Germany.....

Thanks Thomas

[Jeffer]

The amount of advance is defferent per type of engine. It all comes down to your engine specs (compression ratio, valve timing etc) and other variables like fuel, outside airtemp, altitude, intercooler efficientie, fuel temperature, etc etc. A conclusioncan be made from this that there is not a generic figuere available for your ign. advance. Highly advised is to have the car mapped on a (load)dyno with proper knock detection on the engine to map it correctly. Thats the way to go. Good luck

[th.b.w.]

Hi,

i know that every engine is different.

But i want to know what is on the other engines here in the forum the limit.

The difference can be only in the range of 2-3°, or not ....?

Who can show an other workable ign. map ?


Thomas

[Jamo]

I 100% agree with Jeffer quickest way to blow the engine up using VEMS is to try and use another cars ignition map if it has been dyno or professionally tuned.

A basemap could be used as it's not going to be pushed. The map is going to be different depending on the turbo and peak torque in the map range

[Billman]

that is a good base....for the rest read above

http://www.s2forum.com/forum/showpost.php?p=307150&postcount=71

[GazzaG60]

get a set of dec cans and take it on the road. the only way to get real looad and airflow.

billmans figures look pretty good as a base. your correct there will only be a few degrees either way.

i dont think its totally fair to send this guy on his way saying they are all different. I know jamo has collected a few sample maps along the way.maybe he could send some examples? in essence what Jamo and Jeffer say is correct though.

my basic advice would be.

make some cans. bolt them to the cylinder with best airflow. thats usually the one farest from the TB. drive it making small changes. if yuor not using the knock detection in VEMS and i doubt you are. try bolting the cams to the sensor hole over cly 1. these items are designed to pass knock through coolant. the sensors sit over coolant channels. this reduces phantom knock signals.

[Jamo]

It's not that at all he's asked

I run now at map 270~ 20° and map 300~ 19°, is it to much?

Without being at the engine listening for knock I couldn't give an honest answer to that

[GazzaG60]

fair point. missed that.

id make up some cans and have a listen.

checking plugs will help. also take a good torch ande shine down the plug hole. you will see small pitting on the piston if you have too much.

[th.b.w.]

Thank you Billman for the ign. table.

Mine is in my album.

I have wired some earphones to the oem knock sensor.
When the engine is cold there is some noise over 4000 rpm.

When it get the right temp. ~ 90°, there is no knock i mean....

i runed with det cans last week, i cant hear any knock i mean....



P.S. perhaps there is an other user who can give an workable ign. map.


I dont want to copy that map, i only will get sense where the knock limit is to be +/- 2-3°


Thomas

[Billman]

checking plugs will help. also take a good torch ande shine down the plug hole. you will see small pitting on the piston if you have too much.

what is this pitting?

Ok found it!

What if an engine run lean and the pistons got these small marks but now runs fine? I have this on my motorcycle? Is it a problem???

[GazzaG60]

im not a massive expert here now somebody can help.

personally i think its from hot conditions gonig on load around 2500-4 k. i think its small det. maybe somebody can confirm. maybe bad fuel, timing around the limit

the man who did skim my pistons at the shop said this too to confirm my suspision

my engine never seemed out of sorts at all always ran well. these pits are usually on the flat part of the piston jkust up from the dish.

[th.b.w.]

Hi,

is only one ready to give an ign. table ?

Where are the other vems user ?

Please give a little help.....



Thomas

[Jamo]

Download the megatune package on the EFIexpress website, it did have multiple example files in it.

What turbo are you running?

[th.b.w.]

Hi jamo,

i run 3071 AR82, 2bar boost, comp.lowered to ~8,5:1, Wagner IM and ExM, etc.....

Where are the files ?

Thanks Thomas

[Jamo]

On the efiexpress website under vems