There seems to be so much information on A/F ratios but timing is more particular to the different types of engines. It would be interesting to gather and compare timing for different Turbo S2ks and try to analyze how people are making power and what the general thresholds are.

What are people seeing for timing at at some different boost points? please boost, some specs, hp

GT3076r, 8.5:1 cp pistons, kpro, cast log manifold

24' @ 1psi
22' @ 5psi
17' @ 10psi
15' @ 15psi
13' @ 19psi

 

I'll have to look at my map to know for sure what timing is at all my boost levels but I know at 15psi it's 7.96 degrees. I see you're at 15 degrees, I'm assuming you can run more timing being that you have lower compression? I'm still on stock compression...hence the conservative tune.

 

theres actually a nice thread floating around where people posted their timing maps but the problem is most of those people didnt post their mods.

 

timing is one of those touchy things people dont want to just "give out" numbers for....because you can tune 5 cars that have the exact same set up, and 99% of the time you are going to have different timing values for each.

everybody has different theory's on timing as well. fuel curves are pretty easy to shape. most people dont seem to shape the timing curves at all, they just pick XX number for XX boost level. which typically means they have too much timing in them at a certain rpm, and not enough at another.


another thing...is with AFR....if somebody tells you to run 12.0 and you run 12.2 your not going to hurt anything. but if somebody tells you to run 12 degree's....but your sync is off, and even though you think you are running 12 degrees, but really its 14 degree's....it could be enough to pop the motor. nobody wants to be responsible for that.....which is why all that stuff gets taken care of on a dyno

 

WOW good point...shows how little most people know about timing. I had no idea 2 degrees was enough to ruin a motor...anyone have any good reading for learning how to tune timing? Only way I've ever heard of is using MBT but I don't have a dyno so how would one street tune timing? Not that I intend to...I got my car tuned after my setup was installed and haven't touched the timing b/c I know nothing about it...but it would be good info...

 

i was kind of using the 2 degree thing as an example, MOST set ups are not THAT touchy.....but lets say your particular car wants 10, somebody suggests 12, and you really run 14. 2 degrees just turned into 4. get my point?

truthfully IMO (im sure there will be others on here that may disagree) but there really is no good way to street tune timing. MBT is what your looking for....but how do you know your at that point with out something telling you so? you can make pulls down the highway, pull the plugs and see where your at..... but thats only going to get you so close....not to mention its dangerous. not only for the motor, but for you and everybody else around you as your doing high mph pulls, and then pulling over to check the plugs.

and once again...... by doing that.....your not going to end up with any kind of a timing "curve". your just going to end up with a flat line for each boost column.

 

For timing I always start conservative and then tune it out on the dyno. Like Joe said its not something you want to mess around with and everybody's setup is different. Just have somebody that knows what they are doing tune it on a dyno rather than guessing and using someone else's maps.

 

oh yea....and lets not forget that timing values are totally different, with different EMS's. lol

 

8.5:1 cr.........................................you got to be kidding me!!

and only pushing 19 psi peek boost.

can i ask you why, you built a block at 8.5:1 cr

 

Thats cause alot of tuners dont really know whats up.