Just wanting to know if my maps are conservative or agressive. I currently run about 9 lbs of boost on 93 octane on the complete stock block. Here is more info on the setup:
https://honda-tech.com/zerothread?id=520599

Here is the low speed one:


High Speed one:


Now, my other questions are, what if I used 100 octane? Can I add more timing? More boost? And still be safe?

What about when the built engine goes in, can/should I increase the timing more than I would with the stock engine?

Thanks for any advice you can give.

Brad

 

thats very aggressive in my opinion. max timing at high boost should be no more than 22-23deg. perhaps youre ok with race gas.

 

Judging by your lowest vacuum column 9 and 10, your base timing is at 14 degrees. Using the old .5 degree retard per pound of boost you should be at approximately 25.75 degrees total timing at 9psi, so your timing maps are a bit aggressive. I would bet if you pulled back a little timing in columns 12 and 13 you would pull a bit more power. I have noticed with alot of the cars I tune there isnt much, if any gain using the conventional .5 degree per pound of boost theory. In most cases backing the timing out i lose 2-5whp, but reduce cylinder pressure greatly. At this point I would pull columns 12 and 13 back down by 2 degrees. With race gas you can easily run alot more boost if you keep the timing out on a stock block. The rings lands are first to go on stock cast pistons, the cylinder pressure goes hand in hand in destroying these.

On a side note, I have a SAE article where bosch created a special spark plug that was able to measure cylinder pressure. I am researching on this more to see if buying/creating such a device would be possible. Tuning with such a device would be the most optimal since you can directly monitor the cylinder pressure, giving the tuner a way to know exactly how much timing is optimal. Comparing both the cylinder pressure with the device, and a egt gauge mounted optimally in the exhaust runner would give the tuner a direct PV=nRT relationship. For example increasing the timing would create more cylinder pressure, while lowering the temperature in the cylinder using the universal gas law keeping both volume and density constant.

 

smaller bore motors need less timing, those are pretty good numbers for a b18/b20. Far too aggressive by my standards for sohc 75mm bore

 

good thread, keep it coming.

-PHiZ

 

Thanks guys. I will back it out a bit and post the new numbers for approval.

I will make the changes tonight when I get home from work and post up.

So really I wasn't making anymore power with this aggressive maps? I was just increasing the cylinder pressure?
On 100 octane gas can/should I increase them or should I still leave them and just turn up the boost a little?

Thanks for the help again.

 

Vaportrail you are correct in the smaller bore needing less timing. The SAE article i have concerning cylinder pressures vs engine timing established a smaller bore has less air/fuel/residual moving across its boundary therefore needing less timing to burn the mixture compared to the larger bore cylinder. This is also the same situation when looking at timing maps for the vacuum columns, vacuum conditions need more timing to ignite the mixture since the air density inside of the combustion chamber is much less then near atmospheric/boost conditions.

 

My roomate popped his Y8 with less timming than that under boost, with decient a/f too.

 

What was his base timing set at with the Hondata? Without matching the base timing, he could actually have been more advanced timing than what the numbers display on the maps.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted hybrid &raquo;</TD></TR><TR><TD CLASS="quote">Judging by your lowest vacuum column 9 and 10, your base timing is at 14 degrees</TD></TR></TABLE>

How exactly did you come to that conclusion??

VTC- who one day hopes to tune

 

Here are the new maps. Let me know what you guys think.

Low


High


So should I use the first map for high octane gas? Or is it even worth the risk? The car has been running great with the first timing maps shown above.

Thanks for the help again.
Boosted, I PM'd you back.

 

TTT

 

really your best bet is to put it on the dyno, and use the least amount of timing possible. You cant really *** tune ignition timing, you need a dyno for that.