Low compression ratio spark advance tuning?
#1
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I can't find much info on tuning a low C/R engine. I know you can run more advance, but how much more? I bought a car with 8.5 C/R Wiseco's and it just feels sluggish until the boost comes on. My current map is similar to what most people run with a stock bottom end. Anybody with a low C/R engine care to provide some insight or share their spark map?
#3
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![](https://cimg0.ibsrv.net/gimg/www.miataturbo.net-vbulletin/667x342/spark_map_cd2d75ef9858bf1554f51c3cc99f635b8df6c271.png)
Here is my spark map. It is a 8.5 compression ratio 1.6 running a 50 trim T3. I'm mostly looking to improve spool up and drive-ability out of boost. Yes, I know a 1.8 would help, but the car came with a fresh built 1.6 with Wiseco's, Manley rods and boundary oil pump, so I'm going to see what I can get out of it.
#4
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Why don't you post a log of two so we can see how your car responds to WOT into boost?
There's only so much that can be done.. and your spark table looks about normal under 100kpa...
#6
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PPS. Two relevant threads for you to digest relating spool data and your T3.
2554 vs T3 on a 1.6
Spool data galore megathread.
I bet you can find LOTS of great info there and help set your expectations on what your car is capable of.
2554 vs T3 on a 1.6
Spool data galore megathread.
I bet you can find LOTS of great info there and help set your expectations on what your car is capable of.
#7
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You have to remember, out of boost it's a 1.6 with low compression. Pistons, rods and an oil pump don't add power, they just help with reliability.
Why don't you post a log of two so we can see how your car responds to WOT into boost?
There's only so much that can be done.. and your spark table looks about normal under 100kpa...
Why don't you post a log of two so we can see how your car responds to WOT into boost?
There's only so much that can be done.. and your spark table looks about normal under 100kpa...
I will get a new log soon. I had a few saved on my dedicated tuning laptop, but my daughter killed the laptop with a chocolate milk incident.
#8
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The half point in lower compression isn't making any less power than the engine made at the factory. It just doesn't make that much of a difference.
As said above, post a catalog of a 4th gear run from 1k rpm, WOT, to whatever speed you are comfortable with. Let's see how the turbo is responding.
EDIT: I went a read one of the links above, about using a t3 on a 1.6. It was basically 3 pages of people saying it does, and always will.suck on a 1.6. So.....I guess your car is proof of this? Not being a jerk. Just reading the words.
As said above, post a catalog of a 4th gear run from 1k rpm, WOT, to whatever speed you are comfortable with. Let's see how the turbo is responding.
EDIT: I went a read one of the links above, about using a t3 on a 1.6. It was basically 3 pages of people saying it does, and always will.suck on a 1.6. So.....I guess your car is proof of this? Not being a jerk. Just reading the words.
#9
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No offense taken. I know the T3 probably isn’t optimal. I will eventually build a 1.8, so I’m not looking to buy more parts for the 1.6. Looking over some of the data it looks like some are getting 12psi at 3500 rpm on a 1.6. I will try my best to get a log tomorrow, but I know mine isn’t spooling that fast.
#11
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I attached a datalog and my current tune. I did a 4th gear pull at the 18 second mark, there was some hesitation and it didn't feel that strong. I also did a few quick 3rd gear hits after the 4th gear pull. It does look like I'm hitting 12psi by 3500rpm.
Feel free to insult my intelligence and tell me how awful my tune is. That's how I'll learn.
Feel free to insult my intelligence and tell me how awful my tune is. That's how I'll learn.
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thesnowboarder
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03-01-2009 11:14 AM