MS 109 is only 100 octane. It’s on VPs website

 

Just did a round of intake temp testing.

When I do this I try and control test conditions so for my test protocol on the "stock" runs I did...

1. Bring oil and ECT up to operating temp.
2. Do one 0-130mph run. Take iat data point.
3. Immediately stop car after run to 130mph and do 5 min timed heat soak. Take data point 2.
4. Immediately after heat soak do second 0-130mph run. Take data point 3.
5. Do second 5 min heat soak. Take data point 4.

So far on my stock system in 83f ambient I got.

96.8f - after 130mph run 1
118.4f - after 5 min idle heat soak
107.6f - after heat soak run to 130mph
127.4f - after heat soak idle #2

All in all not bad at all and all under iat offset timing tables.


Max timing on 93 octane was 22 degrees. I've heard people getting 28 degrees on e30 or race gas

 

Thank you. I was told it was 110.

 

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How did you measure the timing?

 

Did you get any knock?

 

As far as i know the only way to log knock on the C8 is using the GM Scan tool...

Normal OBD2 scanners dont show the knock sensor.

 

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I didn't hear/feel any. But I was running 150 mph on a noisy road.

 

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All in all not bad at all and all under iat offset timing tables.
Tell me what this is. Where would I find this?

 

HP tuners will log all of those perimeters

 

I used my portable scan tool for convenience sake but I could have used HP tuners





Ms109 is 105 octane aki

Different calibrators use different triggers but generally most gdi OEM tuners tend to set offsets around 60c or 140f.

​​​​​​Some use progressive offsets and some use very hard ones I'd better term them as "safety tables"

The progressive ones may reduce timing advance requests by ...let's say...3 degrees timing for every 5 degrees temperature increase in IAT over 140f. That's just a random example of similar to how I'd calibration Honda ECUs.

Others like Audi and Porsche have the hard limit ones. As an example if my iats were 139f in the Audi I could get full 23 degrees of factory timing advance assuming no knk is present. If they were 141 degrees I'm stuck on the safety ignition timing table and max timing is 16 degrees.

I haven't messed with the C8 to see precisely how theirs works yet since I haven't seen able to trigger them yet.



My current testing is on intake temps.

Only when that is done I'll move onto octane and see where our ignition knk control is being used (as I have to assume it is with being told we will target up to 28 degrees.)

In other cars Ive found our high quality east coast shell 93 can sometimes support in the 20 to 23 degrees range. That's showing true on the c8

Then I need to look at how much timing is pulled out on 93 (I assume it's 6 to 8 degrees if we really do target 28) and that will tell me about what level octane we can benefit from on the stock timing maps. If it's 28 degrees we can benefit all they way up to around 100 octane or e30. Generally for 32 degrees I get on the Audis you need at least e40 which almost always will require tuning the fueling as that will max out your trims (assuming no hardware limitations)

 

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Will HP tuners log the C8? If so, can we log a lot of PID’s? Thanks