Eva X

I’ve tried high and low to better understand these cams. Here are some of the things I’m hoping to gain clarification on.

S3s are bigger and have more blowby, thus causing your wideband to read a leader AFR than is actually the case. Is this actually true?

Do S3 cams require more timing than a smaller cam when tuning? I am experiencing knock with pretty conservative timing, and am wondering if it’s too conservative thus leading to too much EGTs and the knock. I.e. less is not better. Any truth to this? Seeing knock at high RPMs when the timing ramps from 3-4 at peak to 7-8 at redline.

Can anyone who has some more knowledge shed some truth to this?

I did drain half my tank and filled up 2.5 gallons of 98 octane with the 93 that was in my tank ( a small chance of bad gas?) and the knock was pretty much eliminated but wondering if that’s just because the increased octane, and not because it’s running too much timing now. I have a hard time 3-4 at peak and 7-8 up top is too much to be getting knock. I put in new plugs 1 step colder and same thing. Just trying to understand the dynamics of these cams.

Cam filtering is set to 25 for high rpm btw. Thanks I’m advance

LetsGetThisDone

iTrader: (1)

What fuel? Boost?
Post timing map and a data log. But 3-4* at 4000ish is too much.

Eva X

I've seen your name a lot in the past, its awesome to interact with an OG.

Here is my timing map, and here are a few cleaned up logs.
Knock multipliers are adjusted to: 17, 20, 24

Boost wise - I've had this occur with as little at 24 pounds of boost. I then did some reading on leaning out the AFRs during spoolup and that seemed to really help because now I'll get the occasional spike to 28ish pounds.

Gas is pump 93

I have a question.... Here is my timing map, the Lines are NOT representative, they are just as an aide to this question to visualize what I'm asking.
The blue line represents starting at a low RPM (dyno pull) and hitting Full boost around 4,000 RPM... I have heard max torque is around 500 RPM after this. From the dashed line we can see timing is around 2 degrees at max torque... Nice.
The red line represents real world condition of downshifting on the highway at a higher RPM and stepping on the gas. Your starting RPM is already higher than where you hit full boost in the dyno run, and it takes your 6,000 RPM to hit full boost. Is your max torque still 500 over that? If so, the map would be hitting 7-8 degrees of timing at this point which is obviously more than the 3-4 limit.

This scenario assumes there is no boost taper and just holding X boost until redline. I hope this question makes sense, and that is my actual timing map, so please advice on how to tweak it or if you see anything majorly flawed..

LetsGetThisDone

iTrader: (1)

What turbo is this? Built motor? Compression ratio?

On 91 we don't usually run more than 22-23psi on anything not a stock turbo. Even 93 I'd prob keep it at 25-26. Try running 1* at 4000, but it "should" be able to run 10-11* at 8000 with reasonable boost.

You're not in the range of not enough timing raising EGT and hurting it. My FP red setup wouldn't run less than 25.5psi so we ran -3* at 4000 and 7* at 8000 on 91.

Also, your log doesn't have knock voltage, I need to see that.

Eva X

Sorry, I was away and just got back. I’ll post a log and my latest timing map tomorrow / this weekend.

As for your other questions:
Stock bottom end
93 octane

25-26 psi seems inline with what I’ve seen. I have seen some respectable tuners on here post graphs of them tuning stock block fp black cars on 93 at 30psi to redline, but who knows what their timing is.

I was thinking of 30 psi peak and taper to 25-26 at redline. I don’t plan on revving mist past 7500. Maybe 7800.

At what point would timing be getting too low to induce hot EGTs?


I’ll also try to play with fuel again and richer things up a bit






With regards to the