Turbo cams, boost and maf values.

Advanced discussion of improving KA-T components
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modulation
240sx Wannabe
Posts: 114
Joined: Fri Jun 12, 2015 4:55 pm

Turbo cams, boost and maf values.

Post by modulation »

Recently installed some Kelford 272 cams in to my ka24de-t with a GT2876r. No I wasn't maxing out the old cams, but wanted some dedicated turbo cams and I love the difference they made make more area under the torque curve. I also do see higher maf values (4.43 v 4.38) then I use to at redline with the old cams (old setup was 248/248).

One thing I found interesting is that I made less boost after the cam swap. Searching around this is common as the better cams reduce restrictions in airflow, and since boost is a measure of resistance it would go down with better breathing cams. I decided to graph MAF/Boost values and compare the 248/248 setup to my new 272 setup. Blue is the 272 setup, orange is 248/248. As you can see I am pulling the same MAF values with less boost on the new cams. Makes me realize even more questions like "how much boost can I run" and "how much power will I put out at X psi" and "how much timing do I run at x PSI" aren't good ones (and yes I use to ask them too.)
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p00t
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Re: Turbo cams, boost and maf values.

Post by p00t »

This is a really great comparison (both the actual change and the method by which you are comparing them).

Are these plots just driving around or one pull to redline? Why are there a few "high fliers" at low boost?
Current Experiment: Project Twin-Charge 2022
modulation
240sx Wannabe
Posts: 114
Joined: Fri Jun 12, 2015 4:55 pm

Re: Turbo cams, boost and maf values.

Post by modulation »

The plots are made of multiple WOT (TPS 4.0v) runs that I generate for virtual dyno out of my nistune log files.

Those outliers might be me shifting from 3rd->4th in boost vs building boost in 3rd, or maybe deceleration, or hard downshifts, not sure. If I was a real data-scientist I'd have some sort of outlier detection and remove those
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