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Discussion Starter · #29 ·
So the 7163 is more or less tuned. I think there's quite a bit more left if I knew someone locally who could spend some time with it on a dyno. Mail order tunes only get you so far and some guys don't want to do a million iterations. It's quicker than the 6758 but not a night and day difference. Surprisingly I can tell no difference between the 6758 and the 7163 in terms of lag and boost threshold. The 7163 is every bit as responsive at the 6758. There doesn't seem to be any downside to the larger turbo other than it's about $300 more up front. The biggest seat of the pants difference is actually the mid range in 2nd gear - not what I was expecting.
 

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I love your build! 50 Lbs/min that's awesome!!! There is definitively room for improvement not sure on what type of fuel you are running, but going back to your previous post you mentioned e5x and meth injection, if that's correct your spark timing is really low you can run 20 degrees of timing without any problems or if the fuel is good up to 25. The other thing that the delta between the MAF and VE is very large! Since I don't have all the details may be your tuner decided not to add more timing since you are on the stock block, but can probably can pick up another 30 whp. That a screenshot of my KO4 on e85 tune at 25 psi at the end of a 1/4 mile pas. I upgraded to the WR-2 the lag is noticeable in comparison to the k04, but from boosting from 5 psi to 25 psi is much faster
107613
 

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Discussion Starter · #31 ·
Thanks for the feedback SSolstice. I agree completely with everything you said. I'm running E54 straight from the pump with direct port methanol injection (Boost Juice).

Comparing the 6758 vs. 7163 logs along with SOTP feel I'm estimating I picked up right around 20-25 rwhp. The goal was 50. There are a couple of Cobalt guys that have hit 480 and 500 whp with similar setups although I don't know what MAF flows they were seeing. I'm very surprised that we couldn't get more than 14 deg. total timing but anymore than that we started seeing what appears to be real knock (2.5-3 deg). Another 5 degrees would make a significant difference. I'm not sure how to interpret the large delta between MAF and VE. It's always been there even on the other setups.
 

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The only other thing I noticed from the screen capture was that your desired EQ is really lean .95 lambda (assuming you were on WOT), but again i am not sure if it was set up that way, since you might be injecting meth (I don't know how your meth controller was set up).
 

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While I know this is an older thread I was looking at that screen shot of the HPTuner scanner and things don't add up.

How is it that the MAP sensor reading is 37.0 the barometric pressure is 13.9 and the boost is at 30???
MAP - baro = boost

The other thing is the VE airflow compared to the MAF airflow is showing the engine in only using up 33lbs/min compared to the 50 lbs/min that is being reported by the MAF. Where is the rest of the air going? The VE airflow is reading correct for the amount of boost if you use the MAP - baro way of doing it..

58mph in second gear @ 6644RPM?????
stock tire size at that RPM the speed would be 63 MPH

Or the tire diameter is almost 2" smaller in diameter then stock.

On a stock LNF engine the boost pressure would have to be in the 40PSI area to see 50lbs/min or airflow
 
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