New dyno graph and tune takes a dive aroun 4500 rpm.

[jordanvraptor]

Went to the dyno today and tuned with the predator. The tune seems to stumble and the AF ratio dives for the ten mark at around 4500-5000 rpms. I noticed from the datalog, that around 4500 is where the MAF voltage reads about 4.6-4.7 and it went to 4.9 today at around 6000 rpm. I wonder if the remnants of the Ford tune is seeing all this air coming in and adding a lot fuel in response. Or is the MAF getting weird on me when it nears its limit. Mods are 2.75 upper pulley and idler, 74 inch belt, NGK TR6 plugs gapped to .035, JLT true cold air intake, Accufab throttle body, Magnaflow X pipe w cats, MAC 3 inch catback. Here is the dynograph of the best run. Any advice would be appreciated.

 

[46stang]

Mine does the same exact thing! I spoke with James "RWTD" and he gave me a very good answer to why! I'm 99.9% his answer is correct and i'm waiting to find out! Speak with him and see what you think. this is his forum.



www.diablosporttuning.com/forums/

Leon

 

[TERMIN8TR]

What tune do you have in the car? Custom or box?

 

[BOOOOST]

Originally posted by jordanvraptor
Went to the dyno today and tuned with the predator. The tune seems to stumble and the AF ratio dives for the ten mark at around 4500-5000 rpms. I noticed from the datalog, that around 4500 is where the MAF voltage reads about 4.6-4.7 and it went to 4.9 today at around 6000 rpm. I wonder if the remnants of the Ford tune is seeing all this air coming in and adding a lot fuel in response. Or is the MAF getting weird on me when it nears its limit.

Actually, your problem is that the overtemp tests are not disabled in the defaulted Predator programming, and many TOONS from other Diablosport dealers. Most of the dealers do not have the latest templates that actually include all 3 of the overtemp tests, because they are clueless to request new ones. These tests command maximum fuel if the pcm determines what it thinks is the exhaust system being too hot. They need to be switched off fully, otherwise 99% of the time your fueling will do exactly what your's is doing. As 46stang stated, contact a real custom *tuner* who can rectify that situation for you.

 

[04MystiCobra]

I had the same problem today as well! Right after 4000 it goes sub 10:1 a/f ratio.

 

[04MystiCobra]

Originally posted by 46stang
Mine does the same exact thing! I spoke with James "RWTD" and he gave me a very good answer to why! I'm 99.9% his answer is correct and i'm waiting to find out! Speak with him and see what you think. this is his forum.



www.diablosporttuning.com/forums/

Leon

So what is it?

 

[46stang]

BOOOOST explained it! The overtemp switches have to be turned off. the problem is most tooners don't have the latest software to do so. Talk to James at rwtd. he has all the latest shit and will tune it right! jmho.
Leon

 

[jordanvraptor]

Cool, thanks guys, I was just doing manual adjustments on the R12D Predator tune. A local tuner also says it is adding fuel to cool the cats, he says he can turn them off. As for the exhaust getting hot.... Yep, after just installing my MAC 3 inch catback, I went to the dyno and one of the rubber hangers was touching the pipe and it went up in smoke.... Kind of form fitted itself...