I know we can use HPT to raise the rev limiter, however aren't the fuel and spark tables limited to 7000rpm? After that we don't really know what the ECU is doing with fuel and spark, and the only detail I can remember reading is about PJ's old build/dyno where the AFR would get all nutty after 7k rpm, and he was not seeing additional advance after that range either.
I ask because I need to tune my eco cav and will eventually get comp stage 1 cams. My choice for stage 1 was strongly based on the 7k rpm limit and where my powerband will be with the 2.4 mani and comp stage 1. Why get something that makes power well above 7k rpm if you cannot tune for it right?
Now I see Airtronics rockin the MP62/comp stage 3 build and revving to over 8k rpm. I'm waiting to see what his tuning method is, but its probably not HPT...
I believe it maintains the current settings past that level.
so if at 7000rpm you have a VE value of 30(this is just numbers out of thin air BTW) it continues thaat value on up.
So I.e.
7000....8000
30 30
-Chris
^ exactly, when I did the dyno run my spark and fueling stayed at the exact value it was at 7k and stayed constant.
Cool, so could we effectively tune comp stage 2, which advertises to make power out to 7500rpm?
K. Vega..Mr. M62 L61 himself. wrote:why not
Zero resoluton above 7k rpm. I guess its not as big of a deal as I thought. PJ's dyno just stuck in my head. Does someone have an WBO2 log above 7k rpm that shows a consistant AFR? Thats the biggest concern for me - consistent and adequate fueling in the zero resolution area...
I have a log of my dyno run with hpt. Just have to find it.
It seems to keep the last value like others said. Be sure though to change your spark ramp out to a higher rpm though, otherwise it will start retarding timing after whatever the factory setting is if i recall.
You can't fine tune up in the high rpm area but the data didn't change much to worry me.
12.770 @ 111.99 Intercooled Eaton M62
I run mine out to about 7900. The only thing I had to do was increase fuel a lil bit in the last cell to account for the slight increase in air about 7k. I had to richen it up like 1% in the last cell to keep my afr in the 11.5-11.8 range.
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4 Cams...32 Valves...5 Liters...This Could Get Fun!
Skunk wrote:I run mine out to about 7900. The only thing I had to do was increase fuel a lil bit in the last cell to account for the slight increase in air about 7k. I had to richen it up like 1% in the last cell to keep my afr in the 11.5-11.8 range.
Makes sense. I guess I made the mistake of basing my plans on one person's experience. Something about PJ's build or the dyno's WB make it the outlier. Everyone else turning high RPM seems to maintain consistent AFR's.
I was not too worried about not having resolution up top, just maintaining consistent parameters and not going all nutty.
I may have to consider going with comp stage 2 instead of stage 1...
Well the other thing is that your spark maps only go so far too, as long as you're fine w/ repeating the last cell out and the engine can do it w/o knock go nuts, hell I say go stage 3 cams they are all the same price lol.
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4 Cams...32 Valves...5 Liters...This Could Get Fun!
