turbo egt ?

[hcrider]

2011 m8 cutler stage 2. bumped boost from 6 to 12#s and noticed egt fluctuating up to 400* difference at times, then would even back out. never had this happen at lower boost. sled ran awesome, what might cause this difference only at higher boost levels? 10,000 feet 3 gallon race fuel.

thanks

 

[Snopro_69]

On the m with only two injectors 12lbs of boost is too much for long pulls. The injectors run out. Did testing on my buddies last year compared to my 4 injector proclimb. I'd only hang around about 10lbs with only two injectors.

 

[MAINJET]

2011 m8 cutler stage 2. bumped boost from 6 to 12#s and noticed egt fluctuating up to 400* difference at times, then would even back out. never had this happen at lower boost. sled ran awesome, what might cause this difference only at higher boost levels? 10,000 feet 3 gallon race fuel.

thanks

Did you get similar results at 8 or 10 lbs? Cutler suggests straight race gas at 10 lbs.

 

[hcrider]

Did you get similar results at 8 or 10 lbs? Cutler suggests straight race gas at 10 l

egt temps would even back up with each other. i never noticed this difference at 8 or 10 pounds. ill back it back down and see if temps stay closer to each other. i could feel it run out of fuel on long runs but did not notice anything in short bursts of throttle. i was thinking might be ok in the trees.
thanks again.

 

[sidehill]

Are your spark plugs in good shape, and are they gaped properly. Mine egts would do this if I was blowing out the spark. I run close to the same mix on race gas as you and have run 13 pounds with no issues. Cutler stage 2 with only the stock injectors. I ride at 10,000FT in Wyo.

 

[hcrider]

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ill check plug gap tonight and condition. dale told me at 10,000 feet i could damn near run 91 at 10 psi boost so i figured with a little race fuel i could squeze out 12.

 

[Snopro_69]

The elevation an octane level make sense, but from my Understanding no matter what elevation it dosent change how much your injectors put out. So if ur at ur limit on injectors one could be a little weak too. Try bout 9 pounds for a day an see if makes a dif.

 

[hcrider]

The elevation an octane level make sense, but from my Understanding no matter what el

guess i need to go back to the mountains and ride again. damn. ill try 9 and see what happens. at 12 psi the sled is a real arm stretcher thats for sure.
stage 3 might be in the futurecant imagine 15 .

thanks again,

 

[Snopro_69]

Oh yeah 12 is a blast. All I run is 10-12 on 100ll at 4-8 feet

 

[hcrider]

egt guages

fired sled up and guage for right side cylinder egt is all over the place fluctuating from 300 or so up to 750 then back down while other cylinder maintains steady 300*. connection on exhaust is tight, wonder if i dont have a bad koso guage or defective exhaust probe.

 

[backcountryislife]

The elevation an octane level make sense, but from my Understanding no matter what elevation it dosent change how much your injectors put out. So if ur at ur limit on injectors one could be a little weak too. Try bout 9 pounds for a day an see if makes a dif.

Elevation changes your fuel "needs" to make a certain boost, but not what you CAN put out for fuel, also when you talk about a 2 injector kit compared to 4, if you're talking about BD compared to bd that's different than Cutler 2 injector kits compared to BD 4.

As to the fuel, a Cutler kit at 10k+ can easily run 13, with plenty of DC left in the injectors, as we've got more fuel pressure to feel them.


At 10k with 3 gal of race, you've got plenty of octane for 12psi, you must be having an issue with the fuel regulator (pull it apart & clean the diaphram, it's easy) or perhaps an issue with the pump?

I'd also look at the BOV...I got a tiny chunk of belt in there once & it made the 09 we had run like crap for a bit & made temps swing around.

This isn't an issue of the KIT being able to make enough fuel for the boost, but somehow I'd guess you're just not getting it, so something is off. Btw, I've NEVER seen a swing in EGT of more than 100-150 at WOT (and that is climbnig a big climb, steady increase in EGT temp from 1100 to 1200-1250 max, and that's at 14 psi.

 

[backcountryislife]

fired sled up and guage for right side cylinder egt is all over the place fluctuating from 300 or so up to 750 then back down while other cylinder maintains steady 300*. connection on exhaust is tight, wonder if i dont have a bad koso guage or defective exhaust probe.

Could this be an EGT problem maybe? Just trying to think of the simple answers first.

Curious, does it FEEL different when the temps bounce around? A change of 300 degrees should change how the sled is running pretty noticeably.

If it's just one side, I'd bet on the EGT, or a clogged injector... but I suck at betting & usually lose my azz..

 

[Hardass]

Swap the good probe to the other side and see what it says good way to rule out that

 

[hcrider]

Curious, does it FEEL different when the temps bounce around? A change of 300 degrees

no difference in feel when guage fluctuated. sled ran absolutely awesome. i believe i will be on boost forever, cant get enough.

 

[WyoBoy1000]

x2 on swapping probes, that will tell you if its the gauge or probes, only time I have had that problem was with to much fuel.

 

[wapitihunter]

Take it to your local cat dealer. they will have all the answers you need.lol

 

[hcrider]

problem found

pulled wires apart at connection to attitude box to inspect all looked just fine. started sled up and problem seems to have gone away. maybe as simple as bad connection.
thanks to everyone for their input. apprecieate the advice

 

[mynewuseddoo]

I had actually burnt and egt probe cable and it had the same effect. Check the length of the entire cable for freys or melting.