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2011 Challenger 392 6.4 with a Maggie 2300 . I am only making 552 whp . With a 2.8 upper , 18% overdrive crank pulley, kooks long tube headers, KB boost a pump, CAI, all forged internals, FIC 1000cc injectors, 2 stage colder plugs , a stage 2 snow meth kit, making 13 lbs of boost. I was making 515whp on 6lbs before i forged it and upped the boost .Then* It made 600 whp before it ran out of injectors . So I had FIC 1000cc injectors installed and it's made 590 whp . Then I was told then it was pulling timing because of high IATs. So I added the meth kit and 2 stage colder plugs plugs* And lost 40hp ? Now my tuner is telling me I have to have racing fuel to make 650 or more whp** 12.5 was my spark and it was pulling 3 degrees because of knock
 

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what meth mixture are you running? If your running straight water you won't get much of a power boost, running half water and meth gets a little better, but running straight meth with say 91 octane fuel will get you just as much power as e85 or race fuel. So thats what I'm wondering.

it's a good idea to run the best pump gas as you can, make sure it's pure gas and not the 10% mixture if you can help it.

the retarded timing is saying it's seeing knock, so I would be looking at pump gas what your using and make sure your running 100% meth, if you use straight gas of 91 octane or better and straight meth this will put you around the same as running 105-110 race gas. another words you would not see much difference in over all power between expensive race fuel and your meth injection with pump gas

If anything back off the boost to where you was before (6psi),before all the other upgrades and see if you can re base line it to the 515 rwhp or better, if you back off the boost run the same pump gas as you did when you got 515rwhp the first time. Then you can turn on your meth kit and you be able to squeeze more power out of it and see how the meth kit is adding more power- since the tuner will be able to crank up the timing. even with 6lbs of boost you should see something in the 530- 540 rwhp range with the meth kit. depending on the internals of the engine it might be heavier now so you could have lost a little power, but never the less you should see fairly close to the same 515 wrhp and then see an increase in power with meth. this will just show everything is ok as before and show you the meth kit is doing it's job


if all goes well then start increasing boost till it levels off, this would require some pulley changes and you can find the limit of your fuel and see where adding boost is no longer a good trade. adding boost increase inlet temps and taxes the intercooler where it can longer help you without upgrading it.

another words more boost does not always equal more power, there will come a time where boost is just creating way to much heat and drawing to much power to turn the blower where the returns diminish quickly.

so if you move from 6 psi let's say your new base line with meth is 530 rwhp, then 10 psi makes 600 rwhp and then you move to 13 psi with no other changes and you make say 590 rwhp. that extra boost is just creating to much heat, your beyond what the fuel can do and your pumping against 3 more lbs of boost which eats crank hp because you have to work against that resistance. working up the boost level will show you the best power you can make with current fuel and meth and intercooler effeciency. you might even find moving up 1 or 2 more psi might only make 5 hp and pushing more boost past this you see hp fall.

there could be a chance at 13 lbs of boost your backsliding and you might make more power with less boost. the more you push the boost more time things need to cool down so if your tuner is doing back to back pulls will will just keep loosing power, everything is too hot.

My sons car just for example lost 40 hp with 1 degree of extra timing, this was on a 5.0 mustang boosted at 570 rwhp, his total timing was set at 13 and 14 degrees knocked it back to 530 hp, backed the timing back to 13 and ran a 570 again. this was on 91 octane fuel with no meth and it was straight gas, he was pushing around 12-13 lbs of boost.

I went from 11 lbs of boost to 15 lbs of boost any only gained 15 hp, so I need to upgrade my intercooler system, add a meth kit to get more of a gain from that boost, that four lbs of boost is really taxing my fuels ability to prevent knock and really taxing my intercooler system and I knew it would, but thought I would see if I would gain anything, I barely did, but once I upgrade the fuels ability to cool inlet charge (meth)and resistance to knock and improve my intercooler efficiency I know I will get some decent gains.

hope this helps
 

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Yeah it makes sense. I have always run shell 93 octane . Sometimes Bp 93 . I was thinking about changing to Sunoco 93 ?
 

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what meth mixture are you running? If your running straight water you won't get much of a power boost, running half water and meth gets a little better, but running straight meth with say 91 octane fuel will get you just as much power as e85 or race fuel. So thats what I'm wondering.

it's a good idea to run the best pump gas as you can, make sure it's pure gas and not the 10% mixture if you can help it.

the retarded timing is saying it's seeing knock, so I would be looking at pump gas what your using and make sure your running 100% meth, if you use straight gas of 91 octane or better and straight meth this will put you around the same as running 105-110 race gas. another words you would not see much difference in over all power between expensive race fuel and your meth injection with pump gas

If anything back off the boost to where you was before (6psi),before all the other upgrades and see if you can re base line it to the 515 rwhp or better, if you back off the boost run the same pump gas as you did when you got 515rwhp the first time. Then you can turn on your meth kit and you be able to squeeze more power out of it and see how the meth kit is adding more power- since the tuner will be able to crank up the timing. even with 6lbs of boost you should see something in the 530- 540 rwhp range with the meth kit. depending on the internals of the engine it might be heavier now so you could have lost a little power, but never the less you should see fairly close to the same 515 wrhp and then see an increase in power with meth. this will just show everything is ok as before and show you the meth kit is doing it's job


if all goes well then start increasing boost till it levels off, this would require some pulley changes and you can find the limit of your fuel and see where adding boost is no longer a good trade. adding boost increase inlet temps and taxes the intercooler where it can longer help you without upgrading it.

another words more boost does not always equal more power, there will come a time where boost is just creating way to much heat and drawing to much power to turn the blower where the returns diminish quickly.

so if you move from 6 psi let's say your new base line with meth is 530 rwhp, then 10 psi makes 600 rwhp and then you move to 13 psi with no other changes and you make say 590 rwhp. that extra boost is just creating to much heat, your beyond what the fuel can do and your pumping against 3 more lbs of boost which eats crank hp because you have to work against that resistance. working up the boost level will show you the best power you can make with current fuel and meth and intercooler effeciency. you might even find moving up 1 or 2 more psi might only make 5 hp and pushing more boost past this you see hp fall.

there could be a chance at 13 lbs of boost your backsliding and you might make more power with less boost. the more you push the boost more time things need to cool down so if your tuner is doing back to back pulls will will just keep loosing power, everything is too hot.

My sons car just for example lost 40 hp with 1 degree of extra timing, this was on a 5.0 mustang boosted at 570 rwhp, his total timing was set at 13 and 14 degrees knocked it back to 530 hp, backed the timing back to 13 and ran a 570 again. this was on 91 octane fuel with no meth and it was straight gas, he was pushing around 12-13 lbs of boost.

I went from 11 lbs of boost to 15 lbs of boost any only gained 15 hp, so I need to upgrade my intercooler system, add a meth kit to get more of a gain from that boost, that four lbs of boost is really taxing my fuels ability to prevent knock and really taxing my intercooler system and I knew it would, but thought I would see if I would gain anything, I barely did, but once I upgrade the fuels ability to cool inlet charge (meth)and resistance to knock and improve my intercooler efficiency I know I will get some decent gains.

hope this helps
Great post! :cheers: I agree that there is a point of diminishing returns when it comes to engine tuning. More is not always better.

Would turning up the amount of meth that you're using help? You could turn it up and then log your IAT's and see if it helps. By turning it up, you'd be essentially adding more fuel and making the AFR fatter. You might lose a bit of power, but fatter makes things cooler.

Could you add a can of Torco or Boostane to increase your octane and see if it makes a difference? Are you self tuning or having her tuned?

I ask because if self tuning, you can try quite more things than having to wait for your tuner to send you an updated file.
 

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As a tack on to what has already been written-

The relative volume of injection with water/meth is going to change your IATs, EGRs and AFR readings.

Depending on where, when, and how much w/m or straight meth you’re injecting, a couple of things could be happening.

You should be able to pull about 650ish from that setup, if you have no knock, your IATs are low enough and/or tuned for, and you have sufficient fueling.

1) You’re running out of fuel, getting STKN, and it’s recording the data for LTKN table adjustments.
The added heat is asking for more fuel to cool it, not getting enough at that end with that temperature, and it’s pulling timing (looks like 5-6 degrees worth).

Solution: fuel system upgrade

2) Too much injection with the water/meth

Depending on how this is set up, it’s possible you’re putting in too much, and quenching some ignition. It seems unlikely, but you need to figure out how much in percentage ratio you’re injecting against fuel. More than .6/1 (60%,) and you’re going way too hard in the paint on injection.

Solution: tune your water/meth injection.

3) Too little injection with the water/meth

Run the calcs, see what you’re putting in. If it’s less than .2/1 (20%) at WOT/max boost, you’re not injecting enough. This can cause you to pull timing, which will show up as a loss of power under confirmed boost numbers.

Solution: check logs, run injection calcs for w/m, and add in the appropriate amount. Make sure you know your AFR numbers for the fluid being injected. Have it re-tuned as needed.

4) Some combination of the above.

KB says that BAP is good to 320L/HR, and the 21V is good to 401L/HR (“around” the “750” whp mark)
As that works out to about 80% of 750... it is going to be fuel limited on the pump at around 600 hp... which is exactly what you saw at 10 lbs. pushing it harder just leaned on the w/m injector for extra fueling from the methanol, and it looks like it was insufficient to prevent lean condition knock, resulting in about 5-6 degrees of reduced “safe” timing... or roughly 40-42 hp. Which you saw on the dyno.

Recommendations:

Time to do the fuel system. You can upgrade the BAP, and extend it a bit to that 13 lbs, but probably not much more (maybe 15 max if the numbers hold true... puts you at 700ish.)
All else being equal, sufficient octane should get you there, but may not off pump gas.
My math on that follows:
If timing is unchanged, and if running stock compression.

93 gets you 8
96 gets you 10
99 gets you 12
103.5 gets you 15

You need to mitigate additional heat at 15 lbs, which is likely to be a substantial increase by the time it hits the cylinders.

Which means you need effective octane preferably above 105.
Your w/m injector should be doing that already if it’s within the operating range it needs to be. Try a mix that is .5 lbs per lb of fuel. Run the numbers, and adjust accordingly.

If you do that and the BAP upgrade, you may see some results there.


Keep in mind- I’ve been researching this same issue for a year, but I am not an expert or a mechanic- your tax dollars send me out of airplanes to do things that are accomplishable with a tenth grade reading level and reduced concern for one’s own safety, so this is not my forte. I would ask someone you trust to not blow up your engine to check my math, check your logs, and go from there.

But if I ever see you later at a car meet, I’ve got your choice of two beers or ten bucks on it being the fuel system being maxed out and the w/m mixture not making up the additional needed points on AFR.

New BAP at 21v, w/m adjustment, and a new tune to tie it together.

Cheers,

Chuck

ETA- running 100% methanol at more push might temporarily cover the issue, but won’t fix it. Bet it will come out as higher than anticipated EGRs, and the relatively rapid failure of the system- snow isn’t built to take full-time 100% methanol for extended use. 50/50 is fine, but 100% will eat the rubber on it much faster if I recall what I think I know- I’d double check that with them, but I bet you will have to replace some parts on their system to keep it from corroding connectors and tubes. Part of the reason other systems have different hoses from the start.

You will also be riding the line, so to speak, on detonation if your CR is still even close to stock because it will still be likely you will be lean on actual gas, and will end up with too much meth covering it up until it doesn’t.
 

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Dat can ‘o worms...

Been losing my mind trying to spec out a head refresh and port for this same issue as well.
Probably better for another discussion.

The Apache heads should flow well in excess of what it would take to be the limiting factor for forced induction in this application.

Doesn’t mean it can’t burn up a few things, but that’s another discussion, and probably not an issue with the w/m injection unless there’s epic heat production and retention going on.

Back to our scheduled program?
Like, does anyone have hard and fast fuel flow numbers for the scat pack with a 17.5 KB BAP, and what their upper limit was?
 

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In the same boat bought the mmx forged internal package went from 6 to 12 psi boost bigger injectors already got the better fuel pump. Before the forged internals 6 psi I made 603 whp and 542 rwt after the forge I made 588 whp 586 rwt at 5500 rpm after that the graph literally went down in the wrong direction till 6700 rpm I almost cried. But across the board it made an extra 50 whp and 70 rwt well till 5 k rpm. And it's due to iats being way to high just installed that emp Stewart w29 reprogrammed pump. And it's crazy how much more it flows than the Bosch pump on a side by side comparison just from flow I cant keep the cap off now with out it splashing out the Bosch pump no splash at all. I took it for a ride and i feel like it has a major difference from when it was last tuned 2 weeks ago and the blower does not feel nearly as hot to the touch. After driving hard on it i could not keep my hand on the blower now it just feels warm. We will see if it really makes a difference numbers dont lie when it's on the same dyno. It's there now hope to have it back Friday with some flippin great results !!! Fingers crossed
 
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