need a little help explaining this chart. This was my first time on a dyno, i realize that it was in the low 90's, but the corrected number would still be 426hp. i feel like i should have put down quite a bit more power than i did running the setup in my sig. im thinking the tuning is off. and why would it show my max hp past 3500rpm? thanks for the help.
pulled in 5th gear, i always thought that the pulls should be made in which ever gear is 1:1 in the trans, that being 4th. the operator said otherwise, truck didnt shift.
thats kinda what i thought, i had never been on a dyno before today, but i have seen alot of dyno graphs. mine looks completely out of the norm. i dont know why i would have a big dip where i would be under full boost, unless the truck defuels under boost. if that were the case why would it be showing peak hp above 3500rpm where boost is around 53psi.?
Dirk, final drive being 5th? i am running a valair ceramic button. its rated at 600hp and 1100ft/lbs and it never seemed like it was slipping.
no, the power is smooth all the up. i just put a big mallory pump in. i would think that if i was low on fuel that it would drop off. how is it possible that i have a 100hp and 150ft/lb jump in a 50rpm window, all the way up at 3400rpm? the pulls all felt smooth.
the rear axle seems to be operating fine, i would think if there were an issue bad enough to rob that much power that something would have gone out by now, and that it would be seen across the board, but i guess weirder things have happened.
im going to hook up some gauges for fuel and hpop, that will rule those out. i do have some data logs from awhile back when i first got the tunes.
well, from the day i got the tuning i havent been really happy with it. it puts out a constant haze of smoke on the freeway, the mileage dropped by 3mpg, and even in the stock tune i cannot accelerate without putting out smoke. the turbo makes almost no boost until im over 2000rpm. i dont know where to turn.
kinda what i was thinking, i was also in shock when they told me the reading after the first pull. there is no smoke out of the stack at idle. even if a cylinder was low on comp wouldn't the graph still be a nice curve, just not make as much hp. even if i had a boost leak wouldnt the pull still look somewhat normal. that drop, big flat spot, then the sharp peak is what has me worried.
plenums are sealed, i have hit 60psi max on the street. typical boost is around 53psi.
i am going to hook up some fuel and hpop gauges to monitor them to make sure they are in check.
sorry about the long post, but i really want to get this figured out as soon as possible.
check the intake plenums good.... had mine spring a leak at only 90k on her... two weeks later had to do it all again.... same spots... bad thing is that noone that i talked to had ever heard of the plenums leaking... and thats only with mid to high 30's in boost psi... anyone else hear of this?
It looks like there is something odd going on with your truck that is very predictable and repeatable.... and it just happens to lose 50-100HP through your mid range everytime it happens.... I would think that you would feel the truck lay over and give up when you get to about 3100 RPMs everytime you are out running it.
after the first three runs i changed from my drag tune to my pull tune to see if it changed. it didnt, made more power but has the same weird shape to it. it doesnt sound like it lays over at all.
Hey guys talk to Matt. Yuba is a middle spot for you both and I'm sure he would be happy to help out and let you use his shop. Let me know what you think. You both should have his cell #.
well... no boost leaks, fuel pressure doesn't drop below 50psi on a wot run at 53psi of boost. hpop pressure at wot gets up to 3000psi and holds there. what else can i check?
Not sure. Probably taken the boat out on the river. I just sent the videos to Dave at swamps, not sure i need to do data logging. Also ordered a set of coated headers today from Jason at Murff racing. cant wait to get those on, i really hope they are going to clear the steering.
thank you Dave. if the HP number is still valid then why soo low? i can do some data logging that may show something happening at 3100 rpm but i cant feel it fall off based on my seat dyno. i have those headers on their way and i'd like to put on some water/meth injection. after those i will do some more dyno runs.
I could build 3 sets of injectors...use the same intensifier piston, same plunger & barrel assembly, use the same nozzle annnd tuning...and by setting up some internal clearances differently between the sets have (literally) hundreds of hp of variance.
you could have something else going on with the truck...but the injectors are suspect.
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