low compression 548 dyno testing has begun!!
03-27-2017 | 05:29 AM
#221
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From: frankenmuth michigan
You arent taking intake manifold air temperature readings are you smitty ? I noticed on non intercooled roots setup, with carbs, man, the intake air temp drops when the throttles are opened. At cruise speed in the boat, even at 0 boost, the temps are hotter than they are at wot and 8lbs of boost. Id imagine the fuel has to have a decent cooling effect on the air charge.
I guess if you saw say a 20 plus degree increase in intake air temperature, along with the decrease in power, it would kinda make sense. But if the temps were nearly identical, then id think something else was going on . It really be interesting to see how a carb would stack up against port efi when its mid august and the ambient is 90+ degrees.
At 4400rpm, where shes down 60ft lbs, what was the carb setup timing at 4400, vs the efi setup?
I guess if you saw say a 20 plus degree increase in intake air temperature, along with the decrease in power, it would kinda make sense. But if the temps were nearly identical, then id think something else was going on . It really be interesting to see how a carb would stack up against port efi when its mid august and the ambient is 90+ degrees.
At 4400rpm, where shes down 60ft lbs, what was the carb setup timing at 4400, vs the efi setup?
03-27-2017 | 05:29 AM
#222
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From: frankenmuth michigan
You arent taking intake manifold air temperature readings are you smitty ? I noticed on non intercooled roots setup, with carbs, man, the intake air temp drops when the throttles are opened. At cruise speed in the boat, even at 0 boost, the temps are hotter than they are at wot and 8lbs of boost. Id imagine the fuel has to have a decent cooling effect on the air charge.
I guess if you saw say a 20 plus degree increase in intake air temperature, along with the decrease in power, it would kinda make sense. But if the temps were nearly identical, then id think something else was going on . It really be interesting to see how a carb would stack up against port efi when its mid august and the ambient is 90+ degrees.
At 4400rpm, where shes down 60ft lbs, what was the carb setup timing at 4400, vs the efi setup?
I guess if you saw say a 20 plus degree increase in intake air temperature, along with the decrease in power, it would kinda make sense. But if the temps were nearly identical, then id think something else was going on . It really be interesting to see how a carb would stack up against port efi when its mid august and the ambient is 90+ degrees.
At 4400rpm, where shes down 60ft lbs, what was the carb setup timing at 4400, vs the efi setup?
03-27-2017 | 07:25 AM
#223
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From: Fredericksburg, Va
Smitty, I am not surprised at all by what you are seeing, I have have followed many intake/carb/EFI shootouts, one stands out as they did a LS one a while back, the carb setup had the most HP of all the ones tested, including several EFI's, again great work !!!!
03-27-2017 | 10:50 AM
#224
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From: frankenmuth michigan
What size tb was on the intake you sold to rob, i am going thru his outdrives soon and if it's smaller i may borrow it from him
03-27-2017 | 08:03 PM
#225
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From: FredVegas, Va
Thanks again for doing all this. I feel like we need to setup a GoFundMe page for you to help pay for the gas at least!
03-27-2017 | 10:43 PM
#226
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From: frankenmuth michigan
I like to know im at least helping a few people, out of the little bit of tuning i have done this time i mentioned finding yet another stumbling point, motor dropping the green black batch of injectors out after a while. The cool thing after i found the high ect causes rpm reduction and threshold was set at 69 c, i have spoke to two people since then that have had this problem and never figured it out!! Guy named frank from Maryland told me he built a motor, tuned it for somone, when his friend drives it and comes off plane, it starts cutting out and chugging but goes away before they can ever see why. He opened up the tune while we were on phone and sure enough, the threshold was set the same, thats cool stuff, bam, ghost problem fixed by a key stroke!thats the kind of stuff that makes this stuff worth it!!
Last edited by articfriends; 03-27-2017 at 10:57 PM.
03-27-2017 | 11:39 PM
#228
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From: frankenmuth michigan
Funny thing is found the 69.9 in several tines i had, frank found same number and a michigan guy found same number, the return number was like 65c, some stock tunes its turned off, some tunes its set at 98/99 c, now most boat stats are actually at 140 degrees? Not sure if thats true as ive never looked hard but strange there are 3 tunes in 3 different areas with THAT number!
03-28-2017 | 05:57 AM
#229
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From: Fredericksburg, Va
thats sounds about right, we tried one of those big ones accel was selling and could not get the boat to idle, same one gimme fuel has I'm pretty sure, talked to accel and they had issues and discontinued them. PS Smitty, know you are busy...but damn how long before you call me back ??????????
