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Any power guesses?

  • Thread starter Thread starter SMOKEDYA
  • Start date Start date Sep 18, 2010
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Cobra912

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Sep 20, 2010
#21
  • Sep 20, 2010
  • #21
you saw me with that pipe? I guess 450 is on the weak side, I made that with my little 331/1220 so I re-estimate (is that a word?)

I'll say 550.
 

NIKwoaC

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#22
  • Sep 20, 2010
  • #22
Cobra912 said:
you saw me with that pipe? I guess 450 is on the weak side, I made that with my little 331/1220 so I re-estimate (is that a word?)

I'll say 550.
Click to expand...

The thing is, turbos don't suffer from parasitic losses to the extent that superchargers do, specifically from driving the compressor with the belt drive. Turbos typically make more power per pound of boost, so basing a guess on a similar setup using a supercharger will almost always low-ball the result. You can usually get ball-park by taking the NA power of the engine times [1+turbo boost/14.7].

Example: 318rwhp X [1 + (10psi / 14.7psi)] = ~534rwhp

318rwhp X [1 + (15psi / 14.7psi)] = ~642rwhp

642 is probably wishful thinking, especially considering his fuel system.
 

FastDriver

I was uncomfortably high & wearing a helmet
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Sep 20, 2010
#23
  • Sep 20, 2010
  • #23
Interestingly to me, my car made only 362 rwhp n/a and 762rwhp at 14.5 psi, which is more than double. The difference may have been in the tune, though. A/F for the n/a run was close to 14:1, but just less than 12:1 under boost. I've read stories where boosted vehicles made more power than the formula indicated possible, but I wonder if there's any substance to that. Should it be physically possible (in the scientific manner) for a vehicle to make more than twice the power with less than twice the air if both setups are tuned correctly? There are so many variables when it comes to air-flow that it makes my head spin when I try to work out any semblance of a solution.
 
M

mwood

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Sep 20, 2010
#24
  • Sep 20, 2010
  • #24
I've never understood spending big money on heads, intake, ..., and then putting in an ots cam. As already recommended, find a custom cam grinder. Discuss your combo and be ready to be told the weak link in your setup. Ask if your should change one thing before a new cam what that would be. Listen. If the cam grinder is worth anything he should have some good advise coming your way. He is also likely to ask of your goals, so think about what those might be. You'll be much happier in the end if you do.
 

1991notchbackLX

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Dec 25, 2007
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Sep 20, 2010
#25
  • Sep 20, 2010
  • #25
mwood said:
I've never understood spending big money on heads, intake, ..., and then putting in an ots cam. As already recommended, find a custom cam grinder. Discuss your combo and be ready to be told the weak link in your setup. Ask if your should change one thing before a new cam what that would be. Listen. If the cam grinder is worth anything he should have some good advise coming your way. He is also likely to ask of your goals, so think about what those might be. You'll be much happier in the end if you do.
Click to expand...



Is there an echo in here?
 
M

mwood

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#26
  • Sep 20, 2010
  • #26
1991notchbackLX said:
Is there an echo in here?
Click to expand...

(goes back up to read)... I guess so. Great minds huh.
 

90lxcoupe

20+ Year Stangneter
Oct 7, 2003
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Sep 20, 2010
#27
  • Sep 20, 2010
  • #27
FastDriver said:
Interestingly to me, my car made only 362 rwhp n/a and 762rwhp at 14.5 psi, which is more than double. The difference may have been in the tune, though. A/F for the n/a run was close to 14:1, but just less than 12:1 under boost. I've read stories where boosted vehicles made more power than the formula indicated possible, but I wonder if there's any substance to that. Should it be physically possible (in the scientific manner) for a vehicle to make more than twice the power with less than twice the air if both setups are tuned correctly? There are so many variables when it comes to air-flow that it makes my head spin when I try to work out any semblance of a solution.
Click to expand...

My car also disproved that formula, should have made a max of 445 by those numbers at 10psi.
 

NIKwoaC

中國製造
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Sep 20, 2010
#28
  • Sep 20, 2010
  • #28
FastDriver said:
Interestingly to me, my car made only 362 rwhp n/a and 762rwhp at 14.5 psi, which is more than double. The difference may have been in the tune, though. A/F for the n/a run was close to 14:1, but just less than 12:1 under boost. I've read stories where boosted vehicles made more power than the formula indicated possible, but I wonder if there's any substance to that. Should it be physically possible (in the scientific manner) for a vehicle to make more than twice the power with less than twice the air if both setups are tuned correctly? There are so many variables when it comes to air-flow that it makes my head spin when I try to work out any semblance of a solution.
Click to expand...

Exactly, there are so many variables in engine thermodynamic principles, no formula can predict anything exactly. For the cars that stray significantly ABOVE the predicted result, I have to believe that something wasn't quite right before the boost, or maybe not "optimal", and then with the boost and/or tune, it was "optimal". Hell, even atmospheric conditions could play into that quite a bit, consider that a lot of people probably don't luck out enough in having the exact same weather the day they dyno NA and the day they dyno on boost.
 

SMOKEDYA

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Sep 20, 2010
#29
  • Sep 20, 2010
  • #29
The tuner is thinking right around 600 WHP,but i didnt ask or did he say if that was with my fuel system.He knows my car as he's the one that tuned my N/A tune.I know the cam is the hold back!I found that out after i bought it and ran the dyno.BUT i did ask on here for suggestions for the cam when i built the N/A motor.But like i said i will be getting a custom grind once i switch to roller (hopefully over the winter),and then onto the fuel system.I will also run the meth Then we'll see if i can take the lower intake off and see if the block will fall apart in 2 pieces?This is part 2 of my 3 part build and part 3 is gonna be some $$$$$$$$$$$$$$$$$$$$$$$$$$$$$ so it might be a year?Or even 2 but it will be worth it! Ben you better step up! I should have everything by this weekend so i'm hoping to dyno the 2nd week of oct. peace










john
 

bentley429isBAC

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Jul 23, 2009
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Sep 20, 2010
#30
  • Sep 20, 2010
  • #30
FastDriver said:
It's a rare event, but I disagree with you bentley. He's not going to run out of injector at 600rwhp. Now, he didn't mention the fuel pump or the rest of the system. Stock lines would not be appropriate, and even a 255LPH pump is going to be on the ragged edge at best especially at the pressure the system will have to withstand at full boost (55-65psi), but the 60# injectors should be up to task.

Chris
Click to expand...

Na your right was having a space cadet moment I guess.
 
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