Take a look at this HIGH HP dyno sheet.... questions.
02-11-06, 05:21 PM
#2
Senior Member
When did that turbo reach full boost? It looks like the pressure is not being made until 7100rpm. What is causing that flat spot in the torque curve?
Apparently the VE on the engine is always increasing over those rpms. I can only imagine that is due to ever increasing boost.
Justin
Apparently the VE on the engine is always increasing over those rpms. I can only imagine that is due to ever increasing boost.
Justin
02-11-06, 06:23 PM
#3
Original Gangster/Rotary!
iTrader: (213)
Call up Shane Racing and ask Ray Lochhead.
Pretty weird lookin' sheet. why let off when hp is still climbing? Maybe the motor was a full bridgeport or peripheral ported turbo? weird.
Pretty weird lookin' sheet. why let off when hp is still climbing? Maybe the motor was a full bridgeport or peripheral ported turbo? weird.
02-11-06, 06:31 PM
#4
Banned. I got OWNED!!!
The curve being exponential to 6500rpm means it was climbing up onto boost till this point (max boost setting at 6.5k)... The flatness can be a number of things, but after that the tapering off sector of the torque cure is what the engine as a system is doing (boost generation not dependant). It would be a built engine of some descrition combined with a overly large turbocharger that is not working to its potential for those revs.
Its great to make a peak power figure but its fairly useless when its so narrow and works for less than 1500rpm.
*** Note *** It would be nice to see it for a full 9500rpm pull which it most probably would do given that graph, then all would look much better
If it was goign to stick to 8500rpm then I would use a smaller turbo that gave a bigger band.
Its great to make a peak power figure but its fairly useless when its so narrow and works for less than 1500rpm.
*** Note *** It would be nice to see it for a full 9500rpm pull which it most probably would do given that graph, then all would look much better
If it was goign to stick to 8500rpm then I would use a smaller turbo that gave a bigger band.
02-12-06, 05:07 AM
#6
A WAR WITHOUT WEAPONS
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I have two theories.
My first guess as to why there is a flat spot in the tq curve is due to timing, or there lack of. I can only guess but I think they started to pull timing before peak tq.
My second, basically what Rice_Racing said. I also concur.
Ty
My first guess as to why there is a flat spot in the tq curve is due to timing, or there lack of. I can only guess but I think they started to pull timing before peak tq.
My second, basically what Rice_Racing said. I also concur.
Ty
02-12-06, 05:40 AM
#7
id say a combination of too much timing retard (or rather not enough advance at high revs) and too large a turbo. The flat spot could be caused by the timing at that point as this is where the timing wants to start advancing really.
On the other hand, im sure your asking this question not to get an answer (You already know the answer) so i wont make any more of a fool of myself haha.
On the other hand, im sure your asking this question not to get an answer (You already know the answer) so i wont make any more of a fool of myself haha.
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