Vortech 2.93 pully
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From: Charlotte, NC
Originally Posted by prescience
Booger, I agree. However, at same level of boost (S/C vs TT) it would seem to me that a S/C which builds torque up progressively from 1000 rpm say (to a max at redline) would have less dramatic effect on the rods than a TT where the boost is zip until 3000 rpm say when it whams in with full force.
What I mean is that the rate of change of torque would be nice and linear (a continuous function vs time) with S/C and very large (a discrete step-change) with TT.
Still a TT will always win a drag race (all else being equal) provided the guys takes off at >3k rpm!
Plus I'm surprised it takes 20% at the top end to turn the compressor - that is high; I don't doubt it, but it is a high percentage
What I mean is that the rate of change of torque would be nice and linear (a continuous function vs time) with S/C and very large (a discrete step-change) with TT.
Still a TT will always win a drag race (all else being equal) provided the guys takes off at >3k rpm!
Plus I'm surprised it takes 20% at the top end to turn the compressor - that is high; I don't doubt it, but it is a high percentage
This is correct. The rate of change in power is more dangerous than the actual power (this does not necessarily mean the actual power cannot be dangerous, though). A rapid rate of change in power is more stressful to the system. This is the reason nitrous is very dangerous way to get power if it is not set up properly.
Originally Posted by prescience
Booger, I agree. However, at same level of boost (S/C vs TT) it would seem to me that a S/C which builds torque up progressively from 1000 rpm say (to a max at redline) would have less dramatic effect on the rods than a TT where the boost is zip until 3000 rpm say when it whams in with full force.
What I mean is that the rate of change of torque would be nice and linear (a continuous function vs time) with S/C and very large (a discrete step-change) with TT.
Still a TT will always win a drag race (all else being equal) provided the guys takes off at >3k rpm!
Plus I'm surprised it takes 20% at the top end to turn the compressor - that is high; I don't doubt it, but it is a high percentage
What I mean is that the rate of change of torque would be nice and linear (a continuous function vs time) with S/C and very large (a discrete step-change) with TT.
Still a TT will always win a drag race (all else being equal) provided the guys takes off at >3k rpm!
Plus I'm surprised it takes 20% at the top end to turn the compressor - that is high; I don't doubt it, but it is a high percentage
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Joined: Jul 2005
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From: Across the Pond United Kingdom
Originally Posted by Barzten1
A member here on the boards called me out in a G35 with the Turbonetics single turbo and he's getting like 40more lbs of torque and I spanked him from a line by over 2 cars.
Booger, I edited my last post with a link to a det/pre-ign article
Originally Posted by prescience
Thanks Booger, thats $$ saved on lots of levels.
Presumably you got no warning signs with your detonation then? Did the piston break at the edge or on the crown? You were sick, sick, sick that day I'm sure.
This article is quite interesting on det. and pre-ignition
http://www.streetrodstuff.com/Articl...tion/index.php
with the following comments from an Automotive Engineer:
Typically APMAX (angle to Pmax) is around 7-10 deg not 14 as he states.
Knock is typically most easily defined in the 12-16kHz region not 6.4kHz as he states (it would pretty much then be a combustion and engine noise measurement device rather than a knock measurement device if it used such a low frequency)
Presumably you got no warning signs with your detonation then? Did the piston break at the edge or on the crown? You were sick, sick, sick that day I'm sure.
This article is quite interesting on det. and pre-ignition
http://www.streetrodstuff.com/Articl...tion/index.php
with the following comments from an Automotive Engineer:
Typically APMAX (angle to Pmax) is around 7-10 deg not 14 as he states.
Knock is typically most easily defined in the 12-16kHz region not 6.4kHz as he states (it would pretty much then be a combustion and engine noise measurement device rather than a knock measurement device if it used such a low frequency)
I don't think that too much boost is the issue the vortech head unit that comes with the kit is efficient to about 15psi which I don't think you would see with that pulley. There are three things you have to look at, one air flow I would not suggest going with that small of a pulley with out full exhaust. Another thing is with a plenum, full exhaust and the 3.12 pulley we have been 400-420hp you have to remember the 350z rods are not the strongest rods in the world you are getting close to the limit. Last your deff going to max out the stock injectors going with 2.87 so you would have to step them up also.
Thread Starter
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From: Across the Pond United Kingdom
My reading of this is that it should (repeat should) on balance be OK to run with a 3.12 pulley with a modified tune and belt with stock rods etc - but you can never be sure that you won't get unlucky.
Dropping to 2.87 pulley, the odds are a bit more stacked against you and you need to very sure that your tuner is competent and understands the s/w and car thoroughly.
Dropping to 2.87 pulley, the odds are a bit more stacked against you and you need to very sure that your tuner is competent and understands the s/w and car thoroughly.
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