SMALL SUPERCHARGER
Discussion
LINDEN said:
525 BHP AT 5PSI PROVEN ON OUR DYNO..
339 BHP STANDARD
CAR FEELS GREAT, REALLY STRONG ALL THE WAY TO THE RED LINE.
339 BHP STANDARD
CAR FEELS GREAT, REALLY STRONG ALL THE WAY TO THE RED LINE.
Normally I'd expect the power gain to be less than the pressure increase. Here, a pressure increase of 1.36 has apparently increased the power by a factor of 1.55. Are you sure you got those figures right? Did you measure the 'before' figure on your dyno too?
GSI_Daz said:
Excuse my ignorance, but where does then 1.36 come from?
*prepares to learn*
*prepares to learn*
It's the absolute pressure in bar, i.e. the ratio between the absolute pressure with and without the supercharger. This tells you how much the charge density will have increased by assuming perfect intercooling, and this is pretty much the upper limit of the power increase you can expect. Normally you'd expect to get rather less than that because the intercooler is never perfect, and you're likely to be compromised on the ignition timing.
GreenV8S said:
GSI_Daz said:
Excuse my ignorance, but where does then 1.36 come from?
*prepares to learn*
*prepares to learn*
It's the absolute pressure in bar, i.e. the ratio between the absolute pressure with and without the supercharger. This tells you how much the charge density will have increased by assuming perfect intercooling, and this is pretty much the upper limit of the power increase you can expect. Normally you'd expect to get rather less than that because the intercooler is never perfect, and you're likely to be compromised on the ignition timing.
This is like going back to school
OK, I am nearly there
Normal atmospheric pressure is 1.01325 bar and 5psi = 0.344738 bar. So the increase is: 1.357988 / 1.01325 = 1.34 = 34% increase.
One of my figures must be wrong but thanks for the lesson GreenV8S
FULL TECHNICAL INFORMATION AND DYNO GRAPH WILL BE POSTED ON THIS SITE AND LSV'S FORUM TOMORROW......
Just to keep you all interested the POWER FIGURES are at the flywheel, and in answer to the " Boost Verses Power Increase" these figures are down to acturate dyno mapping in an climate controlled cell.
The engine is a LS1 that the small supercharger has been fitted to and the LS2 version is coming soon.
The car is ready for test drives, please call to arrange and you can then see for yourself.
Also as a matter of interest we have fitted....6.3 supercharged - intercooled - trackspec - huge horepower - Monaro
Just to keep you all interested the POWER FIGURES are at the flywheel, and in answer to the " Boost Verses Power Increase" these figures are down to acturate dyno mapping in an climate controlled cell.
The engine is a LS1 that the small supercharger has been fitted to and the LS2 version is coming soon.
The car is ready for test drives, please call to arrange and you can then see for yourself.
Also as a matter of interest we have fitted....6.3 supercharged - intercooled - trackspec - huge horepower - Monaro
Who needs miles on them !!! I was racing mine with less than 500 miles on it lol.
Many people have different theory's on how to run an engine in, but lately, more down to timing than anything else, most engine's Ive been involved with, simply havent had the time to be "run in"
I havent seen any ill effects from not doing so. My own with about 2000 miles on it now, and some extreme useage, doesnt even use a drop of oil !!
Not that I'm reccomending others do it, just though it was nice to see, lack of run in procedure isnt doing them any harm.
Good luck with both projects..
What blower are you using for the 6.3 ?? What spec build ?? I'm spinning the YSi pretty hard, and can barely make 18psi.
Many people have different theory's on how to run an engine in, but lately, more down to timing than anything else, most engine's Ive been involved with, simply havent had the time to be "run in"
I havent seen any ill effects from not doing so. My own with about 2000 miles on it now, and some extreme useage, doesnt even use a drop of oil !!
Not that I'm reccomending others do it, just though it was nice to see, lack of run in procedure isnt doing them any harm.
Good luck with both projects..
What blower are you using for the 6.3 ?? What spec build ?? I'm spinning the YSi pretty hard, and can barely make 18psi.
GreenV8S said:
GSI_Daz said:
Excuse my ignorance, but where does then 1.36 come from?
*prepares to learn*
*prepares to learn*
It's the absolute pressure in bar, i.e. the ratio between the absolute pressure with and without the supercharger. This tells you how much the charge density will have increased by assuming perfect intercooling, and this is pretty much the upper limit of the power increase you can expect. Normally you'd expect to get rather less than that because the intercooler is never perfect, and you're likely to be compromised on the ignition timing.
I'm running about 6psi on my sbc, I figured that its about a 100bhp increase. Just checked last nights datalogs, 140kpa on boost - vs 97kpa ambient - that's a PR of 1.44.
Edited by eliot on Monday 7th August 23:27
all sounds very interesting - all i need is a car :-)
and a spare £3k :-(
the boost pressures are all so low in comparison to the delta i had with a monster 1.7bar of boost (obviously a very different engine of course)
just shows how poorly the LS1 must breathe - such small boosts making a massive difference.
is the breathing valve or cam lift related?
and a spare £3k :-(
the boost pressures are all so low in comparison to the delta i had with a monster 1.7bar of boost (obviously a very different engine of course)
just shows how poorly the LS1 must breathe - such small boosts making a massive difference.
is the breathing valve or cam lift related?
never thought of it a restriction before - yeah makes sense.
still to get a car to not self destruct at 1.7bar is quite an achievement in my books ;-) - shame the clutches were the week spot on my old car.
back on topic - had a blast around the block in the linden SS/C car today - very impressive for the money (cheers mark for the blast around the block). Very neat installation - ideal for a road car - i asked myself do you really need any more power? errrrrr.... in the real world no - in the pub yes perhaps....
I'm on to the insurance people in the morning to see if its feasible or not regarding cost of premium :-)
still to get a car to not self destruct at 1.7bar is quite an achievement in my books ;-) - shame the clutches were the week spot on my old car.
back on topic - had a blast around the block in the linden SS/C car today - very impressive for the money (cheers mark for the blast around the block). Very neat installation - ideal for a road car - i asked myself do you really need any more power? errrrrr.... in the real world no - in the pub yes perhaps....
I'm on to the insurance people in the morning to see if its feasible or not regarding cost of premium :-)
Smaller engines, or those with poor breathing simply need to use more boost to make similar power...
Or that extra boost, is created, because the engine cannot breathe.
Most ive used on an engine so far is about 2.4 bar ( not an LS1 obviously, as that would be mental )
I like boost
Or that extra boost, is created, because the engine cannot breathe.
Most ive used on an engine so far is about 2.4 bar ( not an LS1 obviously, as that would be mental )
I like boost
Edited by stevieturbo on Thursday 10th August 00:01
Edited by stevieturbo on Thursday 10th August 00:02
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