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I dont know much about turbo's so just a random logical guess lol but is 7psi for both but different bhp results between the 2 not more to do with the internal goings on of the engine ie, the compression?
Turbo's benafit from lower compession where as SC dosent necceseraly need it to function fully?
Turbo's benafit from lower compession where as SC dosent necceseraly need it to function fully?
Stevieh
You cant really "add" power lost by the charger. The net result is what is important.
Whats the spec of your engine?
Has the turbo been properly matched to it?
Have the camshafts been matched to this?
Im guessing not. Im guessing its a hit-and-hope conversion, which with turbochargers is always going to be more make or break. (this isnt a dig at you, more a reflection of reality when companies bolt random parts on and hope for the best).
With a s/c you dont have as large an issue with compressor mapping for c/r or cam profiles, and as said the na spec cams will be more suited to a sc application in general.
This cumulative error could easily be 50bhp.
I aggree, it would be nice to see some of the claimed figures for s/c kits verified, but I am no way suprised by the difference.
You cant really "add" power lost by the charger. The net result is what is important.
Whats the spec of your engine?
Has the turbo been properly matched to it?
Have the camshafts been matched to this?
Im guessing not. Im guessing its a hit-and-hope conversion, which with turbochargers is always going to be more make or break. (this isnt a dig at you, more a reflection of reality when companies bolt random parts on and hope for the best).
With a s/c you dont have as large an issue with compressor mapping for c/r or cam profiles, and as said the na spec cams will be more suited to a sc application in general.
This cumulative error could easily be 50bhp.
I aggree, it would be nice to see some of the claimed figures for s/c kits verified, but I am no way suprised by the difference.
182 Cup
This is badly written, but it's the only thing I can find on the net at the moment -
http://www.200sxs13.nismo.org/turbo_conversation.html
Read the first question - "How can different size turbochargers running the same amount of boost produce different BHP results?"
Now relate this to your question. I'm wondering whether you may not even be comparing like with like when it comes to size.
http://www.200sxs13.nismo.org/turbo_conversation.html
Read the first question - "How can different size turbochargers running the same amount of boost produce different BHP results?"
Now relate this to your question. I'm wondering whether you may not even be comparing like with like when it comes to size.
Hello mate thanks for the constructive replies.
My cars spec is.
GT28 turbo
Janspeed cat back
Decat
Open induction kit.
Front mounted IC
Standard internals CR etc...
I find it hard to accept that they are a mish mash of components as theres a number of clios running these components quite successfully.
All I can suggest, is that if there are other clio's running the same turbo orientated spec/set-up, with more engine output, then you find out why yours is less as seamingly there is a problem with your car.
But as for a comparison between yours and a SC set-up, theres numerous reasons for the difference.
But as for a comparison between yours and a SC set-up, theres numerous reasons for the difference.
Vw caddy tdi
Very hard comparison to make both technically totally opposite systems. The sc takes power from belt system, and turbo pre heats/compresses exhaust gasses. Maybe other peoples turbos havent been checked on acurate rollers? Known fact that rs tunning is an ego buster, also not excatly cold/ low pressure weather at moment maybe at 0'c on diff roller set up could make 220 easy.
Folks without trawling the entire thread of responses the answer is simple. Pressure is pressure but flow is different based on the both compressor & turbine wheel sizes.Whilst you mention a 28 housing there are many trims in which that can be supplied which will affect flow. Also noting that 7 psi is nothing in terms of boost even on a converted set up. I'd suggest that you would be perfectly within the limits of stock internals at 10 psi. What is more important to consider is torque delivery as too much low end will fatigue the rods whereas a peak torque at close to rev limiter speeds on stock internals will probably cause ringland failure as the rate of inertia between the top & bottom of the bore stroke again can become fatigued on non forged components. Suggest you PM if you want to go into more detail as turbo's are my specialty subject
Regards Jamie
Regards Jamie
ValverInBits
This is excellent stuff.
It explains that turbos create high pressures in exhaust manifold due to the restriction they make. This can increase the exhuast pressures so much that when the exhaust valve and valve cam are open at the same time (valve overlap - NA cams will have this) there is back flow of exhaust gas through the cylinder.
It suggests no valve overlap and opening the inlet valve later (30 deg after TDC).
With a bit of research (turbine maps, compressor maps) on your GT28R you should be able to calculate your pressure ratio (exhaust to inlet) at different points in the rev range and see if you are likely to be seeing backflow
not a snowball's chance in hell of doing that.
Stans got it.
Boost is boost when your simply looking at it from an absolute level in the inlet manifold, but when you apply the dynamics of a working engine system, it means very little.
Even assuming the relative corrected air density is exactly the same, the actual mass of air consumed will differ AND the efficiency of the energy converted will differ.
A turbo IS more efficient than a supercharger, but not when your running (probably) a log manifold, a cylinder head that has no concept of turbo efficiency, IO/IC/EO/EC timing events which are apalling for low boost application, a vvt system which works against efficient cylinder filling in a turbo app....so on and so forth.
The supercharger is simply adding positive boost on one side with no system changes anywhere else. The effect is the same as running the car at roughly -15,000' below sea level.
Boost is boost when your simply looking at it from an absolute level in the inlet manifold, but when you apply the dynamics of a working engine system, it means very little.
Even assuming the relative corrected air density is exactly the same, the actual mass of air consumed will differ AND the efficiency of the energy converted will differ.
A turbo IS more efficient than a supercharger, but not when your running (probably) a log manifold, a cylinder head that has no concept of turbo efficiency, IO/IC/EO/EC timing events which are apalling for low boost application, a vvt system which works against efficient cylinder filling in a turbo app....so on and so forth.
The supercharger is simply adding positive boost on one side with no system changes anywhere else. The effect is the same as running the car at roughly -15,000' below sea level.
ITB'd MK1
or actuate the VVT correctly
ITB'd MK1
ITB'd MK1
not as much as 10%!!!! more like 1hp
other way around, 10C is worth about 3%, it's not quite that straightforward as the ECU may do strange things, but it's a ballpark figure.
Mate everthings going well have done 4000 miles hassle free.
Had a run out with a few of the clio trophy boys a couple of weeks ago and they were pretty impressed at the performance difference.
It really is a blast to drive as nobody expects a little red clio to be so quick lol
Had a run out with a few of the clio trophy boys a couple of weeks ago and they were pretty impressed at the performance difference.
It really is a blast to drive as nobody expects a little red clio to be so quick lol
It's not quite a straightforward as that full stop unfortunately and not just because of how the ECU may be calibrated. It's far too complicated and there are far too many variables to simply stick an XdegC is worth Y% power formula on it and thats before you factor in various forms of forced induction and fuel types.
Cheers
M
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