My Large Extended Ports
06-04-2005, 07:22 PM
#51
Senior Member
Join Date: Jun 2003
Location: Stacked outside you're trailer door
Posts: 1,430
[quote name='cjr' date='Jun 4 2005, 03:15 PM']would be good to see you going up the strip. come to think off it I have never seen you or your cars. 
yet you keep on talking
[/quote]
No kidding, the guy just keeps talking...
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[/quote]
No kidding, the guy just keeps talking...
06-06-2005, 03:39 AM
#52
Junior Member
Join Date: Nov 2004
Posts: 20
[quote name='cjr' date='Jun 4 2005, 03:15 PM']would be good to see you going up the strip. come to think off it I have never seen you or your cars. yet you keep on talking
[/quote]
Probably because Bill is working on more than just rotaries for people over here in the UK.
Ontop of that he has a very good reputation too and seriously does know what he is talking about.
He has helped me on a number of occasions with tuning issues,specialist parts,tuning equipment,all to good effect.He owns a Westfield with a 13b in it running fuel in jection,seriously quick,and a number of other rotaries.
Like my self he is not all consumed by the drag strip,but is invloved in fast road and circuit tuning too.He also has written a number of articles in magazines over here using his experience and knowledge to help others who are willing to listen.
There is an old adage,"A little knowledge is a dangerous thing",that seems to be apparent in tuning cars with many people,to the point where any advice offered from a knowledgeable person is put on the scrap heap because there may be some criticism that is perceived as a personal attack,when it is just someone trying to help.
I am good friends with Bill and know him to be extremely enthusiastic about rotaries,take note if you wish to of someone who can help with your rotary engine car in a very positve way.
I have learned this not just by words but also by Bill putting all that knowledge into practical applications that have worked,both on piston engines and rotaries.
And note this folks,there is much more to come from his fertile mind.
Regards
Carl
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[/quote]
Probably because Bill is working on more than just rotaries for people over here in the UK.
Ontop of that he has a very good reputation too and seriously does know what he is talking about.
He has helped me on a number of occasions with tuning issues,specialist parts,tuning equipment,all to good effect.He owns a Westfield with a 13b in it running fuel in jection,seriously quick,and a number of other rotaries.
Like my self he is not all consumed by the drag strip,but is invloved in fast road and circuit tuning too.He also has written a number of articles in magazines over here using his experience and knowledge to help others who are willing to listen.
There is an old adage,"A little knowledge is a dangerous thing",that seems to be apparent in tuning cars with many people,to the point where any advice offered from a knowledgeable person is put on the scrap heap because there may be some criticism that is perceived as a personal attack,when it is just someone trying to help.
I am good friends with Bill and know him to be extremely enthusiastic about rotaries,take note if you wish to of someone who can help with your rotary engine car in a very positve way.
I have learned this not just by words but also by Bill putting all that knowledge into practical applications that have worked,both on piston engines and rotaries.
And note this folks,there is much more to come from his fertile mind.
Regards
Carl
06-06-2005, 05:41 AM
#53
Senior Member
Join Date: Nov 2003
Location: Ireland
Posts: 907
Yep, Bill has a bit of a reputation this side of the pond, IIRC he does great work in the engine management system line. I don't know what hass gone on behind the scenes but it's an awful shame that it has come to this bantering.
Mark
Mark
06-06-2005, 07:29 AM
#54
Senior Member
Join Date: Nov 2004
Location: Europe, Belgium
Posts: 147
[quote name='bill shurvinton' date='Jun 4 2005, 02:35 PM']As for my 'torque theory' Its not a theory. Its the ideal gas law. A law of physics. Read any book on turbo theory (even maximum boost, which is not that good) and you will see that you cannot make more power than the stock engine power times the pressure ratio.
[/quote]
Stock engine is not a modified engine, If you take a stock NA engine, place other camshafts, port the cilinderhead, bigger valves, better manifolds, better ignition and more advance you'll be able to make a lot more torque then the stock engine, by still not adding any boost..
So if you want to follow your law you need to dyno the modified engine first without turbo and then add a turbo and then it might work out..
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[/quote]
Stock engine is not a modified engine, If you take a stock NA engine, place other camshafts, port the cilinderhead, bigger valves, better manifolds, better ignition and more advance you'll be able to make a lot more torque then the stock engine, by still not adding any boost..
So if you want to follow your law you need to dyno the modified engine first without turbo and then add a turbo and then it might work out..
06-06-2005, 08:23 AM
#55
Senior Member
Join Date: Nov 2003
Location: Ireland
Posts: 907
[quote name='Rub20B' date='Jun 6 2005, 01:29 PM']Stock engine is not a modified engine, If you take a stock NA engine, place other camshafts, port the cilinderhead, bigger valves, better manifolds, better ignition and more advance you'll be able to make a lot more torque then the stock engine, by still not adding any boost..
So if you want to follow your law you need to dyno the modified engine first without turbo and then add a turbo and then it might work out..
[/quote]
That's not true, you can alter the curve, but peak torque is by and large determined by the engine's displacement.
Mark
So if you want to follow your law you need to dyno the modified engine first without turbo and then add a turbo and then it might work out..
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[/quote]
That's not true, you can alter the curve, but peak torque is by and large determined by the engine's displacement.
Mark
06-06-2005, 08:57 AM
#56
Senior Member
Join Date: Dec 2002
Location: Bayou-self Louisiana
Posts: 947
I enjoy BillS comments.... we are hear to exchange ideas. And if for some reason someone points out something amiss or incorrect then take it as a comment of expressed opinion 1st and then that person can reply with supporting info.(if warrented)
Wouldnt it be something if the numbers BillS mentioned were correct and the tuning numbers dont jive with the dyno numbers but it helped us all cause of an oversite? I am too ignorant to have noticed but if it were me I would go WTF? I would ask some more question to verify because I do want the most out of my setup especially with the money and time in it. I just want performance and to be proud enough to show it here. I have the means but I dont have the time to experiment like BillS ,BDC,Judge ITO,LynnHan,etc. so thats the guys I want to say something. All it can do is make the setup better.Even if its self resolution do to this.
Now go in peace and may the Lord be with you
AAAAAAMMMMMEEEEEEEEEENNNNN............
Wouldnt it be something if the numbers BillS mentioned were correct and the tuning numbers dont jive with the dyno numbers but it helped us all cause of an oversite? I am too ignorant to have noticed but if it were me I would go WTF? I would ask some more question to verify because I do want the most out of my setup especially with the money and time in it. I just want performance and to be proud enough to show it here. I have the means but I dont have the time to experiment like BillS ,BDC,Judge ITO,LynnHan,etc. so thats the guys I want to say something. All it can do is make the setup better.Even if its self resolution do to this.
Now go in peace and may the Lord be with you
AAAAAAMMMMMEEEEEEEEEENNNNN............
06-06-2005, 05:17 PM
#57
Senior Member
Join Date: Dec 2003
Posts: 162
[quote name='Rub20B' date='Jun 6 2005, 04:29 AM']Stock engine is not a modified engine, If you take a stock NA engine, place other camshafts, port the cilinderhead, bigger valves, better manifolds, better ignition and more advance you'll be able to make a lot more torque then the stock engine, by still not adding any boost..
So if you want to follow your law you need to dyno the modified engine first without turbo and then add a turbo and then it might work out..
[/quote]
Don't disagree at all. But its the scale of the gains. lets throw some random figures out. This is a first order approximation, so perfect intercooling is assumed to make the numbers easy to present. They are also not related to any real measurements, just plucked out my head for the purposes of discussion.
Lets say a stock FD produces 260FWHP@7000RPM and 8PSI boost. 8PSI is 0.55bar so a PR of 1.55. Therefore the underlying engine power is 260/1.55 or 167HP.
Now we port it. Lets say we go bit on the porting and get a 25% increase in flow. This ups the underlying engine power to 209HP, so at the same 1.55PR we will get 325HP. Now we up the boost to 1.5 bar (2.5PR) and we get 522HP.
But of course we don't because other things prevent us ever reaching these sorts of efficiencies. Heat being the main one. Also getting a 25% increase in flow is hard work as other threads will point out. 15% is probably nearer the mark. Bigger ports will move the torque curve up higher, making more power, but all the data I have (and its not exhaustive) suggests that, even with 9.7:1 rotors you are hard pushed to exceed 160ftlbs. To get 550 flywheel at 7500RPM and 1.2 bar would require a base torque from the engine of 175lbft at that RPM IF you had a perfect isothermal compressor...which you don't have. To date I have only seen bridgeports get that level of torque, but I am always on the lookout for a real example to show it can be done.
I can go into some of the 2nd order effects if anyone is interested, but that shows the basic, back of an envelope sums that anyone can do to get an idea if something is within the realms of reality
So if you want to follow your law you need to dyno the modified engine first without turbo and then add a turbo and then it might work out..
[snapback]721721[/snapback]
[/quote]
Don't disagree at all. But its the scale of the gains. lets throw some random figures out. This is a first order approximation, so perfect intercooling is assumed to make the numbers easy to present. They are also not related to any real measurements, just plucked out my head for the purposes of discussion.
Lets say a stock FD produces 260FWHP@7000RPM and 8PSI boost. 8PSI is 0.55bar so a PR of 1.55. Therefore the underlying engine power is 260/1.55 or 167HP.
Now we port it. Lets say we go bit on the porting and get a 25% increase in flow. This ups the underlying engine power to 209HP, so at the same 1.55PR we will get 325HP. Now we up the boost to 1.5 bar (2.5PR) and we get 522HP.
But of course we don't because other things prevent us ever reaching these sorts of efficiencies. Heat being the main one. Also getting a 25% increase in flow is hard work as other threads will point out. 15% is probably nearer the mark. Bigger ports will move the torque curve up higher, making more power, but all the data I have (and its not exhaustive) suggests that, even with 9.7:1 rotors you are hard pushed to exceed 160ftlbs. To get 550 flywheel at 7500RPM and 1.2 bar would require a base torque from the engine of 175lbft at that RPM IF you had a perfect isothermal compressor...which you don't have. To date I have only seen bridgeports get that level of torque, but I am always on the lookout for a real example to show it can be done.
I can go into some of the 2nd order effects if anyone is interested, but that shows the basic, back of an envelope sums that anyone can do to get an idea if something is within the realms of reality
06-07-2005, 02:34 AM
#59
Senior Member
Join Date: Dec 2003
Posts: 162
[quote name='Old Splatterhand' date='Jun 6 2005, 10:46 PM']how does that formula count the flow-abilities of the T51 in?
[/quote]
Its a first order approximation and assumes the turbo can flow whatever the engine can ingest. Good enough for the purpose of a sense check. Just because a T51 can flow enough air for XYZHP does not mean the engine is capable of injesting that amount. You have a fixed volume being injested each revolution. You can only get more air in with either pulse tuning (inertial supercharging) or boost.
Second order analysis looks at the temperature/density issues. However here there is generally only power to be lost, not gained from the first order numbers.
Remember the second law of thermodynamics roughly says 'you lose'.
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[/quote]
Its a first order approximation and assumes the turbo can flow whatever the engine can ingest. Good enough for the purpose of a sense check. Just because a T51 can flow enough air for XYZHP does not mean the engine is capable of injesting that amount. You have a fixed volume being injested each revolution. You can only get more air in with either pulse tuning (inertial supercharging) or boost.
Second order analysis looks at the temperature/density issues. However here there is generally only power to be lost, not gained from the first order numbers.
Remember the second law of thermodynamics roughly says 'you lose'.
06-07-2005, 03:39 AM
#60
Senior Member
Join Date: Jun 2004
Location: Germany
Posts: 240
maybe i'm misunderstanding something, but let's start it simple:
at 0,8 bar the T51 flows a certain number.
are you sure this certain number equates 260 fwhp? i feel that this base number is too low to start with. i can't back that up with experience though.
at 0,8 bar the T51 flows a certain number.
are you sure this certain number equates 260 fwhp? i feel that this base number is too low to start with. i can't back that up with experience though.