my extended street port
06-19-05, 05:51 PM
#51
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Originally Posted by BLUE TII
Bill, it seems to me there are more factors involved in comparing a streetported NA motor to a streetported turbo motor than adding in the additional atm. of pressure available. I don't see how simple division is going to work (ie. 470rwhp turbo @ 1atm. boost = 235rwhp na w/ no boost.)
For one, I would consider how important intake air velocity is on an NA streetport. You can't just port big and expect power- you have to match the intake mani. length and increase the engine RPM in order to get the velocity to support filling the engine w/ the bigger ports.
When Dave Lemon @ Mazdatrix was developing the 6-port motor w/ the aux and 2ndary ports siamesed so it was a 4 port "street port" motor for the rules of the racing class he had a hard time playing w/ manifold lengths (intake/exhaust) in order to get the peak torque under 10,000rpm. He needed to limit RPM for reliability as the race class allowed only "limited" internal changes. It is rumored the leading cars in this class are running more than 200rwhp- you can bet he wasn't going through all this effort and reliability issues if the siamesed 6 port wasn't showing promise of making more.
A large streetport 3rd gen motor has a LOT of port area (consider how tiny even max ported NA primary ports are), but one doesn't need to worry about intake air velocity since the turbo keeps the velocity up and the power will peak at a far lower rpm than the same ports NA.
In another thread you mentioned the same RWHP with a BDC half bridge S4 TII engine was believable? I was confused because it seems to me a large streetport 3rd gen has more port area, better flow and timing dynamics than a BDC half bridge S4 TII. The 3rd gen iron has a lot more material at the top of the port before you hit waterjacket than the S4. If you cut the long 3rd gen port 2-4mm into the cornerseal track on all 4 ports you gain more port area than the small shorter bridge on the two 2ndary S4 ports that don't even go into the water seal groove and have to keep the inner cornerseal track for strength. Not to mention the flow dynamics are better for the larger single port than the port w/ small bridge. The intake opening/closing timing on the 3rd gen streetport is going to suit the stock intake manifolds length A LOT better than a half bridge on stock TII manifolds as well.
Others have made similar power at similar boost and dynoed and raced to back it up. For example Kabooski made 480RWHP at 15psi and 520RWHP at 20psi on his streetport and is pulling wheelstands and the high MPH you would expect w/ his power in his 2nd gen.
Being sceptical is a good practice, but I think asking about the details of their set-ups might help one make the power they are.
For one, I would consider how important intake air velocity is on an NA streetport. You can't just port big and expect power- you have to match the intake mani. length and increase the engine RPM in order to get the velocity to support filling the engine w/ the bigger ports.
When Dave Lemon @ Mazdatrix was developing the 6-port motor w/ the aux and 2ndary ports siamesed so it was a 4 port "street port" motor for the rules of the racing class he had a hard time playing w/ manifold lengths (intake/exhaust) in order to get the peak torque under 10,000rpm. He needed to limit RPM for reliability as the race class allowed only "limited" internal changes. It is rumored the leading cars in this class are running more than 200rwhp- you can bet he wasn't going through all this effort and reliability issues if the siamesed 6 port wasn't showing promise of making more.
A large streetport 3rd gen motor has a LOT of port area (consider how tiny even max ported NA primary ports are), but one doesn't need to worry about intake air velocity since the turbo keeps the velocity up and the power will peak at a far lower rpm than the same ports NA.
In another thread you mentioned the same RWHP with a BDC half bridge S4 TII engine was believable? I was confused because it seems to me a large streetport 3rd gen has more port area, better flow and timing dynamics than a BDC half bridge S4 TII. The 3rd gen iron has a lot more material at the top of the port before you hit waterjacket than the S4. If you cut the long 3rd gen port 2-4mm into the cornerseal track on all 4 ports you gain more port area than the small shorter bridge on the two 2ndary S4 ports that don't even go into the water seal groove and have to keep the inner cornerseal track for strength. Not to mention the flow dynamics are better for the larger single port than the port w/ small bridge. The intake opening/closing timing on the 3rd gen streetport is going to suit the stock intake manifolds length A LOT better than a half bridge on stock TII manifolds as well.
Others have made similar power at similar boost and dynoed and raced to back it up. For example Kabooski made 480RWHP at 15psi and 520RWHP at 20psi on his streetport and is pulling wheelstands and the high MPH you would expect w/ his power in his 2nd gen.
Being sceptical is a good practice, but I think asking about the details of their set-ups might help one make the power they are.
- I'm not trying to make the power 'they' are. I have a turbo project, but its a single rotor destined for a half ton or so clubman. In a light car 300HP goes as far as 600 in a big heavy FD. I don't drag race, but that does not affect the physics of the issue.
- I'm well aware of the fundamental thermodynamics of things. Now if there is a disagreement between theory and practice, the correct approach is to try and find out where the issue lies. Only Peter G (RICE RACING) has been able to propose a mechanism. He has instrumented cars and we have exchanged a few PMs, more of which in a min.
- Runner size is not the issue hear. That affects ultimate flow, and we are not in a regime at these boost levels where i believe that to be the case.
So back to Peter's input to this. the ideal gas law states PV=nRT. To get more power you need to either get more volume of air in, higher pressure, or lower temperature. To exceed a straight torque multiplication you need to increase the volume of air ingested. The only mechanism available for this is improved scavenging over a NA streetport. So lets try out this theory. Using the engine calculator at http://not2fast.wryday.com/turbo/glo...rbo_calc.shtml (BTW this was produced by someone who writes engine simulators for the big OEMs, so it is backed up by a lot of practical experience), let us consider the following.
A 2.6L engine with air at 21°C (roughly STP) and 100% VE (complete scavenging) produces on this 190HP at 6000RPM. This is only possible if you can get Exhaust back pressure lower than inlet boost pressure, which Peter assures me a large turbo on a good manifold can (with data to back this up).
I've picked a GT42 as closest available to the sort of unit Brian is running and set boost to 20PSI. This gives 414HP at 6000RPM, with a compressor efficiency of 77% and a 75% efficient intercooler giving inlet temps of 48°C. With an 85% efficient intercooler you get up to about 425HP (all flywheel remember).
With a healthy dose of water injection on top of this (say 10% of fuel flow), 460HP can be reached due to inlet cooling. But that is ideal conditions with everything going your way, unless someone can prove to me that VE's above 100% can be achieved.
Obviously with simulators you can play all sorts of tricks as it has no sense checker, but I am comfortable that I have fed in the right assumptions.
Now up the RPM to 9000 and you have the potential for close to 650HP at the same boost. A well built FD block should handle those revs.
So there you go. Be interesting to see if Peter has some other snippets he is hiding from me. Too few people take the time to do detailed measurements of the vital parameters sadly.
08-06-05, 12:53 AM
#52
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after reading all of this i have to tell you the truth. By everything I have learned is that horse power does not exsist. It is just Diverged from Tourqe. So basically there is no HP if you think about it. Not to be an ***. Just My 0.02
08-19-05, 09:53 AM
#54
Originally Posted by fcdrifter13
after reading all of this i have to tell you the truth. By everything I have learned is that horse power does not exsist. It is just Diverged from Tourqe. So basically there is no HP if you think about it. Not to be an ***. Just My 0.02
08-19-05, 11:11 PM
#55
Banned. I got OWNED!!!
Originally Posted by 13btnos
Since RiceRacing opened this up here's a good read. http://www.yawpower.com/tqvshp.html
"So there it is. Horsepower is the determining factor in the rate of acceleration of any vehicle."
100% totaly correct ^^^^ Power is all that matters.
Now back on topic, whats going on with this engine BNA?
08-22-05, 12:18 PM
#56
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Hi Rice,
Engine has now done 4,000 miles since it's build. It still goes like a rocket.
Only running 1.2 bar with water injection on the road at present.
Will be back to the dyno within next two weeks, watch this space!
Engine has now done 4,000 miles since it's build. It still goes like a rocket.
Only running 1.2 bar with water injection on the road at present.
Will be back to the dyno within next two weeks, watch this space!
08-25-05, 11:29 AM
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This was Bill's last reply on nopistons, same thread but different forum.
Sounds like a bit of a back track to me? maybe he came up with some new formula of calculating horsepower?
Quite simple. As an Engineer (in fact a chartered engineer) I do not b#$@. I do however try and make sure that important issues get discussed. I never said that Brian's car would not make a very respectable HP once full boost was available and it had been properly tuned. I said that I did not believe the dyno. And I still don't. He does however have the capability to produce a genuine 500HP at 6000RPM, and well over 600 by 9000
Sounds like a bit of a back track to me? maybe he came up with some new formula of calculating horsepower?
Quite simple. As an Engineer (in fact a chartered engineer) I do not b#$@. I do however try and make sure that important issues get discussed. I never said that Brian's car would not make a very respectable HP once full boost was available and it had been properly tuned. I said that I did not believe the dyno. And I still don't. He does however have the capability to produce a genuine 500HP at 6000RPM, and well over 600 by 9000
08-26-05, 04:58 PM
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He does however have the capability to produce a genuine 500HP at 6000RPM, and well over 600 by 9000
Good luck Brian, stop over complicating things and make some power will you!
08-28-05, 12:26 PM
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Originally Posted by mattmaclennan
No he doesn't, I dressed and fitted his engine.... he doesn't stand a chance. I still haven't found that ratchet
Good luck Brian, stop over complicating things and make some power will you!
Good luck Brian, stop over complicating things and make some power will you!
Are you coming santa pod next week to hold my camera for me while I whip your boss. lol
09-02-05, 10:23 AM
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Was supposed to hit the track tomorrow, but unfortunately I still have a problem with my secondary fuel rail. The injector no longer lifts 4-5 mm before spraying out fuel, i've sorted that, but even with the injector nice and stiff in it's slot as soon as you get on boost at about 4,000 rpm it still spray out fuel.
I must of got a bad batch or something cause I know lots of people use kgparts secondary fuel without problems. Just as well the rolling road I go to they have someone standing in fornt of the engine bay while the car is being mapped so they can see these kind of things.
I have added pic of the fuel stain on the turbo & lim.
Well cheesed off I will have to do some fabrication on this kit & make sure it's safe before I go back to the dyno other wise my car is likely to be ashes.
I must of got a bad batch or something cause I know lots of people use kgparts secondary fuel without problems. Just as well the rolling road I go to they have someone standing in fornt of the engine bay while the car is being mapped so they can see these kind of things.
I have added pic of the fuel stain on the turbo & lim.
Well cheesed off I will have to do some fabrication on this kit & make sure it's safe before I go back to the dyno other wise my car is likely to be ashes.
09-02-05, 08:28 PM
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I know when we put O rings on it , it took a lot , i mean a , lot more down force to get those injectors in deep. Then one person screwed it down flat and tight while the other was holding it.
I hope its goodntight!
I hope its goodntight!
09-03-05, 11:21 AM
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Originally Posted by APEXL8T
I know when we put O rings on it , it took a lot , i mean a , lot more down force to get those injectors in deep. Then one person screwed it down flat and tight while the other was holding it.
I hope its goodntight!
I hope its goodntight!
http://dave.newbern.org/rx7/InjectorBushing/
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