Portings effects on compression?
#71
08-15-2006, 02:45 AM
Portings effects on compression?
Originally posted by: rcoop
Mike would obviously see some benefit but not an incredible amount. He would be able to make a greater improvement with more aggresive timing and dual carbs. While still having the option of going back to stock timing to spray on. Why have 14-1 and spray 15 horse jets when you can have 11.5-1 and spray 25 horse jets. The nitrous will always make greater torque gains then static compression. So then you would have the best of all worlds.
Mike would obviously see some benefit but not an incredible amount. He would be able to make a greater improvement with more aggresive timing and dual carbs. While still having the option of going back to stock timing to spray on. Why have 14-1 and spray 15 horse jets when you can have 11.5-1 and spray 25 horse jets. The nitrous will always make greater torque gains then static compression. So then you would have the best of all worlds.
I run 15.5:1 true static compression and our 20 hp shot on the dyno was yielding 23 to 24 hp increase. There is no reason we couldn't run alot more NOS except that we didn't need more power. We couldn't get that power effectively to the ground anyway with the two passes we got.
I do hear what you are saying.........for a dune bike, 11.5:1 is great and it keeps you out of the really spendy fuel........even when spraying. I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
#72
08-15-2006, 03:17 AM
Portings effects on compression?
I was talking real world over the counter setups for the normal owner who wanted a hard running dune bike. That could also go to the hill and hold its own against all but the fastest bikes. I also feel this combo is better for drag racing as you said you couldn't get that power to the ground. Lower your compression and run a larger nitrous system with stages or a controller and you would have more power total. You would also be able to control the power to the track better. Airforceone's bike is a good example of this.
#73
08-15-2006, 08:53 AM
Portings effects on compression?
[quote]
Originally posted by: DSNUT
I think you mean Pricey not spendy ... LOL. Also, are you really sure about the higher compression making a bigger hp hit? Really?
Originally posted by: DSNUT
Originally posted by: rcoopI do hear what you are saying.........for a dune bike, 11.5:1 is great and it keeps you out of the really spendy fuel........even when spraying.
I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
#74
08-15-2006, 10:21 AM
Portings effects on compression?
Originally posted by: DSNUT
Ok, I had a little more time to mull this over tonight. This isn't a reall scenario. If you only had the option of either 14:1 or 11.5:1 and you only had 15 shot nozzles and 25 shot nozzles, you would run 14:1 with the 25 hp shot and turn your timing back just a touch more.
I run 15.5:1 true static compression and our 20 hp shot on the dyno was yielding 23 to 24 hp increase. There is no reason we couldn't run alot more NOS except that we didn't need more power. We couldn't get that power effectively to the ground anyway with the two passes we got.
I do hear what you are saying.........for a dune bike, 11.5:1 is great and it keeps you out of the really spendy fuel........even when spraying. I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
Originally posted by: rcoop
Mike would obviously see some benefit but not an incredible amount. He would be able to make a greater improvement with more aggresive timing and dual carbs. While still having the option of going back to stock timing to spray on. Why have 14-1 and spray 15 horse jets when you can have 11.5-1 and spray 25 horse jets. The nitrous will always make greater torque gains then static compression. So then you would have the best of all worlds.
Mike would obviously see some benefit but not an incredible amount. He would be able to make a greater improvement with more aggresive timing and dual carbs. While still having the option of going back to stock timing to spray on. Why have 14-1 and spray 15 horse jets when you can have 11.5-1 and spray 25 horse jets. The nitrous will always make greater torque gains then static compression. So then you would have the best of all worlds.
I run 15.5:1 true static compression and our 20 hp shot on the dyno was yielding 23 to 24 hp increase. There is no reason we couldn't run alot more NOS except that we didn't need more power. We couldn't get that power effectively to the ground anyway with the two passes we got.
I do hear what you are saying.........for a dune bike, 11.5:1 is great and it keeps you out of the really spendy fuel........even when spraying. I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
#75
08-15-2006, 11:03 AM
Portings effects on compression?
[quote]
Originally posted by: OregonDunePatrol
Of course. If you take a bike that is 11:1 and running Boss Noss with a 15 shot nozzle and compare it with exactly the same build with 14:1 and a 15 shot nozzle.........they will use the same amount of Nitrous but which motor will more likely make more power?
You must have been being sarcastic..............[img]i/expressions/face-icon-small-wink.gif[/img]
Btw, that was pretty funny about the the pricey thing[img]i/expressions/face-icon-small-wink.gif[/img].........you would think someone as pedantic as myself would have caught that[img]i/expressions/face-icon-small-happy.gif[/img]
Originally posted by: OregonDunePatrol
Originally posted by: DSNUT
I think you mean Pricey not spendy ... LOL. Also, are you really sure about the higher compression making a bigger hp hit? Really?
Originally posted by: rcoopI do hear what you are saying.........for a dune bike, 11.5:1 is great and it keeps you out of the really spendy fuel........even when spraying.
I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
You must have been being sarcastic..............[img]i/expressions/face-icon-small-wink.gif[/img]
Btw, that was pretty funny about the the pricey thing[img]i/expressions/face-icon-small-wink.gif[/img].........you would think someone as pedantic as myself would have caught that[img]i/expressions/face-icon-small-happy.gif[/img]
#76
08-15-2006, 11:07 AM
Portings effects on compression?
Originally posted by: 650VIPER
Whoa!! wait just a minute! Ron what system were you running that yielded those results? Was it the NOSS? Was this on a dyno in Oregon?
Originally posted by: DSNUT
Ok, I had a little more time to mull this over tonight. This isn't a reall scenario. If you only had the option of either 14:1 or 11.5:1 and you only had 15 shot nozzles and 25 shot nozzles, you would run 14:1 with the 25 hp shot and turn your timing back just a touch more.
I run 15.5:1 true static compression and our 20 hp shot on the dyno was yielding 23 to 24 hp increase. There is no reason we couldn't run alot more NOS except that we didn't need more power. We couldn't get that power effectively to the ground anyway with the two passes we got.
I do hear what you are saying.........for a dune bike, 11.5:1 is great and it keeps you out of the really spendy fuel........even when spraying. I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
Originally posted by: rcoop
Mike would obviously see some benefit but not an incredible amount. He would be able to make a greater improvement with more aggresive timing and dual carbs. While still having the option of going back to stock timing to spray on. Why have 14-1 and spray 15 horse jets when you can have 11.5-1 and spray 25 horse jets. The nitrous will always make greater torque gains then static compression. So then you would have the best of all worlds.
Mike would obviously see some benefit but not an incredible amount. He would be able to make a greater improvement with more aggresive timing and dual carbs. While still having the option of going back to stock timing to spray on. Why have 14-1 and spray 15 horse jets when you can have 11.5-1 and spray 25 horse jets. The nitrous will always make greater torque gains then static compression. So then you would have the best of all worlds.
I run 15.5:1 true static compression and our 20 hp shot on the dyno was yielding 23 to 24 hp increase. There is no reason we couldn't run alot more NOS except that we didn't need more power. We couldn't get that power effectively to the ground anyway with the two passes we got.
I do hear what you are saying.........for a dune bike, 11.5:1 is great and it keeps you out of the really spendy fuel........even when spraying. I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
#77
08-15-2006, 02:22 PM
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Portings effects on compression?
Originally posted by: 650VIPER
Chooses bike is fast because one, it weighs 300lbs. And two, he knows how to setup, and get the parts working together that he has. Its a stock motor, nothing fancy in there.
I run 12-1 comp. I also run a very aggressive cam. It builds alot more pressure than a 3 cam per say. But it requires it to rev alot higher. The place my bike lacks, is in the low to mid rpms. Where if I were to raise the compression, I could get goo pressure at the low and mid that I lack.
So take Duneits bike for example. If his cams build the best pressure at say 7500, and then he goes and adds more compression. The gain he will see will more than likely be below that 7500. The lower end will be the biggest difference. He will probably suffer a little from it on the top. Compression is great for acceleration, but can hurt the top end. After all, it takes more power to compress the higher comp.
Chooses bike is fast because one, it weighs 300lbs. And two, he knows how to setup, and get the parts working together that he has. Its a stock motor, nothing fancy in there.
I run 12-1 comp. I also run a very aggressive cam. It builds alot more pressure than a 3 cam per say. But it requires it to rev alot higher. The place my bike lacks, is in the low to mid rpms. Where if I were to raise the compression, I could get goo pressure at the low and mid that I lack.
So take Duneits bike for example. If his cams build the best pressure at say 7500, and then he goes and adds more compression. The gain he will see will more than likely be below that 7500. The lower end will be the biggest difference. He will probably suffer a little from it on the top. Compression is great for acceleration, but can hurt the top end. After all, it takes more power to compress the higher comp.
Thanks Jed.
Duneit, Yes, Porting will have an effect on the compression in terms of performance....but not in terms of raising or lowering your compression ratio.....unless your talking about shaving the dome surface of the head.
#78
08-15-2006, 11:36 PM
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Portings effects on compression?
I am learning a lot here on this post.I am asking a lot of questions lately because i want to squeeze every bit of performance out of my stock bore possible and all of this is good information for me to use.So the bottom line on this is that porting has no effect on the fuel needed for a particular compression?
#79
08-16-2006, 09:11 AM
Portings effects on compression?
[quote]
Originally posted by: DSNUT
Actually Ron, I was just testing to see who I was really talking to here. Now I know. [img]i/expressions/face-icon-small-wink.gif[/img]
Originally posted by: DSNUT
Originally posted by: OregonDunePatrol
Of course. If you take a bike that is 11:1 and running Boss Noss with a 15 shot nozzle and compare it with exactly the same build with 14:1 and a 15 shot nozzle.........they will use the same amount of Nitrous but which motor will more likely make more power?
You must have been being sarcastic..............[img]i/expressions/face-icon-small-wink.gif[/img]
Btw, that was pretty funny about the the pricey thing[img]i/expressions/face-icon-small-wink.gif[/img].........you would think someone as pedantic as myself would have caught that[img]i/expressions/face-icon-small-happy.gif[/img]
Originally posted by: DSNUT
I think you mean Pricey not spendy ... LOL. Also, are you really sure about the higher compression making a bigger hp hit? Really?
Originally posted by: rcoopI do hear what you are saying.........for a dune bike, 11.5:1 is great and it keeps you out of the really spendy fuel........even when spraying.
I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
I am not afraid of compression though. As long as you don't detonate, I think you can run as much juice through a 14:1 as you can an 11:1. It will rev much quicker and will make bigger hp out of the same amount of NOS.
You must have been being sarcastic..............[img]i/expressions/face-icon-small-wink.gif[/img]
Btw, that was pretty funny about the the pricey thing[img]i/expressions/face-icon-small-wink.gif[/img].........you would think someone as pedantic as myself would have caught that[img]i/expressions/face-icon-small-happy.gif[/img]
Actually Ron, I was just testing to see who I was really talking to here. Now I know. [img]i/expressions/face-icon-small-wink.gif[/img]
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