| Author |
Message |
    
Srwitt
| | Posted on Monday, December 20, 2010 - 09:07 pm: | 
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+1 Jbolt. You get funny looks from people when you explain what boost truly is. |
Speeder_388
| | Posted on Wednesday, December 22, 2010 - 12:56 pm: |
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That is a good idea but it would be better if it was on a XB12Rr than i would sell my mother for it. |
Kalali
| | Posted on Wednesday, December 22, 2010 - 01:18 pm: |
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"..I have a Kawasaki backpack blower.."
That's what I was thinking except in a riding lawn mower... |
Speeder_388
| | Posted on Wednesday, December 22, 2010 - 02:14 pm: |
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That is also a good blower. |
Firemanjim
| | Posted on Wednesday, December 22, 2010 - 03:55 pm: |
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I think I will take issue at that boost statement.We run up to 32 lbs of boost on our Bonneville 750's and it is not a measure of intake restriction. We changed cams and put a ported head on,still ran 32 lbs of boost.Certainly made more HP.
Volume of air moved will depend on turbo size as well.
Moved up to a bigger(again) sized turbo and ran the same boost.
The heat comes from compressing the air and the more you compress it the more heat--thus the need for an intercooler. We run a water to air with an ice box.Greg's bike will take about 4 lbs of ice and make warm water by the time the run is over, mine not quite so bad. |
Srwitt
| | Posted on Saturday, December 25, 2010 - 10:14 pm: |
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Of course you made more power with the ported heads/cam, you would have made the same power as before the heads/cam with even less boost, less intake charge temp. Now your flowing that much more to create the "same" 32lbs of "boost". |
Rageonthedl
| | Posted on Sunday, December 26, 2010 - 10:59 am: |
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I had a Merkur XR4Ti that was running 18psi. I was racing a DSM and my waste gate blew and boost went crazy high like around 30psi it not more. I had to drive home 40miles with it blown. By the time I got home headers were RED hot. |
Skidonenko
| | Posted on Friday, December 31, 2010 - 09:27 am: |
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fire man, The way i worded it was to simplify. There are most always exceptions/what ifs.
The heat comes from compressing the air and the more you compress it the more heat
and the higher the pressure. Sure on a drag/top speed bike you can sick a crazy big blower or turbo with an ice box or methanol injection to drive the temps down. In your case your dump valve is set to a lower pressure than your combo will generate. You still improved the engines VE and made more power because you are pumping more air through the cyl head.
Stick your setup on an engine with double the displacement/similar rpm range and I am sure the "boost" would be lower unless you are running some gargantuan turbo/blower. The idea here is to size parts properly not just stick some turbo off a 6.0 powerstroke and stick it on a 500cc enfield and say if I run it to 60k rpm ill make eleventy billion PSI of BOOST yo. Sure in particular motorsports lag or response is not a top concern, but then people building street bikes start Oscar Mayer measuring with "boost" and HP peaks i cannot help but giggle. |
Ericz
| | Posted on Friday, December 31, 2010 - 09:56 am: |
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I think it is fair to say that the common term "boost" is used to describe a scale of power that a turbocharged engine can reach. I bet that if you put two different turbocharged vehicles in front of someone they would think that the one that produces more "boost" makes more power.
I sized my turbo a bit large for my motor and it has worked well, but as I have worked to set it up to run even more boost the turbo gets closer and closer to operating at the surge line. My next step will be to increase the displacement and things will move right back into the peak efficiency range for the turbo.
A critical component of the design and function of a forced induction motor is for the charger to be properly sized for the application. If this isn't done, the charger will only restrict the power output of the motor. |
