Reply With QuoteCome on over. It will be boring during the day when I am at my real job. I would have you clean parts but everything is brand new. You can help me take pics and post progress.
Thanks info, can I come live at your house till you get that motor done?
Come on over. It will be boring during the day when I am at my real job. I would have you clean parts but everything is brand new. You can help me take pics and post progress.
Infomaniac:
Come on over. It will be boring during the day when I am at my real job. I would have you clean parts but everything is brand new. You can help me take pics and post progress. Well, that's good and dandy, but you still need a test driver. I am more than qualified. I have a strong right leg and my left one is good to brace myself. Whattayasay?????!!!!!! wink
78Eliminator:
Infomaniac:
Come on over. It will be boring during the day when I am at my real job. I would have you clean parts but everything is brand new. You can help me take pics and post progress. Well, that's good and dandy, but you still need a test driver. I am more than qualified. I have a strong right leg and my left one is good to brace myself. Whattayasay?????!!!!!! wink Bring you depends, I have a feeling when you hammer tha throttle you are going to shit your pants.
Top fuel cars run standard style roots blowers. Screw compressors are not allowed, there trying to limit the HP, not make more at this point. They don't even run the hi-helix roots, it's against the rules as well. The alcohol classes all run screw, where it positevely blew away the standard and hi-helix roots including the thousands of retrofits.
Some top fuel cars run up to 60lbs. of boost. The alcohol cars run up to 65lbs. with screw compressors. Typically speaking, if you installed a screw on the top fuel cars, you could lower boost to approx. 45lbs. and make the same power because of less parasatic losses and denser air charge, but at the same time, you can run the boost back up and make a incredible amount of torque and hp.
Screw compressors are less likely to blow off, are more cost effective, last longer, are all the same (every roots in racing varies in flow and efficiency) and are safer, but don't get me going on NHRA rule makers
Dustin
Same with top fuel drag boats?
This is why a lot of times I answer with "I think" or "I am pretty sure". If you speak up as much as I do, you are bound to be wrong or say something stupid sooner or later. cry
[ January 23, 2003, 05:14 AM: Message edited by: Infomaniac ]
Blown 472:
Bring you depends, I have a feeling when you hammer tha throttle you are going to shit your pants.
Whipple Charged:
The question was, 500ci engine, 15lbs. of boost, but under ideal conditions meaning properly sized compressors, proper amount of airflow on the inlet. Turning a supercharger by hand gives you little information about 15lbs. of boost. A roots should never be run at a level above 12lbs., typically speaking, you will not gain anymore HP with anymore than 12. You will net more torque, but not HP. At 40lbs, theres over a 300hp differential between the properly sized screw vs. roots on a 500ci engine. That would be comparing a high helix/teflon stripped roots. It's been proven many, many times.
Dustin I disagree on part of that statement. I went from 11.8 lbs of boost to 13.5 and gained about 70 H.P.,1471 Littlefield with no bells or whistles.Gaining torque at a specific rpm cannot happen without a corresponding increase in horsepower,check out the formula for horsepower.Lets also consider Power versus price.What is the cost of a whipplecharger vs a good ole roots? I would like a cost comparison.Not on a 65 psi deal but something more relative to performance lake boating.Thanks,Chris
picked up 70 hp from 11.8 to 13 with a 1471? Was that steady state? Thats pretty rare in a marine roots blower.
And, yes, you can pick up torque and not hp, not at the same rpm, thats not what I said, but at a lower rpm while not making much hp. To give you an example, figure the cost of 100+hp on that same engine with 13lbs. of boost, not to mention you can achive a higher psi before detonation because of the cooler air charges. Not only that, it doesn't vary over time, they last longer, smaller, more compact, quieter, etc.
There is no comparison, call up Littlefield, he has to run a screw compressor on the alcohol car that he runs because the roots is no wear near competitive, even though it has major rule advantages with weight and engine size.
Thanks,
Dustin
Example of approx. price:
Whipple quad rotor (will make 700-1600 hp on pump gas, more on race, 2000 on methanol): Retail pricing $5000-6500
Roots 1471: $3000-6000
Approx. pricing, theres also race compressors, etc. A new race supercharger from SSI or Kobelco runs near $10,000.
Thanks,
Dustin
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