For those who have bought into the myth that the Twin Screws are so much better for low end torque than the centrifugals - Here is a dyno sheet from the other day on a car with a vortech s/c making 14 psi. Bear in mind this car has an auto trans and is losing 25% from the crank to the wheels. No N20, just motor and blower.
BTW - this dyno run was started and completed in 3 seconds....
do you have a twin screw dyno at 14psi on a similar car in similar conditions to compare it to? Otherwise I'm not sure what the proves other than those are some kick ass numbers
No offense but to anyone who knows anything about these cars - this proves a whole hell of a lot...lol NOBODY is going to be able to produce a dyno with a auto twin screw at 14 psi producing those numbers, no way, no how.
Nowhere have I ever seen an S197 with a centrifugal making more torque than HP. This includes prochargers factory ride, and Justin Burcham's car. The low end torque multiplication you are seeing is caused by an awesome trans/TC set-up. The custom JDM heads in the car are also making the car spin ridiculous fast so the the old adage of centrifugals waiting to see boost is gone. This thing starts boost as soon as you step on the gas (like twin screws).
It just goes to show that there is no advantage to any set-up either turbo, centrifugal, Twins Screw, or roots. It all comes down to how the car is built and how it is set-up. There is no single mod that is going to produce these kinds of numbers and results. This car is a beast, no doubt, and anyone in the know will tell you how powerful those numbers are on an auto trans.
The main point is to end the debate of which type of s/c is better which has been going on forever. It proves that not one is better than the other. Differences in efficeincy, of course, but no one goes forced induction for efficeincy - they go forced induction to make power... And the s/c that will make the most power is not dependent on brand or type - it all depends on how well it's set-up.
That looks like a fun powerband for the street but how is it for racing. Now I've never driven a 500hp anything but I would think that you would want the car to keep making torque after 3500 rpm instead of falling off. But most T/S are making 500 RWHP at 10 psi so I def think that a T/S could match those #s at 14 psi. To this date the most power I've seen out of a S197 with a centrifugal is Livernois's example puting down 740 RWHP.
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First Livernois numbers are to the crank (this car is almost 700 to the crank) and they are not seeing those torque numbers.
Second, your statement about twins screws making 500 at 10 psi? LOL Show me a single one. (won't happen) FYI: No TS is seeing over 550 torque even on 16 psi. The fastest TS I have seen yet is the JDM Auto Saleen clone and that is putting down slightly less numbers (540 torque) and has 16 psi as well as a rebuilt and stroked 298 motor. Rememeber this is an auto and losing 25% to the crank. If this was on a manual car, the RWHP would be almost 650.
Lastly, it's obvious you're not knowledgable about racing. I don't mean that offensive, just an observation. This kind of power is very difficult to handle on the street. If you punch the throttle with this level of torque, you will go nowhere through all the gears. It is the exact opposite, with these numbers, the car is a drag monster. The car is a low 10 sec car on slicks.
Just a little leson for ya, HP means nothing in eqaution to track times. HP = MPH - NOT et's. Prime example is livernois car you're referring to. Though much more HP than this car, it is set up for the standing mile and would get smoked by this car in the 1/4.
First Livernois numbers are to the crank (this car is almost 700 to the crank) and they are not seeing those torque numbers. Second, your statement about twins screws making 500 at 10 psi? LOL Show me a single one. (won't happen) FYI: No TS is seeing over 550 torque even on 16 psi. The fastest TS I have seen yet is the JDM Auto Saleen clone and that is putting down slightly less numbers (540 torque) and has 16 psi as well as a rebuilt and stroked 298 motor. Rememeber this is an auto and losing 25% to the crank. If this was on a manual car, the RWHP would be almost 650.
Lastly, it's obvious you're not knowledgable about racing. I don't mean that offensive, just an observation. This kind of power is very difficult to handle on the street. If you punch the throttle with this level of torque, you will go nowhere through all the gears. It is the exact opposite, with these numbers, the car is a drag monster. The car is a low 10 sec car on slicks.
Just a little leson for ya, HP means nothing in eqaution to track times. HP = MPH - NOT et's. Prime example is livernois car you're referring to. Though much more HP than this car, it is set up for the standing mile and would get smoked by this car in the 1/4.
1. The #s I read for the livernois WERE RWHP not crank.
2 PJ's Speed shop has a Kenne bell putting down just over 500rwhp in the july issue of MM&FF as well as a prototype whipple in that same issue.
3. Thats kinda what I said earlier, I would think a car making all its torque early on would be difficult to launch.
I haven't been working on muscle cars for 30 years nor do I live on a drag strip but I understand the hp/mph thing. I'm not here to get in a pissing contest with ya or diss centrifugals. I'm just stating what I have seen or at least read.
-Tim
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the numbers are actually RWHP not to the crank, im looking at the motor trend right now, so i guess ur not knowledgable
Quote:
ORIGINAL: fordfanboy
First Livernois numbers are to the crank (this car is almost 700 to the crank) and they are not seeing those torque numbers. Second, your statement about twins screws making 500 at 10 psi? LOL Show me a single one. (won't happen) FYI: No TS is seeing over 550 torque even on 16 psi. The fastest TS I have seen yet is the JDM Auto Saleen clone and that is putting down slightly less numbers (540 torque) and has 16 psi as well as a rebuilt and stroked 298 motor. Rememeber this is an auto and losing 25% to the crank. If this was on a manual car, the RWHP would be almost 650.
Lastly, it's obvious you're not knowledgable about racing. I don't mean that offensive, just an observation. This kind of power is very difficult to handle on the street. If you punch the throttle with this level of torque, you will go nowhere through all the gears. It is the exact opposite, with these numbers, the car is a drag monster. The car is a low 10 sec car on slicks.
Just a little leson for ya, HP means nothing in eqaution to track times. HP = MPH - NOT et's. Prime example is livernois car you're referring to. Though much more HP than this car, it is set up for the standing mile and would get smoked by this car in the 1/4.
There is no debating the fact that Mark's car is awesome. Hell, for $16k worth of motor work it better be awesome. But I will say the same thing about Marks dyno sheet that I did about Don's. And that is the torque is deciving because of the multiplication being seen by the trans/TC. I would seriously like to see the same setup on a manual trans car to see how different it is.
ORIGINAL: hawgman
There is no debating the fact that Mark's car is awesome. Hell, for $16k worth of motor work it better be awesome. But I will say the same thing about Marks dyno sheet that I did about Don's. And that is the torque is deciving because of the multiplication being seen by the trans/TC. I would seriously like to see the same setup on a manual trans car to see how different it is.
a. Wasn't that $17K?[:@]
b. It will likely be awhile before we get an apples-apples on that (same setup on a manual) - I guess we will have to settle for 60's/ETs after whatever new traction issues that curve brings are worked out...
Awesome build - good luck with the belt...
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As I stated earlier I don't live on a drag strip and this is comparing oranges to apples but what kinda blowers do top fuel and funny cars run? Know I know the fastest street stangs run 9s with prochargers but end the end who's really the man?
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TS More Torque than centrifi's - THINK AGAIN!
