Hurricane turbo intake upgrade

[earthling]

Oh, a 300 HP winder would never ever run with my old Pro-Stock 800, even a 350 HP winder wouldn't cut it. That not what I'm saying, you are not picking up what I'm putting down here....

I had a Simon turbo setup on a old Attak, we dynoed it on the engine dyno, it made 265 HP on a brand new zero mile engine with 11.8 lbs of boost on the engine dyno, took it right off the engine dyno, installed it right onto the track dyno and it made 150 Track HP with a bit less boost at 11.0 lbs. within an hour of running it on the engine dyno. So the Apex made 150 track HP not 132 track HP. The .5 would not work properly here.

Now, if you use a factor of .5 like there are using now that would be equal to a 300 HP Winder. We always used a .57 factor previously. Suddenly TD only has a track dyno at their facility and starts using a .5 factor. I'm just trying to figure out why as the .57 was always the most accurate in the past, not the .5 factor. Everyone and their brother used .56-.57 previously. Now I'm hearing .5 all the time. I just question why the change.

I fully understand what you are saying. You have the empirical data of having run your sled on an engine dyno (265 HP) and backed that data up with a track dyno showing 144HP, that is a driveline efficiency factor of .545 which means you lost ~45% of the power through the driveline components. If you look at a car scenario, you typically see 15-20% loss from engine HP to wheel HP, and another 4-7% on top of that if you use an automatic instead of a manual gearbox. That number, whatever it is, is not transferable from sled model to sled model because the drivetrains change quite a bit. .57 is a rule of thumb but in your case you can see that the actual loss was higher resulting in .545 or 45% loss in power through the drivetrain. When you improved your track HP to 150, the engine HP would have to go up proportionally to ~275HP unless you changed something fundamental about the driveline. My guess is that to get to 150, you were tuning more HP into engine, not playing with the driveline or a bit of both, but mostly engine because driveline changes are harder and result in lower gains. Your position on TD is that their track dyno number and conversion rate of .5 is artificially inflating their engine number. If they are, lets look at that. Their stated baseline was a 211HP stock winder. If the real world HP of a stocker is closer to 200, they are off by .053%. Their 300 HP corrected number would be closer to 271HP at the crank. Why the change? Marketing, miscalculating the driveline efficiency, marketing…. But Hurricane at least is in the same ballpark of stated numbers, and PEFI has a slightly different set of numbers but also a different approach to tuning. MCX has always said that any number over 250 HP with the stock turbo was questionable.

(Before I get flamed for talking smack about the tuners ——- I am not making any claims about what HP they are really producing)

 

[KnappAttack]

I fully understand what you are saying. You have the empirical data of having run your sled on an engine dyno (265 HP) and backed that data up with a track dyno showing 144HP, that is a driveline efficiency factor of .545 which means you lost ~45% of the power through the driveline components. If you look at a car scenario, you typically see 15-20% loss from engine HP to wheel HP, and another 4-7% on top of that if you use an automatic instead of a manual gearbox. That number, whatever it is, is not transferable from sled model to sled model because the drivetrains change quite a bit. .57 is a rule of thumb but in your case you can see that the actual loss was higher resulting in .545 or 45% loss in power through the drivetrain. When you improved your track HP to 150, the engine HP would have to go up proportionally to ~275HP unless you changed something fundamental about the driveline. My guess is that to get to 150, you were tuning more HP into engine, not playing with the driveline or a bit of both, but mostly engine because driveline changes are harder and result in lower gains. Your position on TD is that their track dyno number and conversion rate of .5 is artificially inflating their engine number. If they are, lets look at that. Their stated baseline was a 211HP stock winder. If the real world HP of a stocker is closer to 200, they are off by .053%. Their 300 HP corrected number would be closer to 271HP at the crank. Why the change? Marketing, miscalculating the driveline efficiency, marketing…. But Hurricane at least is in the same ballpark of stated numbers, and PEFI has a slightly different set of numbers but also a different approach to tuning. MCX has always said that any number over 250 HP with the stock turbo was questionable.

(Before I get flamed for talking smack about the tuners ——- I am not making any claims about what HP they are really producing)

On the Attak. I improved from 144 HP to 150 track HP by making only changes to the clutching, no HP improvements at the engine at all. If anything, we were down on engine HP because the boost was down .8 lbs. from the engine dyno, which would be about 8 HP down, I don't know why I'd have been down on boost from engine dyno to track dyno like that, its possible the track dyno was not loading then turbo as hard as the engine dyno, I don't know exactly, but we're splitting hairs here. The fact remains of all the tuners that have actually been on a track dyno and an accurate engine dyno is going to be using that .55-57 factor when the clutching is in the goldilocks zone. You'd need to be outta whack on the clutching a fair amount to be in the .5 factor range.

IMO the track dyno is for finding efficiency in the clutch department and the engine dyno is for developing engines and engine programs. Thats not to say that you cant improve on power like Allen is doing here testing the intake tube, but its not the best to determine engine power improvements, that best left for the engine dyno. A shop developing tunes and engines, needs to be doing so on an engine dyno, not a track dyno. I fully believe a 150 track HP sled is more than likely going to be around that 270 HP on a real engine dyno that its is to make 300 HP on the engine dyno. Yes, I fully believe engine HP numbers are inflated all the time in this industry. I've seen it happen for as long as I can remember. Check out Tommcats Facebook postings to get an idea on how far out to lunch they really are, he's posted some dyno sheets on there.

 

[Simplespeed]

Also worth noting the 2.52 is 3lbs heavier than 2.86. Additional rotating mass. No doubt, Allen's dyno doesn't lie!


Ahhh Allen beat me to it! ha

Is 2:52 more costly to make ? I would think their is good reasons we don’t see 2:52 on the sidewinders ?

 

[sideshowBob]

Is 2:52 more costly to make ? I would think their is good reasons we don’t see 2:52 on the sidewinders ?

Without changing suspensions the only SWs that can be easily converted to a 2.52 track is the 141" XTXs. Cat sells a shaft with 2.52" pitch and with a 144" 2.52 track its an easy conversion. I have all the parts to change my XTX to a 144 but the 141 x 1.75 track on the sled still looks new and works great.

 

[earthling]

Is 2:52 more costly to make ? I would think their is good reasons we don’t see 2:52 on the sidewinders ?

If it weighs more, it likely cost more.

 

[1nc 2000]

Who else purchased the turbo intake pipe????

 

[fatchance]

I installed mine a while back but the sled isn't quite finished and there's no riding around here anyway.

 

[Doc Harley]

Who else purchased the turbo intake pipe????

 

[1nc 2000]

The intake pipe I got looks like it's 1/4 scale.
Must be working on the venturi principles.