[seruzawa]

It's kind of hard to increase one without increasing the other.

"Tuning for torque" is sort of misleading because in that case you are not increasing the torque as much as you are just widening the rpm range of the usable torque. You get less peak torque when you widen the torque band and lower the peak HP. However the motor feels stronger because the torque is more available.

So to answer your question, "Does adding a turbo increase the hp or the torque?" Yes.

None of these rules are absolute. you can always find exceptions so they are just general rules of thumb.

BTW there are no good engineers here. If you are looking for a good engineer I hear there is one on the CW forums who knows everything.

 

[seruzawa]

I have plenty of both...

So was the little turbine spinning in your Oxygen Destroyer Bomb spinning for volume or velocity?

.. volume AND velocity.

And you would too if you got one of these nifty new Harley credit cards to go with your pink armchaps and EZ leaker. Sign up today. don't waste a second. (offer not valid where anyone has a clue)

 

[seruzawa]

There are just...

Not that I am a turbo expert, but you can't run much boost with a high-compression engine without burning holes in the pistons. The first step for running high-boost turbo applications is a cylinder spacer to lower compression and then usually C-16 gas to control detination. If you are pinging on boost, you will have a motor meltdown sooner, rather than later. Low boost and mild cam timing, and high rpm's is what makes a turbo go. Like I said, I am not an expert, but high-compression and high boost = BAD!

... too many variables to make any accurate generalizations.

My rule of thumb for gas engines is: "If you want more HP get a bigger engine." Turbos just introduce too many problems. That's what happened with the turbo bikes the Japanese introduced all those years ago. Why put a turbo on a 750 to get 1000 performance? Just get a 1000.

Anyone who thinks they need a turbo on a Hayabusa is welcome to the problems.

 

[seruzawa]

Not quite.

At the boost levels the OEM's ran the turbo was more of a marketing scheme than a performance booster. The reason most guys run turbos compared to buying new or building the motor is expense and ridability. Build a non-boosted 200+ hp Busa, and you lose rideablity AND it costs an arm and a leg. With boost you retain stock rideability until the turbo spools and then hang on! I have heard of 500 HP streetable Busa's out there. Crazy!

If you lower the compression on a boosted engine you lose performance until you are on boost. My brothers old Merkur was a very irritating car to drive because it was gutless until it was on boost. So you were either poking along or pressed back in your seat. It was a rush that got very fatiguing after a while. That and the fact that the POS quit running at random moments and had to be towed. I got very tired of driving 25 miles to pick him up on the side of I-5. LOL!