Next Question

[Accord2nrz]

What's the best way to lower point at which your turbocharger spools up? There are multiple right answers for this.



Second Part: HP/Boost is increased on a supercharged setup via changing a pulley out. How is this increase possible?

[Slick66]

Decreasing restrictions (lowering backpressure) in the exhaust flow path should allow the turbo to spool faster. Also a cheat method to lower it would be to add a N2O system to spool the turbo.

Second part by changing pulley's on supercharged engines, (either up or down) boost can be increased or decreased from mild to wild. An increase in the Driven (pulley on the supercharger nose/housing) will effectively slow down the rotation rate of the supercharger, this will decrease the output of the supercharger. By decreasing the Driven pulley, it will increase the rotation speed of the supercharger resulting in more boost/hp. The Drive pulley on gilmer style pulley systems that only run the supercharger can be switched also, which has the opposite affect of the above in reference to size change.

[zx10r07]

What's the best way to lower point at which your turbocharger spools up? There are multiple right answers for this.

Get a turbo with an exhaust side that is matched for your setup. You wounldn't run a huge T70 turbo on a little honda, poor thing would never spool... lol

I forget the order but there are different types of turbos based on their bearing type. Floating ones use the oil surrounding the tubine to support it, others use ball bearings, etc. More efficient turbo means faster spool.

More air flow = more exhaust flow - Better head on your motor. Port, polish, etc.

Better exhaust system - More flow - Bigger exhaust, bigger down pipe, bigger exhaust.



Second Part: HP/Boost is increased on a supercharged setup via changing a pulley out. How is this increase possible?

Lets say the diameter of the superchargers pulley 6 inches, and the pulley on the motor is say 6 as well just for simplicity. The ratio that the engine turns = the ratio that the supercharger turns as well would be 1:1. If you when and change the pulley on the supercharger so it was smaller say 4 inches, then the ratio would be 1:1.3 (I think I did the math right there... anyways) this results in the supercharger pulley turning faster than the engine RPM wise causing the supercharger to make move more air which results in an increase of air pressure. The same can be said if you change the engine pulley and kept the same pulley on supercharger.

[Turbineguy]

What's the best way to lower point at which your turbocharger spools up? There are multiple right answers for this.

Second Part: HP/Boost is increased on a supercharged setup via changing a pulley out. How is this increase possible?

#1 Lower pre turbo back pressure. Advancing the timing in the lower load and rev range will also reduce spool time. On cars with variable cam advance increasing the intake cam advance will have a huge impact on spool time. A manual boost controller will spool faster than an ECU controlled solenoid based boost control system and also switching from a bleeder type solenoid to a three port interupter type solenoid will help with spool. One of the best methods is to keep the heat in the exhaust stream prior to the turbo with either ceramic coatings or insulating wrap. The turbo runs on exhaust gas velocity and the hotter the gas the faster it moves through the system. The other thing to look at is post turbo restrictions like cats and small diameter exhaust piping along with restrictive mufflers and resonators. These things have the effect of reducing overall flow through the system and therefore flow through the turbine housing.

#2 Same as was said by others. Smaller driven pulley spins the blower faster and vice versa.