High Tech Turbo engineers, without question, the most technically advanced diesel turbo systems that your money can buy. The High Tech Turbo turbo charger reputation is supported by awards and recognition throughout the racing industry. High Tech Turbo diesel performance products are 100% drag, race and endurance tested. The unique thermal properties of the High Tech Turbo stainless housing allows much faster spool-up. The result being the ability to run a larger turbo with all the benefits of increased air flow, low EGTS and of course, great increaases in power without the surging and slow spool-up.
High Tech Turbo, in partnership with Borg Warner Turbo Systems, spawned the evolution of the new High Tech Series product line for 1991-2006 Dodge Cummins engines (adaptable to 1988-90 also). Borg Warner’s race proven large shaft combined with the High Tech Turbo bearing system was the key development in the creation of the HTB2 turbo line:
- Improved oil drain tube clearance.
- Twin-ported wastegate gives up to 50% more wastegate flow, resulting in better single and twin turbo boost control.
- Adjustable boost pressure regulators utilize higher spring rates supporting higher pressures, and utilize the new "Easy-Adjust" feature.
Turbo Upgrade Guidelines
Turbochargers are designed to work with specific engine sizes and thier most used RPM range. Using a bigger turbo will not necessarily improve the engine's performance. More offen than not, they perform even worse, providing that the original turbo wasn't mismatched to start with. An increase in boost will not always create more horsepower. Small turbine housings and wheels can increase boost pressure, however back-pressure will enevitably stifle performance. There are tradeoffs.
Two basic changes can be made to a turbocharger to increase performance, depending on engine specifics … Turbine housing A/R and compressor size.
Turbines
Change the turbine housing size (A/R ratio). Typically, the turbo will boost earlier in the RPM range with a smaller turbine housing and will offen provide more power in the torque range and reduce turbo lag. There is the possibility of better boost with a smaller turbine housing, but there is the concern of excessive exhaust restriction.
Larger turbine housings allow for increased high RPM engine breathing due to decreased exhaust restriction which in turn creates greater horsepower, though the boost will come in later in the engine’s RPM range. Larger housings, in many cases, yield lower exhaust temperatures.
Compressors
Changing the compressor size alone wont necessarily increase performance, providing that the engine has been modified to require more air. Such mods include; increasing the RPM potential, fuel need and delivery, drastically changing timing, changing the cam, the addition of a performance computer chip, exhaust and/or air intake alterations, head porting or any other modifications that can also benefit from increased compressor flow. An engine that needs an increase in fuel delivery, for whatever reason, will also need more air. Modifications of the sort to the engine will call for a larger compressor size to raise the volume of flow. Very minor changes can be made to a compressor such as changing to a different compressor wheel style (Ford Powerstroke diesels), but more likely a change of the compressor wheel and housing are needed in order to increase flow. Surge and noise are temperament exhibited by engines that require more compressor volume. Just as adding more fuel or advancing the timing won’t offer greater performance, installing too large of a compressor won’t offer a gain in performance.
Potential turbo modifications require assessment of current and future engine modifications and driving requirements.
Common Concerns and Questions:
"How much boost will a High Tech Turbo upgrade give me?"
Changing to smaller or larger turbine housings will likely increase or decrease boost pressure, but many things determine boost including: timing, fuel delivery, inlet restriction, exhaust restriction, and many other factors other than the turbo itself. So nobody can really make accurate boost claims. Changing compressor housings may or may not change boost pressure. If you have too large or small a compressor for your engine’s needs, the increase in efficiency of a properly sized compressor and MIGHT allow for increased boost. Boost isn’t directly related to horsepower. A well-matched turbo for your driving conditions is what you’re looking for. Consider where you want your power. For low-end response you want a smaller housing but smaller housings will choke-off top-end power. If you don’t care about low-end response but wants maximum horsepower then a larger housing will be what is needed.
"How much boost do I need?"
Once again, every engine is different. Dodge Cummins engines might be able to handle 50 plus pounds of boost without major modification but high boost pressures might also simply be an indication of exhaust backpressure. High boost pressures might not mean more power. They might point toward the need for a larger turbine housing. But many people are willing to sacrifice some top-end horsepower potential on the dyno in order to have great throttle response and driveability. It is important to keep in mind that boost is in direct relation to turbine speed and all turbines have a "rated maximum speed" before wheel exposion becomes likely. This WILL happen to the "strongest" turbo. Automotive applications usually run between 5 to 15 pounds boost. More boost more often results in potential harm to the engine (blown head gaskets, detonation or worse) than benefits gained. If you have built your engine with a very strong bottom end, uses low compression forged pistons and wants to o-ring his heads, and use aviation fuel then you can get away with 20 pounds of boost or more without trouble.
"I want the biggest High Tech Turbo available."
Too often consumers expect a larger turbo to make more power by itself. But if you install an HX40W (for example) on a stock 215 horsepower HX35W equipped engine, this engine will perform poorly. HX40W turbos are used on engines pushing over 350 hp. Now, if you have changed to a free-flowing intake system and installed a 4" exhaust system, installed 370 HP injectors, and changed the injection pump or added a 350+ HP performance chip … then, YES, you need larger turbo. You should then pick the appropriate size compressor to match your air flow requirements and then choose a turbine housing in accordance with the amount of low-end response you expect.
*The advantage to a hybrid turbo is that the turbine wheel has less mass so it spools up quicker.
Stage I with a 12cm2 turbine is best for most "daily driver", low-end performance trucks - 245-300 hp. Stage II upgrades with a 14cm2 "quickspool" housing match up well for approx. 300-350 hp engines. A stage II upgrade is a pretty good compromise for low-end performance along with horespower potential. Stage III upgrades or HX40W turbos with 16cm2 turbine housings meet the performance potential of 350-420 hp engines. HTB2 and High Tech Series 71 upgrades meet the performance potential of 350-675 hp engines depending upon compressor and turbine housing choices.