Take an inside look at some bits and pieces that you should start giving some consideration to.
On Broadway, no stage production is complete without a supporting cast of actors. That, along with the set, lighting, sound and props all go into making a show successful. The same applies after you’ve made the decision to go turbo. You have to have all of the right parts in all of the right places. With that in mind, here’s an inside look at some of the bits and pieces you should consider when assembling your supporting cast.
Street car owners may have the option of choosing pre-packaged kits engineered to fit their vehicle only, but race cars almost always have to have the installation done by a fabricator because of the variables involved. This includes the architecture of the race car, the preferences of the installer and the physical size of the components, along with the class rules of the sanctioning body. Just as in building an engine, mounting the turbo(s), placing the intercooler and routing the tubing is an exercise in compromise.
If your car is under construction, the best choice is to always order a non-working mock-up of the turbo in order to facilitate fabrication. The same goes for wastegates, intercoolers and blow-off valves as well. It’s important to ensure that all of the components you need have room not only to fit, but also to operate. There is some movement going on under the hood not only with the engine, but with the turbo too. Remember that access is also an important consideration.
For single-turbo cars, the turbo is almost always placed in front of the engine, either directly behind the grille or through an opening in the lower fascia or valance. Putting weight on the nose of the car certainly isn’t desirable, but you want to keep the turbo close to the engine for spooling purposes.
On twin turbo arrangements, it’s not uncommon to see them mounted in a variety of ways. Above the valve covers, closer to the firewall; on the nose of the car; and even in a remote location in the trunk are all locations that have been used in the past, and each comes with their pros and cons. Some of the most successful cars, however, have recently been placing the turbos underneath the exhaust headers and back up against the firewall. Locating there provides the shortest path for the engine’s exhaust gases to start spooling the turbos, while also keeping their weight set further back and down low in the chassis for better handling characteristics.
Stay tuned for the rest of this three-part segment which will cover intercooling and boost control!
Text and Photos by Rod Short