Which Clamp Should I Use?
Standard T-Bolt Clamps
T-Bolt clamps are the strongest hose clamps made.
A wider band provides for superior system stability. This means your entire intake system will be less likely to move around.
Thicker metal in the band means higher strength and longer life.
The disadvantage to the T-Bolt clamp is its narrow range - you absolutely must have the correct size in order for it to work properly.
A related disadvantage is, in some circumstances, it may be difficult to tell if a T-Bolt is fully tightened or not. If the clamp is too big, you may run out of threads before the clamp is fully tightened. This makes it feel like it is tight against the hose, but some of the pressure you feel may be the nut binding up against the end of the threads on the bolt. If you hear of a T-Bolt clamp “popping off” a hose, this is almost always the cause (the only other cause being a crushed intake tube). The solution, again, is to be sure you have the correct size clamp.
On a properly tightened T-Bolt clamp, the nut will be near the center of the threads on the bolt. If the bolt seems too long and is sticking out at a weird angle, you probably have the wrong size clamp.
T-Bolt clamps are fully lined, so can be used on silicone hoses.
Our standard T-Bolt clamps have a stainless band with an anodized bolt and locknut.
Spring-Loaded T-Bolt Clamps:
These clamps maintain a constant tension on silicone hoses on charge air coolers.
Largely superseded by newer constant-torque technologies, but still widely used, widely available, and popular with customers. They also happen to look really cool.
The only real disadvantages compared to Constant-Torque are a narrower range, less capability to handle rapid pressure spikes, and slowly losing tension in the spring over time (which is easily combated by adjusting the clamp periodically, which should be done with any style of clamp anyway).
Their ability to compensate for the expansion and contraction of hoses and fittings due to temperature is about the same as Constant-Torque.
Ours are floating-bridge type, using a trunnion-style bridge, which keeps the clamp aligned during tightening, and tightens more evenly around the entire diameter of the hose.
Fully lined, so can be used on silicone hoses.
Stainless band and bridge. Plated or anodized bolts, nuts, washers and springs.
Constant-Torque clamps are the only type of clamp available that both maintains constant pressure on the joint regardless of expansion or contraction due to heat, and resists rapid pressure spikes. Widely used in charge air cooler systems.
Requires proper adjustment to work correctly (see below).
Actually a high-tech worm-gear clamp, it offers a wide range within each size. This means one size Constant-Torque may fit more than one size hose. Far less critical than T-Bolt as far as sizing goes.
Constant-Torque clamps were developed to solve an uncommon, but important issue with spring-loaded clamps, that being how to handle rapid pressure spikes.
The metal discs on the bolt that look like washers are not actually washers – they are a type of spring called a Belleville spring. The use of Belleville springs provides the ability to handle expansion and contraction due to heat similar to traditional spring-loaded clamps, but with the added benefit of being able to maintain clamping pressure during rapid spikes in pressure. They also resist movement of the hose on the fitting during these events much better than traditional spring-loaded clamps.
Fully lined - protects soft hoses, such as silicone.
Complex construction means higher cost.
Constant-Torque Clamp Adjustment: Use of a torque wrench for initial adjustment is recommended. Adjust to between 90 and 125 in/lbs. These clamps utilize a "Torque-Check" feature - you can visually check for the proper torque. Look at the end of the bolt opposite the hex end. It should extend out of the housing about 1/4". At rest, the bolt extends about 1/8", so you need to make sure it is closer to 1/4" - then you know the clamp is properly tightened.
DO NOT OVER-TIGHTEN - these clamps will strip if grossly overtightened. You would also lose the benefit of having a constant torque applied if you get them too tight. Let the Belleville springs do their job by maintaining proper torque on the adjustment bolt (see above).
Worm - Gear Clamps:
Inexpensive and lightly constructed, we are reluctant to recommend standard worm-gear clamps on any permanent installation. They should never be used on silicone hoses, because the back of the saddle can cut into the soft silicone, and silicone can flow up through the open slots if tightened too much.
We do offer them, because customers request them, and there are legitimate uses for them such as prototyping a system, or for use on the smaller sizes of rubber hoses (not silicone).
Prototyping a System : When planning an intake system from scratch, it is difficult to predict exactly how many intake pieces will be needed, their length, or even their location. Particularly difficult is to accurately predict the size, type, and number of clamps for the final version.
Many builders will order either all worm-gear clamps, or a combination of T-Bolt clamps for the connections they are sure of, plus some worm-gear clamps for further prototyping. Once the final configuration is reached, any worm gear clamps are replaced with the proper size T-Bolt, Spring-Loaded T-Bolt, or Constant-Torque clamps to make it a professional-looking and reliably performing installation.
Our worm-gear clamps are all-stainless, including the screw.
Can be used in pairs for more holding power.
OK, So Which Clamps Should I Use?
T-bolt Clamps are the industry standard and our recommendation for all connections except charge air coolers. They are the strongest, most reliable, and have the best cost-to-performance ratio of all the clamps we carry. It is critical to use the proper size to avoid problems.
Spring-Loaded T-Bolt Clamps are popular for charge air cooler connections, and look great any place they are installed. They can be used in place of T-Bolts if appearance is important, such as on show cars.
Constant-Torque Clamps are the best type available for charge air coolers, especially if your system is running at near max pressures.
Worm-gear Clamps are great for prototyping a new system, and can be used on the smaller sizes (3” ID or less) of black-rubber intake hoses. Do not use on silicone hoses.
Why T-bolts do not work well on charge air coolers : T-Bolt clamps are intended for high-strength, long-term, stable connections. The one place where they do not well is on charge air cooler inlet and outlet tubes. The reason for this is that many charge air coolers have cast aluminum inlet and outlet tubes. These tubes expand and contract significantly depending on temperature. Let’s say you install T-Bolt clamps on charge air cooler tubes, obviously while the engine is cold. During operation, the tubes expand from the heat significantly, stretching the band on the T-Bolt clamps. Now when the engine cools back down, the clamp will be slightly looser because it has been stretched. After many cycles of heating and cooling, the clamp is too loose to properly secure the hose, and the connection can fail. Spring-loaded T-Bolt clamps, and later, Constant-Torque clamps, were developed to address this problem.
Important Note: All types of hose clamps should be re-tightened after the first few weeks of use.