In response to many requests to determine the compatibility of our new Tru Turn system with other manufacturer’s suspension components, we have gathered and evaluated some fitment and geometry data for the following combinations.
We realize fully that this does not cover all the possible combinations. It ONLY evaluates the most likely [and requested] combinations of the Tru Turn system with other manufacturers components. We did not evaluate any aftermarket combinations with the oem Camaro steering arm because it’s length and position typically prevents the use of the wider 10″ width wheel, which has been a primary requirement of most customers.
It is very important to note that we have NOT evaluated other manufacturer’s COMPLETE systems. It is very possible that their complete systems will generate better geometry data.
That is why we strongly recommend that your use a complete engineered and compatible system instead of trying to piece together a suspension system from scratch!
Most manufacturers should be able to give you this level of geometry evaluation on their own suspension systems.
| A | B – Complete TruTurn Package | C | ||||
| Ridetech Control Arms Stock Spindle Stock Steering Arm NO Tru Turn |
Ridetech Control Arms Ridetech Spindle Ridetech Steering Arm Tru Turn |
Ridetech Control Arms ATS Spindle Ridetech Steering Arm Tru Turn |
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| Suspension Travel | Camber Change | Total Toe Change |
Camber Change | Total Toe Change |
Camber Change | Total Toe Change |
| 3.0" Compression | ||||||
| 2.5" Compression | -0.5 | -0.600 | -2.9 | -0.040 | -2.5 | -0.260 |
| 2.0" Compression | -0.4 | -0.440 | -2.3 | -0.020 | -1.9 | -0.240 |
| 1.5" Compression | -0.2 | -0.280 | -1.8 | 0 | -1.5 | -0.140 |
| 1.0" Compression | 0 | -0.250 | -1.2 | 0 | -1.3 | -0.120 |
| 0.5" Compression | 0 | -0.120 | -0.5 | 0 | -0.5 | -0.050 |
| 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 0.5" Extension | 0.2 | 0.040 | 0.2 | 0 | 0.6 | 0.120 |
| 1.0" Extension | 0.2 | 0.120 | 0.7 | 0.020 | 0.8 | 0.240 |
| 1.5" Extension | N/A | N/A | 0.9 | 0.040 | 1.2 | 0.300 |
| 2.0" Extension | N/A | N/A | 1.3 | 0.060 | 1.5 | 0.480 |
| 2.5" Extension | N/A | N/A | 1.4 | 0.070 | 1.7 | 0.540 |
| Max Toe Variation | .600" Toe In @ 2.5" Compression | .070" Toe Out @ 2.5" Extension | .540" Toe Out @ 2.5" Extension | |||
| Total Toe Change | Total Toe Change .720" | Total Toe Change .110" | Total Toe Change .800" | |||
| D | E | F | ||||
| Ridetech Control Arms Heidts Spindle Ridtech Steering Arm Tru Turn |
Heidt’s Control Arms Heidt’s Spindle Ridtech Steering Arm Tru Turn |
Heidt’s Control Arms Heidt’s Spindle Ridtech Steering Arm Tru Turn Outer Tie Rod Shimmed Down .750" |
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| Suspension Travel | Camber Change | Total Toe Change |
Camber Change | Total Toe Change |
Camber Change | Total Toe Change |
| 3.0" Compression | -0.520 | -0.250 | ||||
| 2.5" Compression | -2.6 | -0.500 | ||||
| 2.0" Compression | -2.0 | -0.400 | -0.500 | -0.200 | ||
| 1.5" Compression | -1.2 | -0.270 | ||||
| 1.0" Compression | -0.7 | -0.250 | -0.274 | -0.170 | ||
| 0.5" Compression | -0.3 | -0.120 | ||||
| 0 | 0 | 0 | 0 | 0 | ||
| 0.5" Extension | 0.4 | 0.250 | ||||
| 1.0" Extension | 0.9 | 0.400 | 0.274 | 0.170 | ||
| 1.5" Extension | 1.2 | 0.420 | ||||
| 2.0" Extension | 1.5 | 0.500 | 0.500 | 0.200 | ||
| 2.5" Extension | 1.7 | 0.550 | ||||
| Max Toe Variation | .550" Toe Out @ 2.5" Extension |
.520" Toe In @ 3.0" Compression | .250" Toe In @ 3.0" Compression | |||
| Total Toe Change | Total Toe Change 1.050" | Total Toe Change 1.020" | Total Toe Change .450" | |||
Data summary:
Example A – This is a OEM spindle with an OEM steering arm…just like GM delivered it. The camber curve is nearly nonexistent, meaning that the tire will NOT lean into the turn as we would like. The toe variation @ .600″ of toe IN during compression and total change @ .720″ are both excessive.
Example B – The Tru Turn system shows 2.9 degrees of camber gain at a 2.5″ compression position. It also shows a toe variation of only .070″ toe out and a total toe change of only .110″.
Example C – Substituting the SpeedTech ATS aluminum spindle within the Tru Turn system changes the camber curve little, but seems to make a dramatic increase in both max toe variation @ .540″ and total toe change @ .800″.
Example D – Substituting the Heidt’s spindle in the Tru Turn system created geometry similar to example C only with even more toe variation and change
Example E – Substituting the Heidt’s control arms for the RideTech arms did not significantly alter the geometry from example D
Example F – Shimming the outer tie rod DOWN by .750″ made a huge improvement. Max toe variation was .250″, and total toe change was .450″
Overall summary
These examples DO NOT tell us that other manufacturer’s components or systems are inferior to the Tru Turn system. Instead they tell us that just because certain components will bolt up together, it does not necessarily mean that they will function properly together. Yes, your car will likely go down the road just fine for many years. No, a mismatched combination of parts will not offer “just as good” of handling performance as a complete system.
All the aftermarket examples showed a similar and significant improvement in camber gain. The differences seemed to be in the bumpsteer measurements. Bumpsteer is radically affected by the precise location of the various steering components. Different manufacturers will use slightly different locations for these components. When used as intended [as a complete system] they will achieve the intended goals. When combined with other [unknown] components, the end result may coincidently bolt together, but may not achieve the geometry that was originally intended.
