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Frequently Asked Questions

1. How does the core charge work?

The core charge is added to the order. After you install the ordered product you return the stock part(core unit) to us. We inspect the stock unit and refund the core charge within 24hrs. as long as the core unit is acceptable. You have 10 business days starting the day after you receive the product to postmark your core. If you require an extension of the core unit holding period you must request this via email. All core units MUST BE the same model product purchased. For example: you can not purchase s50/s52 regrind cams and return m50/m52 camshafts. Another unacceptable core exchange is to purchase our m20a or m20b BBTB and return a TB from the 325"e" engine.

2. I have an M50 or OBD1 intake manifold on my S52 engine. Which Big Bore Throttle Body model do I order?

The Big Bore Throttle Body model must match the current Throttle Body model you are running on your vehicle. Another simple way to look at it is, order the Big Bore Throttle Body model based on your vehicle model/year. This same scenario applies to cars that have swapped to the M52/S52 engine but were originally a M50/S50 vehicle. Scenario 1: If you have a 98 3 series running the OBd1 intake manifold, you require the M52.S52 Big Bore Throttle Body. Scenario 2: If you have a 93 3 series running an S52 engine, you require the M50/S50 Big Bore Throttle Body.

3. After installing the Big Bore Throttle Body you are experience the throttle pedal sticking at idle only.

We try our best to have the idle stop screw adjusted correctly out of the box. Every car is different so the setting may not be set correctly for everyone. This is an easy adjustment. We are working on creating a video of how to adjust the idle stop screw with the Big Bore Throttle Body still on the engine. For now, follow these instructions to adjust the idle stop screw.

4. After installing the Big Bore Throttle Body a Check Engine Light (CEL) or Automatic Stability Control (ASC) light illuminates.

First it is very important to make sure that the throttle plate is not sticking at idle. If the pedal is sticking at idle this can sometimes cause the CEL to illuminate. As long as there is nos ticking at idle, then it is safe to assume that the CEL has illuminated due to a Throttle Position Sensor (TPS) fault code. In most cases this is caused by too high of a throttle plate position. To correct this, the idle stop screw needs to be adjusted to lower the throttle plate position.

5. When purchasing the regrind camshafts is software required or recommended

A software upgrade is not required if only the regrind cams are being installed. Your ECU will automatically adjust to accommodate the new cams. We do not recommend one software option over another, t