how to get a exciting engine sound for a racing game like CSR, on cell phone?

I have tried many way to build a engine sound for a racing game on cell phone, however failed. I generally put three loops, which is high loop ( engine loop over 5000 rpm), mid loop ( idle engine loop), and bass loop ( the engine loop get from exhaust pipe). I played them together, and gradually fade out the mid loop. It sounds really good on computer, but not on cell phone. Because the bass loop is hardly heard. My friend told me, the reason is the most cell phone amplifier can not play sounds lower than 500 Hz. But I figured out a racing game like CSR(made by natural motion games) can still have a very nice engine sound.
Is anyone give me some advices to build it?

My suggestion would be to raise the pitch of the bass sound. If the phone is trying to play a sound it can’t, there will be no sound output. However if you raise the pitch until it is above the minimum level that the phone can handle, you will hear the sound, and since mobile phone speakers are tinny to begin with, the higher-pitched bass sound will still work the same way as it does on the PC.

That’s the theory, anyway.