Back in my Lotus newb days (last summer), I bought a TopSpeed Pro1 intake with K&N filter as shown below.
I installed it and let the car idle for some time then shut it off. Then went for a drive. This intake gave immediate problems including bogging, hesitation, extreme slowness, and finally after about 5 miles threw a CEL. Though this intake sounded AWESOME, i reverted right back to the stock airbox and the car ran normal again. My dealership reset my ECU and all was well. I continued using the stock airbox with a Green Filter and velcoity funnel for several thousand miles.
Then I installed my Greddy/BOE supercharger kit. I continued using the stock intake with the supercharger and everything was cool, but i really yearned for that aftermarket intake scream right behind my left ear. I figured it would also help the supercharger sound a bit meaner.
Through trial and error, and reading the forums, I learned that the intake diameter is crucial for the MAF to properly function. Just by looking, I could tell that the aftermarket intake was much larger than the stock airbox. I knew this was my problem. So i started by measuring the inner diameter of both the aftermarket TopSpeed Pro1 intake and the stock airbox using my digital calipers.
TS Pro1 = 2.90" ID
Stock AB = 2.51" ID
My solution was to perform a BBmod on the TopSpeed Pro1 intake by removing the MAF area of the tube and replacing it with the MAF area from the stock airbox. This is common practice on the celica forums. I bought an extra airbox (as not to ruin my original) and cut the MAF area from the rest of the unit.
I then cut off the MAF area of the TS Pro1 intake and mated to two together with a rubber coupler.
Then i connected the stock MAF tube directly to the throttle body using another rubber coupler. I chose to put the MAF closer the to TB (opposed to near the filter) because I figured the air would be smoother entering the MAF sensor in that location. Here is the final setup.
This intake RULES!!! The supercharger now sounds like it is going to suck you out of the driver seat! The SC WHINE IS CRAZY! You and your passanger are GUARANTEED TO SMILE! The sound is absolutely incredible and best of all, the car runs just fine. I have driven with this intake for a few months and about 1000 miles with no CEL and zero hesitiation or bogging. It runs like a stock airbox because it has the proper MAF tube sizing, but it has the sound of the aftermarket intake.
I'll give this mod a solid 5 tumbs ups! :up: :up: :up: :up: :up:
just to update this thread. its been another month with this intake and I have zero issues. I have modifed the setup a bit however. I relocated the MAF to the original orientation using the stock rubber coupler. This was done just for personal preference. I also added an extra mounting bracket for stability; sturdy as a rock now. In the process, the airfilter was moved several inches and now resides directly infront of the driver-side air vent. Sure, it'll get dirtier faster, but the sound is just UNREAL!
A forum community dedicated to all Lotus owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, maintenance, and more!
The SC WHINE IS CRAZY! You and your passanger are GUARANTEED TO SMILE! 
