After reading some of the threads about drilled airboxes, and having enjoyed the sound (but not the the heat) of my Vectra's 57i kit, I thought I'd have a go at the Toledo's box.
Removing it was easy, two screws and out it comes. After seeing where the filter came to on the lower box, I drilled a series of holes on the side that ended up nearest the bulkhead. I also took a 19mm spade bit and drilled twelve holes on the bottom (three lines of four holes, following the contours). I then cleaned it up and replaced it. I did look at the air feed and put that down as a future job, as this was only meant to be a quick ten minute job.
I started the car, and was dissappointed to find absolutely no change in sound. It was late so I called it a day, planning on taking it to work the following day.
The following day it was fine, ran smoothly with no additional noise while the car warmed up. Once I got up to temperature and a place to boot it, I had a go. And feck me, the noise was unbelievable!! At certain throttle positions the rumble from the V5 seemed loud enough to shake windows as I went past, absolutely awesome and exactly what I was after.
Off throttle it was as silent as stock, and full throttle high revs it also quietened down, but mid revs acceleration was full of V5 bass, far better than any ICE I could ever put in the car! I am tempted to put in a cone filter and put some sort of heat shield up the side, but the drilling was free, and cone filters aren't.
And now on to the interesting results. First off, the blip at 5000RPM has all but dissappeared. It was a noticeable drop before, you could feel the car stop accelerating at a fixed point. Not any more, there was no pause. I'm hoping that the dip has come up to the level of the power band rather than the power band dropping to meet it, but that needs a dyno to prove.
The second one was a very peculiar increase in fuel economy. I use the M6 toll road and cruise control set at 75, which is about as repeatable as a test can get. Normally I average 30 mpg for a full tank. Now it's peaking at around 40, and the average is around 36! I don't actually believe that is the case, so I'm going to keep an eye on it for the full tank full and see what happens. The only thing I can think of is that with the extra bit of air allows the car to run leaner than usual, although I'd have thought the MAF sensor would compensate for the airflow and just add more petrol to suit.
The next stage will be to replace the existing constricted pipe with a decent bit of free flowing pipe, once I figure out the best place to leave the end.
Removing it was easy, two screws and out it comes. After seeing where the filter came to on the lower box, I drilled a series of holes on the side that ended up nearest the bulkhead. I also took a 19mm spade bit and drilled twelve holes on the bottom (three lines of four holes, following the contours). I then cleaned it up and replaced it. I did look at the air feed and put that down as a future job, as this was only meant to be a quick ten minute job.
I started the car, and was dissappointed to find absolutely no change in sound. It was late so I called it a day, planning on taking it to work the following day.
The following day it was fine, ran smoothly with no additional noise while the car warmed up. Once I got up to temperature and a place to boot it, I had a go. And feck me, the noise was unbelievable!! At certain throttle positions the rumble from the V5 seemed loud enough to shake windows as I went past, absolutely awesome and exactly what I was after.
Off throttle it was as silent as stock, and full throttle high revs it also quietened down, but mid revs acceleration was full of V5 bass, far better than any ICE I could ever put in the car! I am tempted to put in a cone filter and put some sort of heat shield up the side, but the drilling was free, and cone filters aren't.
And now on to the interesting results. First off, the blip at 5000RPM has all but dissappeared. It was a noticeable drop before, you could feel the car stop accelerating at a fixed point. Not any more, there was no pause. I'm hoping that the dip has come up to the level of the power band rather than the power band dropping to meet it, but that needs a dyno to prove.
The second one was a very peculiar increase in fuel economy. I use the M6 toll road and cruise control set at 75, which is about as repeatable as a test can get. Normally I average 30 mpg for a full tank. Now it's peaking at around 40, and the average is around 36! I don't actually believe that is the case, so I'm going to keep an eye on it for the full tank full and see what happens. The only thing I can think of is that with the extra bit of air allows the car to run leaner than usual, although I'd have thought the MAF sensor would compensate for the airflow and just add more petrol to suit.
The next stage will be to replace the existing constricted pipe with a decent bit of free flowing pipe, once I figure out the best place to leave the end.
I have since replaced it with an enclosed cone filter and have to say with my power-flow system it sounds soooo good ![[B)]](/forums/styles/seatcupra/oldforumsmileys/shades.gif "Cool [B)]")
