Elise S1 Supplementary AirBox / Filter
Discussion
I need to pick the brains of the PH massive.
I have an S1 with a DVA modified engine in it. It currently has throttle bodies mated to a Bernard Scouse Airbox, the inlet to which is connected to some 100mm flexible hose ending up in a Pipercross conical filter mounted just above the nearside air scoop. This is not enclosed in any way.
The only problem with the set up is that it is very noisy - not so much at full chat, but using partial throttle openings at low revs produces a big, booming 'honk'. It's doing my head in, and it is attracting the unwelcome attention of the local Police Community Support Officers. What I want to do is to quieten things down a bit by fitting some sort of supplementary filter box, perhaps like the original one, but which flows more air. I've had a look at the original filter box with a view to modifying that, but I can't see any way of getting 100mm inlets and outlets onto it without major surgery.
So, does anyone know of anything that is on the market that might either do the job, or could be hacked about to fit?
I have an S1 with a DVA modified engine in it. It currently has throttle bodies mated to a Bernard Scouse Airbox, the inlet to which is connected to some 100mm flexible hose ending up in a Pipercross conical filter mounted just above the nearside air scoop. This is not enclosed in any way.
The only problem with the set up is that it is very noisy - not so much at full chat, but using partial throttle openings at low revs produces a big, booming 'honk'. It's doing my head in, and it is attracting the unwelcome attention of the local Police Community Support Officers. What I want to do is to quieten things down a bit by fitting some sort of supplementary filter box, perhaps like the original one, but which flows more air. I've had a look at the original filter box with a view to modifying that, but I can't see any way of getting 100mm inlets and outlets onto it without major surgery.
So, does anyone know of anything that is on the market that might either do the job, or could be hacked about to fit?
The Exige S1/340R 190 airbox isn't much better to be honest.... it's essentially the same system.
The 177bhp cars DID have a butterfly in the inlet tube (between the airbox and the large diameter flexiduct) that was actuated by vacuum and controlled (via solenoid valves) from the ECU. The butterfly would be shut at low throttle openings and below a certain RPM, and would open above it. This was done to get around the driveby noise regs of the time.
If you had an Emerald, it's possible that you could programme one or two of the output channels (especially one such as the air-conditioning compressor clutch output) to drive a similar system that you could tune to open above a certain throttle and/or RPM limit.
An airbox would only work to a degree unless you made it more restrictive. To get it working as a sound damper while not adversely affecting airflow would be an exercise in acoustic damping... or certainly trial and error.
The 177bhp cars DID have a butterfly in the inlet tube (between the airbox and the large diameter flexiduct) that was actuated by vacuum and controlled (via solenoid valves) from the ECU. The butterfly would be shut at low throttle openings and below a certain RPM, and would open above it. This was done to get around the driveby noise regs of the time.
If you had an Emerald, it's possible that you could programme one or two of the output channels (especially one such as the air-conditioning compressor clutch output) to drive a similar system that you could tune to open above a certain throttle and/or RPM limit.
An airbox would only work to a degree unless you made it more restrictive. To get it working as a sound damper while not adversely affecting airflow would be an exercise in acoustic damping... or certainly trial and error.
Esprit said:
The Exige S1/340R 190 airbox isn't much better to be honest.... it's essentially the same system.
The 177bhp cars DID have a butterfly in the inlet tube (between the airbox and the large diameter flexiduct) that was actuated by vacuum and controlled (via solenoid valves) from the ECU. The butterfly would be shut at low throttle openings and below a certain RPM, and would open above it. This was done to get around the driveby noise regs of the time.
If you had an Emerald, it's possible that you could programme one or two of the output channels (especially one such as the air-conditioning compressor clutch output) to drive a similar system that you could tune to open above a certain throttle and/or RPM limit.
An airbox would only work to a degree unless you made it more restrictive. To get it working as a sound damper while not adversely affecting airflow would be an exercise in acoustic damping... or certainly trial and error.
Tipper, thanks for the suggestion, but the Beauty of the Scouse Airbox is that it only sticks into the boot a couple of centimetres, so in effect I've still got the whole boot. ISTR that the Exige airbox takes up a huge amount of space, and I'd lose that.The 177bhp cars DID have a butterfly in the inlet tube (between the airbox and the large diameter flexiduct) that was actuated by vacuum and controlled (via solenoid valves) from the ECU. The butterfly would be shut at low throttle openings and below a certain RPM, and would open above it. This was done to get around the driveby noise regs of the time.
If you had an Emerald, it's possible that you could programme one or two of the output channels (especially one such as the air-conditioning compressor clutch output) to drive a similar system that you could tune to open above a certain throttle and/or RPM limit.
An airbox would only work to a degree unless you made it more restrictive. To get it working as a sound damper while not adversely affecting airflow would be an exercise in acoustic damping... or certainly trial and error.
Esprit, as it happens I do have an Emerald! I'm not sure how to take your suggestion forward though. Given my fabrication skills, I might end up choking off so much air that the car wouldn't run at all.
I appreciate the point about a supplementary airbox potentially restricting the airflow, but what I was envisaging was something that would surround the filter without affecting the amount that the engine can breathe. I'm not an engineer, but I'm surmising that what I have is the whole of the airspace in the engine compartment resonating at certain throttle/rev combinations, so if I can make the space that the existing filter sees a different (smaller) size, then the noise will be reduced, because there is less air to resonate.
What I might try first is to partition off the filter from the rest of the engine space - like the example on the Auto Teknix (Scouse) website. They suggest that with a view to stopping hot engine compartment air being drawn into the engine, thus sapping power. I've shied away from doing this though for two reasons. First, I'm going to have to take the clam off so i can see what I'm doing, and second, the engine compartment runs very hot as it is without effectively blanking off one of the two scoops that feed cooler air into it.
Why don't you just fit an ITG, Hurricane etc. in place of the cone filter? You might want to get it remapped to make sure it runs properly (presumably it was set-up with the cone filter?), but that'll take some of the noise out. Not much though tbh. Personally I'd leave as is and get a new cone filter every couple of years to keep it in decent condition.
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