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I just got lucky in The Marketplace section here, and was able to purchase this kit cheaply, as the owner sold his car and never installed it. I recently had my exhaust done, new catalytic converters, removed and eliminated center mufflers, custom pipes and new performance rear resonators and tail pipes. I will install this once the weather turns mild here on Cape Cod. It should growl better, and gain some horsepower with these enhancements...Thoughts?
You will be better off to bring air in from outside the engine compartment, especially in the summer. You want as dense (cold) air as you can get, and if your air source is still inside the hot engine compartment, your gains will be limited.
Consider mounting the air filters behind the headlights, then routing air ducts to the intake pipes. That will mean some metal cutting, but it's quite doable even by a non-mechanic such as myself.
Below shows some of it. The white pipe bend leads to another pipe bend that goes behind the headlight. The black air duct runs back to the throttle bodies.
You will be better off to bring air in from outside the engine compartment, especially in the summer. You want as dense (cold) air as you can get, and if your air source is still inside the hot engine compartment, your gains will be limited.
Consider mounting the air filters behind the headlights, then routing air ducts to the intake pipes. That will mean some metal cutting, but it's quite doable even by a non-mechanic such as myself.
Below shows some of it. The white pipe bend leads to another pipe bend that goes behind the headlight. The black air duct runs back to the throttle bodies.
Thanks,
John
1987 XJ-S V12
Sorry pic is sideways!
Thanks...that makes sense about the coldest air possible. Did you gain noticeable power, and I assume it sounds much sportier too?
Actually I don't know if it gained noticeable power. I was doing a lot of other things to it when I rigged the "cold air" system, so it was down for over a month. By the time I had it running again I couldn't remember what it felt like before :-)
It did completely change the sound of the car, which I like.
If you do take cold air from outside the engine bay DO NOT take it from the wheel arch, this is a low pressure area and the engine will have less air available.
This is how TWR did it in the race car. This is a video capture of Tom's car from 1985 Bathurst, They used a similar method in the TWR road car just much smaller.
If you do take cold air from outside the engine bay DO NOT take it from the wheel arch, this is a low pressure area and the engine will have less air available.
This is how TWR did it in the race car. This is a video capture of Tom's car from 1985 Bathurst, They used a similar method in the TWR road car just much smaller.
This is what the install will look like. I don't abuse or push the engine...With my new modified exhaust and the addition of the air intakes...I'm sure it will sound much sportier.
I like cold air intakes, I also prefer a bit of intake noise, but I like the factory air boxes quite a lot. Aesthetically they’re a large design element in the engine bay. I’m planning to retain them but replace the intake funnels with 2.5” dia. tubes for cold air ducts.
I never have understood the benefit of the curved aluminum intakes and conical filters. It looks like less square inches of filter area than the OEM air boxes. Otherwise, basically same as stock but with more view of the exhaust heat shield. I’m sure they do sound better and flow better than the OEM tapered funnels.
More power is good. And some intake sound is nice, too.
I've been contemplating some air intake changes....but I'm a bit hesitant.
Years ago I experimented with some DIY intake mods on my XJS and I was never fully satisfied with the results. If there was a power increase it was only at very high RPM. As for the sound, I was hoping for a authoritative snarl when I gave 'er the boot. I ended up with a not-very-pleasant moaning sound, even under light or moderate throttle.
I have an extra pair of air cleaners. I've been toying with the idea of cutting the snorkels of the spare set and modifying the front of the air cleaner boxes to accept two original, tapered snorkels.
Roger Bywater once wrote an item about the V12 intakes and made a persuasive case that it was the best overall compromise. IIRC he stated that cold air is good for high rpm power, whereas hot air is good for fuel economy particularly at lower rpms. He argued that the XJS setup took advantage of hot air when it was needed, and that there was plenty of cold air available at higher speeds. He also said a lot effort went into acoustic tuning the intakes and it was quite tricky.
I don't think Jaguar introduced cold air induction until after ECUs were able to more finely tune combustion for maximum efficiency.
Last edited by Mac Allan; Feb 23, 2019 at 02:18 PM.
Since I have a Series III sedan without ABS I might have a bit more room, as the air cleaners are situated a bit rearward of what's seen in your pic. But, still, space will be tight.
I went a slightly different route. This is 90mm poly pipe. Did it make a difference, I don't think so. The plenum is the issue that needs to be addresses.
I hacked out the front face and trumpets on my filter boxes and fitted the face with a mesh insert 1/8th" of an inch, makes accessing everything else a breeze.
Anglicomarine0326 what do you want for your old filter housing assembly?
Performance Air Intake Kit.
