Car appreciation... the aesthetics, the engineering, etc

Getting a good cosmetic surface finish with carbon is properly difficult.

The internal surface matters more, since I'd hope he'll spend more time driving it than looking under the bonnet.

since I'd hope he'll spend more time driving it than looking under the bonnet.

What about the gram tho?

Maybe with internal and external formers, which I assume is used for steerer tubes? Sounds complicated.

If you don't mind the extra weight, form the inside then mould the outside using way too much resin. Applying pressure evenly might be tricky since the interior will already be rigid.

That noise is incredible. Sounds like end times.

There are various ways to ensure a good finish on both the A&B surface, internal and external formers is one but you can also achieve a pretty good finish by putting the part on a single sided tool and vacuum bagging it

I have an SBD crabon airbox on my jenveys and the inside surface isn't as good as the outside by any means, i don't think surface finish on the inside of the airbox is really that important as it's going through a set of trumpets anyway normally

The internal surface shouldn't really matter at all, since what you're aiming for is just a big volume of air, rather than a smooth surface for the air to flow over. The surface would only matter if the airbox was acting as a restrictor, so that you're trying to squeeze as much air through a confined space as possible. If you airbox is acting like a restrictor, you be doing it wrong. In any event, a little bit of turbulence is not necessarily a bad thing. Cylinder head ports flow better with a slightly rough surface than a polished one.

Yep, a friend of mine is getting pretty good at doing vacuum resin infusion, and the inside surface quality is very good.

Resin infusion is really the only proper way to do wet lay. It's quite high investment in kit though for a hobbyist.

Maybe i can design and build a pattern for @Dammit and your pal could lay it up?

That sounds great - Jenvey themselves provide a selection of airboxes that can enclose their trumpets, but I'd like to connect to the stock airbox that would have a BMC panel filter in it, and also the MAF housing en-route to the plenums.

This means that the ideal design is two distinct enclosures that are then fed from one central point.

I could do that with OTP Jenvey parts, if I came up with a suitable Y-pipe that would come off the airbox via the MAF, then divide and run into each plenum.

Reminiscent of

https://youtu.be/J187Pw6UkCM

Porsche is better though!

The battery keeps going dead on the E39, I can't put it on a charger because I live in a flat, has anyone got a decent battery tester I can borrow to test my battery?

I've jumped it off the MX5 about 5 times now and it's get real old, real quick, I've read online that the more you jump start a battery, the unhealthier it gets, so I'm slowly killing it.

There's lots of stuff online about a few different E39 common faults that cause a battery drain but my car doesn't seem to exhibit any of those symptoms, and they seem to cause an overnight drain rather than a 4-7 day drain. So I'm thinking it's just a tired battery, any thoughts?

Also, ECP want £200 for a battery!! Anyone got any experience with Advanced Battery Supplies?

In case I've missed it, y u no ITBs? If you like a 911 to sound awesome ITBs are the answer and then you don't need to faff on with an air box.

Concern about losing torque at lower revs due to the shorter induction path, the complexity of moving to Alpha-N, that the current induction system has a snorkel to draw in cool air.

But other than that, with the low-loss exhaust and the lightweight flywheel yes - ITB's should be awesome.

This is why I had to cut the heater box out of my engine bay, otherwise on the 16v you can only fit 30mm trumpets with gauze filters.

Now I have 90mm trumpets on with a full size air box

I know the torque thing is a thing. Or at least I know people say it is. But the scream of ITBs is worth at least 30bhp and despite what Americans may tell you power is where the fun lurks.

The top of a 911 engine bay is a fairly cool, drafty place at speed, intake temp isn't usually too much of a worry. At least in an air cooled car.

Air cooled cars have a lot more engine exposed - on a 996 onward you get what is basically a letterbox that you can see a small part of the engine through.

The Jenvey kit comes with 90mm trumpets.

I guess the 996 kit has quite a short TB and manifold and a long trumpet?

the total inlet tract length from the valve to the end of the trumpets is all that really has any effect, which you could in theory make using a variety of combinations of spacers, manifold and length of TB

These are them:

I'd need to do some measuring but it looks like there would be plenty of room for taller stacks.

This is the standard intake:

The Jenvey ITB's replace both the silver and the black section pictured, but looking at the relative heights there might not be much room at all. I suppose curved horns could be used.

Although that said when you look at it from a different angle it appears that there is loads of room:

Look at all that lovely room. There are heat shields above the block, it won't get too hot.

Ditch the air box.

Honestly.

Ditch it.

And fit a good silencer. 911s should make intake noise, not exhaust noise, they're a racing car, not a hot hatch.

I recon, using my vernier eyes, by the time you’ve got the jenvey manifold, bodies and 90mm trumpets on its about the same as that stock manifold setup height wise.

And fit a good silencer. 911s should make intake noise, not exhaust noise, they're a racing car, not a hot hatch.

I think that this is the exhaust which I have:

https://www.youtube.com/watch?v=eivefHKcu80

I recon, using my vernier eyes, by the time you’ve got the jenvey manifold, bodies and 90mm trumpets on its about the same as that stock manifold setup height wise.

I'm clearly misunderstanding something as this would appear to suggest that I need ~45cm from valve to tip of trumpet, and I'm deffo not going to fit that in:
http://www.exx.se/techinfo/runners/runners.html

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