Modifying the Stock Air Intake System

[goldstar]

bonsai,

Very nice work and an excellent description of your scoop construction. The photos you posted really made the whole process quite clear and easy to understand. I noted with interest that you found some improvement in performance. One suggestion I have is to seal up at least some of the drain holes in the snorkel to see if you notice any additional benefit. Perhaps you could leave the drain hole closest to the inlet open and seal the rest. I would imagine the more sealed the intake system, the greater might be any ram effect. Keep in mind the dangers of water ingestation, however.

You've inspired me to attempt to build my own scoop although I may try sealing my snorkel first to see the result. Once it gets warmer that is because right now it's too bloody cold up here to work on the car. I see you used .5 mm clear plastic sheeting. I have a sheet of .020" polystyrene which is easy to cut and bend but I don't know how well this material will withstand the heat involved without deforming or melting. I could try the same thickness in a sheet of ABS plastic which I think is tougher and may be more heat resistant. I'll have to do some research here.

02 DX Millenium Red

[bonsai]

Thanks for the input goldstar, after resetting the ECU and putting Shell Optimax (98 octane) the car absoloutley goes off. The accelleration especially in the lower gears is quite noticable.

I will try and seal up the snorkel drain holes, also just looking at the service manual, would the ressonance chamber jsut before the air box let air out aswell?

Dont use any polymer they all break down very easy with high heat exposure ABS plastic would be perfect. What I would do if i were you is to get some off cuts and practice moulding them around corners, and around nuts. It helped me alot when i did it (i made 2 prototype moulds before that one).

Good luck with it! tell me how u go!

bonsai,

Very nice work and an excellent description of your scoop construction. The photos you posted really made the whole process quite clear and easy to understand. I noted with interest that you found some improvement in performance. One suggestion I have is to seal up at least some of the drain holes in the snorkel to see if you notice any additional benefit. Perhaps you could leave the drain hole closest to the inlet open and seal the rest. I would imagine the more sealed the intake system, the greater might be any ram effect. Keep in mind the dangers of water ingestation, however.

You've inspired me to attempt to build my own scoop although I may try sealing my snorkel first to see the result. Once it gets warmer that is because right now it's too bloody cold up here to work on the car. I see you used .5 mm clear plastic sheeting. I have a sheet of .020" polystyrene which is easy to cut and bend but I don't know how well this material will withstand the heat involved without deforming or melting. I could try the same thickness in a sheet of ABS plastic which I think is tougher and may be more heat resistant. I'll have to do some research here.

02 DX Millenium Red

[goldstar]

bonsai,

Apparently you're getting significant performance gains from your scoop. That's great. That's in line with what Edgar reported in Part 5 of his article, "Eliminating Negative Boost". Thanks for the info about ABS vs. styrene-obviously ABS is the way to go.

As for the drain hole at the bottom of the resonator, I would imagine that it leaks air from the intake system as well thereby reducing inlet air pressure. However, I'm not sure if it also has some function in aiding the operation of the Helmholtz effect. If it did, sealing it might adversely affect performance. I think it is just a drain hole but I'm not absolutely sure. It might be a good idea to temporarily seal the resonator hole with duct tape (assuming it will hold) and then test for any noticeable change in performance. I plan on doing this when I can start working on my car again.

Thanks again for the information and advice and I'll get back to you when I have something new to report.

02 DX Millenium Red

[ProtegeDriva]

Sorry about the retarded question from before .....hope I'm not on posting probation , but do you need to reset the ECU after you do this mod?? and if so, what do you have to do to reset it?

Thanks for the input goldstar, after resetting the ECU and putting Shell Optimax (98 octane) the car absoloutley goes off. The accelleration especially in the lower gears is quite noticable.

[goldstar]

ProtegeDriva,

I'm not really sure if you have to reset the ECU in this case but it can't hurt. Just disconnect the neg.batt. cable from the battery for about 10 minutes and maybe depress the brake pedal a couple of times. That should reset the ECU. Then reconnect the cable and you should be good to go. The idea is that the ECU has to "relearn" the new air intake parameters and by resetting it you are aiding the "relearning" process. Don't worry about the 'retarded' question, we all ask them from time to time.

02 DX Millenium Red

[Pokiarchy]

If retarded questions were candy id be fatter

[dbuenger]

Vapor Lock Possibility?

Greetings all,

I've been seriously thinking about doing a scope similar to bonsai (nicely done by the way!), but have been a little concerned about the possibility of vapor lock. In reading about cold air intake systems I've heard horror stories about water getting into engines and seizing them up. I was thinking about designing a metal scope with certain angles that would build up positive boost while giving water a channel to exit the air intake system before being pulled into the snorkel, the air filter and eventually the engine. I also wonder if those holes in the snorkel area are there for exactly this reason.

Maybe I’m just being paranoid… what do you guys think?

I work closely with some engineers that are obsessed with cars and will ask their opinions... and of course pass what I find along.

[bonsai]

Greetings all,

I've been seriously thinking about doing a scope similar to bonsai (nicely done by the way!), but have been a little concerned about the possibility of vapor lock. In reading about cold air intake systems I've heard horror stories about water getting into engines and seizing them up. I was thinking about designing a metal scope with certain angles that would build up positive boost while giving water a channel to exit the air intake system before being pulled into the snorkel, the air filter and eventually the engine. I also wonder if those holes in the snorkel area are there for exactly this reason.

Maybe I’m just being paranoid… what do you guys think?

I work closely with some engineers that are obsessed with cars and will ask their opinions... and of course pass what I find along.

Thanks for the compliment! :D

From what i can gather (and what i have learnt from different sources) the way that the snorkel works is that those chambers where the holes are in are deep enough for the water molecules to become trapped. Simple physics shows us that steam (hot water) rises and cold water falls, this is the principle used by the chambers in the snokel and there's 3 or 4 (i cant really remmeber) so it gets rid of almost all of the water.

However I live in sunny sunny too sunny Australia where it rains for 1 day a month so there's not too much of an issue with water as there would be probably in the Sates. I probably would have made provision for some kind of water filter however there is some very limited room in what you can and cant do in that space provided.

[MisterT]

Is water more susceptable of getting in to the intake with this modification?

[goldstar]

Is water more susceptable of getting in to the intake with this modification?

It depends on which modification you mean. If you only remove the horizontal grill piece exposing the snorkel inlet to outside air flow and you do not plug the snorkel drain holes, then I believe there is virtually no way water ingestion can occur short of driving through standing water almost as high as the hood. I make this statement from personal experience but I also suggest you look for a discussion of the air flow path involved earlier in this thread.

If you utilize a scoop and/or block the drain holes in the snorkel then the possibility of water ingestion exists either from directing water into the air inlet or preventing it from draining from the system. Since I have not yet done either of these mods, I can't give you a definitive answer here. Right now, this is strictly a matter for investigation as to any negative effects.

Removing the MAF sensor screen has absolutely no effect on water ingestion for obvious reasons.

02 DX Millenium Red

[dbuenger]

I would agree with goldstar. The original 2 mods discussed in this thread look to be pretty safe. As mentioned earlier, water is heavier than air (especially where I'm from) and will not be sucked up into the snorkel. Any small amount that does either drains through drainage holes or is not enough to cause problems.

[MisterT]

Thanks goldstar. Looks like an easy mod to do. I will have to try it out.

[bonsai]

It Rained!!!!!

AND NO WATER CAME IN!

It pissed down today like a baby shower and there was no water in my airbox. Water did fly up the the scoop but was very little in the front of the snorkel and nothing by the airbox.

Thought id let yas all know that the scoop didnt let my engine ingest any water.

[goldstar]

AND NO WATER CAME IN!

It pissed down today like a baby shower and there was no water in my airbox. Water did fly up the the scoop but was very little in the front of the snorkel and nothing by the airbox.

Thought id let yas all know that the scoop didnt let my engine ingest any water.

Bonsai, that's great news! You just made it a lot easier for the rest of us would-be scoop builders. Just curious, what was your maximum road speed during testing as I'm guessing that the greater the forward velocity, the more likely that water ingestion would occur?

Thanks very much for posting this important information.

02 DX Millenium Red

[bonsai]

My max road speed was 110kph (about 65mph) thats the max road speed round here. Yes I would have to agree with you that it is more likely to have water ingestation at higher speeds, however i do beleive that the snorkel takes adequte care of this issue. I am still weary however of sealing up the drain holes as another thing came to mind.

If the drain holes are sealed and water is contained at the bottom of the holes, because the snorkel is infront of the radiator that quite obviously generates alot of heat, the water would evapourate and becuase there is no other way the water can escape other than to follow through the air inlet there would be a significantly higher risk of water ingestation.

This is my thought anyway which stopped me from sealing those holes up.

Also another note is taht tehre is a drainhole in the bottom of the airbox aswell.