93 RX7 OEM air intake hose explanation
06-19-12, 12:12 PM
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93 RX7 OEM air intake hose explanation
I am interested in making my own air induction kit, but I'm having trouble finding out the exact purpose for all of the hoses on the stock intake. I performed an internet search, but I'm still not certain. I wanted to start a thread, and remove any doubt.
The two big ones which feed into the turbos are pretty clear. I'm pretty sure but not certain that one of the smaller hoses is for the factory blow off valve? From my internet search I can only guess the other two are for the air pump? Is that right?
If I make an intake for the two turbos what should I do with the other three hoses?
If I am right in my assumption that there are two hoses that feed into the air pump, can I simply disconnect them since I will be eliminating my cats before I make the intake?
The two big ones which feed into the turbos are pretty clear. I'm pretty sure but not certain that one of the smaller hoses is for the factory blow off valve? From my internet search I can only guess the other two are for the air pump? Is that right?
If I make an intake for the two turbos what should I do with the other three hoses?
If I am right in my assumption that there are two hoses that feed into the air pump, can I simply disconnect them since I will be eliminating my cats before I make the intake?
06-19-12, 08:28 PM
#2
There are 4 that you need to worry about (i.e. keep and not delete) - the two big ones (intake for turbos), and the two routed to the passenger side of where the two big hoses enter the stock intake box. Those are the BOV and CRV (Charge Relief Valve). It is necessary for the secondary turbo to work properly.
Note that for the purposes of building an intake the BOV and CRV have no reason to be filtered as they are vents for the FI system, but if you wanted it to look clean then they of course can be.
The other two or three that are routed to the box are unnecessary for a car with emissions removed, one goes to the Air pump, one goes to ACV (I believe), and the last one I can't even remember clearly where it goes haha, I think it just went to atmosphere.
Note that for the purposes of building an intake the BOV and CRV have no reason to be filtered as they are vents for the FI system, but if you wanted it to look clean then they of course can be.
The other two or three that are routed to the box are unnecessary for a car with emissions removed, one goes to the Air pump, one goes to ACV (I believe), and the last one I can't even remember clearly where it goes haha, I think it just went to atmosphere.
06-19-12, 10:39 PM
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There are 4 that you need to worry about (i.e. keep and not delete) - the two big ones (intake for turbos), and the two routed to the passenger side of where the two big hoses enter the stock intake box. Those are the BOV and CRV (Charge Relief Valve). It is necessary for the secondary turbo to work properly.
Note that for the purposes of building an intake the BOV and CRV have no reason to be filtered as they are vents for the FI system, but if you wanted it to look clean then they of course can be.
The other two or three that are routed to the box are unnecessary for a car with emissions removed, one goes to the Air pump, one goes to ACV (I believe), and the last one I can't even remember clearly where it goes haha, I think it just went to atmosphere.
Note that for the purposes of building an intake the BOV and CRV have no reason to be filtered as they are vents for the FI system, but if you wanted it to look clean then they of course can be.
The other two or three that are routed to the box are unnecessary for a car with emissions removed, one goes to the Air pump, one goes to ACV (I believe), and the last one I can't even remember clearly where it goes haha, I think it just went to atmosphere.
Is it common for the two turbo relief hoses to be left unfiltered?
06-22-12, 08:44 AM
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The two big intact hoses obviously need to be filtered. The only other hose that is recommended to be filtered is the air pump intake. It's the hose with a 90 degree bend in it connected to the air pump. Mazda has a TSB on the airpump intake stating it needs cold-filtered air to prevent premature airpump failures.
The two hoses on the far passenger side are vent hoses, as was previously mentioned. On my cold air intake I have them plumbed together going to a lawn mower muffler to reduce the whoosh sound a bit. The other hose into the back of the stock airbox is the ACV, which makes a Moooo sound if it is not muffler adequately. In the airbox is a muffler device, and the ACV air goes through this and out the airbox hose on the IC side that goes to nothing. I also used a lawnmower muffler on the ACV hose to turned the Mooo into a noisy growl.
The two hoses on the far passenger side are vent hoses, as was previously mentioned. On my cold air intake I have them plumbed together going to a lawn mower muffler to reduce the whoosh sound a bit. The other hose into the back of the stock airbox is the ACV, which makes a Moooo sound if it is not muffler adequately. In the airbox is a muffler device, and the ACV air goes through this and out the airbox hose on the IC side that goes to nothing. I also used a lawnmower muffler on the ACV hose to turned the Mooo into a noisy growl.
06-24-12, 02:44 PM
#5
It's also a good idea to put a pair of breather filters on the end of the CRV and BOV lines to prevent spraying oil all over your engine bay. Plus it makes it look a little more cleaner and helps reduce the noise ( i drove around for a couple days with unfiltered BOV and CRV and noticed an increase of noise, although everyone is different i didn't like it) and as mentioned previously be sure to filter the airpump.
06-24-12, 04:39 PM
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Can any of you suggest a good filter for the BOV, CRV, and air pump? Is it really just called a lawnmower muffler? If so, where can you buy them, home depot?
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06-24-12, 07:16 PM
#8
I used these Style crankcase vent filter made by K&N http://www.knfilters.com/vent.htm
they look good, do the job and you can almost get them anywhere, But if you can't any quality breather/vent filter will do.
they look good, do the job and you can almost get them anywhere, But if you can't any quality breather/vent filter will do.
06-25-12, 10:52 AM
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I really appreciate the help. I've compiled a parts list for everything needed to make an intake. Does this list look complete? Should anything be added or isn't needed? Are these decent prices?
1. Universal piping kit from ebay:
http://www.ebay.com/itm/2-5-Intercoo...ht_3329wt_1163
2. K&N intakes for turbos x2:
3. K&N crankcase filters x3 (is 3 enough?)
1. Universal piping kit from ebay:
http://www.ebay.com/itm/2-5-Intercoo...ht_3329wt_1163
2. K&N intakes for turbos x2:
3. K&N crankcase filters x3 (is 3 enough?)
08-17-12, 12:42 PM
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Things turned out great. I was able to suppress the low rumble which comes from the metal pipe which extends behind the intake with a crankcase filter. Cutting the piping turned out well too. I went with the pineapple racing air pump eliminator pulley. It was a little more expensive than other option, but its really well made. My first upgrade went well. I can't wait to get more done. Thanks for all of the help.
08-22-12, 07:21 AM
#13
The OP's intake is still an improvement over stock. It should improve spool-up and he's not taking air from the intercooler for them. But ideally, if he could shield the filters from the hot air and have them source just the ambient air from the nose (via the gap just below them) that would be best. I don't have a picture of a shield installed, but Pettit offers one with their kit... Trak Pro Cold Air Intake - Pettit Racing - RX-7,RX-8 & Rotary Performance - Racing - Engines - Rebuilds - Parts
It doesn't appear they sell the shield separately, and it wouldn't fit on his intake anyway. So he'd have to fab it himself.
OP....I can't see in the picture, but if you haven't already, make sure you block off that hole in the top of the stock intercooler duct.
It doesn't appear they sell the shield separately, and it wouldn't fit on his intake anyway. So he'd have to fab it himself.
OP....I can't see in the picture, but if you haven't already, make sure you block off that hole in the top of the stock intercooler duct.
08-22-12, 11:53 AM
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I did see a shorter spoil time. I thought about making my own heat shield as well. My main obstacle was where to purchase sheet metal. I looked at home depot, but wasn't able to get what I was looking for. Any suggestions?
10-11-14, 12:13 PM
#20
sorry to bring up an old thread but does any one know what the hose is that connects on the right side of the airbox? I am having boost issues and want to know if this is a contributing factor....My car wont boost past 6 psi on my boost gauge. I just bought the car so im new with this.
10-11-14, 02:14 PM
#21
That's for venting. From the factory a hose ran from that, looped down and under the box and vented to atmosphere...the hose to no where. Not a cause of your boost issue. https://www.rx7club.com/3rd-generati...ction-1043655/
First thing I'd check is the 'Y' pipe to cross-over coupler. A common issue since the factory coupler is rubber and exposed to a lot of heat. A quality silicone coupler is called for there.
A side note...is that a ground wire running from the firewall to the overflow neck? If so, I'm not seeing a purpose.
First thing I'd check is the 'Y' pipe to cross-over coupler. A common issue since the factory coupler is rubber and exposed to a lot of heat. A quality silicone coupler is called for there.
A side note...is that a ground wire running from the firewall to the overflow neck? If so, I'm not seeing a purpose.
10-11-14, 08:13 PM
#22
That's for venting. From the factory a hose ran from that, looped down and under the box and vented to atmosphere...the hose to no where. Not a cause of your boost issue. https://www.rx7club.com/3rd-generati...ction-1043655/
First thing I'd check is the 'Y' pipe to cross-over coupler. A common issue since the factory coupler is rubber and exposed to a lot of heat. A quality silicone coupler is called for there.
A side note...is that a ground wire running from the firewall to the overflow neck? If so, I'm not seeing a purpose.
First thing I'd check is the 'Y' pipe to cross-over coupler. A common issue since the factory coupler is rubber and exposed to a lot of heat. A quality silicone coupler is called for there.
A side note...is that a ground wire running from the firewall to the overflow neck? If so, I'm not seeing a purpose.
Thanks ive been scratching my head on that one for a while...also it looks like alot of the couplers have been swapped out for blue silicone couplers the same time the vacuum lines were done (at least the ones I can see)...what do i need to take apart to get to the y pipe coupler? I also read something that says if you "loop the wastegate solenoid and the turbo pre contol solenoid vac lines" it makes it run at 6 psi. What loop are they talking about just redirecting air from the wastegate to the turbo precontrol?
as for your afterthought It appears to me to be a connection point from the block to the chassis.....no clue why. I just bought the car and started digging. I bought it off a guy on craigslist and had it shipped to me. he claimed it was stock but it definitely has been tinkered with...
10-11-14, 09:29 PM
#23
The crossover pipe is the pipe leading to the upper port of your intercooler. If you follow that back it should lead to the top of your 'Y' pipe. You will see a coupler secured by two clamps connecting the crossover to the 'Y' pipe coming of the turbos. Just check that coupler closely. May not be the issue in this case but easy to check.
I'm not an authority on the sequential system or the result of messing With those controllers. Check out the FAQ stickies in the third-generation section.
As for the ground cable usually there is just a short section of cable running from the mounting bolt on the rear engine hoist hook to the firewall. That is one of the factory engine to chassis grounds. Running that ground from the firewall all the way to the overflow mounting bolt doesn't make much sense to me. You're just making a circle...engine to chassis; chassis to battery and battery to engine.
I'm not an authority on the sequential system or the result of messing With those controllers. Check out the FAQ stickies in the third-generation section.
As for the ground cable usually there is just a short section of cable running from the mounting bolt on the rear engine hoist hook to the firewall. That is one of the factory engine to chassis grounds. Running that ground from the firewall all the way to the overflow mounting bolt doesn't make much sense to me. You're just making a circle...engine to chassis; chassis to battery and battery to engine.
