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Hi everyone
I have a 1896 GXL FC and I was wondering if deleting the factory air pump and the stainless tube that runs down to the main cat will cause issues with ports 5 and 6 opening? I've heard that the air pump creates the backpressure needed to have these ports open properly. I was going to install aftermarket headers and have a custom 2.5" exhaust made for the car, and it wouldn't have the bung for the air pump tube. Is this bad for my car? Or should I just run the air pump? Thanks in advance.
Lukas Hart
First of all, if you have a cat installed, you require an air pump. This is to allow the cat to function properly. Without an air pump you will quickly clog it up and ruin it.
If you intend to run without a cat, or you have removed the pre-cats and left just the main cat, it will alter the back pressure so that the auxiliary ports do not open until later in the RPM range. The popular mod is to add a small electric air pump with a rpm switch that will actuate the ports at the desired rpm. There is a write up for this:
I have no pre-cats, but I do have a main cat, and mine feel like they are opening a little later than 4000. It's almost a jolt when they do open. I have some parts on their way that will allow me to convert to an electric 6-port system that will open at my desired rpm (3800 or so).
In short, anything that reduces backpressure in the exhaust will raise the required rpm to actuate the ports, but the actual effect depends on your particular setup. I would perform the exhaust modifications you want to do first, then take it for a drive to feel when the ports are opening. If they open too late for your liking, or not at all, convert to an electric 6-port system.
To my knowledge, the air pump on its own does not displace enough air to really create this backpressure, as that is not it's purpose. It is designed to assist the cat in burning up hydrocarbons.
Oh Okay. I must have mistaken thinking the air pump creates back pressure. I hollowed out my main cat but still have the first 2 up front. I think I'll be getting a header soon so I should run a resonator just for the back pressure? I was originally going to go with straight through to a muffler. Single exit exhaust not duals. Is it recommended to have a resonator for back pressure? Or is it alright without one
Thanks
Lol I did not realise I put 1896. My mistake!
And as for the headers, I have a guy close by who is willing to sell me a Pacesetter header cheap. I have heard mixed reviews, but i can't see why it would hurt. Especially considering they are longer than RB ones and don't require the presilencer. I dont want to be a quiet RX7 lol. Any recommendations?
Pacesetter is Ok in a pinch but if you listen to guys here they say it's junk..( I ran one and Meh,it's a damn header..does it's job!).
NOW with that Header..IF you do NOT want to run your hollowed out cat,which would be fine to do as the hook up is there,etc and no mods necessary..Try THIS:
Pacesetter header: take where the header Collects the 2 runners..drill a hole and place a steel tube there for the AUX Port activation.You can make a 1 foot tube there and then run a hose to the OLD stock connection.(weld it on to the header)
You can now either cut the stock steel tube and just leave a "nub" that would consist of the Bell shaped valve and little hose connection on the engine...OR just create enough of a run to go to your newly formed tube on the header.
I DID this on my N/A and had Absolutely Zero Problems with it.
*some Racing beat headers already have a tube connection for the Aux ports.They do not need a lot of pressure either to open up..about 3 Psi.
Pacesetter is Ok in a pinch but if you listen to guys here they say it's junk..( I ran one and Meh,it's a damn header..does it's job!).
NOW with that Header..IF you do NOT want to run your hollowed out cat,which would be fine to do as the hook up is there,etc and no mods necessary..Try THIS:
Pacesetter header: take where the header Collects the 2 runners..drill a hole and place a steel tube there for the AUX Port activation.You can make a 1 foot tube there and then run a hose to the OLD stock connection.(weld it on to the header)
You can now either cut the stock steel tube and just leave a "nub" that would consist of the Bell shaped valve and little hose connection on the engine...OR just create enough of a run to go to your newly formed tube on the header.
I DID this on my N/A and had Absolutely Zero Problems with it.
*some Racing beat headers already have a tube connection for the Aux ports.They do not need a lot of pressure either to open up..about 3 Psi.
Oh okay. Do you have pictures? Or will this be self explanatory once I have the damn thing apart haha. I just had a very hard time getting the front 2 cat things off. I will try again with heat and see if I can see these tubes you speak of.
how can I let you picture this?...Enjoyably????
GOT IT!.........SEX!
Where the 2 LEGS of the exhaust come together at the end of the Header...Drill it Baby..Oh YA!....Stick your Small Pipe in that Crevice!..lol!
What you are doing essentially is using the meeting point of the 2 runners at the Collector of the header as a place that the exhaust gases merge before it goes to the Cat..or resonator or into the length of pipe to go to the muffler.
That area has enough pressure to open the aux ports.
*Unfortunately I cannot do anything about your small pipe..!..sorry Dude,you are on your own..slap your dad....good luck to ya..!
HERE IS A HEADER FROM RACING BEAT WITH A PORT TUBE ALREADY INSTALLED, FROM MY UNDERSTANDING IT DOESNT MATTER WHAT KIND OF EXHAUST YOU RUN AFTER THIS HEADER, IT WILL CREATED ENOUGH BACK PRESSURE TO PROPERLY RUN THE PORTS. I ASKED IN YOU OTHER EXHAUST THREAD AND CURIOUS TO KNOW, ARE YOUR PORTS WORKING CORRECTLY NOW?
HERE IS A HEADER FROM RACING BEAT WITH A PORT TUBE ALREADY INSTALLED, FROM MY UNDERSTANDING IT DOESNT MATTER WHAT KIND OF EXHAUST YOU RUN AFTER THIS HEADER, IT WILL CREATED ENOUGH BACK PRESSURE TO PROPERLY RUN THE PORTS. I ASKED IN YOU OTHER EXHAUST THREAD AND CURIOUS TO KNOW, ARE YOUR PORTS WORKING CORRECTLY NOW?
Thanks for the link. I looked at them before but to ship them to me is crazy. Maybe I'll save up for them. But don't I need the presilencer with this one too? I can always get a custom flange though. And sorry I didn't reply before. My ports do seem to function and are not stuck
No, problem, and yes you could have a flange welded to any manifold/header just copy the racing beat design. and if done correctly you will retain working ports, woohoo. I just removed mine completely, I am running a full exhasut, header, straight pipe to straight through dual mufflers out the back, yes there is a low end drop in power but only in heavy throttle. I noticed that if I try to floor it between 2,000 and 3,500 rpms it does fall flat on its face, but driving normal in the lower rpm range I noticed no difference. I also removed my air pump and blocked off the ACV and EGR and added some timing. I also hear about fuel mileage, well I didnt buy an rx7 for fuel economy so BAM.
Last edited by littlebit421; 02-08-17 at 09:04 AM.
Reason: MORE INGO
No, problem, and yes you could have a flange welded to any manifold/header just copy the racing beat design. and if done correctly you will retain working ports, woohoo. I just removed mine completely, I am running a full exhasut, header, straight pipe to straight through dual mufflers out the back, yes there is a low end drop in power but only in heavy throttle. I noticed that if I try to floor it between 2,000 and 3,500 rpms it does fall flat on its face, but driving normal in the lower rpm range I noticed no difference. I also removed my air pump and blocked off the ACV and EGR and added some timing. I also hear about fuel mileage, well I didnt buy an rx7 for fuel economy so BAM.
Oh okay cool. I could always wire the ports open for now until I get enough money for proper headers. Next thing is taking off the air pump and such. All I need to do is take them off then put on the block off plates right? There's not much more to it?
Oh okay cool. I could always wire the ports open for now until I get enough money for proper headers. Next thing is taking off the air pump and such. All I need to do is take them off then put on the block off plates right? There's not much more to it?
I will take some pics of mine tonight, It was very simple, buy a block off plate and new gasket, I got mine from atkins rotary (I did have to modify the block off plate by drilling two of the holes just slightly bigger to get it to line up properly). You will have to remove a stud and replace with a bolt, again very simple, I will get the parts list together and the pics tonight with some more detail.
I will take some pics of mine tonight, It was very simple, buy a block off plate and new gasket, I got mine from atkins rotary (I did have to modify the block off plate by drilling two of the holes just slightly bigger to get it to line up properly). You will have to remove a stud and replace with a bolt, again very simple, I will get the parts list together and the pics tonight with some more detail.
Thank you! I have been reading about it but it wasn't 100% clear on what all goes into it. Most people don't have pictures and there's no videos really. It didn't affect your idle or anything did it?
When putting on the block off plate it is thinner than the casting of the acv so you will need to buy some bolts because the ones you take out are going to be to long and one is actually a stud with a nut that is easily removed. I bought bolts and lock washers, just remove the acv put on plate and new gasket amd snug it down. You can see where I capped the feed tube for the actuators beacause my header did not have a supply tube.
This is what started all this, I was trying to free up my ports when snap.
I broke the actuator rod. I had the sleeve turning and was about half open then pop. So decided that theu were coming out. I called in the help of a good friend and went at it. As far as idle goes, no problems, mine idles nice amd steady between 700 and 800 rpms. With the sleeves out it does have different tone, and with blocking the acv and egr it has a little and please dont judge me, but here goes baaaaa baba baaaa ba ba ba bbaaa. You know what Ill take a video. My point is you shouldnt have to worry. That being said, what direction are you going with the car. More stock, more modified. That would be my deciding factor before I start removing a bunch of stuff. The good thing is that it can always be put back on.
Last edited by littlebit421; 02-08-17 at 07:30 PM.
Reason: spelling and additions
This is what started all this, I was trying to free up my ports when snap.
I broke the actuator rod. I had the sleeve turning and was about half open then pop. So decided that theu were coming out. I called in the help of a good friend and went at it. As far as idle goes, no problems, mine idles nice amd steady between 700 and 800 rpms. With the sleeves out it does have different tone, and with blocking the acv and egr it has a little and please dont judge me, but here goes baaaaa baba baaaa ba ba ba bbaaa. You know what Ill take a video. My point is you shouldnt have to worry. That being said, what direction are you going with the car. More stock, more modified. That would be my deciding factor before I start removing a bunch of stuff. The good thing is that it can always be put back on.
Okay awesome. Are you running the actuators just open then? This has helped me so much more than any other thread lol. I plan on modding it yes. Nothing crazy yet though. Still needs to be my reliable summer daily. But I want to clean up the engine bay and make it As light and as fast (and fun of course) as possible. Within reason of course. No porting yet hahaha. Thays next winter...
I have no port sleeves at all in my lower intake, when the rod snapped I decided to remove the lower intake and completely and remove them, my friend had an extra rod so when we put it back together I replaced the broken rod. That being said the actuators on my car do absolutely nothing, the only reason they are on there is because I could not find any block off plates for them.
What is you exhaust situation now, is it factory, do you have cats, etc?
What about Intake, is it factory?
Here is a suggestion on exhaust, Header, straight pipe with a flowmaster hp2 Search Results
into a pair of nice muffles with a little restriction, nothing straight throug and it shouldnt be crazy loud. the hp2 has a 12" and 18", this is the next thing that im doing to my car because it is extremely load right now and I want to tone it down, So I am going to come off my header with the 18 inch hp2 (fyi there is no fiberglass or packing in the hp2, I called flowmaster.) through the y pipe and into some muffles my exhasut guy has, the are round and chambered and he said they should keep the sound down a little, just remember, without cats it is still going to be loud, its just how much can you keep it down.
I have no port sleeves at all in my lower intake, when the rod snapped I decided to remove the lower intake and completely and remove them, my friend had an extra rod so when we put it back together I replaced the broken rod. That being said the actuators on my car do absolutely nothing, the only reason they are on there is because I could not find any block off plates for them.
What is you exhaust situation now, is it factory, do you have cats, etc?
What about Intake, is it factory?
Here is a suggestion on exhaust, Header, straight pipe with a flowmaster hp2 Search Results
into a pair of nice muffles with a little restriction, nothing straight throug and it shouldnt be crazy loud. the hp2 has a 12" and 18", this is the next thing that im doing to my car because it is extremely load right now and I want to tone it down, So I am going to come off my header with the 18 inch hp2 (fyi there is no fiberglass or packing in the hp2, I called flowmaster.) through the y pipe and into some muffles my exhasut guy has, the are round and chambered and he said they should keep the sound down a little, just remember, without cats it is still going to be loud, its just how much can you keep it down.
Currently I have All stock but my cat is gutted. One muffler was gone when I bought it and it's still gone lol. Didn't bother with it. I think what I'll do first is get a pipe made up to get rid of the 2 pre cats between the header and the main cat, then I'll just go no mufflers for a bit to see how unbearable it is. (i have to learn for myself lol). But honestly when I get some more funds I'll get a proper setup. Straight back to 1 muffler. I want to go single exit because I'll save a bit in the fabrication. If that turns out too loud for me to daily then I'll throw a muffler or resonator in. I think I'll keep the gutted cat in just so my ports will actually work.
Currently I have All stock but my cat is gutted. One muffler was gone when I bought it and it's still gone lol. Didn't bother with it. I think what I'll do first is get a pipe made up to get rid of the 2 pre cats between the header and the main cat, then I'll just go no mufflers for a bit to see how unbearable it is. (i have to learn for myself lol). But honestly when I get some more funds I'll get a proper setup. Straight back to 1 muffler. I want to go single exit because I'll save a bit in the fabrication. If that turns out too loud for me to daily then I'll throw a muffler or resonator in. I think I'll keep the gutted cat in just so my ports will actually work.
I have run single out before its not to bad and it is a little less expensive, I ran a stock manifold through a straight pipe all the way back to a big open ricer (fart can) muffler
it was loud but back then I didnt care. I you run no muffler it is going to be REAL LOUD (you wont have a stereo loud enough to get rid of the drone) As I am older now and have learned for myself and live in a neighborhood now I dont want all my neighbors to hate me and be that guy so I have decided to figure out how to keep it down a little.
Over time you will learn what you like and dont like. Good Luck and you can always pm me with any questions or just post here, I am not an expert but will be glad to help in any way possible.
I have run single out before its not to bad and it is a little less expensive, I ran a stock manifold through a straight pipe all the way back to a big open ricer (fart can) muffler
it was loud but back then I didnt care. I you run no muffler it is going to be REAL LOUD (you wont have a stereo loud enough to get rid of the drone) As I am older now and have learned for myself and live in a neighborhood now I dont want all my neighbors to hate me and be that guy so I have decided to figure out how to keep it down a little.
Over time you will learn what you like and dont like. Good Luck and you can always pm me with any questions or just post here, I am not an expert but will be glad to help in any way possible.
Thanks a bunch man! I'm sure all this into will help me a lot with my build. I'll keep you posted on what I do and if I have questions I'll hit you up.
01-30-17, 07:34 AM
and live in a neighborhood now I dont want all my neighbors to hate me and be that guy so I have decided to figure out how to keep it down a little.