mr g lord focker

I just installed my Apexi intake. So I get back in my car and let it warm up for about 5 mins then test it out. While idling I took my car up to 2500 rpm and everything was nice and smooth liek normal. Right when the RPM hits 3000 I hear a noice that is like a loud low grinding noise. and then the sound goes away as the RPM clears 3000. Then when the gas is let off suddenly the sound will come back again on occasion. Also if I hi the gas hard under 3000 rpm the sound comes again for a second then goes away. It has happened now liek this after trying out it a couple times. SO of course I look on the forums under the search category to make sure it was installed correctly.
When I took a look I saw my Apexi intake was a lil different than others. As soon here: http://flathat.woodstream.net/RX7/Power_Intake/ the top intake connects all the hoses to the rest of the car and it looks as if the bottom intake is capped off on its one pipe. With my intake the top has two pipes connecting the same hoses except the hose leading to the CRV (i think it is the CRV...lil brown piece inside engine looks much like BOV but a lil deeper in...) anyways...this CRV hose is connected on mine to the bottom intake. And where it connected to on the top intake in the picture I have a K&N filter with a hose that then goes and attaches to a small hole with a little nipple on the top intake. I hope you understand what the set-up looks like I dont have a digi . Any help would be appreciated as I need to drive around but am too scared to with this problem.
I was thinking to myself that this sound might be usual but is covered up with the stock airbox? Thinking that 3000RPM or when I floor it is usuallyu when turbos kick in so that might be what I'm hearing?
Other details: Car otherwise is stock for now as I was going to wait to put on all other stuff until I got my PFC. This intake is not complemented with any upgraded ECU or fuel as. But with just an intake I didnt think it was going to be essential to do that. I also recently cleaned out fuel system (or so I think) with uel system cleaners.
Thanks for any help you might be able to give me! U can IM me at mr g lord focker on aim or post reply here or PM!

mr g lord focker

I have also been running on 89 octane gas *plus* since I was told it was OK to do that with a non-modded car. With this intake could this sound be because I now have more air and more power and now need to compensate with higher octane gas? But if that was the case why isnt the sound there when I had the car at 4500 RPM? Just a thought

rynberg

Who in the hell told you THAT? No one on this forum! You should NOT be running 89 octane gas, unless you live in Denver....

As far as your noise, perhaps your air pump is toast.

xchaos

What do you know about your turbos? The stock box does hide alot of noise that you are now going to here with the Apexi.

Have they always boosted good 10-8-10 before install? How many miles are on them?

xchaos

Use 91+ man! Always! He's right, could be the air pump also.

skotx

I think you're just hearing your airpump for the first time. Disconnect the grey connector on top of the airpump and go for a drive. Does the sound go away? Don't leave it disconnected for good. Just for this test.

mr g lord focker

Miles on turbos run about 75k as with rest of engine. All ran well before (smoked a 300zx TT about two weeks ago). Never checked boost yet but have boost gauge and could check it out now just a lil weary about doing WOT with this problem. When I pop hood and check to see if turbos smoke I saw a very very small amount of smoke come out with WOT at higher RPM. As for who told me 89 octane plus unleaded is OK....Mazda dealership said it is OK on the stock 93 FD.

mr g lord focker

going out to car in 5 mins to disconnect grey connector on airpump and taking for drive. If it is just the airpump I assume this noise is just normal then? Will update

Fatman0203

91 OCTANE!! GET IT!! then let us know about the air pumP!!! JEsus!! I mix in 101 octane whenever I got the extra cash.

mfigr1

I also think it might be the airpump. The air pump clutch disengages before or around 3k RPM. The air pump was originally designed to reduce emissions when driving around town at low rpm's.


- Ohh by the way run 91 octane or higher man!!!

mr g lord focker

going to car right now...checking to see if airpump and pumping 91 octane gas on in. Will updtae you in 30 mins or so. Crossing my fingers it is airpump

SERIES7

I would be hard pressed to find out that those folks who have the KDR anti-Det. device are still running the 87 octane.

mr g lord focker

Ok guys...just got back from my lil test drive. Gas is upgraded...I also hooked up my boost gauge for this little drive. Here's how it went. Disconnected the tube from the air pump to intake and noise was still made. Just making sure this is what I was instructed to try. Went on the road after warming it up and stepped on it. Boost was fairly normal. around 11-9-10. The noise when stepped on is only made for a brief second at 3000 RPM. Once again it is a low kinda grinding noise. Also, when I stepped on it in idle to take it around 6000 RPM and 9 boost a lot of white smoke came out my exhaust. What is the normality of this? Vaccum was 19 at idle..normal? I do not know. This is the update. What do you guys think. The power and smoothness of drive is normal.

911GT2

No no, you were supposed to disconnect the grey ELECTRICAL connector that goes to the airpump, effectively shutting it off. All you did was give it unfiltered air, which really doesn't matter since it's just flowing the air into your exhuast.

Airpump sounds are usually described as a "moo" kinda like a cow You're describing it as a low grinding noise, which leads me to believe that either a) the airpump is toast or b) it's not the airpump. But try driving with the airpump's electrical connector disconnected and see if the noise persists.

And whatever you do, never trust a Mazda dealership. I repeat, NEVER trust a Mazda delearship. Put the highest octane gas in your tank that you can find.

mr g lord focker

i figured that it would still be taking in air with the hose disconnected. but eh...sometimes i am just a dumbass. Ok...not sure where this electrical connector is...but I am sure I will find it and try it out. Thanks for your help 911GT2...will update. Hope it works because right now I am driving my girlfirends toyota echo. A whopping 95 HP!!!!

911GT2

The electrical connector is visible in the pic you posted above. It comes off the airpump and goes straight back towards the rear of the car. In the pic it is like 1" under the crossover pipe (black pipe that goes from y-pipe to intercooler).

Good luck with that echo man, whoop some civic ***

mr g lord focker

Ok, disconnected air pump and sound dissapeared. Good call 911GT2. now is this sound something indicating my air pump is bad? Or is it just normal and was covere dup by stock airbox? After this Q is answered this discussion should be done. Thank you all so much for your help. Was scared to buy the RX-7 but there arent many cars liek this one where you can get answers to any question from a handful of guys any time of day or night. Makes owning this car much easier. Plz let me know about if air pump is toast or normal

911GT2

My suggestion on the noise would be to find someone else in OC that knows FD's listen to the airpump and see if they can find the issue. I know mine is obnoxiously loud, but functioning properly. It moo's a lot, especially loud at part throttle and deceleration. Theres really no good way to find out if its ok by describing the sound, so have someone look at it.

Fatman0203

Why not just get rid of it. I cant stand mine and its gone. Its pretty easy just the hard part is finding an approritate belt for it.