Hello-

I have a bone stock engine, with the only mod being a DP. I'm contemplating an intake, in particular the "cheap bastard" variety that involves putting a big hole in the airbox, fabbing a shield/duct, and swapping out the stock filter for a drop-in K&N. My question is this: is there any notable power gain, or will I maybe get 2-3hp and that's it?

I of course realize that an intake would be much more useful if I had a CB, MP, etc... you know, stuff that makes the engine want to breathe a bit more that pulls on the airbox more than stock to start with. However, I really have no plans at all to get any of these... I'm just looking for a no-consequences, cheapy add-on, but don't want to waste my time if there's no notable gains.

I tried searching (I use the search for 90% of my questions you never even see me ask :-), but I couldn't find the exact answer I was looking for.

Thanks in advance!

Take care,

 

Yes, based on my own experience, an intake mod on the stock box is worth the effort. I think that the stock box with a K&N filter is okay, one just needs to get more COLD air into it. The most noticable effects from the mod is it that boosts faster and produces a much quicker transition from primary to pri + sec turbos. It also seems to improve power once in secondary boost.

The downpipe itself makes a noticeable improvement in power once in secondary boost (4500+ rpm), and works well with the intake mod.

 

I second that.

 

I hope that you have a boost controller or at least a boost gauge... Many people reported a +1 psi of boost gain with the cheap bastard intake mod. A stock ECU with higher than stock boost levels is not a good thing.

 

I second that. i recommond saving up for that little PFC and commander you're gonna need to have any fun then then $200 or whatever for a real intake will seem like pennies. do it right, or don't do it at all my friend... that's the only way these cars run

 

I would expect about a 12 rwhp gain by adding this mod with just a DP. It is significant.

 

I have a DP and drop in KN filter with a stockbox... and the difference between that and original stock is night and day.

 

Just to clarify, expect an additional 12 rwhp gain above what you have with the DP already installed.

 

OOOOOH i like this thread. I'm on my way of buying a DP, MP, and CB. i like adam c and rx 4 speed's replies . I do hope I carry on these statements .

Jeremy

 

[QUOTE=jeremyb]OOOOOH i like this thread. I'm on my way of buying a DP, MP, and CB. i like adam c and rx 4 speed's replies . I do hope I carry on these statements .

Jeremy[/QUOTE

I wouldnt get those mods If I were you unless you already have or will be purchasing a PFC.

 

Those mods will be fine as long as boost levels are kept in check. A PFC is not required.

 

I second that.

 

Not to say your claims are false adam c, but I felt no significant difference when adding intake to my car (had downpipe and catback already). Of course that's on the butt dyno, which may only pick up gains 20hp+

 

I am basing my claim on an independent test performed by another forum member on a dyno. That test was performed by "Sonny". He gained 12 peak rwhp on a 280 rwhp FD using a stock filter with and without the intake mod. He would have gained more by using a K&N filter with the modded box, as compared to a stock box with stock filter. I lowered the estimated gain to 12 rwhp for Shad's case because this is a lower HP car.

 

Wow Adam, I would never run the 3-mod rule AND a mid-pipe on a stock mapped ECU, even at 10 psi without add'l fuel! I run an A'Pexi Intake, HKS DP and Tanabe Racing Medallion CB and have no idea what a stock FD feels like anymore, but I know I don't want to feel what bouncing off the cut, coughing out an apex seal, or boost spiking is like either.

 

That's all the proof I need

 

Toadman,

We had an in depth discussion regarding this issue, in the advanced tech forum:
https://www.rx7club.com/3rd-gen-archives-73/stock-ecu-10-psi-myth-308996/
The consensus seemed to be that 10 psi on the stock ECU was OK with just about any mods. The trick is keeping it at 10 psi with a midpipe. If you can do that, you should be safe. I dont' believe in the "3 mod rule", but I do support the "10 psi on the stock ECU" rule

 

I dunno if this is enough proof for me to prove that I'll get 12rwhp from this. That test was on an already 280rwhp engine. I have a 225-230rwhp engine with a stock catback. That's a major restriction, and it's not getting replaced. If you remove it, then intake mods become much more useful. With it in there, I know that an intake may still reap some benefit, but I dunno if it'd be as much.

I really don't want to lose the stock catback. I really like having a quiet car :-).

Take care,
Shad

 

The stock airbox mod is the cheapest HP you can get on an FD. If you don't like it, you can always replace the airbox bottom with a used one for around $20. Its not much of an investment money-wise.

"Sonny" would have gained another 4-5 HP with a K&N, for a total of around 16 rwhp. My estimate of 12 rwhp for your car was conservative.

 

Most agree that the Racing Beat Dual catback is just barely louder than stock if louder at all and it flows pretty well.

 

[QUOTE=nitrohaulik]I have a PFC. It was the first thing i bought for my FD, it was the most important/expensive unit needed and i'd rather have the feeling of knowing i can raise the boost and add exhaust mods without the hassle of knowing ill need an aftermarket ecu if i cant hold the stock psi. So I third adam on the non-requirement of a pfc with the included mods. Just as long as you can keep away boost creeps and spikes you'll be fine. This is why they say to get an ecu upgrade, because alot of people cant control the spikes or creeps, or just don't know how.

 

That is the challenge, especially with a stock ECU in the cooler oxygen-rich winter air. A boost controller is an obvious must-have.

 

The stock ECU will work fine with a DP, Intake and Catback at stock boost levels. (In my experience, it was actually quite rich and would support a little extra boost OR you could take some fuel out. ) If there's a CAT in there, boost creep and spikes really should not be a problem.

 

I decided to go DP and cutout. Sorry, felt like the right time to say this since people that are reading what I said read that i was going DP, MP and CB. Buhhhhhhhhhh

Jeremy

 

Cutout? You will need something to keep warm air out, or you will defeat the purpose of having a cold air intake. I have an idea of something that will work