porsche4786

So currently my car has a bunch of suspension stuff done to it and handles amazingly. The only HP gaining things I have done are intake, corksport catback, and pineapple 5/6 port sleeves. It would be nice to gain some more power, I was thinking about getting an SAFC, but not sure where you mount it, I would like it to be hidden but easy to access and see. Also thinking about adding a RB header and high flow cat, but I'm not sure if it would be street legal (because of the noise level). How much power do you think these things might add? It would also be a plus if the SAFC could help out my 13 mpg.

SwiftTone

hide it where the ashtray is. And pu tthe ash tray door over it.

Sideways7

iTrader: (7)

If you still have all of the stock cats in place, you are looking at a noticable gain from the headers/high flow cat. I have no idea of actual numbers, though, as a lot of it depends on the condition of your current cats, etc.
For the s-afc, you can get some pretty good hp gains, especially up top. There was a dyno sheet somewhere that had a before and after run, but I'm nor sure where it is. You can drill a hole in the back of the glove box and mount it there with velcro.

porsche4786

my car has about 65k original miles.

The only thing about mounting it....it will be a pain to run the wires into the glove box won't it? I would to the ashtray thing but I think it would be more work, plus i like to stick my cell phone there.

porsche4786

another thing that i'm not sure of is if i can pass DEQ with an RB streetable header, Bonez cat, and corksport catback. Would it be too loud? Maybe if I threw the silencer thing on the muffler?

http://rx7.com/store/rx7/fcexhaust.html

http://corksport.com/store/category/...rx-intake.html
corksport makes a header now...they say 14hp gain.

Sideways7

iTrader: (7)

If you put in the silencer , you should be ok. As is, its questionable if you would pass. I don't know how stringent they are about that up there. I killeen the cops are so used to loud cars that they didn't even say anything when I ran open header for a few days.

porsche4786

It's not really the cops I'm afraid of...it's DEQ. If I pass DEQ then they can't give me a ticket. I'm due for DEQ in December.

ericgrau

iTrader: (1)

There's no way you're getting anywhere near 14HP from a header on an N/A. You'll get 20-25HP from a full exhaust. A header is just to squeeze out the tiniest bit of leftover horsepower after you change your cat and muffler. Also bad for noise, I hear.

Corksport could have done a better job of doctoring their dyno sheet. If you look closely at it you'll notice all the line shaking from measurement errors is exactly the same on both the "header" and "no-header" dyno. Kind of like when two guys get the exact same wrong answers on a test, you know they're cheating. The "header" dyno looks like it was simply scaled up from the "no-header" dyno in photoshop. A real dyno would show much less gains at low rpms, whereas on Corksport's dynos the gains are exactly the same % at all rpms.

If you're getting 13mpg on an N/A (is it N/A?), fix your car. The FAQ has info on this. 17/25 is typical. I only get 13mpg if I'm forced to drive 20mph stop-and-go.

Sideways7

iTrader: (7)

Ok, ok, we don't have anythink like that around here. I just thought it was like in Cali where you can take it and prove that it passes to avoid a ticket. At least thats how I understand it from the article.

porsche4786

That's what I get pretty much every time I fill up, except when I go on the freeway, which is kinda rare. It's been like that when I got it with 45k original miles. yes n/a. 1989 Well, they say 15 as a minimum, so I'm only a couple mpg off, and I usually don't shift till 3500-4000 rpm. And I step on it somtimes. I don't granny it around and keep it below 2000 rpm.

ericgrau

iTrader: (1)

Even when I push my car pretty hard I get at least 16mpg. What's the speed limit in your city? What do you get on the freeway? What speed do you drive on the freeway?

Nobody should ever drop below 1800rpm, no matter how softly they drive. Shifting at ~2500-3000 (to get back to 1800) under low throttle is grannying it.

porsche4786

Well around town it's usually 35 on the main roads...so to me that means 40. But I'm never on a main road for too long. I usually only drive on weekends to a friends house, and nobody lives very far away, I'm talking like 5-15 min drives max. On the freeway, which I rarely go on is like 60mph. When I drive to Corvallis (about an hour and half away) and back then I will still have like a quarter tank left or a little more, so I use that till empty for around town I get like 18-20 mpg. When driving to corvallis the speed jumps up to 70mph and I will do between 75 and 90mph.

edit: when i was saying grannying it I meant I don't go below 2k rpm, not that I drive at 2k rpm.

ericgrau

iTrader: (1)

A steady 60mph on the freeway should net 24mpg or more (probably 25-26).

I don't want to speculate on your city conditions, since it depends a lot on how often you have to stop. Stop lights in my home city are half a mile apart, so that helps a bit and I get 16-18mpg. Around my college there are stop signs every 1/8th mile and I have to go ~20mph. Trips are so short I barely get to warm up. There I get 11-14mpg.

porsche4786

I've never driven a full tank on the freeway, so I'm not sure what it would get out of a full tank freeway use only. I was thinking that if I get an SAFC I would get a good HP gain along with MPG increase.

ericgrau

iTrader: (1)

Yeah, I've heard that about SAFC's.

I'm just saying if something's ruining your mpg you should fix that first. But if you've got lousy roads and a bunch of stops in your city, or a ton of traffic, that would be the cause.

Oh, and I took another look at that corksport dyno. They did make the effort change the static in some places, but in others it's a direct copy. Plus it shouldn't be such a linear increase over the original - it should be much more at higher rpms than lower. The increase is so perfectly even it's silly.

porsche4786

I will probably just go with the RB header anyway, since it's cheaper. I will also probably take it to an exhaust shop and have them put it on, it looks kinda difficult to get the stock collector off. Plus they have a lift and all, quick and easy for them.

Sideways7

iTrader: (7)

Unless you don't have any jacks or stands, then don't take it too a shop. In fact, use the moeny you would spend on taking it to a shop to buy a cheap jack and stands. It is very easy and straightforward to install the header and such, just a little time consuming and tireing from all of the wrenching. Just make sure to soak all of the bolts in PB blaster before you try to remove them.

Sgt. Pepper

^ Yeah, I just installed my heat wrapped Racing Beat header last night. I got fiber glass all over my arms and hands because I was too dumb to use gloves. It's not hard at all, just pick up a Haynes manual. Like he said, it's just time consuming. And remove your 5th and 6th AUX ports, they are both held on by 2 nuts and a vac hose. It gives you a lot more room to work with. Hey, if a newbie 16 year old can do it, you can to But if you feel more comfortable with a muffler shop doing it then go for it, they will just charge you up the *** and take their sweet as time because they get paid hourly.

porsche4786

I just don't want the headache of doing it right now. Plus it would take me twice as long as it would take them. It's just a 2 man shop and they can get you in and out pretty quick. I do know how to work on my car, I've done everything myself, took it to a shop once to have the oil metering lines replaced and when I got it back I had to do the job myself because they messed up and broke a couple bolts and stuff, plus they didn't bother replacing the waterpump to engine gasket. And this was a place that pineapple racing recommended! I will see what they want to do it and go from there if I go this way.

https://www.rx7club.com/showthread.p...ghlight=garage