xshp7

hello all rx-7 owners,

i have a 93 mazda rx-7 touring. i am currently doing a few mods to the car and was wondering if anybody had any suggestions. a little about my car. it has 52,000 miles on it. a strut bar and a apexi dual chamber bov have been put on. i was looking into a downpipe and a intake. i was wondering if anybody had any suggestions on which intake and downpipe i should buy. also, the car is a daily driven car. i am not looking for intense hp gains. i just want more air for the engine and turbos. i have heard intake and downpipes are a great mod for quick hp and better air flow.

thank you, i really appreciate all the help and suggestions

SpeedKing

iTrader: (4)

Performance-wise, all downpipes are more or less the same. What to look for is one that's made out of stainless steel as opposed to mild because the latter is more prone to corrosion. Here are some of the more popular ones:

http://www.rx7store.net/subcatmfgpro...210&1=254&2=-1

Also, SR Motorsports, RX-7 Fashion, and M2 Performance make good quality downpipes.

As far as intakes (or exhausts, or both) go, I'd recommend you not get get one without getting a boost controller first as you will most likely see boost spiking with an intake/downpipe or downpipe/exhaust combination. Ideally, you want to keep boost at 10 PSI max. And since your car will be a daily driver, for reliabilty's sake, I recommend getting just a boost and water temp. gauge, do the fan or Miata thermoswitch mod, and leave the car alone. My $.02.

SpoolinRX

iTrader: (6)

I have a intake, downpipe, midpipe, and catback, with now boost controller, and i dont see boost spike. I still need to do that fan mod thou. But what really is needed next is an ECU upgrade. PFC cant go wrong there.

RX7UP

1st mod should be ECU.....

pugg57

if you ONLY do the intake and dp, you should be ok without a new ECU... but yeah, i have a 93, its my daily driver. i'll put my sig on this so you can see what i've done. its not all that much, but its definitely a good bit for reliability and by replacing your current ECU with a PFC (Apex'i Power FC) you give yourself a much safer setup... not to mention an excellent base to start from if/when you decide that you want more power. boost controller is a good idea too. as far as the dp goes, i bought a used RX7store.net 3" SS dp on the forum in the for sale section and had the boys at the shop (my work allows me access to an EXCELLENT machine shop) slot the bolt holes for the cat side by .1" to the outside to allow for better fittment and i find that it works GREAT (just had it installed this last Tuesday though, so no time for anything to go wrong). make sure you read the newbie sticky in the 3rd gen forum and actually read the webpages it gives you. its very useful. if you want that car to last, i think you need to get back on track as a BOV and a strut bar don't do anything to help the engine. yuo might wanna look into a cat-back too.

SpeedKing

iTrader: (4)

A'PEXi PowerFC: $1200 + Tuning: ~$300 vs. Greddy Profec B Spec II: $315

For an otherwise stock car w/ basic bolt-ons, IMO don't know if you can justify ~$1500 for the PFC.

Different story if you run a bigger IC and crank up the boost and/or add a mid-pipe.

MrDizzy

hmm isnt heat the nr1 reason why the engines die? To solve that problem i would say nr 1 mod = vented hood

Tho myself got a DP/apexi power intake and some gauges(oil temp, boost and O2)
But i wish i put on a vented hood as 1st mod

RX794

Save yourself $, and just buy this set, the dp and mp are of good quality, I have 3 friends of mine which have used these, and they work fine, no problems:
http://optionimports.com/ststdosetfor.html

SpeedKing

iTrader: (4)

Nope, I'd say detonation is the no. 1 killer.

As far as the heat issue, as I mentioned above, you can either do the fan mod or Miata thermoswitch, and you can also run the AC all the time to keep water temps. low.

SpeedKing

iTrader: (4)

How is anyone going to save money when you'll have to spend more money for an ECU to accomodate the mid-pipe?

jeff p

do the adam c cheep bastard air box mod . add the down pipe and catback plus boost controller. look into the anti detonation device from kd rotary. keep the boost at 10 psi . no ecu upgrade needed.

911GT2

What? There is no need to get an ECU for a stock car. It's really just no necessary. Many owners never go farther than an intake, dp, and definitely don't require an ECU.

mr g lord focker

I have a SRMotorsports downpipe. Fit perfectly. Also have their midpipe, radiator, and got my pfc from them. Good company. If you want to talk about upgrades feel free to IM me on mr g lord focker on AIM anytime. Really with intake and downpipe you should think a new ECU. Just a cheap upgrade to M2 or something unless you plan on more mods in future in which case PFC is best IMO.

RenoCYM

What are your smog requirements in Illinois? Removing the precat and replacing it with a downpipe could cause you to fail, either a visual inspection or actual sniffer test. I know I can't do it here in the county I live in, they see in their manual that it is supposed to have 2 cats, and if it doesn't, you fail.

tt2323

Do you plan to mod the car further? Have you done the basic matinence, fuel filter etc? The downpipe doubles as a reliability mod cuz it eliminates stress, and heat in the engine bay. Be careful with some of those cheaper downpipe and midpipe combos, some only work together so you wouldn't be able to use your stock cat.

PVerdieck

Ignore part of this advice. The MP is a mid-pipe, which means no cat/no emissions equipment.

People should not blindly tell others to toss their emissions, just because they choose to, or can get away with it where they live.

RX7UP

I have a HKS DP rapped with DEI header rap for sale

rotoryspeeddreamz

Search the forum for reliability mods...I believe it includes dp, aluminum radiator, and silicone hose kit. That should keep your fd fairly reliable for daily driving...

GL

technonovice

I have had several downpipes. By far, the M2 is the best. Its worth every penny. I bought one off ebay from Megan Racing and decided not to use it. It looked ok, but it required some grinding on it to make it work. I have a used mild steel HKS that I'd sell dirt cheap. Its not pretty/shiny, but its functional if you are on a tight budget. PM me if you are interested.

TracyRX7

You also don't want to toss the main cat for a MP without a bunch of other things done as this creates real "boost spikes" that can't be controlled easily. Higher boost from intake/better IC/better IC piping/Efini Y-pipe can be controlled much better with a boost controller than you can control a straight through exhaust with no backpressure.

As far as controlling engine bay temps from my research reading through all I can find it sounds like a good heat wrapped or coated (i.e. jet-hot or other thermal coating) downpipe lowers engine bay temps more than vented hoods do. I'm personally doing both as it gets to 100F+ all summer here and I'll be autocrossing the car (hard run then stop and sit on a grid waiting for next turn).

As far as emissions go you may have to put the precat back on for testing but the added reliability in the meantime seems worth the effort to me. I'm actually curious how much more emissions are put out with DP/main cat than pre-cat/main cat. If anyone has tested this I and I'm sure others here would love to see the data.

Senna

Ditto this---may want to consider a high-flow cat instead of MP---unless you're looking to track it etc. Otherwise Hi-flow should get you thru smog and if you happen to get pulled over and they take a look under the car MP may be a violation.