I Killed Tupac

I did try the search button, didnt find much.

First, can i do the downpipe mod without modding the ECU? What about intakes/boost controller?

Thanks in advance....

futurerexowner

Your not gonna get a whole lot of respect with that user name, guy...

Silex

Future is right, I'm never going to answer any of your posts now.

futurerexowner

haha... good call DJ! sorry dude you have just been unofficially black-listed.

I Killed Tupac

blacklisted? gimme a ******* break. Like i said in my introduction thread, that name has a long story behind it. I liked Tupac, and did not kill him. But I use that name at all 6 or 7 car forums i belong to.

You want the story behind it? Fine. When i was in high school, Tupac got shot. A friend of mine wrote "i killed tupac" on the back of his shirt and got beat half to death at school by these 3 white guys trying desperately to be inner city black gangsters in Boise, ID, like they had anything in common with Tupac and his clique. Thought it was one of the funniest things I've seen, little white boys in Idaho yelling "thug life".So there's the story. No need to be offened.

rxrx7

you don't need to modify the ECU if you do the DP. Definietly the first mod you should do.

I Killed Tupac

cool. what about intake/boost controller? Do RX7's use a mass airflow sensor, or a MAP? MAS is easy, usually you dont need to mod the ECU to up the boost (can you tell i work on alot of DSMs? )

Silex

They use a MAP sensor actually. [/me will answer this guy's posts from now on...]

futurerexowner

Im with you DJ, sorry we gave you such a hard time, just jumped to conclusions. I could name myslef the Ultimate C**k Sucker, and as long as I had a story to back it up I would expect people to accept it...

Silex

Yea, I think he should include that story in his sig for every post, just so he doesn't get more turds like us jumping to coney island like we did [err conclusions, damn Phantom Tollbooth (and yes i know it's a 6th graders book...)]

93TTRX7

No. But like someone previously said a downpipe should be your first mod since you'll get good power, great throttle response, and LESS HEAT because of it.

You get an ECU when:

Personally I stick to the 3 mod rule. Basically if you add 3 performance bolt ons that increase air flow, you will need an upgraded ECU. For instance, you can stick with the stock ecu if you get intake, downpipe, and a cat back. The downpipe on the 7 only gets rid of the pre cat, leaving the main cat in place. DO NOT RUN A STOCK ECU WITH OUT A MAIN CAT. At this point I recommend your mods go in this order...

1. Downpipe
2. Boost gauge-to diagnose common boost leaks
3. Water temperature gauge- monitor your coolant temps (biggest reason 7's blow engines is from coolant seals...keep the temps normal, have a happy engine)
4. Intake
5. CB exhaust (some people like to do the GReddy pulley upgrade instead of the Cat back exhaust.
6. THEN the ECU

Kinds of ECU's

There are basically two sorts of ECU's. Some are the piggy back ECU's like the Pettit and the M2, and others are the fully tuneable ones like the apex'i power fc. How do you know which one is for you? Personally, if you're not gonna run incredible boost levels or go single turbo, you should just go with a Pettit unlimited. The Pettit unlimited will allow you to do ALL the bolt ons without fear of detonation. How ever there are certain circumstances. [read below]

Circumstances [Rotaries aren't unreliable, bad tuners are]

1) Going more than 13 psi on the stock turbo's shortens their life spans IMO. Others will tell you 14, some will tell you 15, some 16, and a I've even heard a few say that the amount of boost you run makes no difference as long as you take care of them [let it idle after long runs to get all the oil out of the turbo's so it doesn't bake].

2) At about 14 psi you will need upgraded fuel system. You should get a fuel pump. And I would get upgraded injectors as well, although others would argue this case.

3) If you plan to run higher boost levels, you may want to port your wastegate to prevent what's known as boost creep. Boost creep is different from Boost spike. Boost creep is when your wastegate can't get rid of exhaust quick enough sending your boost levels through the roof (and shooting apex seals into your turbo's--7k worth of damage). Ported wastegate=no boost creep.

4) Boost controller. The boost controllers on the rx-7 are mainly used to keep boost in check to most drivers rather than add cheap horsepower. Boost controllers prevent boost spike. So a boost controller=no boost spike, ported wastegate=no boost creep.

5) Fuel pump-upgrade to a supra fuel pump, skyline fuel pump, denso etc...when you are running higher boost levels.

6) Do not run higher boost levels without an upgraded intercooler. The stock intercooler is a joke. You will detonate (=knocking=new motor) without a proper intercooler for higher boost levels. Getting a front mount has one con to it, being that it will prevent air flow to getting to your radiator making your car run hot (see coolant seals). Stock mount IC's are fine for bolt ons, however if you're gonna go single turbo you may wanna seek greddy's front mount.

7) Injectors--again, bigger injectors= more fuel which is very important if you run at higher boost levels. 14 psi I think is the highest you should run on stock injectors to be safe.

Before you look for power, look for reliability

Gauges help a lot like I said. I think the water temperature gauge is a very underrated mod. I think before you spend the bucks to increase power you should get an upgraded radiator like the fluidyne, or koyo. You should also look into a silicone hose job to prevent boost leaks. (You may not wanna deal with the rat's nest).

Best reliability mods in order
1) down pipe
2) boost gauge
3) water temp gauge
4) radiator
5) silicone hoses
6) Evans Coolant

Cautions

If you are into drag racing, you will need to upgrade your rear support with what's called a "launch kit." You can snap so many things if you run lots of power with the stock suspension. You would also need bigger tires maybe drag radials with high power.

Bolt On performance mods for the 3rd gen
downpipe, cb exhaust, mid pipe (middle piece of your exhaust system, comes after the downpipe and before the cb exhaust-adding a midpipe gets rid of your main cat preventing you from passing smog and adding boost creep...*note* you can still BOOST SPIKE even if you have your main cat.) cold air intake, power pulleys, intercooler.

For higher horsepower applications you will need clutch and flywheel combos depending on how much power you plan on running. Lighter flywheels hurt you at drag strips but are great for road racing.

Since you aren't looking for an engine rebuild anytime soon, I wont get into street port and such. Just some words of advice, be smart in your tuning and ask lots of questions if you're not sure about stuff. And remember, the cars aren't the problem, the tuners are

happy rotoring

RX7_Fast_Lane

VERY nice post man... a good lesson for all!

vishnu rx7

Damm good post.

-nD-

arguably one of the best posts i've seen on this forum

*copies & pastes into a word doc*

jspecracer7

First off, I would like to commend 93TTRX7 for an outstanding newbie write-up. I would also like to add my 2 yen to this.

I agree that at 14 PSI, you will need to upgrade your fuel system. HOWEVER, getting bigger injectors/fuel pump does nothing to add fuel. It is the ecu that controls the amount of fuel the injectors run. You can not simply run 14 psi AND a ND fuel pump.


Absolutely. Port your wastegate. Port your wastegate. Port your wastegate.

Not necessarily the fuel pump that needs to be upgraded. You can put in 1300cc injectors, and with the PFC, modify your fuel map for more fuel w/o upgrading the fuel pump. Your fuel pressure will not decrease because of this. You will need to get a bigger fuel pump if you up your fuel pressure. You can use the stock injectors and with the addition of a FPR, you can turn your fuel pressure up and then simply turn the duty cycle of your injectors down.

Yes. The stock intercooler sucks big hairy Arabian camel *****. The size and the materials used to make this IC were designed for cost, not for performance. Because of the plastic end tanks, the stock IC will bust open with enough boost. That and they'll heat soak like the Sahara desert.

To be safer, I suggest running less than 14 psi. I was getting 98% injector duty at 14 psi. You want your injector duty to be less than 85%

Not really a lot to snap. The power plant frame WILL crack under heavy launches though. The MazdaSpeed PPF is supposedly 10% stronger, but I have cracked mine, and I am not even single turbo yet. You can keep rewelding the PPF where it cracks and add to it to stiffen it up. Also, the stock torsen diff does not take well to wheel hop. To cure this, I suggest getting the Toe Linkages and Trailing Arm Linkages from K2RD or from M2. They help TREMENDOUSLY(I have yet to experience wheel hop with them in).

JimmyJimboJet

this has to be one of the best threads for noobs I've seen. I haven't been here for long but I've searched a lot for 'best mods' and the like. this one blows them all away. just like someone said up there, just ask questions here and more times than not, you will got someone like 93TTRX7 or JSPECRACER7 to answer you with exactly what you need to hear. it's great to have people like you (93TT & JSPEC) here to help fellow owners out with their problems.


Ok i'll stop preaching now. GREAT ANSWERS!:BIGTHUMB: