N/A Mods?
 

Hey, I am new to this forum, so I have no idea if this has been discussed or not, so I'm going to ask anyway. I'm planning on getting a 1990 RX-7 GXL soon, and am planning on doing some upgrades. My plans right now include full exhaust system using Racing Beat headers and a custom 2" exhaust with Dynomax mufflers, and K&N panel filter with some sort of Home Depot cold air intake. Any suggestions on this so far? My main concern with this is having the car run too lean and bad things happening to the engine. What upgrades will I NEED to perform on the fuel system to make sure this doesn't happen? Should I use bigger injectors from a Gen1 13B, or will I need a fuel controller like what Apex'i makes? Cost is definately an issue, but I would rather spend the money now than have to rebuild the engine later. Are there any other fairly inexpensive mods that I should consider? I'm wanting to have at least 190hp and 180lb-ft, but numbers closer to 200 would be preferable.

OK, the exhaust sounds good. The air filter sounds good. Do not worry about running lean. My 91 actually runs rich, as most rotaries do. And plus, running lean is not bad for a n/a. Only upgrade the fuel system if you are porting the engine or running nitrous oxide, or you will actually hurt top end performance.
I am running a Weapon R intake, and am purchasing a Bonez racepipe (replaces all 3 catalytic converters) and Racing A single exhaust. With n/a's, the main goal is to make it lighter. Remove the a/c, p/s, air pump, spare tire if you are brave. Another good purchase is a Hayne's Manual to help when you work on it. Good Luck and keep us posted!!!!

Keep the air condition, keep power steering. Just port the intake and exhaust, upgrade to somewhat bigger injectors (Not too big). Get a racing beat exhaust manifold, use a single 2 1/2 inch exhaust tubing as straight as possible, msd or jaycobs coils. Lean is bad for apex seals, when you rev hard a lean engine it vibrates sometimes causing the rotors to hit the housing very hard and breaking an apex seal, yes that weird sound you hear at 8,000 plus RPMs is your engine asking for more gas and telling you to lift the foot off the gas pedal.. Rich is always better than lean, lean breaks engines rich does not. So a LITTLE rich is recommended on the secondaries... Our car would not be running the times it is running if it were not for the years of experience we got on the rotary field.

A crane HI-6 is a good ignition upgrade...summitracing

Is a header really a good investment? I just hate the weed-whacker sound it makes!

I have also really heard that lean ain't too bad on a n/a. Mine always runs rich, though.

First off, what the heck is a racing beat exhaust manifold? Did you mean a header. Also, straight pipe after the header, not even a presilencer to quiet down the excessive noise? Injectors, what do you recommend, ones from GSL-SE or TII?

Ok the Bonez racepipe has a small pre-silencer on it, and that is the set-up I will be running in the next few weeks. About the fuel, form everything I have read, which may or may not be correct, is that by upgrading the fuel system, you run the risk of running too rich at the top end. This will actually hurt performance. Also, in all of the threads I have read, there is no real reason to upgrade the fuel delivery system unless you are running a street ported engine, or you are running nitrous oxide. Correcet me if I am mistaken, but this all I know.

And yes, you will want some form of noise reduction other than high-flow mufflers. I removed the enitre exhaust when I gutted all my cats, and I decided to fire up the engine just to hear what it sounded like. Bad idea. Gave me a headache when I floored the gas, an I really pissed off the neighbors! Rotaries are LOUD at WOT and a high flow exhaust!

You may want to look into RB presilencer and midpipe instead cause Rarex had a Bonez in his gtu before and claims the RB pulls harder on the top end, possibly because it's manrel bend at the RB midpipe and a "kink" at the bonez "midpipe". But it's an extra $100.

Dont waste your time until you have done EVERYTHING else, including a ported motor. There will be no increase in power at all unless you have forced Induction at greater than 10 PSI. Theres dyno proof to back this up.

Do exhaust and intake, and you are on a good start to having a quick n/a.

Racing beat header, no pre silencer and racing beat first gen muffler. No loud noise at all!!!!

You have no need to upgrade the fuel system
I only need to upgrade my fuel pump- I cut out after about 20 seconds at full throttle... I don't even need bigger injectors, and I have quite a bit done to my engine.
If you do upgrade, you will need correction to run properly. (Like AFC)
Fuel pump upgrade will cause very rich running at idle.

this is the best NA mod thread...130+ replies

https://www.rx7club.com/forum/showth...5&pagenumber=1

Bambam
 

Hey bambam... I have a t11 fuel pump but got rid of my afc for a wile.. Will I only run rich at idle??? If so cant I just lean it out with the idle mixture screw??? I want to put it on but heard hore stories with mazdaspeed7

I also cut out at around 20sec. I never new what it was until now and seemes to only happen at slight upgrades. No other ill effects thou. Is it a safety pump warning deviec swich meckanism or something??? anywyays thnx.

Re: Bambam
 

Bambam's engine is ported, I am still on stock ports. The pump was making me run a little more rich on the bottom end, but I havent run it with the tII pump and stock injectors. I swapped both out together. Ill prob put the TII pump back on when I redo me exhaust.

Hi guys i am trying to see if somebody got pictures of a 2nd gen and how to put a upgrade intercooler if somebody can help me out please send me some pictures or information..... THANKS.

intake, full exhaust, standalone, lightweight flywheel

Guys?

The thread is a little old.