Realistic Performance Expectations?
 

I'm new here but did have 5 Rx7s in the past and am in the process of buying an 84 GSL-SE. According to a website called Zero to 60, the 84 with the 13B engine, goes from 0 to 60 in 9.6 seconds which sounds kind of slow. Another site lists it at 8.0 secs. Which is more likely correct? I don't want to modify my car too much from stock. I was thinking of a header and performance muffler, no more. With those minor changes, what kind of performance can I expect or are these a waste of time? Thanks for your patience.

IMHO, waste of hard earned cash...no power gain. Just use a straight pipe instead of a header

sports cars of the 80s really were not all that fast. (by todays' standards)


Also, do this. If you want to go deaf. Or never plan on driving it on any roads, hell most race tracks may not even let you run with that high of db.

He said header, not muffler.

There is no point in putting a header on a stock car. It just adds noise.
The most gains can be had by replacing the exhaust with a straight-thru type, losing the stock catalytic converters, and replacing the mufflers with a less restrictive design.

I am glad I asked
 

See what happens when you get away from the "hobby..." This is all great advice and probably saved me a bunch of money to boot. I am buying an 84 GSL-SE in cream color and want to restore it without changing the color or modifying anything. The problem with straight pipe might be inspection laws. I'll have to check for them in Missouri. For now, I need to concentrate on getting it here and painted. I have a friend who paints and I can do the sanding myself. Not changiing anything on this car. So you all have set me straight and I owe you. My payment will be, when this one is done, to find another one to save and restore.

I forgot to ask, what muffler would you recommend? I looked at racing beat and they are $300+ for the muffler alone. I found cheaper ones elsewhere. For now, I guess I am looking for a stock version.

Racing beats are expensive, but are one of the few mufflers that will actually hold up to the exhaust temps the rotary "spits" out....literally spits.....fireballs lol

Borla proXS 2.5 inch single in dual out. The stock mazda tips will fit on it for an almost stock look. 99 bucks on Amazon. That, with an RB header and presilencer followed by a 2" Magnapack was a sweet sounding system that worked well and didn't break my bank.

Attachment 551988

This was it, sold last summer, went long primary.

Long primary.

there are two good exhaust options for an -SE.

the cheap one is to find an FC exhaust manifold, which is almost the same as the stocker, except the outlet is 50mm instead of 40mm. after that either have a 2.25" pipe made that goes back to the muffler of your choice, or you can buy the RB FC downpipe, and be prepared to mod it. if you need a cat or a muffler under the middle of the car, it isn't a problem

the expensive way is to get the RB road race system.

Good advice
 

I found some cheap ones compared to racing beat but read way too many warnings about how the economy ones hold up. I remember having to replace them on my 86 all the time and they were economy So this is good advice and I thank you all.

all in all, ive been down the modding a gsl-se road, header... open-ish exhaust(later tamed), pineapple AUX port sleeve inserts, then i was hit in the face with the obvious.. the thottle body is TINY and is the major bottle neck in the system. then i swapped an s5 engine, and never looked back. you can get nearly 200 out of an s5 swap, and and s4 swap being a close runner up with about 180-190 being common( for those you go thru ALL the steps.)

just put a muffler on and enjoy. or start planning /saving now :P

on a side note, i ran the stock computer/2 injectors from the gsl-se and it would run out of fuel around 6k. so i dont know how much power it really had in it, but the 2k-5.5k was STOUT.. after adjusting the dizzy for enough timing.

Please forgive my ignorance
 

What are s4 and s5 engines? Any help is greatly appreciated. I am used to so much more power than this.

in the US we always use model year, however model year is almost unique to america, it seems to be a way to assure safety/emissions compliances. in Australia they use a series number, and in japan they will do versions. why the internet settled on the Australian way is anybodies guess

series number, and US model year.
S1 = 79-80
S2 = 81-83
S3 = 84-85
S4 = 86-88
S5 = 89-91
S6 = 93-95
S7 = 96-98
S8 = 99-2002

the Japanese seem to refer to all of the first gens as just SA22, they might do early or late. the second gen car is the FC3S, they will say early or late, or Major Minor Change, MMC, or use the build date.

the FD in Japan, by build date
V1 = 91-92
V2 = 93
V3 = 94
V4 = 95-97
V5 = 98-99
V6 = 2000-2002

Some of you NA fabricators should really try and make a center section exhaust like I have on my NA 20b.

Attachment 554744

Flow goes from left to right. I run this with a 3" Dynomax VT straight through muffler that has a flapper valve inside the muffler to eliminate drone while cruising. The mufflers internal valve opens automatically based on exhaust flow and with 4k miles, is rattle free. My center section uses a vacuum actuator, 3" Race Ready cutout valve, and rpm switch from my ecu to open at 3,100rpms to allow for free flow to the muffler and bypasses my cat. I went vacuum actuated because it's faster than a motor. Keep in mind you would need to install some sort of vaccum chamber and check valve to store vacuum from the intake. This way you will have stored vacuum to operate the actuator during WOT. You guys should try it.

Oops accidentally loaded the low res photos.


Attachment 554748



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Attachment 554750

I will be using something like that for my p port renesis ... nice work

Good, that helps
 

Makes more sense now. I found some rotary site, now I forgot the name, (in Tennessee near Knoxville) that rebuilds these motors, I have an s3. He said the s4 and 5 are the only ones worth rebuilding power wise. I got spoiled driving a Nissan 370z that had a lot of power. My 84 is a bit of a step down. I don't expect it to run they same but it would be nice to have a little more power.

Thx! The pic above is my 3rd version of it and now I finally have it working perfectly. Tip: make sure you have your valve near the back half as it keeps most of the direct heat off it. When closed that distance to the front turn to the cat also acts like an air damper to furthure quiet the pulses. I need to make an updated video but my engine is out of the car now so I can fix some oil and air leaks. I'll make a new video in about a month. Here's and old video I did a few years back with version 2 of that exhaust while my engine was on my test stand.