ka24.ej20

Hi there,

I have a 89 Rx7 GXL NA, these days I felt my car need some hp. Does anyone know how to gain your hp with out swap to the turbo engine by cheapest way? I have Borla cat-back, 1 and 2nd performance cat. stock intake.

Thanks

w0ppe

Well, you really don't gain much horsepower out of the N/A FC. You'll probably hit around 240 HP at most.
The only thing left is to use what you've got:
Weight red.
Suspension
A few tweaks here and there is all you got left kind of...

HAI-TEK7

iTrader: (31)

Header (RB,Corksport)

Honda600rr420

remove the A/c get block off plates for the air pump remove ur cats also i found that my safc freeed up a few hp with a decent tune intake? not a whole lot you can do without tearing the engine down/ internals

RETed

NNOOOOOOOOOOOOOOOOOOOOOOOOSSSSSSSSSSSSSSSSSSSSSSSS SSSS!


-Ted

Black91n/a

Yep, by far the cheapest hp/dollar and hp/effort is Nitrous Oxide. You can do a 50, 100, 150 or whatever shot for under $1000, where to get the comperable hp from other mods would cost a lot more and will suffer from drivability problems.

About the highest you can get is just over 300hp to the ground with a preripheral port.

ka24.ej20

I got a Pace setter, but wrong one so I returned it. keke.

Thank you.

wackaloo13

iTrader: (3)

full headers exhaust, get a fuel computer and get it tuned. ditch a/c ps emissions. if you have some more money oyu can do a port job.

Latin270

lol....Bridge-port, Nos, rtek and exhaust and shut the n/a haters up already! The above video says it all! lol

dw89s5

my question is what kind of numbers are u looking for?

mine is bridge ported, header, AAI, safc other things that dont matter much but anyway its more power than stock but its still not a turbo

Roen

iTrader: (2)

if you're talking stock ports?

Full exhaust (Speedsource, SDJ, ISC) (these are loud)
AAI
Rtek 2.0

~$2k right there, not including labor

You can probably get 180 to the wheels, max

All out power?
Standalone
Full Peripheral Port with Lightened RX-8 rotors, Guru 2-piece E-shaft, bearings, stat gears, etc.
Custom Long Primary Header
Custom Long Primary Collector/Pre-silencer
Custom single muffler Catback
Independent Throttle Bodies with AAI
Clutch
Lightweight Flywheel
Carbon Fiber Driveshaft
Transmission Scatter Shield
5.12 (or higher) LSD diff
Nitrous Oxide if you're feeling lucky

~$10-$15K? Gives you slightly over 300 whp + NOS, expect your engine to last maximum 30,000 miles and be completely undriveable on the street.

How much power are you making? Have you thought about going standalone + ITB and ditching that AFM?

simoncbrr1

NOS! And your in luck i have a fogger setup for 100hp (brand new!) for $450 Om me if you want it!

Black91n/a

I think the most that the ITS guys (stock ports) get is about 175whp. With a massive streetport you can get to just over 200whp. A Bridgeport will give a little more, a J bride will give a little more still, and a PP will max out at a little over 300whp with a short primary header.

You can lighten S5 NA rotors more than you can lighten RX-8 rotors.

Jager

iTrader: (10)

Port
Full exhaust
Fuel computer

Then the rest you gotta be ready to pay to play.

Roen

iTrader: (2)

True, but RX-8 rotors have that extra tiny by more compression.....we are going for all out horsepower, aren't we?

I would think that the p-port would benefit more from a long primary, wouldn't it?

ITS guys have made 174 whp on stock fuel computer and Speedsource short primary exhaust.....I think you can top that with a little bit of fuel and timing tuning with the Rtek.

ka24.ej20

I don't think N/A FC can go to 240hp. It's only have 1.3 L engine, even though I header and all straight pipe it won't hit 240hp. Could you tell me how to hit 240hp? just wondering. Thank you.

Roen

iTrader: (2)

lol @ just a 1.3L......you should read the countless arguments on why the rotary both is and isn't a traditional 1.3L.

Without modifying the engine...the most you'd get with bolt-ons and tuning is topside of 180 whp, with cool temperatures helping you out.

ka24.ej20

No, thanks. I am interested in drift setting.

Black91n/a

From what I've read most PP engines use short primaries, and the Speedsource cars generally run Motec standalones in the stock ECU case. With ITB's you can likely go higher than that on stock ports though.

0.3 compression increase isn't going to make much difference, maybe a little, but then there's the other issues with RX-8 rotors like apex seal compatability (theirs are shorter). I think the extra lightening probably more than offsets the slight drop in compression.

For a really radical side port go for scalloped rotors to increase port timing.

TheAbsence

iTrader: (19)

Unfortunately, its all good fun to dream, but as previously stated, the car will be undriveable on the street. Your exhaust will make your ears bleed, not to mention be completely illegal. You will die of sweat in the summer with no A/C. You'll have sore shoulders from lack of power steering in parking lots. You'll be completely pissed at yourself for getting a heavy clutch in traffic. Your flywheel will be a pain getting used to. With a good size port job, you'll be lucky to push 15mpg on the highway, 12 in the city. Your girlfriend will hate being seen in your car, since theres no dash, no carpet.

What these guys have described is the perfect setup for running in an all out N/A only class for racing. If this is what you want, congrats, your car will be amazingly fun to drive, and also the biggest pain in the butt. Unless of course you have another car to use as a DD, in which case this would be an amazing setup. I'm not trying to be pessimistic, just letting you know the truth before you dive right in. Make sure this is what you want so we don't have to post pictures in the lounge when someone drives by your home and sees cobwebs all over the car.

ka24.ej20

How to cool temperatures? buy an efficiency cool radiator? Damn... I feel like I am lack of rotary knowledge.

ka24.ej20

Thanks a lot!! I got your point!! I am just wondering how can people gain their N/A hp without ported engine and swap to turbo engine. Of course, I understand that keeping in stock is the best way to keep my engine longevity. Thanks again!!

TheAbsence

iTrader: (19)

You're very welcome!

And unfortunately, without porting or doing other internal mods, your horsepower gain will be largely insignificant for the money. Without running forced induction, nitrous, or internal modifications (e.g. porting), you could spend over 2 thousand dollars on a full exhaust setup, custom fuel chip, and removing emissions, power steering, A/C, and the interior. All this could get you anywhere from 20-30 horsepower, maybe 20 at the wheel. For this price, you could probably buy a Turbo II with some miles on it, probably not in the best condition, and it will come stock with 20 horsepower more than your tricked out N/A. Might as well have 2 RX-7s :P

The point is that I've been where you are, I understand fully where you're coming from, and unless you're building an N/A for a certain class of racing, I've found it to be completely not worth putting money into performance if you're looking for horsepower gains. However, if you want to, don't let me stop you, its entirely up to you. Good luck!

** By the way, coming from your situation, I've decided to buy a used S5 Turbo 7 when I graduate from college and dump loads of performance into, and get it to ~350horse at the wheel. Then I can have 2 7's, one as a daily driver, and one that gets less than 10 miles to the gallon but could torch a Vette. (Not that thats what I'm building it for, I'll build it to have fun with my dad, hes buying an S2k)

Have fun man, and I'm glad you're looking so deeply into this before you start throwing money into it, since it can get pricey real quick, and may not yield the gains you thought it would.

Roen

iTrader: (2)

Your max horsepower stock without porting will be 180 whp, and that's with the most expensive configuration. If that's not enough for you, you can go with a streetport, but the most common configurations push around 200 whp and the most expensive have the potential to push 230-240 whp. After that, drivability and streetability, not to mention gas mileage, go downhill.

If you need more power than that, sell your car and buy a TII. NA rotaries just don't have that performance potential. That's not to say you can't be fast with it. I was third fastest in my HPDE run group with a 170 whp NA FC, next to a BMW 130i and a Spec Miata driven by an instructor. Of course, if every car had an equal driver, my car would be towards the back of the pack. I love picking on Z06's when the driver doesn't know how to drive his car. =P

I was always under the impression that PP's were high overlap ports and that high overlap engines benefit more from long primaries due to exhaust scavenging.

0.3 compression counts if you're trying to go all out, no? We're assuming unlimited resources here (at least, I am.) Seals, you use normal 13B seals but mill the rotors to accept them. If they're both lightened, they can both be revved higher, most likely past the usuable rpm.

I was quoting some dyno tests done by Chris Ludwig, making 174 whp with the Speedsource short primary on stock fuel computer.

ka24.ej20

because I have a good condition for my NA if I swap to turbo I need to change whole engine, is it?