What is the fastest way to gain your N/A hp?
 

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

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...

Header (RB,Corksport)

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

NNOOOOOOOOOOOOOOOOOOOOOOOOSSSSSSSSSSSSSSSSSSSSSSSS SSSS!


-Ted

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.

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

Thank you.

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.

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

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

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?

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

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.

Port
Full exhaust
Fuel computer

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

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.

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? :Wconfused just wondering. Thank you.

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.

No, thanks. I am interested in drift setting.

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.

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.

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

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!!

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.

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.

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

Yup. Go run your engine hard for awhile on a track or at an autocross, save up your money for a TII swap, and once your NA engine lets go, swap the TII in.

Or just sell your car and get a TII.

don't worry about HP yet. Do all the suspension and reliability mods and prepare it for TII swap later down the road. When you are ready to swap you'll have everything else prepared.

exhaust and nitrous is what ive heard

im in the same situation too but i decided to just go with the TII engine .I mean i may have a lil lag but that kick will be well worth it

the hp/$ ratio is way off it costs more than its worth to make even decent power (trust me)

take your car drive it learn all u can and then buy a TII oh yea and love it

oh yea and to answer ROEN's ? i have no idea on power never dynoed and i have thought about standalone alot but my wallet and i had a discussion and decided that it would be better to drive this 7 till out of college and then buy the tII and then just go banana's on that

what lag? Fix your car.

I'm thinking the cheapest is to port the intake and to get a intake.

Cheapest? weight reduction. everything else will cost plenty or is not worth wasting your $$ on.

I DD'd my car all last summer with temperatures reaching above 110F at times, we were the hottest spot in the province many times and I have no AC, I didn't die from sweating. Sure AC is more comfortable, but it's not a necessity. I have manual steering and I don't get sore arms or get tired in parking lots because I'm not a panzy.

It all depends on what your tolerance of such things as to how acceptable they are. I love my manual steering (on a 15:1 power rack too) and I wouldn't go back to power. I probably wouldn't add AC either, too much weight, power drag and it compromises cooling.

Guess I'm a pansy. Sitting in traffic for three hours on the freeways of L.A. getting out of work on a Friday trying to get home to your family in 100 degree heat is not my idea of fun.

No need to call me that, I'm just letting the OP know my opinion.

does match porting even do anything??? I wonder why so many ppl do that and the throttle body mod on NA's....

pussy! :icon_no2:

I'm with Tex but you don't need that much HP to thoroughly enjoy the 7.

Did I miss the post where he said if he was building a streetcar or a race car?

I drive the t2 with manual rack, no ac, and sometimes the windows wont go down, and i enjoy every minute of it.

I know. We have people on this thread claiming 240 hp from an NA without nitrous. Some others go the distance to bridgeport a 6-port (WTF?) and still others want him to toss his air pump (meaning goodbye to VDI and 5th/6th port). The OP said he has an s5. He needs his air pump to give him useable power.

To the OP, I suggest doing what a few others here have suggested. Read the FAQ section and do searches on reliability mods and enjoy learning about the 7 and save the money that you will waste trying to beef up your NA and put it towards a TII. I have a s5 that is a trouble-free DD and a s4 TII that I can take to events on weekends. Best of both worlds.

The pansy comment was about the steering, not the AC, and it wasn't really directed at anyone in particular. With the steering it's not that hard at all unless you're stopped or going really, really slow, and even then it's not that bad. I've driven 8+ hours on a converted rack no problem, it's fine at autocrosses, it's fine at the track. I've never found that it tires me out at all. I'll never be convinced to go back to power steering in my FC, but I'd probably leave it on a "normal" car. I agree it's more comfortable with AC, but it's not like everyone died every time it got hot before AC was common.

Your comments were WAAAAAAY over dramatic, and I felt that they needed to be addressed. "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." No and no to those two from experience with my car. "You'll be completely pissed at yourself for getting a heavy clutch in traffic. Your flywheel will be a pain getting used to." my dad's car has a stiffer clutch and a light flywheel and everyone stalls it the first try, but you get used to it really quickly and it's not an issue. It makes rev matched downshifting easier to boot. I prefer it to my relatively soft stock clutch and heavy flywheel.

You can bridge a 6-port, but you have to toss out all the other auxillary equipment and do it properly in order to realize the benefits.

240 hp from a streeport? I haven't seen one yet.

240 hp from a bridgeport? Certainly doable.

240 hp from a p-port? Seen it....loud as hell though.

No nitrous in either of the last two cases.

Incorrect.

The simple answer to this question as to a simple next step to add power when you already have an openedup exhaust is to add a piggy back fuel computer and take some fuel out.

10-15 HP for 300 or less and better gas millage to boot.

Rtek 2.0 for an extra 100 and you get better response to boot....

AH-NODE says: DON'T BE AH GURLEE MAHN!

bahhahahhhahahhhahahahaha

I find these kinds of comments really funny...

I have no working A/C, but I've driven in 110F+ Sacramento summers and even hotter 120F+ Vegas summers!

PUSSIES!


-Ted

You do a forum search, as this topic has been covered before.

You already have most everything. You could get a cone intake and put a cold air box around it to get maybe 2-3 HP. But a cone intake + no cold air box = less power than stock intake. You could get 2-3 HP from Royal Purple oil. For comparision your exhaust probably gave you 25HP. You can shave off some weight and/or get a lightened flywheel to go faster without more horsepower. But basically you can't get much unless you do something major & expensive like: a standalone ECU, street port, turbo swap or NOS.

(and other people mentioned headers too, I think)

On a fuel injected RX-7, RB headers plus cat replacement don't add any significant power compared to cat replacement only. It says right on their website. Jeebus people. And theirs are probably the good ones. Next time someone suggests headers I want to see their own personal before/after dyno sheets, with nothing different between the two sheets except the headers. And yeah, I've seen a poorly photoshopped dyno sheets from a certain unnamed vendor. The new dyno is just a scaled up version of the old dyno. The static is the same on both dynos, or in some places the static is shifted or mirrored. Plus a real dyno would show different gains at different rpms, especially if headers followed the harmonics BS that they talk about. Go look at one of them yourself and see.

on a stock port you can reach just over 200 hp to the wheels. there is someone on here that did it i forget who though

Sure you can, with NOS, but seeing as a radical streetport and downdraft Webers only get you a bit above 200 in EP trim, I doubt it can happen on stock ports with NA.

Alright I'll retract my previous posts then, I'm outnumbered on this one.