want cheap power?

[GINA2MR2]

i had a dump pipe on my mr2 (about a foot of pipe from the cat going down at an angle) it was a nice change from the stock "sound" haha
but.... had a little 'opps' and that pipes now gone, while i was preparing to weld another pipe on there. i noticed a chunk of the inside of the cat was missing (after all it is a 91) so i hollowed out the cat the rest of the way....
omg...
i got such a power gain! low end, high end its awsome.
not going to lie, its a little loud but my k&n (yes its a real full intkake not a pipe with a cone) is very deep. but i dont mind it. its quiet at idle and really only noticably loud at fully throttle. the power gain is well worth any noise.
my MPgS are better and i love it.
no check engine light or high idle FYI
oh yeah it lights up my 18s at its whim.
im throwing the 16s with the goodyear triple treads on tommarow for ****z.
just throwing it out there.
im going to put a 4'' pipe to the bumper with a Greddy resonator this weekend. (i love working at a salavage yard (free stuff))

[shimric]

Is this a joke? Because I really really hope it is. Noticeable gains in low AND high end from gutting the catalytic? Hilarity ensues.

[GINA2MR2]

3500k is where you feel the real gain but low end is improved,
like i said im running intake and exhaust mods. so i didnt get this from "just gutting the cat"
Im going to put a larger throttle body and a different intake manifold on it when i pull the motor to do the head gasket.
I didnt say it would beat anything it saw its just a nice boost in power

dont knock it till you try it

[shimric]

Originally Posted by GINA2MR2

3500k is where you feel the real gain but low end is improved,
like i said im running intake and exhaust mods. so i didnt get this from "just gutting the cat"
Im going to put a larger throttle body and a different intake manifold on it when i pull the motor to do the head gasket.
I didnt say it would beat anything it saw its just a nice boost in power

dont knock it till you try it

Seriously? You think you saw noticeable gains. First of all I didn't know you could see engine horsepower. Do you think you're the first person who's own an mr2 to do this? Wow, Let me point you to the civic forums where they will agree that doing a cold air intake, headers and gutting the cat will get you noticeable gains. Your mind is just perceiving that you actually noticed improvements in power because it's what you want to believe.

p.s. I've done it. It does next to nothing except increase the noise. Your butt dyno is broken. Take it to a real dyno. Then come back and claim you gained significant hp/tq

If you want noticeable gains, swap in a 3sgte.

[GINA2MR2]

dude seriously ....
I im not the first person to do this --yay you got a quick one off
MY MR2 IS SLOW - happy now? i never said its fast i said form my set up its fun to drive
I know what it was before and what it is now and i have a difference. ive done prolly 6 different exhaust set ups( mufflers,different size pipes,stock and other wise,) prolly ten different intake set ups,)from bone stock to the intake i have now) and numerous other things just to see what works FOR ME. Im saying it worked for me, i never said HEY GO DO THIS!
im no novice to cars or a by any means a pro- but i do know my way around them and trust me after experimenting with tons of different set ups i feel this is the best for me.
im not after big power, im just experimenting, ive had big power and yes its fun but im happy with my 5sfe- 7 points with my GTI VR6 got $$ after a while.
and the civic forums-- seriously not cool, im not some punk kid ricer, with a cone filter and a fart can.
im happy with what my MR2 is, and what im making it into.
nuff said .

[Levi_]

Nice, i'm doing this right away.

Edit:
Hollowed-Out Catalysts - Power Increase - Import Tuner Magazine

[mrturrari]

The gains you felt were probably because your cat was melted and limiting the flow. The Import Tuner article that Levi posted is a good demonstration of why the right sized smooth pipe is better then a irregular pipe like a cat or muffler for making power.

[datguydeni]

well least he gutted it.... before more "chunks" fly out and starts a fire (it actually happens)....
but good read levi thanks

[shimric]

Originally Posted by GINA2MR2

dude seriously ....
I im not the first person to do this --yay you got a quick one off
MY MR2 IS SLOW - happy now? i never said its fast i said form my set up its fun to drive
I know what it was before and what it is now and i have a difference. ive done prolly 6 different exhaust set ups( mufflers,different size pipes,stock and other wise,) prolly ten different intake set ups,)from bone stock to the intake i have now) and numerous other things just to see what works FOR ME. Im saying it worked for me, i never said HEY GO DO THIS!
im no novice to cars or a by any means a pro- but i do know my way around them and trust me after experimenting with tons of different set ups i feel this is the best for me.
im not after big power, im just experimenting, ive had big power and yes its fun but im happy with my 5sfe- 7 points with my GTI VR6 got $$ after a while.
and the civic forums-- seriously not cool, im not some punk kid ricer, with a cone filter and a fart can.
im happy with what my MR2 is, and what im making it into.
nuff said .

Well, I'm glad you feel this way, but as levi already posted. (facts) gutting the cat does nothing. As I've previously mentioned. My wife knows that and she knows next to nothing about cars.

Good find levi.

[Oteck]

no such thing as cheap power on a 5sfe.

[GENESIS]

Originally Posted by GINA2MR2

i had a dump pipe on my mr2 (about a foot of pipe from the cat going down at an angle) it was a nice change from the stock "sound" haha
but.... had a little 'opps' and that pipes now gone, while i was preparing to weld another pipe on there. i noticed a chunk of the inside of the cat was missing (after all it is a 91) so i hollowed out the cat the rest of the way....
omg...
i got such a power gain! low end, high end its awsome.
not going to lie, its a little loud but my k&n (yes its a real full intkake not a pipe with a cone) is very deep. but i dont mind it. its quiet at idle and really only noticably loud at fully throttle. the power gain is well worth any noise.
my MPgS are better and i love it.
no check engine light or high idle FYI
oh yeah it lights up my 18s at its whim.
im throwing the 16s with the goodyear triple treads on tommarow for ****z.
just throwing it out there.
im going to put a 4'' pipe to the bumper with a Greddy resonator this weekend. (i love working at a salavage yard (free stuff))

what kind of power gains are you claiming?Im just curious do you have a dyno?if so show it to everyone here so they can stop the hate.

It all depends on the car and design, Its possible to gain 1-2hp from gutting a cat but some of the time you loose power & torque,It all depends on the setup you have.Its also possible that your cats were clogged but Il give you a benefit of a doubt.

My na 5sfe was dynoed with no mods at 107rwhp with a (Dynapack) dyno
by sue at AGP(take note that this is the same dyno that Dinan motor sport use in Morgan Hill)So its as good as it gets direct from the axle.


The second time I got my car dynod again but this time my current mods are

knn panel filter
timing advance to 13dbtdc
4-1headers (NO CATS AT ALL)
87 OCTANE since I forgot to put 91.



Its nothing magical but the point is there's a gain.I ounce had a 455rwhp mr2
I got it de-cat and gained over 10hp all over the rpm,I even gained 15rwhp by making it a 3inch straight pipe but thats because my my 3sgte was
blue printed to my demands.

1.heavily modified
2.serious head work pnp/ 2mm over size valves/5angle/bowled
3.rebuild internals w.forged pistons
4.high boost I played with 22-27psi
5.running on aem stand alone
6.td06 turbo/but ive used 15g also.

I also had a 1.6 spec miata that was all stock except the intake mod,The oem cat was rusted away so i had a muffler shop weld a rough straight pipe lying around. It was dynoed before @92 rwhp when the cats were good,Then i had it dynoed when the cats were gutted a day before a track day and i pulled a 94.7rwhp.(w/no intake) i wish i still have the dyno chart but i gave it to the buyer of my miata.Plus I got nothing to prove to anyone here.You can never get through a one dimensional person.

[datguydeni]

^ooo dyno'd 5sfe. i believe the gains came from that header of yours almost 10hp very nice..
and i think it was timing that gave you lower end power.

[Medusa]

Usually advancing your timing shifts the power more towards the top end, doesn't it?

[GENESIS]

Originally Posted by Medusa

Usually advancing your timing shifts the power more towards the top end, doesn't it?

It actually moves the torque curve down earlier depending on how much you advance it,You usually feel the upper end being robbed if advance too much but for my car and its condition 13 was the sweet spot for me where I felt more torque coming in earlier and still have power in the upper rpm without dying earlier.I also think since the 5sfe is built for torque it had a good effect similar when i advance a ka24.

I tried advancing a miata and found the sweet spot to be 12deg but the gains were not worth it.I didn't feel nothing and only showed 1.5hp gain on the dyno.

[GENESIS]

Originally Posted by datguydeni

^ooo dyno'd 5sfe. i believe the gains came from that header of yours almost 10hp very nice..
and i think it was timing that gave you lower end power.

Yup headers usually give you about 7-10hp , I had 3 runs when my car was stock I pulled a 107rwhp on my second run but first run I did only 106rwhp then my third run with timing advance I pulled 109.7rwhp,I was expecting my cars torque curve to die down a little earlier but I guess it didn't.In my case I only got about 7.2rwhp,I didn't take notes of the gains on the knn panel filter though I probably got nothing but i felt less restriction around 2800rpm and up.

I have seen other people pull a little higher numbers than me on a different dyno though.

Psssst I wish I had web cams.

[GINA2MR2]

I never gave numbers i just said i noticed a difference. i can have it dyno'ed at School im just waiting for two good tires to come through work (and my new headgasket) since why pay for them with i get them for free haha I only posted this to let others know what I got, take it or leave it. all i kow is it car chirp the 18s on dry pavement, haha Granted its not like my GTI, i could light them up through 3rd (miss that car)
im putting a 'b' pipe on it this weekend so it will look legal haha. the specs on my car are as follows. this winter when i do my head-gasket im having my cylinder redone and pp'ed (a shop owes me work) and thats prolly it.

1991 Toyota MR2 NA
5 Speed
Engine(including mods)
2.2 5SFE
SVT Throttle body
K&N Intake off a 5.7 LS3 motor(see link at the end)
140amp Alternator
AC system Delete
No exhaust
i know i missing somthing but its pouring out haha
---
Wheel size (fyi if your wondering)
14'' stockers
16'' 09 camry steelies with goodyear and hankook rubber
18'' Tenzo R passion 5 with conti-extreme contact rubber
----

to quote GENESIS
"Plus I got nothing to prove to anyone here.You can never get through a one dimensional person."

http://akamaipix.crutchfield.com/pro...101-f_dmtp.jpg

[Butters]

my opinion if it makes him happy then so be it. it sounds different he likes it. do i think he got a buttload of power. heck no not a chance. but i dont see the point in cutting him down as a ricer because of it.

shimric your right in that it doesnt do much of anything unless like the other poster mentioned your pushing some heavy mods.

would i do it? sure why not? just my opinion

[GINA2MR2]

sounds different yeah but not much,

[GENESIS]

I just wanted to make my point Its not allot of power but you do get something.When you race on a spec miata certain rules are made for a 1.6 and 1.8 you cant just throw in a turbo or a supercharger so most people gut their cats to get power or do a straight pipe to get a little edge That has an affect on the out come of you winning on a race.

Specially on a 5sfe mr2 since there's almost no mods or support for it every little thing counts,You would be surprise what people do at auto x events before they run.People would come with gutted cats,rip everything apart even the sun visor just to reduce weight,taping the tiny gaps between fender/bumper,doors just to reduce wind drag seconds before a race.

Some People here are just looking to be a smart a$$ and make negative comments to people like(Well, I'm glad you feel this way, but as levi already posted. (facts) gutting the cat does nothing.)

Well gutting a cat does something apparently when your competing at an auto x event,trackday,drag strip,or when you don't have money and just want to have some kind of improvement on you car like just like everyone else.

I spoke with my friend he just got a dyno done today he gained 8hp on his stock srt-4
no mods but I think an intake,Every car is different and its a true 8hp gain but most of all its free
want cheap power?

When I get in touch with my friend I will post his dyno chart here.He said that he gained true power all through the rpm He also said his turbo spooled quicker because of gutted cats.