Hondan

How much horse power would I gain if I removed the first catalyst and
add a cold air intake on a stock D17A?

ES3 Type RS

lowlife9

lol maybe 1-2

baron340

iTrader: (4)

You may gain a maximum of 2 hp and you will likely lose 5 ft*lb of torque.

greeen01civic4d

iTrader: (7)

u will gain 1 million hp

Awjvail

Over 9000.

ProjectMayhemR

iTrader: (1)

who cares, a slow car is a slow car... and you sir have a slow car.

turbo zombie

a few years ago one of the import magazines did a test on the power difference between a stock cat, a high flow cat, and a test pipe (no cat). the vehicle they tested was an already highly tuned R34 skyline. the baseline test, with the factory converters, was somewhere around 540 whp. the high flow cat gained i think 2 hp. the test pipe only gained another 3 or 4.

on a race car, that can matter. on a stock or mostly stock civic, that's more legal and environmental risk than is worth the reward of 1-2 hp. your car would be noticeably louder, even with a factory exhaust. modern oem catalytic converters do not restrict flow a significant amount.

see my sig, my 242 turbo made more "butt dyno" power with a factory cat and a straight through muffler, than with no cat and a stock muffler. it was quieter that way as well.

04 Honda Civic

iTrader: (2)

You can probably keep up with evos

Hondan

With turbo added, driving on race gas.

civicsrcool

you need some nawz too :/.

Jp7

iTrader: (2)

the advantage of taking away a converter is the fun fuels you can use without having to worry about ruining it.

turbo zombie

yeah, but again, what kind of help is that going to be to a stock ecu'd civic? fun fuels are only fun if you tune for them.

Hondan

Whst kind of ecu work can I do?

slowassd17

iTrader: (1)

you cant really do anything to your stock d17 ecu, you could buy a piggy back ems or hondata kpro, but if you dont have any big plans for the car, or plan on spending a decent amount of money then it wouldnt be worth it

Hondan

Ok instead of adding a turbo kit, I am going to sell it and
buy a FD2 SI and add a FD2-R spoiler to it and a few other upgrades.

slowassd17

iTrader: (1)

your going to sell the car?

Hondan

very soon

ProjectMayhemR

iTrader: (1)

I honestly don't think you need to be messing with cars. You first made a post about removing your cat and adding an intake instead of searching. Now you want to sell it and buy another car, and the first thing you want to do is put on a spoiler and other nameless random mods. Pardon my French but **** the spoiler and save up your money for something worthwhile like a turbo kit. You came asking about power gains and now you want to buy a new car and put a spoiler on it. If the reason you are selling your car is a lack of power, buy parts that will add power to the new one and buy your spoiler later.

seoul4korea

NA needs at little back pressure. It really Helps when using on a Turbo car. Turbochargers them self create the back pressure that's needed. Removing you cat isn't going to allow you to gain too much from a d17.

Hondan

Thanks 4 the advice - but the FD2-R spoiler is to give the SI the R look .

ProjectMayhemR

iTrader: (1)

double post

ProjectMayhemR

iTrader: (1)

yea the look without the performance.

Awjvail

Epic win.

Acem2ex

I have to admit that I laughed a little. Going to go buy a big wing for my EM2 now. Give it that rice look.

HLC

that picture there is made of awesomesauce and win

jamis33

guys talk to bomber and he will tell u no cat WILL give you power. All this talk of backpressure is just crazy. you can run 2.5" exhaust on all stock with no cat and STILL have more than enough backpressure. I run 2.25" on pnp head with stage 1 cam and before i put a header on i was running stock exhaust and there was SOOOO much backpressure my header cracked and the crack expanded to a hole. Just an fyi. Our cars have so much backpressure u dont neet to worry about it. Cat is terrible for the environment I will admit and for personal reasons i will probably add a cat but for now its really not that bad. Loss in backpressure is insignificant when compared to the butt dyno results

gearbox

iTrader: (95)

how come all these 200+ hp cars all have cats from the factory and run just fine? but on a civic with 100 hp it causes problems.

sl33pyriceboi

iTrader: (3)

hahah. this thread and the OP's question is epic.

5hp stickers FTW!

lordhelmet

iTrader: (3)

Wait, too much pressure caused a crack in your header?

2005civiclx

FD2 is only type r. SI is FA5 for the sedan and FG2 is the coupe so i think you want to go for the type r look.