decat: loss of torque myth?

[pyn888]

recently change from K1 to a K2 and its a bit quiet for my liking but the K1 was a bit loud

 

was thinking of getting resonated decat pipe (ichiba or kinetix) to give it more of a growl but i ve read it can suffer heavily from loss of torque but other like adam from Z1 disagree with this?

i had my ep3 civic decatted and torque actually increased with the better flow

 

also will the car run lean? with my civic i had to get some sort of engine management when i decatted the car

 

oh and i am too tight to get a sports cat

[GT4 Zed]

Its a UK myth I seen hundreds of dyno printout staeside with only gais to show for!

The only thing to worry about is the smells, rossers/MOT and tthe noise if the you prefer quiet and most important that you have to swap to OEM cats to pass the MOT

Invest in an axle stand and hyraulic jack(under £ 60 from Halfrauds) and do it yourself and it will be useful for other mods etc

Or visit you local dodgy garage to falsify the emissions report or do the swap themselves Afterall its only once a year

[Chris`I]

Its a UK myth I seen hundreds of dyno printout staeside with only gais to show for!

The only thing to worry about is the smells, rossers/MOT and tthe noise if the you prefer quiet and most important that you have to swap to OEM cats to pass the MOT

Invest in an axle stand and hyraulic jack(under £ 60 from Halfrauds) and do it yourself and it will be useful for other mods etc

Or visit you local dodgy garage to falsify the emissions report or do the swap themselves Afterall its only once a year

I think Ian lost some low down torque when he swapped out for decats, put high flow cats back on again. I think its largely a myth though if the car is mapped for it

 

Oh and Wickes do the same jack and axel stands for about 1/4 of the price of Halfords!

[srobrien]

Oh and Wickes do the same jack and axel stands for about 1/4 of the price of Halfords!

 

Yup, got these after Chris mentioned them, decent quality stuff for literally pennies.

 

R

[sunset350z]

I'd spend the extra on a set of high flow cats. Its too much hassle swapping over for the mot every time, and its a very awkward job.

[GT4 Zed]

I'd spend the extra on a set of high flow cats. Its too much hassle swapping over for the mot every time, and its a very awkward job.

 

c'mon Steve, don't be a lazy a---e! It 's car up the stands, 8 bolts each way, disconnect and reconnect the sensors, car down and only once a year

I will do it for extra ponies anytime and save more good change for other mods. The evo/ scooby/RB crowd are at it so why not

[M13KYF]

Ian reported losses

 

viewtopic.php?f=62&t=15038&hilit=decat

[Chris`I]

I'd spend the extra on a set of high flow cats. Its too much hassle swapping over for the mot every time, and its a very awkward job.

 

c'mon Steve, don't be a lazy a---e! It 's car up the stands, 8 bolts each way, disconnect and reconnect the sensors, car down and only once a year

I will do it for extra ponies anytime and save more good change for other mods. The evo/ scooby/RB crowd are at it so why not

High flow cats will likely net you just as much as decats but save the hassle. If you have an FI Zed, sure decat it, but unless you are FI there isnt much point for the hassle.

[Dblock]

I'd spend the extra on a set of high flow cats. Its too much hassle swapping over for the mot every time, and its a very awkward job.

 

c'mon Steve, don't be a lazy a---e! It 's car up the stands, 8 bolts each way, disconnect and reconnect the sensors, car down and only once a year

I will do it for extra ponies anytime and save more good change for other mods. The evo/ scooby/RB crowd are at it so why not

High flow cats will likely net you just as much as decats but save the hassle. If you have an FI Zed, sure decat it, but unless you are FI there isnt much point for the hassle.

 

On other cars there is a big gain, IMO as someone said if you have them fitted and mapped for a decat im pretty sure you will gain. I gained a fair bit in my clio and my mpg went up too!

[Carbon Coops]

What sort of trouble can you get in for no-cats then??

coops

[Chris`I]

On other cars there is a big gain, IMO as someone said if you have them fitted and mapped for a decat im pretty sure you will gain. I gained a fair bit in my clio and my mpg went up too!

What engine was in that?

 

What sort of trouble can you get in for no-cats then??

coops

MOT fail

[Carbon Coops]

i know that its an mot fail but i mean what on the side of the law will happen if caught?

coops

[sunset350z]

I'd spend the extra on a set of high flow cats. Its too much hassle swapping over for the mot every time, and its a very awkward job.

 

c'mon Steve, don't be a lazy a---e! It 's car up the stands, 8 bolts each way, disconnect and reconnect the sensors, car down and only once a year

I will do it for extra ponies anytime and save more good change for other mods. The evo/ scooby/RB crowd are at it so why not

 

Have you ever changed the cats over then Bennet? I doubt it I paid a garage £60 to swap over my standard cats for some HKS hi-flows, and even with all the tools on hand, and up on the ramps above head height, it was a bugger of a job

If your car is purely for the track then its a viable option, but as you use the car day in day out on the roads then it aint worth it.

You'll more than likely have to do a reset every day, due to the engine check light coming on all the time.

The car will be technically illegal to drive on the road, and if you had an accident and the insurance company picked up on it, you'd be fooked

My car ran lovely with the hi-flows connected, it also flew the MOT, no issues whatsoever. I wish i had the car now with the set up it did have, and taken it to RS-Tuning to show you that hi-flows can give just as good gains from a reflash as decats.

In summary, its against the law and too much hassle for similar gains to hi-flows.

[Gaz Walker]

I'd spend the extra on a set of high flow cats. Its too much hassle swapping over for the mot every time, and its a very awkward job.

 

c'mon Steve, don't be a lazy a---e! It 's car up the stands, 8 bolts each way, disconnect and reconnect the sensors, car down and only once a year

I will do it for extra ponies anytime and save more good change for other mods. The evo/ scooby/RB crowd are at it so why not

 

Its a swine of a job to do on axle stands to be fair!

[Ian]

 

What sort of trouble can you get in for no-cats then??

coops

MOT fail

 

Depends who you know

 

When I had my car dynoed with the decats in I was about 30 ft/lb down on standard. I had my car dynoed a few months ago with sports cats on & was at the same torque figure. Steve who had a different set of sport cats made similar torque figures to me

 

Dectas are worth it for the noise alone though

[pyn888]

 

What sort of trouble can you get in for no-cats then??

coops

MOT fail

 

Depends who you know

 

When I had my car dynoed with the decats in I was about 30 ft/lb down on standard. I had my car dynoed a few months ago with sports cats on & was at the same torque figure. Steve who had a different set of sport cats made similar torque figures to me

 

Dectas are worth it for the noise alone though

 

 

ah well there goes the theory that the torque loss was down to the decats if you made the same figures with a sports cat

 

i reckon my K2 with a resonated decat still wont be as loud as the K1 without the bungs in...

[GT4 Zed]

I'd spend the extra on a set of high flow cats. Its too much hassle swapping over for the mot every time, and its a very awkward job.

 

c'mon Steve, don't be a lazy a---e! It 's car up the stands, 8 bolts each way, disconnect and reconnect the sensors, car down and only once a year

I will do it for extra ponies anytime and save more good change for other mods. The evo/ scooby/RB crowd are at it so why not

 

Have you ever changed the cats over then Bennet? I doubt it I paid a garage £60 to swap over my standard cats for some HKS hi-flows, and even with all the tools on hand, and up on the ramps above head height, it was a bugger of a job

If your car is purely for the track then its a viable option, but as you use the car day in day out on the roads then it aint worth it.

You'll more than likely have to do a reset every day, due to the engine check light coming on all the time.

The car will be technically illegal to drive on the road, and if you had an accident and the insurance company picked up on it, you'd be fooked

My car ran lovely with the hi-flows connected, it also flew the MOT, no issues whatsoever. I wish i had the car now with the set up it did have, and taken it to RS-Tuning to show you that hi-flows can give just as good gains from a reflash as decats.

In summary, its against the law and too much hassle for similar gains to hi-flows.

 

 

 

I never said it was easy to swap it. just said it can be done by yourself

 

You don't have to reset it everyday if you have a non fouler

 

If mapped wheel decats will make marginally more power but thats spliting atoms. Also your the supporting exhaust mods makes a difference. you should always aim to flow from small into big So if you do decats or HFC the you need to de restrict the y-pipe atleast with an aftermarket tuned one like nismo or copy of nismo(eg Japspeed, ichiba ESR) and also consider a big bore(3") y-pipe back exhaust. I am guessing this might have been the cause of loss of torque in some cases.

 

i aggree its not legal but where is the fun?

 

for me i would not mind the hasle if i save myself circa £400 in the process.( eg Berk HFC vs Japspeed decat = £490 vs £90 and thats the real issue

[Ian]

I'd spend the extra on a set of high flow cats. Its too much hassle swapping over for the mot every time, and its a very awkward job.

 

c'mon Steve, don't be a lazy a---e! It 's car up the stands, 8 bolts each way, disconnect and reconnect the sensors, car down and only once a year

I will do it for extra ponies anytime and save more good change for other mods. The evo/ scooby/RB crowd are at it so why not

 

Have you ever changed the cats over then Bennet? I doubt it I paid a garage £60 to swap over my standard cats for some HKS hi-flows, and even with all the tools on hand, and up on the ramps above head height, it was a bugger of a job

If your car is purely for the track then its a viable option, but as you use the car day in day out on the roads then it aint worth it.

You'll more than likely have to do a reset every day, due to the engine check light coming on all the time.

The car will be technically illegal to drive on the road, and if you had an accident and the insurance company picked up on it, you'd be fooked

My car ran lovely with the hi-flows connected, it also flew the MOT, no issues whatsoever. I wish i had the car now with the set up it did have, and taken it to RS-Tuning to show you that hi-flows can give just as good gains from a reflash as decats.

In summary, its against the law and too much hassle for similar gains to hi-flows.

 

 

 

I never said it was easy to swap it. just said it can be done by yourself

 

You don't have to reset it everyday if you have a non fouler

 

If mapped wheel decats will make marginally more power but thats spliting atoms. Also your the supporting exhaust mods makes a difference. you should always aim to flow from small into big So if you do decats or HFC the you need to de restrict the y-pipe atleast with an aftermarket tuned one like nismo or copy of nismo(eg Japspeed, ichiba ESR) and also consider a big bore(3") y-pipe back exhaust. I am guessing this might have been the cause of loss of torque in some cases.

 

i aggree its not legal but where is the fun?

 

for me i would not mind the hasle if i save myself circa £400 in the process.( eg Berk HFC vs Japspeed decat = £490 vs £90 and thats the real issue

 

Mine was with the Ichiba Y-pipe & 2.75" y-pipe back exhaust

[Stew]

ZMANALEX has some ace non foulers for sale too for anyone throwing a CEL. He has plenty to sell too!

[Dblock]

On other cars there is a big gain, IMO as someone said if you have them fitted and mapped for a decat im pretty sure you will gain. I gained a fair bit in my clio and my mpg went up too!

What engine was in that?

 

Its the 2.0 RS F4R 172ps engine. Its non turbo. All engines are different e.g. some gain and some dont. Most will gain with a remap though. Its like running hot cams. You will probably lose power unless your car is mapped for it.

[sunset350z]

I paid £250 for my HKS cats from a seller on ebay, they were a bargain at the time even though they were second hand. They were mint Cost wise, you've just spent 1000's and you are concerned about the potential £400 extra for Hi-flow cats!!???

Bennet if you reckon you can change the decats yourself, then how come you paid somebody to change your brakes and everything else you've had fitted? Brakes are easy to change.

Its a lot of work for the mot when you have to take the de-cats off, fit the standard ones back on, get it mot'd. Then take them back off and fit the decats again Whats that gonna cost in labour? and if you can have a go yourself, will you have the spare time to do it, and what if something went wrong like snapping a stud or worse???

Ok, you have the noise factor and it may sound awesome, but would you be happy with it resonating loudly through the car at 70-80mph up and down the M5

Its not legal and there's no fun when you get pulled or stuff it in the hedge.

All for the sake of maybe getting a bit more power out of the Zed.

Hi-flow cats are simple fit and forget

 

Anyway can i interest you in a set of hi-flow cats for £200?

[GT4 Zed]

Mine was with the Ichiba Y-pipe & 2.75" y-pipe back exhaust

 

Just like i thought, though not too badly matched

Most decat/HFC are 2.25" in and 2.5" out. and ypipe eg ichiba which is a nismo copy is 2.5" in both y section joinned up to a 3" single section. All the big brands a sell a 3" y-pipe back system from this point on to keep the flow unrestricted.

With you set up the is a slight rerstriction with the 3" flowing into the 2.75" y-pipe back exhaust. change this even temporally and see what it does

The worst scenario would be to change CATs to decats/HFC and leave it the reso OEM with is mostly 2.25 up to 2.5

 

Steve, I i will get HFC in anycase but i was just saying it's also worth looking at decats as a good option both from a performance and cost perspective . This is appealling especially as i know that my overall mods will cost me 1000s so i have to always entertain other options

[sunset350z]

[pyn888]

I paid £250 for my HKS cats from a seller on ebay, they were a bargain at the time even though they were second hand. They were mint Cost wise, you've just spent 1000's and you are concerned about the potential £400 extra for Hi-flow cats!!???

Bennet if you reckon you can change the decats yourself, then how come you paid somebody to change your brakes and everything else you've had fitted? Brakes are easy to change.

Its a lot of work for the mot when you have to take the de-cats off, fit the standard ones back on, get it mot'd. Then take them back off and fit the decats again Whats that gonna cost in labour? and if you can have a go yourself, will you have the spare time to do it, and what if something went wrong like snapping a stud or worse???

Ok, you have the noise factor and it may sound awesome, but would you be happy with it resonating loudly through the car at 70-80mph up and down the M5

Its not legal and there's no fun when you get pulled or stuff it in the hedge.

All for the sake of maybe getting a bit more power out of the Zed.

Hi-flow cats are simple fit and forget

 

Anyway can i interest you in a set of hi-flow cats for £200?

 

i'd bite your hand off for a set if you had them

[GT4 Zed]

quote="sunset350z"]

Anyway can i interest you in a set of hi-flow cats for £200?

 

**SOLD**

When do i pick it up

Friday OK for you