removing both cats

alanmoose

hi all,how much power would be obtained when both cats are removed,
i know its not legal but i have a mate who runs a mot garage so had a word and opted to remove them
i cannot fully test it out as i blew piston rings lol only yesterday!! engine was well worn anyways,doing 125mph and decided to give in lol
luckily i have a full recon engine(standard)
i had fitted a full stainless steel from manifold back,with oxygen sensors refitted etc
i also have a gas flowed throttle body and have blanked off egr valve
it definately was quicker,just wondered what actual bhp doing this can create
also would a lightened flywheel be advisable?,as engine is out and easy to change?
your help would be much appreciated
thanks

si_c1978

the ecu wont like it i think burt may have gotten close iirc,
stand alone ecu would be best, flywheels an easy job just be thorough :thumbup: re-attaching the clutch pipe will be the biggest pain in the arse!

alanmoose

i drove approx 75 miles with new exhaust on,no eml etc
not sure wether to buy a sports cat,finding it difficult to find 1 suitable at a reasonable cost

Matt

Lighter flywheel will enable the engine to rev more freely.

BURT150

You will get a 420 code eventually.

I managed to cheet it with a 90 degree o2 extention and even after completely de cated after i found out my cat was rattling around im still not getting any codes.

Idealy tho it's best to have a 200 cell sports cat my car feels sh*t without a cat.

alanmoose

i have been looking for a sports cat,people are indicating cheap on ebay yet i cant find any!!

any links anyone, thanks

MikeS

look for 200 cell cat

you want 2.25 " or 2.5"

alanmoose

thing is only last week i had a custom made stainless steel exhaust fitted from http://tiptopperformance.co.uk/haveing no cats at all ,whole system is welded,seems a shame to cut it already lol

i,ll get bore dimensions

are the universal 200 cell cats worth while

si_c1978

you may get away with it, if you try burts technique?

NICKYB

alanmoose said:
thing is only last week i had a custom made stainless steel exhaust fitted from http://tiptopperformance.co.uk/haveing no cats at all ,whole system is welded,seems a shame to cut it already lol

i,ll get bore dimensions

are the universal 200 cell cats worth while

courtenay sport sell the weld in 200 cell sports cat:

http://www.courtenaysport.co.uk/index.p ... oductId=64

which will be as good as a direct fit downpipe one and wouldn't upset too much of your new system, your new system fitted straight to your manifold then?

check the bore of your pipe work tho and then have a look about for a weld in cat with same bore ideally, i know its not something that we all like to spend alot of cash on putting in cats but from all i've read about it unless your willing to spend time trying to cheat the emmisions on your car and run the risk of lossing power or drivablity (as burt says) your best bet is the 200 cell sports cat.

alanmoose

yeah straight to manifold 2 1/2",maybe should have checked all this b4 i just went ahead and had it fitted lol

daft question but will a dbilas manifold make a difference as i have my eyes on one

shortly be ordering the 2.4 inlet manifold too

NICKYB

alanmoose said:
yeah straight to manifold 2 1/2",maybe should have checked all this b4 i just went ahead and had it fitted lol

daft question but will a dbilas manifold make a difference as i have my eyes on one

shortly be ordering the 2.4 inlet manifold too

yeah, the Dblais is a good performance manifold and you should see gains from that.

might sound silly but what restrictions have you got between the manifold and the tailpipe?

reason i ask is the Z22SE relies on back pressure and if you've not got any a new manifold will show less gain than a baffled box in the centre of your system.

as for the 2.4 inlet, i've read stories and i'd only recommend them for highly modded engines, so manifold, cams, head work, etc. this is just me & at the end of it its your engine......

Blue_2_2

The dbilas manifold is great,
i had one fitted for several years
i made the mistake of making modifing it to fit a 68mm throttle body to it.................. and lost 24bhp!

Im back to the standard airbox, inlet manifold and throttle body

It now goes like slippery s#it off a shiny shovel!

My advice, leave the inlet alone, spend the cash on the head, cams, exhasut and remap

NICKYB

Blue_2.2 said:
The dbilas manifold is great,
i had one fitted for several years
i made the mistake of making modifing it to fit a 68mm throttle body to it.................. and lost 24bhp!

Im back to the standard airbox, inlet manifold and throttle body

It now goes like slippery s#it off a shiny shovel!

My advice, leave the inlet alone, spend the cash on the head, cams, exhasut and remap

think he's on about the Dbilas exhausy manifold and getting a 2.4 inlet, and am i right thinking your on about your Dbilas inlet manifold?

Blue_2_2

Oooops!
Yes i was talking about the inlet,
if the inlet is like the exhasut (quality wise) then it would be a great purchase

alanmoose

i might sound daft but i relied on the peformance guy at tip top performance,2 1/4 " stainless steel from manifold,then theres a centre box and then back box,sensors have been refitted into exhaust,,
so basically i take it i can actually lose power???
not sure to change manifold??
damn lol
recon engine is going in next week ,
air box derestricted
vectra c large intake pipe
gas floweed throttle body
also with exhaust/standard manifold how much extra power do you reckon that will achieve?
obviously i,ll have it mapped but once everything is fitted

NICKYB

alanmoose said:
i might sound daft but i relied on the peformance guy at tip top performance,2 1/4 " stainless steel from manifold,then theres a centre box and then back box,sensors have been refitted into exhaust,,
so basically i take it i can actually lose power???
not sure to change manifold??
damn lol
recon engine is going in next week ,
air box derestricted
vectra c large intake pipe
gas floweed throttle body
also with exhaust/standard manifold how much extra power do you reckon that will achieve?
obviously i,ll have it mapped but once everything is fitted

with standard manifold, cat & a decent cat-back system + all mods listed above you'll only see a increase of maybe 5BHP at the very most, them mods are goin to help the car rev up but don't actually give it power just better throttle response.

with a Dbilas manifold (like lightning coupe is selling) & a weld in 200 cell sports cat into your stainless system would maybe give you more & is the best increase for cash that you can buy.

but as you've said and i've said in another thread by a member who has de-catted as well, i don't think the N/A Z22SE engine has enough back pressure with out the cat to give any gains and is more likely to lose the power.

alanmoose

phoned the custom exhaust chap and he isnt prepared to fit a cat or manifold that isnt supplied by him..what a ****

for the short period i was driving the astra b4 engine blew it was definately quicker?

i will go down route of sports 200 cell cat

i got 3 weeks to save as thats when car will be back on road with the rcon engine in,shame really being recon as i dont want to change cams etc yet as obv there new

in your experience will a sports cat lower the noise of exhaust? as i was suprised its a little too loud at moment

also if eml light does come on due to cat removal will that effect power? might learn to live with it staying on if thats the case

so anyone know of exhaust guys willing to fit weld in sports cat? i am in burton upon trent
thanks again

also a full z22se engine going for sale,its running just requires work oil in exhaust and firing on 3 cylinders,would make an ideal project

NICKYB

alanmoose said:
phoned the custom exhaust chap and he isnt prepared to fit a cat or manifold that isnt supplied by him..what a ****

for the short period i was driving the astra b4 engine blew it was definately quicker?

i will go down route of sports 200 cell cat

i got 3 weeks to save as thats when car will be back on road with the rcon engine in,shame really being recon as i dont want to change cams etc yet as obv there new

in your experience will a sports cat lower the noise of exhaust? as i was suprised its a little too loud at moment

also if eml light does come on due to cat removal will that effect power? might learn to live with it staying on if thats the case

so anyone know of exhaust guys willing to fit weld in sports cat? i am in burton upon trent
thanks again

also a full z22se engine going for sale,its running just requires work oil in exhaust and firing on 3 cylinders,would make an ideal project

i would of thought that any exhaust place who could do custom stuff can weld one in, have a look were the nearest powerflow stockists is as they stouldn't have any problem doing it for you.
as for the manifold will be a straight forward swap which would be really easy if your engines out.

the cat will keep the noise down, the same as a backbox keeps the noise down.

you can drive with the EML on as long as it's not putting the car into limp home mode which will limit the car too 3K revs.

i know your goin to kick yourself but the est exhaust set-up imo is 2.5" cat-back with 200 cell sports cat with downpipe plus a nice manifold

hoffman do the downpipe & cat

http://www.sportcats.co.uk/product_info ... 70a7719d3b

but as you already have the downpipe your cheapest way will be the courtenay one i linked before in this thread.

lightning coupes Dbilas manifold would be ideal as well

viewtopic.php?f=6&t=17350

alanmoose

many thanks!!

i have now bought the dbilas from the forum off lighnting coupe !

priced up a 200 cell cat + fitting £160 so that shall be my next move

all your help greatly appreciated

cheers..