Jump to content
SAU Community

Recommended Posts

this is in regards to my exhaust set-up...

currently:

- 3" dump/front-in-one (from BATMBL)

- 3" custom-made mandrel-bent cat-back with 3" cannon muffler and 3" resonator

- stock compliance cat: looks like 2.5" but has been 'high-flowed' if you know what i mean...

so my question is this:

is it worthwile spending the $200 on a 3" cat?

I have done some searches and have read many posts where people change to a 3" cat and say they feel no difference in power...

another option is to get my cat 'converted' to a 3" cat by cutting it and welding on 3" flanges and 3" pipe on either end...

is this possible? has anyone done this before or is it just theory?

has anyone chagned their cat with positive results?

with this set-up i made 132rwkw on 12psi with the auto-trans equipped rb20 (with 10-10.5 AFRs!)

Cheers,

Warren

Link to comment
https://www.sau.com.au/forums/topic/74133-25-cat-to-3-cat-worth-it/
Share on other sites

depends on how much boost your going to run, id say with your setup and only being 2litres you might not gain much.  But at the end of the day the bigger freer flowing system wont hurt.

that's what i'm thinking... i don't want to spend $200 to find it makes no difference. that $200 could go into an SAFC or something similar...

anyone else actually done a swap and noticed a difference?

Not that im hijacking the thread or anything, but since where on the subject of zorsts and size...

Is there much improvement for a 3.5" over a 3" turbo back on an rb20 making 200rwkw ??

Is the extra 0.5" really worth it ? if so how come few people have them...

Not that im hijacking the thread or anything, but since where on the subject of zorsts and size...

Is there much improvement for a 3.5" over a 3" turbo back on an rb20 making 200rwkw ??

Is the extra 0.5" really worth it ? if so how come few people have them...

well, yeah you are hijacking the thread. you will get more responses if you start a new thread...

Alternative.........spend $500 and upgrade to a 4" Magic cat, no restriction there:cheers:

there may be no restriction, but my question is will it make any difference in power?

being a studenti'm after bang-for-buck

$500 for a 5kW gain is not worth it in my book... however $500 for a 20kW gain is a different story... but i know in this case that's not what i am looking at

if you have already 'high flowed' your 2.5 inch cat just stick with it. it will flow more than a 3 inch 'regular' cat. though you are breaking the law and for fine prevention it may be worth looking at a 'proper' high flow cat.

if you have already 'high flowed' your 2.5 inch cat just stick with it. it will flow more than a 3 inch 'regular' cat. though you are breaking the law and for fine prevention it may be worth looking at a 'proper' high flow cat.

yeah its just a temporary measure untill i can get my hands on something better...

thanks all for you help :)

might just save up for a 3" cat in the next few months...

how would they tell your cat had been "high flowed" though if it still has the original housing? I mean its not like a cop is going to pull you over and take your cat off and then defect you.

well that's a debatable point... some say they "have a method" but i have not heard of anyone getting fined

i think the $10,000 fine that you can potentially get scares some people away

It would have to be a very long and very flexible broomstick to snake its way through your muffler, resonator and around any bends in the exhaust.....

I have "heard" of people hacking the ends of their 2.5" cat and putting a 3" pipe straight through and then welding 3" flanges on the ends.

It would have to be a very long and very flexible broomstick to snake its way through your muffler, resonator and around any bends in the exhaust.....

I have "heard" of people hacking the ends of their 2.5" cat and putting a 3" pipe straight through and then welding 3" flanges on the ends.

yeah i have heard stories of it too but never actually spoken to anyone sho has done it

i think its just a myth

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Dear folks My family members have 4 different cars : Triton 2015 and Corolla 2011 and Mazda3 2012 and Hyundai Elantra 2014 Looking to buy engine oil funnel spill free What I found are are below  https://www.amazon.com/gp/aw/d/B0BBTTJNKX?ref=ppx_pt2_mob_b_prod_image&th=1 https://www.ebay.com.au/itm/145553221359?srsltid=AfmBOoqYBU6Ptw0LU_bAp_k67U3qkF97HHvePkA7iHZw8vUmiwoIRaRr https://www.amazon.com/gp/product/B09X23TCS5?th=1 Is there a funnel with attachment that fits most cars ? Don't mind to spend for a decent quality  Thx  
    • Stock ECU (or more accurately stock tune) absolutely refuses to go over 10psi and behaves like you have seen. The Nistune is the same if it is the stock tune. If the Nistune chip has been tuned, the resulting tune could be literally anything for any combination of parts. The Nistune just makes the stock ECU Tunable.
    • So stock ECU does not like anything above 10 psi?  That Nistune one is just for "try" if it will be any different, I know it need to be tune for that. I know but YOU may know about these problem but i/we dont. They few little Skylines here let alone people who know anything about tham so that is why iam asking here  
    • So now we have a radiator with no attachments whatsoever. It lifts up with a particularly tight spot between the drivers side air box mount and the lower radiator outlet, but if you've got this far you will sort that too. This is the lower mounts with the rad out so you can see where the rubber bushes go, it is a straight shot upwards Done! Assembly is the reverse of disassembly, with blood less likely to be shed.
    • Right, onto the second last trick. The Air Con condenser is mounted to the front of the radiator and stays in the car when the radiator is removed. There are 2x 10mm headed self tappers holding the top of the condenser to the radiator, remove those The bottom of the condenser is attached to the radiator with clips. You need to lift the condenser out of those clips and clear (up, then forward). f**ked if  could work out how to do that last bit with the front bumper on. I hope you can, and you share the trick.  Bumper removal probably deserves its own thread one day once I've recovered the will to live, but basically you need to remove the wheels, front inner guard liners (clips and 10mm headed bolts), the self tapper between the guard and the bumper at the rearmost point of the bumper (same as an R32 that bit), any remaining clips at the top/front of the grill, an absolute bastard design with a plate that holds the top of the bumper above the headlight each side (only 1 bolt which is tricky to get to, but the plate catches 2 places on the bumper and must be removed....carefully!) and push clips between the bumper and guard under the headlight. If you've done all that you will be faced with wiring for the fog lights on both sides and in ADM Q50 RS at least, 4 nasty tight plugs on the driver's side for the ADAS stuff. So, the clips at the bottom look like this on drivers side (looking from the front) And on the passenger side (also from the front), you can see this one is already out Clearance on both of these are super tight; the condenser needs to move up but the upper rad support mount prevents that, and the radiator can't move down far because it is (rubber) mounted. Once you achieve the impossible and drop the condenser off those mounts so it does not stop the rad moving, you are good to go
×
×
  • Create New...