Check Out My Compliance Cat

[LotusGTR]

Pretty funny as it looks so patheticaly restrictive. My question is how much difference would a good hiflow cat improve spool up & throttle response? I'm guessing the ultimatle power figure ain't going to change much but how it drives should be affected by getting rid of the stangled cat.....

Other thing, what is the line / wire that comes off the cat and goes back up to he car and is this required?

Thank you.

[Brandon]

I felt it spool faster after changing the cat but might be me imagining and I didnt drive it long enough too, got it tuned the next day.

[lachlanw]

the wire is a temperature switch that goes to the light on the dash to tell you if the cat is hot . if u cut it the light stays on . cut it real short and earth it to something . problem solved .

i read a book once about doing everything to a mr2 including v6 conversion and twin charging and turbo only and so on and replacing the cat with a straight pipe gave 40 more horse power . . they were already up around the 4-500 hp mark tho

[LotusGTR]

Thanks for the feedback, keep it coming

Another question, are the length of cats always the same? I guess I'm thinking will a replacement just bolt straight in or is there the possibility of having the lengthen or shorten the pipe to the rear?

[Brandon]

Get the correct model cat for the car and it should bolt straight on (with flanges already pre-welded), otherwise, you will need to get someone to weld the flanges on for ya (pretty common).

[(OO)SKYLINE(OO)]

A high flow cat should fix your problem as it will help free up the flow of exhaust fumes.

Like what Brandon said, the correct model of high flow cat will just bolt straight in.

[boostn0199]

xforce or catco metal cats ftw if changing cats might aswel get a metal cat first to save you down the track if you want to push 300 + kw

[payback21]

De-cat

[Blitz]

De-cat

Large EPA fine

[bozodos]

meh how can they tell that its not just shat itself rather than been intentionally hollowed out?

[LotusGTR]

Not that I would, but the guy down the zorst shop said that de-cat would end up robbing the car of low end torque, if all else left standard.

If so then I'd guess the same could be said for a high flow cat.

They should know their zorsts, but I doubt they really know their GTRs......

I wonder where the truth lies? Probably down with my tuner at $110 per hour.....plus big margins on all exhaust parts supplied....

EDIT, a question. If you put a very free flowing exhaust (however so you choose) on a standard engine and computer would it run rich / lean / get confused at all, or is that all accounted for in the cleverness of the ECU?

[Brandon]

I dont know much about mods but from my experience, the gain is definitely there with better flowing exhaust system. But the gain would be significant with a tune + boost. Mine went from 165awkw to 255awkw without any mods other than exhaust, ecu and boost kit. Not forgetting to mention the response i got after the tune, never fail to bring a smile to my face.

[LotusGTR]

I dont know much about mods but from my experience, the gain is definitely there with better flowing exhaust system. But the gain would be significant with a tune + boost. Mine went from 165awkw to 255awkw without any mods other than exhaust, ecu and boost kit. Not forgetting to mention the response i got after the tune, never fail to bring a smile to my face.

NI Spec (in your car description) means steel wheeled turbs? Must be, right? 165 is a very low start point. I'd think you'd start at 190 to 200. Could be wrong. My last stocker dyno'ed at 190 pre-fiddling.

[Brandon]

meh how can they tell that its not just shat itself rather than been intentionally hollowed out?

Someone told me you can tell just by smelling the fume. In any case, you're better off with a gutted cat than a proper decat pipe. At least you still have A BIT of chance when you do get hit by the cops. But I wouldnt recommend running 1.

[Brandon]

NI Spec (in your car description) means steel wheeled turbs? Must be, right? 165 is a very low start point. I'd think you'd start at 190 to 200. Could be wrong. My last stocker dyno'ed at 190 pre-fiddling.

Yea its steel wheeled.

I know spec sheet says 206kw but I'm pretty sure thats engine kw. No idea why it was 165awkw but it was running 0.65bar boost. Maybe the wastegate is dodgy cause the tuner couldnt get it to hold boost after 1.15bar, hence the 255awkw... =(

[sav man]

Have you checked to see if your complence cat has any internals? my car was complied with a gutted cat.

[DRD-00F]

Drive behind a car with no cat for long enough and your eyes will start stinging... It is pretty easy to tell if you know what to look and smell for

[Brandon]

Have you checked to see if your complence cat has any internals? my car was complied with a gutted cat.

Hahaha. Your car is for track! No need for compliancy...

[bozodos]

haha yeah as tailgating motorbikes tend to find when I hit the accelerator (typical Microtech overfueling LOL).

My high flow cat blocked itself solid within 3 months of me buying it, due to the computer, so a 'race' option was the only way out of it. When I get a computer which runs an 02 and is tuned properly I'll probably lash out and get a metalcat (just have to make sure its EPA compliant so that its not just an expensive waste of time)

I have been EPA'd for noise, and the tester mentioned the cat, but it does have one fitted, bit hard to talk your way out of having just a piece of pipe there.

You tend to smell the unburnt fuel a lot with no cat, and the smokescreens are bigger, I have a black car so haven't noticed black stuff on the rear bar lol.

[Tony de Wonderful]

Not that I would, but the guy down the zorst shop said that de-cat would end up robbing the car of low end torque,

Then he is a retard. I thought that myth had been exposed ages ago?

The idea that you need an exhaust 'restriction' goes back to days of carbs, when removing the restriction of the stock 'zaust would lean the mixture.