De-cat, Possibly The Same As Supra?

[Ahhhh__Aristo]

While tinkering earlier (adjusted the play in the throttle cable) I thought I'd have a look to see if I could see any of the exhaust system from under the car, so got my fat self down, and from what I could see, the front pipe (from where it's visible to the second cat) looked quite similar to the MKIV Supra one. (this is going from memory)

Has anyone decatted?? or had the car up on ramps??

The rear looked identical to a GS300.

[rallure]

i will get the car up on a ramp on tuesday mate and post up some pics for you

[Ahhhh__Aristo]

Spot on. Thanks.

[Ahhhh__Aristo]

Found this picture of mkiv supra standard cats, the second cat, which is visible from looking underneath looks identical to the one on my car.

Be good news if they're the same as the mkiv supra.

[robjonk]

I decated mine but only the second cat not the pre cat but got the first decat pipe when I got my blitz nur spec single exit system which is made for the mk1. Then when I lowered mine on tien coilovers I had to make a new pipe as it kept grounding out even on little bumps but then I did drop it a silly amount.

Can find out how much to get another decat pipe made if anyone interested. All 3mm s/steel.

[Keith Bowler]

I decated mine but only the second cat not the pre cat but got the first decat pipe when I got my blitz nur spec single exit system which is made for the mk1. Then when I lowered mine on tien coilovers I had to make a new pipe as it kept grounding out even on little bumps but then I did drop it a silly amount.

Can find out how much to get another decat pipe made if anyone interested. All 3mm s/steel.

With a cat removed and only one left how do you guys get on come MOT time with omissions testing.

Just curious as I was considering doing same on my Mk1 GS for some extra BHP.

[Ahhhh__Aristo]

The first is a pre-cat, for when the engine is cold. The second one is the main cat, and should pass OK with just the second cat.

Most garages should swap round your cats for around a tenner if you wanted to put them on for the MOT.

Small price for the extra performance they give.

HTH

[dangerous brain]

second cat is the same the first I think is different

[Leeky]

As far as i know you cannot interchange supra and aristo exhausts/downpipes.

Boths cats are the same and you can pass emissions with just one in (doesnt matter which).

Im having my second cat removed next weekend at Darkside Performance and having a bit of pipe custom made to replace it :)

With only the first cat in i will be able to pass MOT's ok and run much higher boost very nicely :D

[Ahhhh__Aristo]

I'd personally remove the first cat and not the second, if I were to do only one.

Would be much better that way as the turbos would breathe better.

I've convinced myself the front 2 are the same as the Supra's :D

[Leeky]

I dont think it really matters which cat you remove, as the restriction should be the same on both.

Does anyone know what kinda horse power can run through the standard exhaust? i want to improve the flowing but would like to keep the standard exhaust as its smooth and quiet.

[dangerous brain]

All these questions are best aimed over on the mk4 board really. If you get both cats out the car should boost to 1.2 bar easily enough. With an aftermarket exhaust you have to restrict the exhaust to prevent overboost. Then it comes down to supporting mods as to how much power you can push out of stock tubbies.

[Ahhhh__Aristo]

I dont think it really matters which cat you remove, as the restriction should be the same on both.

True, they're identical in restriction terms, but removing the first one will help the turbos spool quicker, and keep temps down a fraction, as your removing the immediate restriction. IMHO.

DB, if we asked everything on the MKIV board, this place would be even quieter (plus I'd have to pay to be a member of a club that I don't have a car for )

My plan is the same as yours by the sounds of it Leeky, keep with the stock rear exhaust and just de-cat.

Think I'm getting old, I used to love loud pipes on me cars, still do like loud pipes, but not on my car lol. (I say that now, although will be a different story when there's some spare cash about)

[dangerous brain]

Yeah I know what you are saying but for quite some time I think we will be waiting for the level of engine expertise to rise sufficiently to know that you'll get an answer to any question you have of a tech nature. I waited 5 months just to find out about the speedo input line and got fed up waiting so went and found out myself using elimination methods lol.

[ColinBarber]

I dont think it really matters which cat you remove, as the restriction should be the same on both.

Does anyone know what kinda horse power can run through the standard exhaust? i want to improve the flowing but would like to keep the standard exhaust as its smooth and quiet.

The first one is more restrictive on the turbos. Removing that gives you a bit more boost without doing anything else as the standard boost controller relies on a set amount of backpressure for calibration.

[Leeky]

Great stuff, thanks for the info Colin :) I'll get the first removed then. :winky:

[Ahhhh__Aristo]

i will get the car up on a ramp on tuesday mate and post up some pics for you

Where's me piccies?? :eerrrmm: :winky: :D

[Leeky]

I found out today that the 2nd cat is identical to the jdm supra. So you can use the whifbits or blitz 2nd decat pipe from the supra.

The first cat is completely different and requires a custom pipe made up :)

[Ahhhh__Aristo]

I found out today that the 2nd cat is identical to the jdm supra. So you can use the whifbits or blitz 2nd decat pipe from the supra.

The first cat is completely different and requires a custom pipe made up :)

Well done that man :winky:

Must admit I'm surprised, I imagine we have a different pipe that comes off the turbos aswell then.

Edited--as I'm dumb :(

[legendswraith]

I found out today that the 2nd cat is identical to the jdm supra. So you can use the whifbits or blitz 2nd decat pipe from the supra.

The first cat is completely different and requires a custom pipe made up :)

Well done that man :winky:

Must admit I'm surprised, I imagine we have a different pipe that comes off the turbos aswell then.

Edited--as I'm dumb :(

anything come of this as i am looking to decat mine at the min will the mk4 supe decat go onto a mk1 gs or just the aristo TT