de-cat

[Anonymous]

Can anyone tell me where the cat is on the pipe. Just had a new pipe fitted and not sure if the cat has been removed?

[Tem]

Can anyone tell me where the cat is on the pipe. Just had a new pipe fitted and not sure if the cat has been removed?

This is the cat:
 m http://spydermagazine.com/2003/Nov/ppe/image017.jpg m

And this is where it originally is:
 m http://spydermagazine.com/2003/Nov/ppe/image015.jpg m

[Anonymous]

So if i've had a pipe fitted which is apparently a de cat and this part is still on my system then they've not supplied what they said!

[Tem]

So if i've had a pipe fitted which is apparently a de cat and this part is still on my system then they've not supplied what they said!

Most exhausts just include the last pipe with muffler and tips, I guess you bought one of those...?

Of course if you actually bought a decat pipe as well, then you shouldn't have that anymore...

[Anonymous]

I bought the full system which was supposed to be fitted by the supplier. It even says de-cat pipe on the receipt. Looks like i'll be making a phone call ine the morning. Cheers for the info and pics, I did have a feeling they'd not taken the cat off.

[markiii]

before you complai too loudly, what benefit to you anticipate by doing this?

[Anonymous]

According to several sources the cat restricts the flow through the exhaust so replacing it with a straighht through pipe should increase power a bit. i've done this on a couple of previous cars and been happy with the results.

[markiii]

ok, up to you if you beleive me or if this matters.

But I've tried what your thinking on this car.

End result is that top end power goes up, but a huge hole appears in your bottom end torque curve.

not nice. I went back to the cat in teh end.

Far more beneficial would be gutting you precats, assuyming you still have a standard manifold.

[Anonymous]

thanks for the advice, i've paid for the pipe now so i might as well get it fitted but if i end up with the same results as you did i guess i'll just have to fit the cat back on.

what mod would you suggest is the best way without spending stupid money to increase power on this car?

[markiii]

bang for teh buck Unichip at £450 inc fitting, gives on average 15-22bhp

[Tem]

End result is that top end power goes up, but a huge hole appears in your bottom end torque curve.

Are you sure about the bottom end?  s:shock: :shock: s:shock:

Did you dyno it..? Or maybe it just feels so, cause of the upper gains..?

The reason I'm asking is this:
 m http://www.ppeengineering.com/dynoresults.htm m

The header itself makes no difference in low end power, but the decat pipe makes a pretty nice difference. Of course that could be completely different with stock header, but it's also very easy to fool the buttdyno...

[markiii]

but dyno but consider this.


PPE's solution is based upon cumulative benefits with their header, which in turn has completely different flow characteristics, ( possibly pipe diameter) and certainly scavenging characteristics.

I'm basing this upon, but dyno, putting the cat back in made for a faster feeling car in general.

and finally that running decated during some spiriteddriving with Steve J stock 03 SMT he had way more acceleratio. I'm talking full throttle me not opulling away when he was on 3/4 throttle and when me following him was unable to keep up.

Putting the CAT back on restored things to normal. At tghis point I'd by a PPE system, and I'd lose teh cat if I was going Turbo. But not lose the cat on a stock N/A

[SteveJ]

End result is that top end power goes up, but a huge hole appears in your bottom end torque curve.

Are you sure about the bottom end?  s:shock: :shock: s:shock:

Did you dyno it..? Or maybe it just feels so, cause of the upper gains..?

The fact that my SMT kicked his arse off the line even with the traction control / VSC / semi-fly-by-wire throttle taking power away from me.

With the cat back in it's a far more even contest - he has the edge more often than not though which is what I would expect.

[Anonymous]

Does anyone know of a link to a labelled diagram of the exhaust system. The place which made my exhausts seems to think the cat is just a hollow chamber so i could do with something i could print out to take in and show them.

cheers.

[Tem]

Does anyone know of a link to a labelled diagram of the exhaust system. The place which made my exhausts seems to think the cat is just a hollow chamber so i could do with something i could print out to take in and show them.

They must be kidding you!

Any exhaust shop should know perfectly well what it is. You should ask them how many hollow chambers they have seen in exhaust pipes?  s:lol: :lol: s:lol:  


Sorry, can't help you, cause I don't have a scanner  s:? :? s:?  There would be a good pic on BGB..

[GSB]

Part number 8 (for some reason its called "pipe, exhaust", but theres no accounting for Toyota's 'Engrish' translations sometimes) is where your main cat converter resides.

[Anonymous]

Sorry, can't help you, cause I don't have a scanner  There would be a good pic on BGB..

thanks for the help. whats BGB?

[markiii]

Big Green Book

Otherwise known as teh official Toyota workshop manuals

[Anonymous]

Markiii, what does 'gutting you precats' mean? What's involved and how do you go about getting it done? I was talking to Liz today at JAE and she mentioned she'd had this done.

Cheers...  s:) s:)

[Tem]

Markiii, what does 'gutting you precats' mean? What's involved and how do you go about getting it done? I was talking to Liz today at JAE and she mentioned she'd had this done.

There are several posts on the Maintenance area about this  s;) s;)  One to look for is called "Precat removal - How I did it..."  s:roll: :roll: s:roll:

[markiii]

ems right their is loads on here. If anything isn't specifically answered PM me.

Good toi see you yesterday by the way, whiye looks great in teh flesh.

[Anonymous]

Thanks guys...  s:D s:D