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Why bump lol?

I took my cat out today to have a look, but it doesn't look melted from what I can see. I am however still doubting how well it flows, as the entrance to the cat was very very dirty and black while the exit was almost as clean as when I put it in there. Not sure if that is normal for a high flow. I also tried shining a torch down one end and looking down the other, and hardly any light makes it through. You can only just see the light coming through to the other side. Normal?

For the lash setup there isn't much of choice, I only found Tomei Type A, B and Supertech. It appears the supertech ones are 15LBs stronger then the Tomei Type B spring kit. I will be using those.

http://cgi.ebay.com.au/Supertech-Valve-Spr...=item3a52093c3b

Hanalado: The cat won't appears as melted like butter. a good performance cat has very big cells. Ie. 120 cells in a 4inch barrel. Also been a .63 rear housing the amount of lag you've got is greater then people using a .82 rear housing. I would suspect leaks on the intake side which including unsecured spark plugs, BOV, head, plus all clamps and hoses.

Hrmmm Im about to change the cams and clean the lifters and go for a retune now Im wondering how worthwhile it would be to change the springs while I got it all out.

Why bump lol?

I took my cat out today to have a look, but it doesn't look melted from what I can see. I am however still doubting how well it flows, as the entrance to the cat was very very dirty and black while the exit was almost as clean as when I put it in there. Not sure if that is normal for a high flow. I also tried shining a torch down one end and looking down the other, and hardly any light makes it through. You can only just see the light coming through to the other side. Normal?

We had a s13 silvia lose 40kw by fittin a cheap highflow cat. Putting the decat pipe straight back in giving it a run without changing anything went from 205 to to 245kw

Hrmmm Im about to change the cams and clean the lifters and go for a retune now Im wondering how worthwhile it would be to change the springs while I got it all out.

Emphatically, YES.

Regardless of whether you're paying for someone else's time, or using your own time, dropping in new valve springs while cams are out is a no-brainer. Just got to be sure the method used will ensure the valves don't drop down into the chamber.

I hate having to go back over my own work to make an improvement I could/should have made the first time around.

Why bump lol?

I took my cat out today to have a look, but it doesn't look melted from what I can see. I am however still doubting how well it flows, as the entrance to the cat was very very dirty and black while the exit was almost as clean as when I put it in there. Not sure if that is normal for a high flow. I also tried shining a torch down one end and looking down the other, and hardly any light makes it through. You can only just see the light coming through to the other side. Normal?

what brand and type of cat?

For the lash setup there isn't much of choice, I only found Tomei Type A, B and Supertech. It appears the supertech ones are 15LBs stronger then the Tomei Type B spring kit. I will be using those.

http://cgi.ebay.com.au/Supertech-Valve-Spr...=item3a52093c3b

Hanalado: The cat won't appears as melted like butter. a good performance cat has very big cells. Ie. 120 cells in a 4inch barrel. Also been a .63 rear housing the amount of lag you've got is greater then people using a .82 rear housing. I would suspect leaks on the intake side which including unsecured spark plugs, BOV, head, plus all clamps and hoses.

thanks stao!! keep us updated!!

what brand and type of cat?

Cheapo brand, Venom or something. Advertised as a 100 cell high flow, 3" inlet/outlet with 5" body. I never really expected it to be that good, but I didn't have the money to pay $400+ for a cat.

I was going to gut the cat, but don't want to change anything until my tuner has his dyno back and can check the tune, make sure it's not leaning out. I'm also not really keen on running a decat, so will probably save for one of the expensive brand name cats.

Cheapo brand, Venom or something. Advertised as a 100 cell high flow, 3" inlet/outlet with 5" body. I never really expected it to be that good, but I didn't have the money to pay $400+ for a cat.

I was going to gut the cat, but don't want to change anything until my tuner has his dyno back and can check the tune, make sure it's not leaning out. I'm also not really keen on running a decat, so will probably save for one of the expensive brand name cats.

i'd consider a new one

just don't buy an xforce one, pretty much the only car guaranteed not to pass emissions tests

something like this will be fine http://www.justjap.com/store/product.php?p...=275&page=1

regarding the x-force one, they say it meets Euro 3 emissions standards or something...I take it that's not enough for Aus?

Also, I wouldn't particularly recommend using that Just Jap one either - since it doesn't specify, I'd assume it's ceramic? That'd be a stupid move to put another ceramic cat back in.

Yup stuff the ceramic. I bit the bullet and bought this metal cat:

http://www.justjap.com/store/product.php?p...cat=&page=1

It has served me well and dynos between cat and no cat were within 5-10kw.

Yeh that's a race cat though, just as illegal as a decat.

What's the deal with ceramic cats? I know they are shit when it comes to modified cars, but why can they not handle the heat? I thought ceramic was meant to be one of the best materials for dealing with heat?

What's the deal with ceramic cats? I know they are shit when it comes to modified cars, but why can they not handle the heat? I thought ceramic was meant to be one of the best materials for dealing with heat?

I think the amount of stock ceramic turbo wheels vs the amount of steel turbo wheels that end up in the cat is good evidence that it is not.

Why this is I do not know, you are correct ceramic is meant to be tougher and withstand higher temperatures, perhaps it degrades faster over time and steel does not? Maybe it is more brittle and cracks easier.

edit: apparently ceramic is cheaper and hence tends to be used in much cheaper manufacturing processes with more flaws which is why they are generally worse, if they were made to the same standard as the expensive steel ones they would perform better, at least that's what the reading I just did told me.

Are all the melted ones we see stock cats? or are we seeing aftermarket ceramic ones melt as well?

Edited by Rolls
Yeh that's a race cat though, just as illegal as a decat.

Incorrect:

http://www.catco.com.au/mainFrameset.htm

CATCO METALcats are ADR approved AND meet EPA requirements

I think the amount of stock ceramic turbo wheels vs the amount of steel turbo wheels that end up in the cat is good evidence that it is not.

Why this is I do not know, you are correct ceramic is meant to be tougher and withstand higher temperatures, perhaps it degrades faster over time and steel does not? Maybe it is more brittle and cracks easier.

Sorry mate, incorrect. There are 2 issues with ceramic turbos.

Number 1 is, the shaft is not ceramic, the wheel only is ceramic which in most cases is fixed to the shaft by an epoxy. When EGT gets too high the epoxy melts and the wheel becomes dislodged. This is why the turbo is generally left with no trace of the wheel beyond the shaft.

Number 2 is the ceramic wheel expands and makes contact with the housing more so than a steel wheel. This sees the wheel shatter in an instant.

Number 2 was shown when the $250 high flow thread was around, porting the rear housing to drop surge proved to also drop EGT which made the turbo last a lot longer (with the standard ceramic rear wheel and at 17psi).

Also you are correct in saying that metal cats melt, not ceramics. Ceramics collapse.

Sorry mate, incorrect. There are 2 issues with ceramic turbos.

Number 1 is, the shaft is not ceramic, the wheel only is ceramic which in most cases is fixed to the shaft by an epoxy. When EGT gets too high the epoxy melts and the wheel becomes dislodged. This is why the turbo is generally left with no trace of the wheel beyond the shaft.

Number 2 is the ceramic wheel expands and makes contact with the housing more so than a steel wheel. This sees the wheel shatter in an instant.

Number 2 was shown when the $250 high flow thread was around, porting the rear housing to drop surge proved to also drop EGT which made the turbo last a lot longer (with the standard ceramic rear wheel and at 17psi).

Also you are correct in saying that metal cats melt, not ceramics. Ceramics collapse.

I should have taken photos of the guts from mine when I bashed it out....well, I might still be able to find them on the ground so I may very well back this up. Mine most certainly was melted. Maybe not from heat as such, could have been acidic melt if any of the unburnt fuel could possibly do this....but it was definitely melted. And as far as I know it was aftermarket as the heat shielding was branded CATCO

Sorry mate, incorrect. There are 2 issues with ceramic turbos.

Number 1 is, the shaft is not ceramic, the wheel only is ceramic which in most cases is fixed to the shaft by an epoxy. When EGT gets too high the epoxy melts and the wheel becomes dislodged. This is why the turbo is generally left with no trace of the wheel beyond the shaft.

Number 2 is the ceramic wheel expands and makes contact with the housing more so than a steel wheel. This sees the wheel shatter in an instant.

Number 2 was shown when the $250 high flow thread was around, porting the rear housing to drop surge proved to also drop EGT which made the turbo last a lot longer (with the standard ceramic rear wheel and at 17psi).

Also you are correct in saying that metal cats melt, not ceramics. Ceramics collapse.

Thanks for the post, I did not know it was the expoxy that failed in the turbos along with expansion, cheers for clearing that up.

Re the cats melting, all I was getting at is they fail, I am still unsure why though as ceramic is meant to be harder, stronger and able to withstand higher temps.

Perhaps it is the expansion in the ceramic cats that causes them to fracture and collapse.

Edited by Rolls
I should have taken photos of the guts from mine when I bashed it out....well, I might still be able to find them on the ground so I may very well back this up. Mine most certainly was melted. Maybe not from heat as such, could have been acidic melt if any of the unburnt fuel could possibly do this....but it was definitely melted. And as far as I know it was aftermarket as the heat shielding was branded CATCO

Obviously it is possible for the thing to melt, yet not common.

Keep in mind the exterior of a space shuttle is also ceramic. If your cat was subject to some atmospheric re-entry temperature, you present quite the challenge!

Obviously it is possible for the thing to melt, yet not common.

Keep in mind the exterior of a space shuttle is also ceramic. If your cat was subject to some atmospheric re-entry temperature, you present quite the challenge!

lol there are different types of ceramics :P

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