Ebay cats...?

[speedyWS6]

Guys....

I have read a thread on this site regarding the exhaust becoming rather raspy after cat removal and it is this one.....

http://www.ls1.com/forums/showthread...7784&highlight

.....After a good read i am wondering if this "cheap" cat route is one i could usefully follow as mine has unquestionably become more raspy to the point it irritates!

There are a few suppliers on ebay after a good look and i wonder if anybody has recommendations as to who to buy from or who to avoid!?

What i WOULD like to know is if these ebay cats

http://cgi.ebay.com/ebaymotors/ws/eB...3004&viewitem=

or indeed any similar ones available, are going to be the same length etc for an easy swap for my, now gutted, SLP cats.

I do look forward to hearing back as i am keen to order up and get them fitted as i see no point in a dyno run/tune to sort out my newly appeared SES light before i fit any!

As always..... Thanks for any thoughts or advice!

Trev.... )

[RyanJM]

The light will still come on with some highflow cats so your better having the rear 02's deleted even if you want cats to change the sound.

[speedyWS6]

Ryan...,

Thanks for the thoughts!

I did a 200 mile journey in the car yeaterday and although it ran fine and i was not concerned about the SES light showing....it sounded almost embarrasingly raspy/drony ! It is at its worst as i accelerate and the revs are going up around 1500 towards 2000. But once levelled out and "off the gas" as it were and just cruising along it is absolutely fine.

I just need to know if there are good and/or bad ebay type cats out there!?

There is a fcompany called race parts direct who sell a product called a Thunderbolt...anybody have any experience of these i wonder?

And going back to the drone/rasp..... i am assuming this is being caused by the cars being gutted as i do have a SLP loudmouth2 and i know you guys do holler a bit when it comes to these!!!!

Thanks guys!!!

Trev... )

[LeadFarmer]

i'm using a pair of the exact cats in the link of your original post for about 3 months now and haven't had any problems. Car did get louder over the stock cats but it wasn't anything obnoxious. I also picked up ~5hp on the dyno over the stock clogged cats and they got rid of the codes the car was throwing for my clogged cats so i love them. I would def. recommend them for the price.

[speedyWS6]

Leadfarmer...,

Great info and i appreciate it!

Please let me know if you mean louder in a general and "nice V8ey" way or do you mean a drone/rasp that i have got now i have gutted SLP cats!?

My drone like i mentioned is as i am on the gas and going up from 1500 ish.

Thanks again...

Trev... )

[KING Z28 HAWK]

Whats your exhaust set up?

[speedyWS6]

Hiya..,

My complete set up ( and before everybody has a quip...the car came with all of it, 'cos i have read about views on SLP stuff) is.... SLP longtubes into an SLP Y heading on back to a loudmouth 2.

Now.... short of changing everything, which cannot/won't happen, i can hopefully get rid of the drone by re-installing new cats into the system!

I also am led to believe that the Loudmouth 2 is a quieter unit than the 1....correct??

Thanks a bunch for any help...

Trev... )

[LeadFarmer]

1)the sound over your gutted cats will def. be an improvement. Since you have LT's there will still be some rasp but much less than b4 and the tone will get deeper and will eliminate drone. Just to give you and idea I'm running stock manifolds with the above mentioned cats, 3in Y, 3in borla catback dumped after the axle with no muffler and I don't drone bad at all. You have a muffler and pipes running out the back, so with cats you shouldn't have a problem.
2) lm2 is quieter than lm1 and would be recommended over an lm1 when using LT's. Your other option over reinstalling new cats(which could be expensive depending on the shop) would be to get a tamer muffler instead(like magnaflow), which would give you IMHO the best ls1 sound apart from a x pipe. It would also be much cheaper to install.

[speedyWS6]

Thanks Lead Farmer!!!!!

Super helpful info...and as far as the fitting goes..... i have a bud who has a garage business, so it will be a nice cheap affair to do the fitting over a few cups of coffee!!

You said "getting deeper and eliminating drone"... all what i want to hear!

One more point.... If this cat fitment takes place will it go back to a "recognised good state" for the computer and turn out the SES light i wonder...or is life not that simple!! lol

Thanks a lot

Trev... )

[JayTA98]

I have a question about changing the stock cats for these ones. Is this really worth it if you have the stock manifolds? I know there is 2 more cats close to these manifolds right? Do these get clog also? Thanks.

[LeadFarmer]

speedyWS6) As long as you reinstall the cats in the same location they were originally(before the 2 rear O2 sensors) then yes, if I'm not mistaken the light should eventually go away on its own. O and just for some sound help with the cats here's a clip of my car with these cats before I dumped the exhaust. [ame]http://www.youtube.com/watch?v=g2dQlCpvOJ0[/ame]

JayTA98) There are only 2 cats on ls1 maro's and T/A's, which are located right after the manifold. To answer your question no it isn't worth it unless your cats are clogged or you're getting LT's. You won't see any power gains unless you've got a decent amount of internal mods or they're clogged(in my case I picked up 5hp over my clogged ones). From experience though these cars do generally have problems with cats getting clogged, so it isn't an uncommon issue.

[JayTA98]

Thanks for the info. How do I know when they need replacement? My car is almost 100k. thanks.

[LeadFarmer]

a couple different ways 1) you may get a SES light. 2) if u have aftermarket exhaust but your car has become very quite at idle. 3) you can smell more gas than usual. 4) on spirited starts the cats may make a rattling/grinding sound. 5) you may feel a slight loss of sensitivity from the gas pedal.
and around 100k is when they typically become prone to having problems

[RyanJM]

I have the slp Power Flo exhaust which is a LM2 with 2 powerflo mufflers at the back and the car has no rasp. It's only loud at WOT and tame at cruising. They sell the powerflo kit as a add on for the LM2 setup.

[JayTA98]

a couple different ways 1) you may get a SES light. 2) if u have aftermarket exhaust but your car has become very quite at idle. 3) you can smell more gas than usual. 4) on spirited starts the cats may make a rattling/grinding sound. 5) you may feel a slight loss of sensitivity from the gas pedal.
and around 100k is when they typically become prone to having problems

So it won't be a bad idea to change them then?

[speedyWS6]

Ryan....,

An interesting bit of information!

To be clear then.... these bolt on as "exhaust tail pipes" and the intention
is to quieten down their Loudmouth1/2

I have just gone to their site and it seems you bolt on these and then finish
up with your existing tail pipe tips and all of this with no cutting of existing components!??

Thanks for the info and although i will still go ahead and order a pair of high flo cats from the link in my first post i will look further into these as i do like low and mellow as opposed to "look out here i come"!!!!

Thanks

Trev... )

[Sommer86@6LE]

Ryan...,

Thanks for the thoughts!

I did a 200 mile journey in the car yeaterday and although it ran fine and i was not concerned about the SES light showing....it sounded almost embarrasingly raspy/drony ! It is at its worst as i accelerate and the revs are going up around 1500 towards 2000. But once levelled out and "off the gas" as it were and just cruising along it is absolutely fine.

I just need to know if there are good and/or bad ebay type cats out there!?

There is a fcompany called race parts direct who sell a product called a Thunderbolt...anybody have any experience of these i wonder?

Edit: My exhaust set-up is: Kooks SS headers to a custom Y with a flowmaster merge collector, and out through a dynomouth (SLP loudmouth piping witha dynomax bullet). Finally through a CME.

And going back to the drone/rasp..... i am assuming this is being caused by the cars being gutted as i do have a SLP loudmouth2 and i know you guys do holler a bit when it comes to these!!!!

Thanks guys!!!

Trev... )

Trev,

Those are also the EXACT cats I'm running. I'm with Lead farmer, GET THEM!!. I love the way my car sounds now. No rasp and very aggressive. I've got full bolt-ons.

-Mike

Edit - My exhaust set-up is: 1-3/4" Kooks SS LT's to a custom 3" Y with a Flowmaster merge collector (and Thunderbolt 3" cats), through a Dynomouth exhaust (SLP piping with a Dynomax bullet) then finally exiting through a CME.

[speedyWS6]

Thanks Mike...,

To hear you exactly the same cats and are happy is good news!

I guess i am going to be buying a pair of those guys, eh!?

Trev )

[speedyWS6]

Guys...,

I have just gotten off of the phone after speaking to a pretty helpful tech guy at Race Parts Direct and i quizzed him on the fitment of these cats to my SLP system.

I had my TA in the air today and accurately measured the in/out of the SLP cats. Correct me if i am wrong, but the 4 into 1 end from the LT's appears to measure 3" O/D to go into the motor end of the SLP cat which physically must be 3" I/D ?? correct?

Now... the rear end of the SLP cat measures 3" O/D which says it must go into 3" I/D Y pipe tubing??? correct?

Stay with me now....... Jeff at RPD said his cats are 3" O/D both ends and if necessary i will have to swage the LT end to 3" I/D at a muffler shop?

Basically ..is this scenario sounding correct from you guys experience or not? He was surprised to hear that my SLP cat differed from end to end.

He assured me that swaging it out this small amount is easy and without problems??!!

Wow... help me out here guys with good info as i have to ship them over and i want to order correctly!!



Trev... )

[LeadFarmer]

if u get an exhaust shop to weld them in for u the sizes don't have to be an exact fit, they can make it work with the tools they have. I have my 3in cats hooked up to the stock manifold piping which if i'm not mistaken is around 2in, and the muffler shop didn't have any problems putting them in, so u shouldn't have a problem.
But if your gonna do it yourself....then yes the size has gotta match in order to insure a tight fit.