Anyone replaced their OEM Cat to High flow Cat? - LotusTalk

monkeyboo · 08-27-2009, 08:32 PM

Was wondering if anyone replaced their OEM Cat to high flow cat only in conjunction with OEM header and exhaust?

Will I likely to see more gains replacing the cat only then an exhaust?
I do like the looks of the Oem exhaust.

Any problems with emissions?

thank you

fpitas · 08-28-2009, 05:02 AM

You might gain a few hp, but you might also start getting a P0420 CEL, I know I did from the ForcedFed sport cat. Some solutions exist:

CEL Eliminator works

monkeyboo · 08-28-2009, 06:37 AM

Quote:

Originally Posted by fpitas

You might gain a few hp, but you might also start getting a P0420 CEL, I know I did from the ForcedFed sport cat. Some solutions exist:

CEL Eliminator works

How much of a difference in terms of HP and noise? As well did you have trouble doing emissions after the sport cat?
Thank you

waydui · 08-28-2009, 07:17 AM

Quote:

Originally Posted by monkeyboo

How much of a difference in terms of HP and noise? As well did you have trouble doing emissions after the sport cat?
Thank you

I replaced the stock cat with a straight pipe.

Noise increase was significant, but I like it. Butt dyno says it is good for some extra hp, but how much is just a guess.

I used a Weapon R eliminator angle fitting (see pic) to trick the O2 sensor. No CELs or engine issues.

Emissions isn't an issue for me as my car is registered as a "Collector" vehicle in Ohio and as such is exempt from emissions testing.

Regards,
Wayne

Vishus_1 · 08-28-2009, 07:48 AM

Monkeyboo

The problem with any exhaust/cat modification is the ECU. On all Elises and Exiges the adaptive ECU detects cerain alterations and adjusts to compensate for it.

Even if there was some HP to be gained from the high flow cat, the ECU will adjust A/F ratios, timing to basically prevent that.

To ever make the sport cat or an exhaust improve performance, you will need a custom ECU tune. Someone like CharlieX can do that but it will be as much, if not more, expensive than the whole exhaust itself.

If you search this forum, you will learn other pro's and con's to header, cat and exhaust changes. There are lingering fuel fumes, codes tripped and emissions issues (in some states) that you might want to be aware of.

Noel · 08-28-2009, 08:11 AM

I run a Komo-Tec high flow cat and use the same CEL eliminator as Wayne.

No problems whatsoever.

FIL · 08-28-2009, 09:23 AM

I run a Larini Decat and a CEL Eliminator from PEP boys ($3). No CEL lights or emission problems. Biggest difference is deeper sound, fumes, and improved throttle response.

rstutts · 08-28-2009, 11:30 AM

Have you thought about getting your header ported? According to a thread on 'Intakes and Exhausts' you will gain hp and not have to get a reflash on your ECU. I am just repeating what was said on that thread, as I have not had it done (although I have considered it).
Rick

monkeyboo · 08-29-2009, 07:17 AM

Thank you guys for all the wonderful reply! I will have to rethink about this one.

Also difference between De-Cat and Sport cat, would this be Night and day interms of performance???

trav34 · 08-29-2009, 06:31 PM

I've got the Larini sport cat with the stock exhaust. Sound remains close to stock and no CELs. Car seems to have slightly more torque. I daily drive my car and can run in high gear at times when I would have downshifted before.

Seb · 08-29-2009, 06:44 PM

High flow cats are bull****, and a waste of money.

trav34 · 08-29-2009, 06:58 PM

Quote:

Originally Posted by Seb

High flow cats are bull****, and a waste of money.

You seem to feel strongly about it. Care to share some more detail?

Seb · 08-29-2009, 07:17 PM

Sure. They are dyno proven to do nothing.

The only thing they do well is break apart. They have a much shorter shelf life than typical OEM supplied catalytic converters.

trav34 · 08-30-2009, 05:56 AM

Got a link so the rest of us could review the dyno data?

Seb · 08-30-2009, 09:37 AM

It was so long ago in the DSM community, I doubt I could find it. It was on a site called MitsubishiUnited.

It's a pretty universal opinion though, so I'll just google it.

I just googled it, and couldn't find what I was looking for, so I'll just explain it myself.

The reason it's a 'high flow' catalytic converter is because it simply has less material than the OEM one, thus increasing the flow. So what? Well that means that the cat won't last as long. If you have ever removed a cat from a high mileage car, they weigh a freakin' tonne and a half. So think about it, by reducing the restriction ever so slightly, what are you really gaining? I can tell you with certainty that it's in the tenths of a horsepower.

Ol'Racer · 08-30-2009, 02:05 PM

Might want to check this out ... 2Bular - Performance Exhausts

"Sports Cat" ... always an exception.

mx1 · 08-30-2009, 02:24 PM

So, after reading the Tubular page on this, I guess the guys who said the ECU won't relearn and that sport cat does not do any good were wrong???

I almost thought no after reading their posts, now I'm back to considering.

Thanks.

Vishus_1 · 08-30-2009, 03:05 PM

2bular is a quality product - absolutely, however reread what Jim (at 2bular) states on the site link above...

Quote:

The Lotus/Toyota ECU will adjust, eventually.

What he means is any actual gain from the sport cat will be taken away by the learning of the ECU. This is just how it works. He then goes on to talk about some of the reflashes available. This is the only way you will get a gain from a sport cat.

The Gotham + 2bular tune is what - about $1400 (goth.am webstore!) - so add that cost on top of the cat and exhaust. Then, according to Charlie, you should be good for about 240-250RWHP.

Seb · 08-30-2009, 03:18 PM

Yes, that is a true exception.

Noel · 08-31-2009, 08:11 AM

I beg to differ that high flow cats don't work. If you can get away with running a test pipe, good for you.

But a high flow cat with (IE - 100 cell count vs. an OEM 500 cell count) will produce a very different exhaust output flow.

Also, the difference between having a cat and no cat in practicality is only 1-3 bhp increase. Anyone can argue, that itself is pointless.

08-27-2009, 08:32 PM	#1 (permalink)
monkeyboo Registered User Join Date: Jun 2008 Location: Toronto Posts: 21	Anyone replaced their OEM Cat to High flow Cat? Was wondering if anyone replaced their OEM Cat to high flow cat only in conjunction with OEM header and exhaust? Will I likely to see more gains replacing the cat only then an exhaust? I do like the looks of the Oem exhaust. Any problems with emissions? thank you

08-28-2009, 05:02 AM	#2 (permalink)
fpitas User, Registered Join Date: Sep 2005 Location: Leesburg, VA Posts: 1,832	You might gain a few hp, but you might also start getting a P0420 CEL, I know I did from the ForcedFed sport cat. Some solutions exist: CEL Eliminator works __________________ Francis 2006 Chrome Orange Elise: LSD/TC, Nitron SAs with 425/650 springs, BWR 7/8" Front Bar, Eliseparts bumpsteer kit, VF Stage 2, 2bular Header + Sport Cat + 8x24 GT3 Muffler, ECU Tune by Jermaine, Smaay's fuel rail, ACT XT clutch, Saikou Michi dual catch can, Moroso pan, Manly's mount inserts & FF Engine Damper 2000 Black Integra Type R: - 213,000 miles...running again!

08-28-2009, 07:48 AM	#5 (permalink)
Vishus_1 Super charged! Join Date: Dec 2006 Location: Missouri Posts: 1,038 Images: 62	Monkeyboo The problem with any exhaust/cat modification is the ECU. On all Elises and Exiges the adaptive ECU detects cerain alterations and adjusts to compensate for it. Even if there was some HP to be gained from the high flow cat, the ECU will adjust A/F ratios, timing to basically prevent that. To ever make the sport cat or an exhaust improve performance, you will need a custom ECU tune. Someone like CharlieX can do that but it will be as much, if not more, expensive than the whole exhaust itself. If you search this forum, you will learn other pro's and con's to header, cat and exhaust changes. There are lingering fuel fumes, codes tripped and emissions issues (in some states) that you might want to be aware of. __________________ 2009 Exige 260 SPORT - Chrome Orange / Carbon Fiber / Black with the mustache Purchased through St Louis Motorsports

08-28-2009, 09:23 AM	#7 (permalink)
FIL Serial Thrilla Join Date: Jun 2006 Posts: 236	I run a Larini Decat and a CEL Eliminator from PEP boys ($3). No CEL lights or emission problems. Biggest difference is deeper sound, fumes, and improved throttle response. __________________ 05' Elise - BWR supercharger, Quaife LSD, Nitron Race Triple Adjustable, LETSLA, Larini Decat, Larini Exhuast, ACT HDSS, Fidanza flywheel, V2 Fuel Tank, V2 Steering Arms, BWR sway bar, desnorkled, ForcedFed CF splitter, Manly's engine mounts, S111 harness bar, Schroth harness w/ S111 seat grommets, Oil Drain Valve, Painted Black Diffuser, Braille battery, Custom Battery Switch 05' Corvette - Z51 Convertible - 630hp 6.6L [DON'T YOU JUDGE ME!!!] (SOLD!)

08-28-2009, 11:30 AM	#8 (permalink)
rstutts Registered User Join Date: Aug 2008 Location: Martin, TN Posts: 243	Have you thought about getting your header ported? According to a thread on 'Intakes and Exhausts' you will gain hp and not have to get a reflash on your ECU. I am just repeating what was said on that thread, as I have not had it done (although I have considered it). Rick __________________ 2005 Solar Yellow Elise touring package, star shield, hard top, soft top, ACT HDSS clutch, Saikou Michi catch cans, LED tail lights and VF II, 288 whp () 2001 Green Toyota Tacoma, 4 x 4 2008 Red 5455 Massey Ferguson, 6 x 6, cab, ipod, GPS navigation, regular beer holder 2001 Yellow Cat D3G-LGP, custom made beer holder

08-28-2009, 08:11 AM	#6 (permalink)
Noel Exige Cup 255 Join Date: Apr 2007 Location: 33.87°S 151.21°E Car: ロータス MKII エキシージ Type: Komo-Tec S300 Posts: 329	I run a Komo-Tec high flow cat and use the same CEL eliminator as Wayne. No problems whatsoever.

08-29-2009, 07:17 AM	#9 (permalink)
monkeyboo Registered User Join Date: Jun 2008 Location: Toronto Posts: 21	Thank you guys for all the wonderful reply! I will have to rethink about this one. Also difference between De-Cat and Sport cat, would this be Night and day interms of performance??? Last edited by monkeyboo : 08-29-2009 at 12:52 PM.

08-29-2009, 06:31 PM	#10 (permalink)
trav34 Registered User Join Date: Oct 2007 Posts: 122	I've got the Larini sport cat with the stock exhaust. Sound remains close to stock and no CELs. Car seems to have slightly more torque. I daily drive my car and can run in high gear at times when I would have downshifted before.

08-29-2009, 06:44 PM	#11 (permalink)
Seb <3 QR25DE Join Date: Mar 2007 Location: Austin, TX Posts: 753	High flow cats are bull****, and a waste of money.

08-29-2009, 07:17 PM	#13 (permalink)
Seb <3 QR25DE Join Date: Mar 2007 Location: Austin, TX Posts: 753	Sure. They are dyno proven to do nothing. The only thing they do well is break apart. They have a much shorter shelf life than typical OEM supplied catalytic converters.

08-30-2009, 05:56 AM	#14 (permalink)
trav34 Registered User Join Date: Oct 2007 Posts: 122	Got a link so the rest of us could review the dyno data?

08-30-2009, 09:37 AM	#15 (permalink)
Seb <3 QR25DE Join Date: Mar 2007 Location: Austin, TX Posts: 753	It was so long ago in the DSM community, I doubt I could find it. It was on a site called MitsubishiUnited. It's a pretty universal opinion though, so I'll just google it. I just googled it, and couldn't find what I was looking for, so I'll just explain it myself. The reason it's a 'high flow' catalytic converter is because it simply has less material than the OEM one, thus increasing the flow. So what? Well that means that the cat won't last as long. If you have ever removed a cat from a high mileage car, they weigh a freakin' tonne and a half. So think about it, by reducing the restriction ever so slightly, what are you really gaining? I can tell you with certainty that it's in the tenths of a horsepower.

08-30-2009, 02:05 PM	#16 (permalink)
Ol'Racer Registered User Join Date: Jan 2007 Posts: 414	Might want to check this out ... 2Bular - Performance Exhausts "Sports Cat" ... always an exception.

08-30-2009, 02:24 PM	#17 (permalink)
mx1 Registered User Join Date: May 2007 Location: Fort Walton Beach FL Posts: 74	Wrong info? So, after reading the Tubular page on this, I guess the guys who said the ECU won't relearn and that sport cat does not do any good were wrong??? I almost thought no after reading their posts, now I'm back to considering. Thanks. __________________ Previous--66 Austin Healey 3000; 79 Alfa Spyder; 72 BMW 2002; 85 944; 86 MR2; 89 944S2; 89 944S2 w M030; Current--01 Audi S4, modded twin turbo;07 Lotus Exige S Lucky enough to have driven the autobahn for 5 years

08-30-2009, 03:18 PM	#19 (permalink)
Seb <3 QR25DE Join Date: Mar 2007 Location: Austin, TX Posts: 753	Yes, that is a true exception.

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08-31-2009, 08:11 AM	#20 (permalink)
Noel Exige Cup 255 Join Date: Apr 2007 Location: 33.87°S 151.21°E Car: ロータス MKII エキシージ Type: Komo-Tec S300 Posts: 329	I beg to differ that high flow cats don't work. If you can get away with running a test pipe, good for you. But a high flow cat with (IE - 100 cell count vs. an OEM 500 cell count) will produce a very different exhaust output flow. Also, the difference between having a cat and no cat in practicality is only 1-3 bhp increase. Anyone can argue, that itself is pointless.