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th4neuk

Bugger - Cats may have gone

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I've noticed a bit of a noise (rattle) for a while and thought it was a heat shield.

Anyway driving home yesterday the exhaust note is different and if you try and boost it stumbles a bit (I'm assuming the cat is blocking the exit of the gasses.

So a trip to daves site to have a look at those sports cats may be in order.

For anyone that hs them do they make a difference both to sound and performance. Can't be bothered with the annual switch from bypass pipes to cats etc for the MOT.

Cheers


Alan Croft

2000 V8 GT

87 Turbo Esprit HC

2000 Elise Sport 160

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Upgrade today to remove Google ads and support TLF.

I've got them fitted to my 350.

Not really a noticable noise difference but on a rolling road recently it clocked a whopping 410bhp.....which was nice.

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Wow - 50-60bhp from Sport CATs along......

..... form an orderely queue please :lol:


1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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Daniel,

Have you got any bhp figures for your car whilst in a stock configuration (i.e. before the cats were changed)? 410bhp with standard boost is a great result.

Regards,

Peter.

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Have you got any bhp figures for your car whilst in a stock configuration (i.e. before the cats were changed)? 410bhp with standard boost is a great result.

... that


1996 Esprit V8, 1998 Esprit V8 GT, 1999 Esprit S350 #002 (Esprit GT1 replica project), 1996 Esprit V8 GT1 (chassis 114-001), 1992 Lotus Omega (927E), 1999 Esprit V8SE, 1999 Esprit S350 #032, 1995 Esprit S4s, 1999 Esprit V8 GT (ex-5th Gear project), 1999 Esprit V8SE ('02 rear)

1999 S350 #002 Esprit GT1 replica

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"Horsepower" who needs that :lol:

? does it mean my 2x2 setup with 90mm/120mm 200cell catalysts lifts me up in the stock range now ?!

....as my car was in the past (in 2003 ->on petrol !) only in the range off 324 crank HP ..hehe


*********************************************************************

to name the things if I see them, that's what I call integrity..

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I've actually heard of 3 different high-flow cats & bypass pipes...

The cat bypass pipe gets my vote, but it may be too loud for many people.

Other than that...I personally like the Larini systems 200 cell cats with the center exit exhaust the best. A little higher pitch tone than what usually the Esprit sounds like. Not too loud, but very very sweet tone.

I believe pukesprit.de has them.

Alan

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I already have the lotus sport centre exit exhaust so just need the cats. I would do the bypass pipes but I can't be bothered changing at MOT time.

Should be interesting for BHP figures with the exhaust, cats, filters, actuators and slight boost increase. Once the chargecoolers are in and possibly the red race ecu (how much diferent is this to the S350 chip) should be "adequate"

Cheers


Alan Croft

2000 V8 GT

87 Turbo Esprit HC

2000 Elise Sport 160

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It's a few years ago now but Superdave organized a rolling road day, ask him about the Bhp results....

3 V8's, all de-catted but pretty much standard otherwise and they all made over 400 Bhp (2 where closer to 420 Bhp!). I remember one car had previously been on the very same rolling road a few days earlier in completely standard trim and it made 350bhp...

I have some video footage of the cars and the results somewhere if you're struggling to sleep at night.....!

On the day there where various other Lotus's present using the rollers, one "know it all" was rubbishing all the V8 figures and rabbiting on about accuracy etc.... Strangely ran out of conversation when pretty much everything there made the power/ torque expected!

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There were two rolling road sessions that day and I was at the other and another V8.

Now Martyn's V8 was completely standard and clocked almost exacty 350bhp so was a good 'control' result for the readings from the rolling road. Mine had the S350 ECM code (though that doesn't affect the maximum power - see below), no cats, straight through exhaust pipes and I even took out the air filters and got 387bhp. I would put the difference down to 25 for the no cats, 10 for the straight exhaust and 3 for no filters.

The results from a rolling road vary wildy. Even if you use the same RR there are loads of parameters which you enter to calculate the result. The only way to get a consistent result is to use the same model car on the same RR with the same parameters at the same time (otherwise the ambient temperature and atmospheric conditions will affect it). And you still only get a comparitive result (i.e. 30bhp more power than before) rather than an absolute one (380bhp now, 350bhp before).

If you're after more power through the rev range (as opposed to maximum power, which stays the same) the absolute first thing to do is to get the S350 ECM code. Otherwise the maximum boost is limited:

With the S350 code you get the same boost in 2, 3 and 4 as you do it 5. So you can see that at 4k rpm in 2nd, the stock ECM only allows 4psi whereas the S350 allows 10psi, which is a big difference. The stock ECM gradually catches up but only matches the S350 at the redline. It's especially significant in normal driving since those are the gears and rev range you use for hard acceleration.

Edited by neal

May: DON'T hit it with a hammer!

Clarkson: Why?

May: Cause it's the tool of a pikey.

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Good news then that the factory fitted the 350 ecu when it had an engine under warranty!!

Anyway I have had the car in the air and tapped the cats. The right hand one rattled a bit so I have taken it of for a look. The bit of cat nearest the turbo has gone and was rattling around in the can. I took the lambda sensor ou and smashed the bits so they would fall out. The other part of the cat seems ok but I need new bolts for the turbo end so will get those tomorrow.

Hopefully though the sports cats are on order.

This was a mod I was going to do later but needs must.

At the end of the day with the chargecoolers and the other mods I'll be pleased to see 450ish which should be reliable.

Just need to decide if I need the red race chip to maximise this??

Cheers


Alan Croft

2000 V8 GT

87 Turbo Esprit HC

2000 Elise Sport 160

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Well the highest power car at this end was an S350! - No surprise there hey?!!

None of them belonged to me - was just there to get an idea of what was worth messing about with on my own as it was built....

The free flowing aftermarket cats offer an improvement over the originals but opt for the very free flowing ones and you may start to suffer problems passing an MOT!

I know there are many parameters that affect rr results, it's ultimately irrelevant anyway... I can only guess at what my racer has power wise but when it's spinning the wheels in 4th gear i'm not wishing there was oodles more! B)

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Flames rather nicely as well!!!!!!


Alan Croft

2000 V8 GT

87 Turbo Esprit HC

2000 Elise Sport 160

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Well the highest power car at this end was an S350! - No surprise there hey?!!

The S350 code doesn't actually produce more maximum bhp than the stock ECM. But it does produce more bhp throughout the rev range in gears 2, 3 and 4 which makes a significant difference in everyday driving.


May: DON'T hit it with a hammer!

Clarkson: Why?

May: Cause it's the tool of a pikey.

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Sorry for the delay, I've been away:

20040303image0006ub5.jpg

dyno1eb3.jpg

dyno2xd0.jpg

Custom exhaust and sport Cats.....no idea what it's making with the bypass pipes.....probably no more I imagine.

Edited by Daniel
Images removed - they were hoooooge!

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Nice,

Looks good

Do you get any flame with the sports cats then??

Cheers


Alan Croft

2000 V8 GT

87 Turbo Esprit HC

2000 Elise Sport 160

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Well after taking the cat off that was rattling and breaking up the ceramic and emptying it out I got to test the car today.

Has anyone realised the V8 is a bit quick!!!!

Can't wait to get the proper sports cats on to get true benefit but the car seems much more 'free' to drive if you know what I mean.

Nice one!!


Alan Croft

2000 V8 GT

87 Turbo Esprit HC

2000 Elise Sport 160

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