Exhausts for Morons

[New Barbie]

The standard Sl before the RXXX (don't know what they have - comp probably) had collectors on the inside and cat/can combo.

 

My system was an option.

 

[F355GTS]

Peter

 

I think the SLR cat replacement pipe does provide the 4-2-1 element as per the attached picture on my 7 (coutesy of Steve Carter)

 

Click here

 

Mark

 

Edited by - F355GTS on 8 Oct 2002 15:44:07

[Anthony Micallef]

Al, this is a very interesting thread as I have the same exhaust as you on my SS. I would like to change also if I can afford it and its not too expensive.

 

The Happy 7 Owner 😬 😬 😬

 

[ewenm]

I've managed to lose track of this thread already ❗

 

As far as I can see Dave_H's bulk buy deal on exhausts is providing a 4-2-1 long primary exhaust, *fitted* for £450 (if he gets 2 more people). This comes with a short silencer and no cat converter.

 

Is this a suitable upgrade for a standard (not SS) factory built 1.6K 🤔 or will I get into trouble with emissions at MOT time 🤔 Also, I assume from some of the comments that £450 is a good price - I have no idea about this sort of thing

 

Ta for the help, E.

 

Ewen Malloch

P979TMV - Yellow 1.6 K Series

[Al Crickmore]

Anthony. I get the impression that upgrade and expensive go hand in hand unfortunately. ☹️

 

Yellow/Carbon '02 Caterham Superlight No.186

[caterhamnut]

Ok - for you who wanted it in laymans terms, here is my take - as a layman!

We have a 1.6k SS, like some of you. We had the standard 4-1 system, where all the pipes met inside the engine bay, and a cat was part of one silencer. We were lucky enough to be able to *borrow* 😬 a 4-1 system from PC, which has the longer primary pipes (the ones actually attached to the individual exhaust ports on the engine)

 

I fitted this with Peter's guidance. Apart from the access to some of the manifold bolts, it was pretty straightforward. Bit daunting cutting a big hole in the ali skin, but it's pretty easy, and not hard to get a good result with the tools Peter has mentioned. We are also using one of Peters old silencers - looks exactly like our old one but without the cat inside - we may need to swap back to the old silencer/cat for MOT, but that is a 5 minute, no big deal job.

 

Peter explained why this set up is better - a lot to do with harmonics, and I understood it all, but will not go into it now! (Maybe he will)

 

So - the big question - did we notice a difference? In a word - yes.

In more words - it made a huge difference - do it now!!

 

I had assumed that it would make such a small difference, we would not really notice, or perhaps only notice on a track, or a full rev. blast etc etc. But as soon as I ambled away from Peters place I could feel the difference. I have no way of saying what the final BHP figure is or was - anyway, that is irrlevant to me in this case. It was obvious that the torque had been improved at lower revs though. Just cruising along in traffic in 3rd, it was instantly noticeable that the power had spread lower down the range (in addition to the higher stuff, which was still there!) The car just seems to pick up better from lower down - which is the easiest way to describe it in laymans terms.

 

Incidently, when you look at the old primary pipes out of the car, you can see how restrictive to flow they must be, four pipes welded into one pipe of the same diameter, with corners and ridges.

 

Another side affect was the noise. The engine note was immediately noticeable as being less 'farty', particularly at higher revs. It's more meaty now. The exhaust pipe/silencer is all the same diameter as our old one - its not some max power drainpipe thing, but it sounds a lot better.

 

Another reason to do it, in layman's terms, is that from what I understand there is really no point in upgrading anything else on the engine until you have done this. It is a first stage upgrade, with instantly useable results.

 

Think not so much as extra power - though that may also happen - rather think of much better driveability and flexibility as the engines breathing cycle is improved. You could argue that some upgrade stuff is only really noticeable on the track, or by someone with great feel, fantastic driving skills etc etc. I think this is an upgrade that anyone should be able to appreciate, and is therefore money well spent, before doing any other type of engine work.

 

Hope that is useful to fellow laymen!

 

Layman's question of my own now - we have the long primaries exiting from the side of the car into a 4-1 collector. To change to a 4-2-1 system do we just have to get a 4-2-1 collector - will this still fit onto our primaries. If so, I guess a slightly shorter silencer is required?

 

😬26,000 miles in 13 months!

angus@tinyworld.co.uk

 

Edited by - angus&tessa on 8 Oct 2002 16:18:47

 

Edited by - angus&tessa on 8 Oct 2002 16:31:32

[scooby dooby doo]

Angus&tessa - that all seems pretty much spot on compared with my experiences / thoughts.

 

I'm pretty sure that the 4-2-1 has shorther primaries and a different collector - the silencer is the same length.

 

The powerspeed sytem shortens the silencer (but makes it 6" instead of 5") to keep the primaries long. The benfits of this can be sen on miraz's car - as its an SV it has much longer primaries as the car is wider and longer, its output on the rolling road was a fair bit better all round than when the engine was in a normal caterham.

 

Regarding the K SS exhaust - when i got my car (1998, but its a 96 car) - it was a spec called the supersport which was like a normal 1.6 but had the SS cams, SS exhaust (as the called it), and SS rollbar (the one over the diff).

 

I can only assume they changed the specs when the roadsport and clubsport models appeared in later and again when the R3/4/500 series came out. I suspect the current line up tries to make the non R models quieter etc.

 

HOOPY Today I shall be mostly wanting to go for a blat R706KGU

[ewenm]

Right, my first ever attack of upgrade-itis has hit. I've signed up to Dave_H's bulk buy of Powerspeed exhausts, meaning that there may be only one left. Thanks to everyone for their advice on this thread

Al - are you going to join in too 🤔

As far as price goes, Ratrace offered to do the conversion for the Caterham parts for £700 about a year ago, so I'm pretty happy with the Powerspeed price.

Cheers, E.

 

Ewen Malloch

P979TMV - Yellow 1.6 K Series

[Dave_H]

Cheers Ewen, one more left....Come on you lot, don't you know a bargain when you see one!!!

 

Edited by - Dave_H on 8 Oct 2002 17:06:46

[caterhamnut]

Dave - I am sure there is a link in the original posting somewhere, but to save time - do you have a pic of powerpsort exhaust?

 

😬26,000 miles in 13 months!

angus@tinyworld.co.uk

[Allan Haighton]

For what its worth, I swapped my exhaust last winter.

 

Starting point was the Caterham 4-2-1 rear exit system on a 1700 xflow.

Change was to a 4:1 long primary system with Racetech 6" silencer, all supplied by 7 Workshop.

 

On the rolling road, top end power was about the same. Peak torque with the 4:1 was lower than the 4-2-1, but the torque curve is much flatter and wider, giving an almost linear power curve from 2500 rpm up 5800 prm, when it begins to turn over.

 

Overall the car is much better to drive: much more grunt at low revs. I wouldn't change back.

 

[scooby dooby doo]

loads here from the last bulk order

 

HOOPY Today I shall be mostly wanting to go for a blat R706KGU

[caterhamnut]

Dave H - I am certainly very interested in the exhaust - subject to doing a little research concerning our set up/future plans etc. I am interested in any exhaust that is stronger than the caterham effort around various welds etc, having had one fail on a number of occasions. Forgive me if I ask a few questions which have been covered already - this topic spreads over a number of threads now and I can't remember what has and what has not been asked! Can powerspeed get the exhausts coated - interested if the outer can be coated to still look like chrome (cannot remember waht this is called - is there a web site?) Will the exhaust be any louder than standard long primaried 4-1? When would the exhausts be ready after placing of order? Is the bore of the pipes larger than the std at the collector joins ie: would I be able to fit my cat silencer to the collector for MOT reasons (accepting the length issue) Sorry to add more questions to your list, but Iwant to be sure its a good thing for us!

cheers

 

😬26,000 miles in 13 months!

angus@tinyworld.co.uk

[scooby dooby doo]

camcoat are the coating people you want. i think google finds it quite easily.

 

HOOPY Today I shall be mostly wanting to go for a blat R706KGU

[Dave_H]

Angus - you have mail.

[scooby dooby doo]

I may have found another for the bulk buy - I've told him to poke his nose round here...

 

HOOPY Today I shall be mostly wanting to go for a blat R706KGU