Exhaust options for K series

[willmac]

Hi All,

 

Just wonder if I could get some feedback regarding options for 1.6 K Series ( standard Roadsport spec at the moment, 120 bhp ) exhausts please.

 

I am looking at gradually stepping up power probably up to R300 type levels over quite a few years. This will be as funds are available, and SWMBO allows / finds out about it !! I also may consider looking at fitting a 1.8 VVC engine as an option.

 

I will be doing on average 3 track days a year, so noise levels will come into it also.

 

Appreciate any feedback you can give me regarding 4-1 systems, 4-2-1 systems. Benefits of each , to have CAT or no CAT etc

 

Many thanks

 

 

[tweeky]

Talk to DVa (aka oilyhands) i had my roadspoty ported and verniers well pleased but he did say the exhaust was now holing it back he rocomended a powerspeed system,

 

its now has one .

 

 

Edited by - tweeky on 27 Feb 2012 05:50:37

[willmac]

Thanks for that Tweeky.

 

Yes I do need to speak to Dave soon, so that I can put together my long term plan for upgrades etc.

 

Glad you are pleased with your results so far. I know it is a slippery slope when you start on upgrades, but pound for pound well worth it I reckon.

[david nelson]

I have used a 4-1 race exhaust on now have a 4-2-1 SLR system. Both are better than the standard system. If money is tight I would go with the cheapest option. At 160 bhp not sure that their would be a big diffrence. If your 7 runs a cat you will need on for mot ect.

 

David

[Stationary M25 Traveller]

Understand 4-1 is better if you live at max revs (on track) and 4-2-1 better for mid range torque. I certainly like my 4-2-1 on the road.

[willmac]

Thanks for replies so far,

 

My understanding is getting better now that I know that the 4-2-1 is preferred for mid range torque. Cheers for that.

 

If I had a lot of time on my hands I would live at the track, however realistically most of my running will continue to be on the road, so I guess 4-2-1 is way I should be thinking

[peter clarke]

Definitely 4-2-1 for road. When I switched from the terrible short4 branch on 1600K to a R 400 4-2-1 with removable cat the whole engine not only burst into life with the other head mods but drivable from 2000 rpm. That was an R 400 system from about 8 years ago as it would fit LHD car. Power speed or others as recommended are natural choice now.

[Gavinsmithartist]

Willmac. YHBM

Check out the Bulk Buy thread for Powerspeed. Give Andy a call at PS and quote the club bulk buy.

Gav

[jerrypike]

very happy with my Raceco with big silencer: no noise issues on track with my SLR (<98dB, prev >105dB)

you may struggle for space with a 4-2-1 and cat

 

jerry

[Stationary M25 Traveller]

My PowerSpeed 4-2-1 has the cat in the 7" diameter silencer

[peter clarke]

Calling M25! Is the cat in the can that you have good enough to pass emmissions for road legal or is it one that is a balance for track power use? Understand that some are made like this. If so would eliminate the bother of changing the cat each mot time. In response to is it possible to 4-2-1 whith long enough silencer mine is 75 cm long, so answer is yes.

[Stationary M25 Traveller]

YHM

 

Edited by - Stationary M25 Traveller on 28 Feb 2012 06:40:06

[bobt]

I would avoid having a cat in the can if you intend doing a lot of track days. In my experience it kills them. I had a Powerspeed 4-2-1 with the cat in the can ( until i had it removed) and was having to get it replaced every other year due to emissions failure at MOT. With the new cat in it's fine. And before you ask YES this is a properly mapped DaveW emerald setup. Cats work well in normal driving conditions but on a track the engine will always be on a transient throttle or RPM. This means it will spend a lot of time breathing richer than normal exhaust gases. It burns them out far more quickly. Sooo, I have two exhausts. One with, and one without the cat. To save costs tho I asked Powerspeed to take my original Caterham cat exhaust and modify it to fit onto the Powerspeed headers. This way at MOT time I don't have to swap the whole system, just the can. Simples.

[willmac]

Quoting bobt: 

Sooo, I have two exhausts. One with, and one without the cat. To save costs tho I asked Powerspeed to take my original Caterham cat exhaust and modify it to fit onto the Powerspeed headers. This way at MOT time I don't have to swap the whole system, just the can. Simples.

 

That's great advice , thanks.

 

I'm a new owner as you can probably tell, so I'm a Caterham MOT Virgin at the moment !

[peter clarke]

Have similar set up. Original R 400 system which is a 4-1 with the cat in place for the mot. Then I have a 6" Techcraft SS silencer to which the 4-2-1 part (same length as the cat),is now fixed and is always on the car except mot time. It then takes less than half an hour from start to finish to swap. Headers stay on and only 4 nuts/bolts to remove. Cat will last forever.

[Richard Price]

Peter,

If you're able to use a 4-2-1 collector in place of your cat, then you'll have the SLR system, not the R3,4,500 system.

On the R3,4,500 system, 1 & 4, and 2 & 3, are diagonally oposite each other, so its not possible to make them 4-2-1 in the correct order.

[peter clarke]

Thanks for the info Richard. 1-4 at bottom and 2-3 at the top on exit of side panel. Was under the impression it was an old R 400 type and that CATERHAM said it was the only one that fitted LHD back in early 2000's because of fouling the steering wheel. I guess, maybe 10 years ago, time flys.