K Series R400/R500

[Tim Smith]

I'm thinking about selling my Supersport R and getting either a K Series R400 or possibly R500. The R500 is an iconic car and doesn't seem to be a whole lot more money so my man logic suggests it's a good idea 😬. However I have a few questions about the R500:

 

1) From what I can gather 8-10,000 mile between engine refreshes doesn't seem unreasonable if it's not purely track mileage. However how much should I budget for an an engine refresh?

 

2) Noise - I assume the standard R500 setup is with the foam filter on the roller barrels and a relatively small silencer can. Any ideas on what dB this is likely to generate for a trackday noise test. If I'm to have any chance of getting it through a 100dB limit is a full carbon induction system and a large repackable silencer(eg Raceco) the only way to go?

 

Any answers and thoughts on the wisdom of going for a K Series R500 much appreciated.

 

 

 

Edited by - Tim Smith on 8 Jan 2013 20:04:11

[skydragon]

Why don't you look at upgrading your existing car?

[Tim Smith]

I did think about it and costed it up but when I looked at the engine cost, a dry sump, ecu, rolling road session and possibly diff change it didn't seem worth it. I am open to the idea of a non factory car with similar power though and have been looking out for something suitable, it's just that R500s seem very good value at the moment.

 

 

[Mark w]

My R400 K has the larger repackable Caterham silencer and noise hasnt been an issue .

 

With the smaller can it came with as standard when i built it it was always marginal and 105DB was a struggle

 

Lots has been said about reliability of the R500 but provided you are sensible ( maybe drop the rev limit a bit ) and are prepared to spend some cash from time to time i wouldnt let that put you off .

 

That said a well driven R400 is almost as quick . Mine showed as 218 BHP on the two Steves rollers when it was remapped .

 

PS you might have to find a friendly MOT garage when it comes to checking the emissions .

 

 

[Tim Smith]

Mark, thanks for that, I suspect the standard silencer on the R500 is the same as the R400 so it isn't going to be much good for trackdays. Will need to budget for a Raceco or similar.

 

Does anyone know if the R500 induction noise is worse, different cam timing from R400? Is a carbon induction system necessary?

 

I have looked for a K series R400 but there don't seem to be very many for sale, strangely there are far more R500s. I think it may come down to what's available when I've sold my car but I still rather fancy the idea of an R500 ❗

 

I already have a suitable MOT station so emissions shouldn't be a problem.

 

[rj]

I think you'll need an airbox and a decent exhaust. I'm running with the rear exit system, which works a treat for me.

 

The induction system of an R500 - with roller barrels that offer next to no noise dampening and fairly aggressive cams is noisier than the R400. Also more revs = more noise. Wouldn't put me off though. Just another challenge...

[Slipper man]

I have had an R500 from new in 2000 and my car has seen a lot of action over the years, including lots of track days, sprints and road use. Of the 18,000 miles it has done, about 10,000 have been on track. When i bought my car i agonised about whether to get an R400 instead, largely because i was terrified of the engine. There were so many stories about them at that time. Some were justified, because the early cars did have reliability issues. These arose for two reasons that i can recall. The first was the use of standard Rover big ends that failed at high revs. They were retro fitted with upgraded items FOC by Caterham and the problem went away. The second was that Minister were too optimistic about rev limits. The early cars were red lined at 9,200 RPM, although that was revised to 9,000 by the time most cars were made. That was too high because some harmonics developed that snapped crank shafts, so the limit was reduced to 8,600. From that point the cars I have known have been very reliable and it didn't affect the power output, which is only developed at 8,600 anyway.

 

The rebuild interval is something that people get too worked up over. Caterham did originally say 3,000 track miles which freaked people out a bit, but that is A LOT of miles. To put in context, an engine builder told me that Swindons recommendation for a fast Vauxhall is 1,500 miles between rebuilds... No one knows how many miles they will do on the road, but those who know about these things say 20-30,000 road miles will be no problem. When my car was last rebuilt it had done 7,500 track miles (i.e. more than twice the recommended limit) and still ran as well as when new. It had been thrashed though and I felt it was prudent to bite the bullet and get a rebuild. The cost was about £1,000 for parts and the same again for labour. Next time, as the car is no longer doing 10 circuit days a year, I will just replace a valves and springs, which cost c£500 because I am sure the last rebuild involved throwing away a lot of perfectly good parts.

 

Over 12 years, my car has been very cheap to run for a car of its staggering performance and has only twice not been running at the end of a track day (and I really don't know many people who have had such a good reliability record over that time). The first was my fault really. I did a DIY rebuild in 2003 and didn't know about getting things balanced. I was also not running the 8,600 limit because I knew I would be carefull. The ECU said I was doing 9,300 when the crank failed... The second failure was when a Barnby wheel failed. Don't EVER take a car on track with those wheels unless you like Russian roulette.

 

The R400 is a great car and certainly is just about as fast as an R500. New slicks on an R400 will overcome the performance deficit compared with an R500 on used tyres. But. For me, the R500 is much more exciting. It feels and sounds much more like a racing car, and is much better equipped. It has things like the aero section wishbones as standard, magnesium dry sump tank and sump, lots of caron bits, Stack instrumentation Watts Linkage etc. many R400's will have some of this stuff, but it was only standard on the R500 when I bought mine. You will have a problem with noise levels though and I think an air box would be needed on either to get through a 100db test

 

Hope all this helps. BM me if you want to talk off line

 

My car has been

[A10ROX]

Slipperman

 

Agreed many R400 have R500 add-on

Mine was a 2004 build R500 with a R400 race engine (same but bench tested) but without the magnesium bell housing ... So it is a R400 however it has been known to be very competitive against R101 upgraded R500

 

You need to keep on top of the maintenance particularly if you are using on track

Only problem has been the head gasket ...

 

Very little to choose between them

Get the best for the budget you have

History is everything

Noise will be an issue ... Don't think of 98db days without air box and larger silencer or rear exist and be prepared tp reduce revs on track

 

 

[Slipper man]

Now, I wonder who I was thinking of, Dave, when talking about new slicks. I forgot to mention crazy nutcase drivers of R400's making a difference....

 

Are you off to Spain in a few weeks?

[A10ROX]

Slipper man

Unfortunately not this year ☹️

Dates don't work

Am thinking we should do a Spa sometime again

 

Edited by - A10ROX on 12 Jan 2013 18:03:37

[Tim Smith]

A10ROX and Slipperman - Thanks for your comments most useful, it sounds as thought the great R400 vs R500 dilemma has been had before.

 

I was thinking of rebuilds every 10,000 miles based on doing about 2k/yr including 2-3 trackdays which seems to tie up with your thinking.

 

Any thoughts on specific airboxes that work well at noise reduction? I had a cheap one on the Supersport R which reduced noise slightly but cracked and fell apart. I've heard that the Caterham carbon one reduces power as it draws hot air? Is the Reverie carbon one worth it?

 

I definitely won't go down the route of rear exhaust as I think it ruins the look of the car, I think something like a Raceco silencer should be ok.

 

[A10ROX]

Tim

Happy to chat off-line if you blatant me your number

 

I don't run an air box and I swap the standard exhaust with a Raceco depending on the circuit

Slipperman has swappable rear exhaust

 

If you choose the right track day event then noise is not an issue

Most of the club days are OK without an air box and on a correctly packed standard exhaust

 

The Caterham box can collect cool air depending on fitment

 

Cheers

[SLR No.77]

The R500 Caterham box is made by Reverie and is designed as a direct fit on the rollerbarrel TBs - it has an integral 6" diameter cone filter and is fed via 4 x 2" inlet hoses from an intake box mounted low down at the front. I've fitted one to my SLR (222bhp) and it reduces induction noise massively.

 

Stu.

[BSA]

I have an all steel 1.9 and the induction is much louder than a standard R500 K with an extra long Raceco style of silencer re packed ever year you won't have any problems apart from at Bedford and lets be honest there are far better Track's to spend you money on.

I attend most of Gold Track's events and never had a problem.

[Slipper man]

As Dave says, I have a rear silencer that I can put on in about 10 mins when needed that gets the car down to about 98db. I also have the Caterham air box that cuts the intake noise down massively. it originally had all the pipes described but they were a real pain, making access to the front of the car very hard, so I removed them. I couldn't tell the difference in power or noise levels without them

 

Dave: I can't go this year either. Dates weren't great and I didn't like the mix of tracks as much as previous years. Agree about a Spa date in the Summer. Do you have any particular trip in mind?

[Slipper man]

Oh by the way Tim - your assumptions for rebuild times are realistic but probably on the pessimistic side. And if I were using the car like that I am not sure I would expect anything very different from a 400 to be honest.

[6speedmanual]

As per Forshaw, for the reverie R500 set up. It was a Caterham exclusive product, but I believe they now sell a version without CATERHAM emblazoned across the top.

I too have the under nose intake but tend not to use it cos it's terribly vulnerable to damage and scooping up debris.

 

I quite like this nose cone blister style intake: Reverie

 

Peter

[Tim Smith]

Thanks again for your comments, my 10k between rebuilds was really just for budgeting, if I do 2k a year then 5 years between rebuilds seems entirely reasonable.

 

Looking at the Reverie website it appears that the air box is fed by hoses from a scoop on the side of the nose cone. Is this the same as the under nose intake referred to? Are we saying that the hose and scoop can be dispensed with and not suffer power loss?

 

Could someone send me a few pictures of their Reverie/Caterham airbox setup?

[A10ROX]

Try here difficult to tell real from model

[Slipper man]

I am afraid I don't know how to place photos on BlatChat. I can send you pictures if you send me an email address

[SLR No.77]

R500 CF airbox

Intake ducting

Intake scoop - radiator removed

Intake scoop radiator fitted

 

Stu.

[Gridgway]

It does the job well, but I think that whole gas-mask affair is pretty hateful.

 

I'm told the scoop is particularly effective with regard to bags of cement on the road and that the air filter in the gas-mask is not very effective!

 

Grahan

[oilyhands]

Auto-teknix do a good airbox for roller barrels, it allows you to fit a regular type of filter or duct cold air. I think I have one or two in stock.

 

Oily

[mav]

Iirc Fred fitted one of these (reverie) to his R400 and took the 4 feeds out to the nose cone sides, using 90^o cf adapters so the air was taken in above the steering arms in the nose cone.

 

 

 

Edited by - mav on 14 Jan 2013 11:34:46

[SLR No.77]

And IIRC it's Fred's car that was used for the images on the Reverie website.

 

The intake scoop on mine is below the lower front chassis tube, some owners have done the same install but with the intake above the lower chassis tube which necessitates raising the radiator a little and cutting an inlet hole in the lower part of the nose cone. At some point I intend to relocate my intake but would prefer a solution that takes air in through the usual grill area rather than behind the number plate.

 

Stu.