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2021 Caterham CSR "CatKong"


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A peak into a CatKong like build at a track!

 

 

The closing speed is crazy on the other vehicles.

 

And then the 2.5 liter variant.

 

 

Croc, your going to need a double coating of that paint overcoat

Edited by seschm1234
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The current problem is getting a Caterham wiring harness to talk with the upgraded ECU. Having the UK shut down with their infection issues has made this challenging. Likely requires engineering a connection solution from scratch – not an easy task I am the first to admit.

 

I went through this as well, getting the MBE 9A4 working with the Cosworth YD8048 engine loom. I'm not sure if there may be pin assignment differences between the ECUs or the harnesses? Happy to help if I can.

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This is super-interesting, Mike. I am harbouring some similar thoughts but whereas your build is intended to be an ultimate track car, I'm thinking about making the best road-car that I can - so similar approach but with different specs and priorities at component level.

 

You mentioned that CC supplied the car as a glider but in the pictures of the car being built in the factory it seems to have a Sadev fitted and, I presume, at least a block in place as the primaries seem to be fixed to something and pointing in the right direction! Can you shed some light as to the extent that CC were able (happy?) to supply without the driveline mechanicals in place?

 

James

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  • 4 weeks later...

Just realized I never responded to a bunch of comments on this thread.

 

 

We know it will take the power/speed title, pretty sure you're also taking the invoice crown from the certain orange Cat.

 

No chance on the invoice crown. The orange car was at least another 50% more. I am not in the range of beating that.

 

 

Looking forward to seeing it running. Out of curiosity did you consider the RST or Hartley V8s as engine options?

 

 

Hi Rahul - hope you are well? I did consider RST, Hartley and the Synergy V8s.

 

RST produce the 2.4L v8 with 500hp as originally developed for the Caterham Levante

http://www.rsperformance.co.uk/

 

Hartley produce a variety of engines with the headline being a 2.5L to 3.3L V8 with 420-500+hp. The owner of the business installed one in his Caterham

https://www.h1v8.com/maxi-v8---specs.html

 

Synergy have a 2L-3L V8 with 400-500+hp

https://www.synergypower.co.nz/

 

 

Not sure Hartley are producing much these days - never got an answer to my phone calls.

 

I also considered a Millington inline 4 engine. 2L to 2.8L and up to 370hp in an inline 4 package.

https://www.millingtonengines.co.uk/new-engines/

 

 

 

With the v8s, they are highly strung, quite difficult to put the entire package together in a bespoke build like this, marrying up to the constraints of a Caterham wiring harness and driveline size/packaging limitations. Then you have the refresh cycle. These engines would require a rebuild at fairly frequent intervals with heavy track usage. Not sure on the Hartley but the Synergy and RST were looking at every 2-3000 miles. The Millington is a more robust package but even so. I went to the workshop to see them being built and find out how easily the engines operate. The Millingtons have a very precise warm up and cool down process and maintenance cycle. Similar for refresh. RST, Synergy and Millington are based internationally - how difficult would it be to refresh locally or do I need to ship back to maker. Most were saying ship it back to them. Importing a non-EPA production approved engine into the US is difficult at the best of time.

 

Then you have to consider that the most hp you can use in a seven is limited by its light weight and ability to put the power down. I have always thought that limit is around 330-350hp in practice.

 

So knowing that, it was fairly easy to go the 2.5L duratec route. They have builds up to 290hp these days. I can get it refreshed locally in country. Its a simple robust package. Refresh life was the longest of the lot. It was far cheaper. Had less issues fitting into a Caterham package - just bolts in. It was a relatively simple decision to spec a hp that allowed a long refresh life but hit a target that was high. No brainer decision at the end of the day.

 

 

 

Biggest changes over the current CSR seem to be the adjustable suspension with trick shocks, traction/launch control, throttle blipper, and the paddle shifter Sadev transmission. It looks like peak power wont be all that different? I thought your current CSR made in the 300 hp range also? Or is torque way up and the torque/hp curve fatter? I didn't see dry sump in your list of specs but am sure its there.

 

More than that. The diff has a proper cage. Caterham has improved the chassis since mine. I will also go to the standard dash as that allows the customization with an integrated digital screen and switchgear that will improve operation. Peak power is a LOT more. Up from around 270hp to 330hp - about 25% more. Torque is substantially up - final figures to be determined with final tune and it is fat across the rev range. It is dry sumped - Titan or Tilton from memory.

 

 

What do you think all of this will weigh (Around 1,400 lbs.?).

 

With full tanks it should be in the 1350-1400lb territory, no driver.

 

 

why no full roll cage.. or is this coming soon?

 

Have not got that far yet. Its yet to be assembled, put toegther and run. Lots of stuff left to happen. Thats last thing after the 3M film.

 

 

I went through this as well, getting the MBE 9A4 working with the Cosworth YD8048 engine loom. I'm not sure if there may be pin assignment differences between the ECUs or the harnesses? Happy to help if I can.

 

Thanks for the kind offer Sean. This a little different. We have a Caterham wiring loom to mate with a MBE 9A9 ECU (not the Caterham MBE 9A4). Its a full motorsport/production level ECU. It has working OBDII. So a lot more channels requiring additional wiring harness additions. The pin out/in are known so thats not a problem. We just need a robust wiring harness connector that will take all the additional pins needed for the extra wiring channels. ST Motorsport in the UK seems to have them.

 

 

This is super-interesting, Mike. I am harbouring some similar thoughts but whereas your build is intended to be an ultimate track car, I'm thinking about making the best road-car that I can - so similar approach but with different specs and priorities at component level.

 

You mentioned that CC supplied the car as a glider but in the pictures of the car being built in the factory it seems to have a Sadev fitted and, I presume, at least a block in place as the primaries seem to be fixed to something and pointing in the right direction! Can you shed some light as to the extent that CC were able (happy?) to supply without the driveline mechanicals in place?

 

James

 

Its definitely a roller (or as you call it, glider) as you see it in the factory photos. No gearbox. No engine. Thats the only legal way it can be imported into the USA. I think it had a diff but that was replaced by the Tracsport one later. Things are just stuck together for shipping. Not sure how how its done as I never saw it that way. The original US import approach for Caterham was CKD kits. Then they moved to rollers without drive train. I believe thats how they supply to other countries as well. Caterham has to be happy with that approach as its their only way to sell into the US market. Importing complete cars brings with it the requirement for full DOT/NHSTA compliance (air bags, crash testing, etc) - so thats a non-starter. The kit/roller approach keeps it low volume and allows Caterham to still participate in the market.

 

I am not sure Caterham will supply the CSR as a kit or roller in the UK? There is definitely resistance there that means its an off-catalog purchase for the USA. However, it is the only thing homologated in Switzerland or Australia as I understand it so they have to keep offering for those markets. Not sure I have the answers.

 

 

 

Croc - Make sure you use a billet or forged crank in the 2.5L Duratec

 

Forged. I learned from your expensive experiences. I also plan to keep the revs to 7500 or less. Don't need to go any higher in the rev range anyway - better to change to maxmize the torque curve.

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HANS.

 

My personal view is that the Simpson Hybrid harness is better than HANS in a seven and thats what I use. It does not need the Caterham belt mount locations modified plus it moves easier from car to car with less issues and it is less bulky for travel. Those considerations are important for me given I drive multiple cars and travel internationally.

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I like that "Croc-zilla" tag. But,

 

"Have not got that far yet. Its yet to be assembled, put together and run. Lots of stuff left to happen. That's last thing after the 3M film."

 

Appearance before saving your cranium? Recent posts have shown how invaluable your knowledge is about Cats. It would be a shame to lose it. Track only car = cage.

 

The main I reason I have not fallen into the track day addiction is cars (not only just mine) with-out a proper cage. Having been wrong side up a few times, one surely fatal without a robust cage, I just won't do it. Unbelievable things can happen. There was a photo some time back of a tin-top about 6 rows up in the bleachers (looked like Sonoma to me). Fortunately an SCCA event so no spectators.

 

I'm just saying, apparently some of these folks love you.

 

MHO.

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I think the F1 rollover bar that Caterham supplies provides decent roll over protection, esp if 6 point belts are combined with a decent seat and if arm restraints are (properly) used. Ditto front and rear crashes as there is a decent crumple zone (occupied by the gas tank in the rear, but Fuel Safe has a fix for that). I have seen photos of Caterham crashes that were injury free, even when the car rolled.

 

My greater concern is a side impact, where the only thing protecting the driver from a T-bone collision is his left elbow. This can occur when the driver spins out and ends up side ways in the middle of the track, and when another driver goes off into the grass and careens back on, out of control, at a right angle to traffic. Just watch the highlights of the Nurburgring for lots of examples.

 

The Caterham issue roll cage is inadequate, IMHO, as it sits flush with the side of the car: the driver's arm is still sticking out, and there is only 1-2" of space separating the driver's body and roll cage, so no real crumple zone. The custom racing cage on my Caterham sticks out maybe 8-10" from the driver's body, so lots of room for it to deform, without hitting the driver.

 

I know a cage spoils the car's aesthetics and no one wants to start hacking away in a pristine new body. Further, the weather gear becomes useless. But my cage bolts in and out in about 30-60', so it could be removed for street use. So, theoretically, it is possible to have it both ways.

 

Just further food for thought for Croc's supercomputer-like brain to process....

Edited by Kitcat
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My greater concern is a side impact...

The Caterham issue roll cage is inadequate....

 

I don't want to turn my build thread into a safety discussion or an analysis of my ability to assess risks. I have had my share of serious impacts and roll overs and I have taken many lessons from that. In 10,000+ track miles in various Caterhams and a Lotus 7 over 35 years, I have only come close to rolling a seven once - last year. Rollovers are fairly rare in the seven world. Mike has pinpointed why I paused on the automatic cage decision that many people automatically made. I am not a fan of the Caterham cage. I do not think it is much if at all better than the standard roll bar with diagonals. I have seen what happens to both of them in roll overs in UK Caterham racing competition. The real danger point in these cars that Mike rightly points out is side impact and a cage does not solve that. I am exploring options around that idea but it is not ready for prime time and I don't share until I am ready to. Otherwise, I would have been sharing this build thread back in 2018 instead of only sharing it in October 2020.

 

By the way, a Caterham is not the riskiest car I drive...

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  • 4 weeks later...

I was visiting Seattle for a project and stopped by to see Bruce at Beachman Racing. This Caterham build got sidetracked for many reasons this year - Bruce in solitary confinement, me in solitary confinement, other distractions, me focusing on other cars, phases of the moon and time of the month, etc. So we spent a good afternoon rolling through the various items needing decisions or in some cases, research to work out a solution - dashboard layout, paddle shifter equipment layout, ECU sensors, missing rear suspension bits from Caterham, etc. The 4 wheel sensors for wheel slip are the next challenge (traction control, launch control, antilock, etc).

 

 

 

tFYHW4u.jpg

 

 

 

The engine is done and first pass dyno for 327hp. Full mapping with correct ECU and wide band will likely put it closer to 335hp+.

 

Close inspection of the engine photo by keen eyed forum members will note the Ford sticker showing 2L displacement. This came from the crate engine donor - the block is now a 2.5L.

Anyway, I think a new cam cover is needed to remove the high mount electrical connection from the rear top of the existing cam cover to give clearance under the bonnet.

 

 

tnFh2YV.jpg

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  • Croc changed the title to 2021 Caterham CSR "CatKong"

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