Some of those avid blog readers will recall that I've attended only a handful of track days this year, starting off with Folembray in France...
Whilst at Folembray I noticed that going up the hill in fourth and fifth gear the car felt, dare i say it a little 'under powered'. I took note of it, and put it down to the ZZR tyres, but thinking back to it I've always thought the car hasn't really pulled that well in fifth and sixth gears...
The car was then flat floored by Rob at Ratrace motorsport, and I went to Cadwell Park for another track day... And once again, I noticed the same feelings... Again putting it down to the additional weight of the ZZR tyres I made nothing of it and just thought that was the way it should be.
Nevertheless, a week or so ago at Snetterton, I had to fit the RaceCo exhaust and going down the back straight there the car felt like it was considerably hesitating. A few calls to Rob at Ratrace, he suggested it could be the throttle bodies out of balance or a top end misfire, I discounted the throttle bodies being out of balance, as the car had just been returned from a service by CC midlands, and this is part of the service. I decided not to run the car anymore on circuit and headed gingerly home.
A few more calls to Rob at Ratrace motorsport, after which he suggested I contacted Steve at Track n Road performance, to get a power run done and take things from there.
Onto the session with Track n Road:-
The car wasn't running great on the way there, and even though the rain was pretty much the worst we've had this year, I was happy to be on my way to get some answers.
I arrived after a slow two hour drive and a proper soaking, and it was straight down to business for Steve and Jim. The aim was to run the car with the cat bypass pipe and standard R500 can, then with the Raceco can, then with the Raceco can and carbon airbox to see how this effected the fuelling...
The car was put on the rollers, strapped down and plugged into their dyno... Immediately they noticed a few things:-
- The map is a Cosworth map, even though it's not a Cosworth engine
- The Cosworth map is locked, so they can't remap this version
- The car was running poorly
- They couldn't get full throttle
- They think the Lambda sensor is burnt out
|Steve fiddling with the throttle
With the throttle bodies being awkward to adjust in situ, they removed the inlet trumpets, and the carbon backplate - which was hard to remove as it had what seemed like the factory glue holding it in place along with the bolts.
|Jim removing the inlet trumpet backplate
|Caterham R500 Duratec roller barrels with inlet trumpet and backplate removed
|Caterham R500 Duratec engine with roller barrels finally in the 'Wide Open Throttle' position
- 255.1 bhp at 8,600 rpm
- 171.1 lb-ft at 6,174 rpm
- 148mph top speed
- 464 bhp/tonne (based on weight of 550kg)
|Caterham R500 Duratec power curve graph
- Map one will be for standard R500 can, cat bypass pipe and piper cross air filter
- Map two will be using the Raceco exhaust, cat bypass pipe and piper cross air filter
- Map three will be using the Raceco exhaust, cat bypass pipe and carbon airbox cover