ITB’s/RBTB’s on 2015 420R

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Mrp
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Hi Scott, yes the back plate

Mrp

Mrp 420R

ScottR400D
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#11 That doesn’t surprise me Toughie. I’m sure CC wouldn’t want to be individually mapping cars!

But there are people out there who can and will. 

Rich420R
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Thanks for all the information guys, I will look into Team Leos as an alternative then, and Rally Prep in Cornwall have also told me they have done similar set ups on west fields and caterhams, and they are 10 minutes from me which is helpful. Good to have a few options to weigh up. 
It would certainly be good to have a better idle as the car really struggles when cold. It's the noise that I love with the ITB's, and I will likely do a cat bypass as well. I know Evo magazine did both those mod's on their Caterham and they said it was instantly the best sounding car on the fleet. 

Richard Craven

ScottR400D
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I fitted the bypass some time after the RBTBs and didn’t notice much of a difference in either noise or performance to be honest. 

The TBs certainly made it sound better and made a huge difference to driveability and idling. Whereas before it wouldn’t idle till it had been running for a few minutes and even then it would hunt between 12/1400rpm. Now, start it, 5 seconds and it’s steady at 850.  Just like a proper car!

Whoever you choose make sure they can remap properly, that’s crucial to get the most from the upgrade.  

Alan Reeves
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CC cannot re map as they dont have a rolling road . they use the two steves if they need work ( I believe ) and the two Steves  have access to re map the ecu

test

 

ChrisC
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Just for the record, there is no reason a 420R in standard form should have problems to idle, from cold or have a drivability issues.  There is a minor hesitation, which is mainly noticeable reviving the car in neutral, which is barely noticeable when driving.   That said care and attention has to be paid to the TPS position, throttle flap / manifold pressure at idle to get that things right.  To get my car spot on I have adjusted the slots a little in the TPS, and it took at least an hour maybe even two before I was happy. 

But without doubt the RBTBs are a step up, and noise is the real improvement.

Rich420R
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Good to know everyone rates the throttle bodies.

My car really struggles with the idle when cold, it's better started in neutral than in gear but still it cuts off a couple of times on a really cold morning. A few people have told me they had this issue and sorted it with a remap. 

Richard Craven

Obodiah
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I had the cold idle issue after I finished the build of my 420R last year.  The throttle body upgrade was always part of the project but because of the lockdown delaying the IVA I asked Stuart at Premier Power to do one of his F225 upgrades with AT throttle bodies and a new ECU which was mapped on the rolling road at Northampton Motorsport.  The idle issue has gone and the noise + performance + drivability is fantastic.  The setup squeezed out about 230hp with the cat bypass and the map also stays within emissions with the cat in place.   It passed the IVA first time in October and  I've run it with both the bypass and the cat since then and don't notice any difference on the public roads, I'll keep the bypass for track days.  This is an expensive way of sorting out the irritating cold idle but the overall performance gain and drivability improvements are the main benefit. As far as I am concerned the car is a keeper and as i built and will service it myself I'm not too worried about the warranty implications of a non CC upgrade.

ScottR400D
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As Chris says, the single throttle set up can be set up to run properly but most of the people I know with new kits/factory cars in the past 5/6 years had issues at the beginning and have had to go to some lengths to sort them. 

I and, I would guess, most who go for RBs don’t do it just to fix the idle!

I was never happy with the way the plenum flexed as the the throttle opens/closes either. I’m not sure whether more recent cars still do that?

 

_Bandit_
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I had the Caterham factory RBTB upgrade done from new when I bought the car in December 2020. I just found the standard induction noise a bit, well, quiet! The noise with them fitted was worth it.

Unfortunately something has gone wrong with them after 500 miles driving and they're being completely replaced ( I don't know what's gone wrong as they can't tell me - the car was in for a huge list of warranty issues, kangarooing and hesitation at 1500-2500rpm being one of them). All being replaced under warranty by CC and they've been very good sorting all the other issues so I can't complain.

However, if I'd bought a car that wasn't new and was out of warranty I'd have gone with the Premier Power F225 upgrade. Stuart is well worth talking to http://premierpowerengines.com/premier-power-f225-upgrade/

Acid green 420R with ITBs