Static Set Up of Caterham (Titan) Roller Barrels

[Geoff Brown]

Is there anyone out there that can explain this dark art?

 

I have all the basic figures: 6mm barrel closed gap, 5Kg/hr each pot @ 900-1100rpm, TPS .43-.45 is this figure Ohms?

 

So which terminals on the TPS : the two outers?

 

And which adjusters do what? The throttle quadrant is obvious - central with the large stop screw at the top LHS as you look down. But what does the small hex insert rod with a tiny lock nut on the quadrant do & of course what function is the other large stop type screw bottom RHS as you look down?

 

I presume the procedure is to set the barrel gap, re-set the TPS & then adjust the flow?

 

Who knows this dark art.

[Klunk]

Hi Geoff,

 

I don't have RTBs but have worked on a few so from memory:

 

The outer pins are earth and 5v with the centre pin being the output you want at 0.45v.

 

The adjusters are:

 

Centre (grub screw and hex lock nut) - balance between throttle bodies to ensure both pulling same air

Nearest head (bolt and locknut) - idle set stop

Nearest filter (bolt and locknut) - full throttle stop (to stop barrels going beyond fully open)

 

Can you clarify what you mean by barrel gap? Not sure what the 6mm refers to.

 

As far as set up goes. To start with fully open the throttle and set the full throttle stop and, at the same time, use the centre screw to roughly set the barrel balance. Use your finger to feel when the barrel becomes parallel in the body. When both pairs are the same that will do to start with. Close the throttle and measure the voltage at the centre pin on the TPS. Adjust the idle set stop until it reads 0.45v. The barrels should just be opening if you look down the barrels. Reset ecu and start car. Until the barrels are balanced properly it may be necessary to wind the idle stop in when first started. Once warm, use a synchrometer and the centre screw to balance the barrels so all flow the same. Once done check the voltage at the TPS again using the idle stop as before. If you have a good base map that should be enough until you get it mapped properly

 

I'm sure others will correct/clarify

 

Regards,

Giles

 

Edited by - Klunk on 22 May 2014 18:27:12

[MartinH]

Not sure if the Duratec set up of RBs and TPS is different but on mine the voltage to go for was 4.62v

 

Which engine and ECU are you running Geoff?

 

[Geoff Brown]

Quoting MartinH: 

Not sure if the Duratec set up of RBs and TPS is different but on mine the voltage to go for was 4.62v

 

Which engine and ECU are you running Geoff?

 

Car is a 2013 2.0 Duratec R400 with MBE ECU.

 

The 'gap' is the static 6mm gap that can be seen with the roller barrels in the closed position. This was quoted by CC.

 

I have used a Go-No Go gauge to determine if they are at 6mm. Rear two nearly, fwd two at least 1mm out.

[MartinH]

I used the shank end of a 6mm drill bit to adjust the idle opening. You need to adjust the TPS until you get a reading of 4.62V when in the idle position. (Assume this is different on K-series/other ECUs ) As Giles says, you could probably do with using a Synchrometer (air flow meter) to adjust each of the four bleed nuts so that you get them all about the same air flow rate.

Martin

[Klunk]

Have to admit I was referring to K set up. Clearly they are very different as I would say the idle gap is 2-3mm on the K. The voltage at idle on the TPS centre pin (with an MBE) is less than 0.5v at the start position in the map according to Steve Greenauld. Strange