Duratec Roller Barrel upgrade BHP

Duratec Roller Barrel upgrade BHP

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DCL

Original Poster:

1,216 posts

179 months

Saturday 2nd March 2013
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For anyone with a roller barrel upgrade on a R400/R300 engine who may be interested in the BHP, here's a graph from my R400 (with a dry sump) taken at a RR session today. It's BHP at the wheels but an earlier spool down run suggested that losses are around 15%. A little surprised as I thought the roller barrels where only worth 10BHP but pre-upgrade it only produced 179 BHP at the wheels, but now I'm getting around 20BHP more smile.





Edited by DCL on Saturday 2nd March 19:45

coppice

8,610 posts

144 months

Saturday 2nd March 2013
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When I had mine fitted last year I was not prepared for just how much quicker the car felt.So not at all surprised at your RR results and if they had shown an even bigger improvement I would believe it..

2slo

1,998 posts

167 months

Saturday 2nd March 2013
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I've never had mine mapped but the induction roar on the RTBs is addictive. Then there's the flames...evil

coppice

8,610 posts

144 months

Sunday 3rd March 2013
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Intrigued by the downward spike in torque at low revs. Sort of assumed it might remain the same - or increase- but not fall off and then spike back up. Anybody to provide an explanation to a not very technical R400 owner?

DCL

Original Poster:

1,216 posts

179 months

Sunday 3rd March 2013
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I wouldn't read too much into that as this is a power run and does not reflect part throttle response. The run starts with full throttle and the dyno holds the start speed. What you are seeing is the ECU trying to make sense of the throttle being wide open but the RPM held at idle speed. Normally at idle speed it uses the lambda reading and an adaptive map, but in this case, it has been disabled because of the throttle is wide open - so it pays safe with the default map until more normal conditions take over.

EDIT: I should also add that the dyno requires power to accelerate the rollers so the initial readings are the transition form constant speed to constant acceleration, therefore the first few readings tend to be over estimated and should really have been edited out.

Here's the same run with the easimap ECU data.



Edited by DCL on Monday 4th March 09:48


Edited by DCL on Monday 4th March 09:49

2slo

1,998 posts

167 months

Monday 4th March 2013
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David, just out of curiosity, have you had any issues with poor hot starting and misfuelling when restarting from hot? This is a problem I've found despite Caterham rebalancing the RTBs in an attempt to cure this when they serviced it last year. I find if I restart on a warmed up engine it'll run badly and be unwilling to rev for a mile or two until it usually clears itself. Any thoughts?

Mark.

DCL

Original Poster:

1,216 posts

179 months

Tuesday 5th March 2013
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2slo said:
David, just out of curiosity, have you had any issues with poor hot starting and misfuelling when restarting from hot? This is a problem I've found despite Caterham rebalancing the RTBs in an attempt to cure this when they serviced it last year. I find if I restart on a warmed up engine it'll run badly and be unwilling to rev for a mile or two until it usually clears itself. Any thoughts?

Mark.
Yes! But, I've never really got to the bottom of it, but, as it ran roughly on the rolling road, I discussed it with the RR guys. The two things: the warm up map is not that good, but without a fuel return , fuel vaporization is also a possibility. If you are using supermarket fuels, try Shell V-power as it is less prone to this problem (also worth a few BHP IMHO).


2slo

1,998 posts

167 months

Tuesday 5th March 2013
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DCL said:
2slo said:
David, just out of curiosity, have you had any issues with poor hot starting and misfuelling when restarting from hot? This is a problem I've found despite Caterham rebalancing the RTBs in an attempt to cure this when they serviced it last year. I find if I restart on a warmed up engine it'll run badly and be unwilling to rev for a mile or two until it usually clears itself. Any thoughts?

Mark.
Yes! But, I've never really got to the bottom of it, but, as it ran roughly on the rolling road, I discussed it with the RR guys. The two things: the warm up map is not that good, but without a fuel return , fuel vaporization is also a possibility. If you are using supermarket fuels, try Shell V-power as it is less prone to this problem (also worth a few BHP IMHO).
Thanks, I'll try that. I have been running it on std 98 RON as that was Caterhams original recommendation.
I've heard that getting it properly mapped makes a big difference to driveability but living in the Caterham wilderness which is NE England, there's no one near me who specialises in such things.

Jack_and_MLE

620 posts

239 months

Thursday 7th March 2013
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I've been told the spike downwards is a characteristic of the roller barrels TB I have something similar on my K series

Jack