Duratec Roller Barrel upgrade BHP

[DCL]

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 .

Edited by DCL on Saturday 2nd March 19:45

[DCL]

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

[DCL]

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).