Today I headed back down to YarrowSport to watch a Randy Webb Pulley Party and get another dyno run on GBMINI (to see if the recent JCW upgrade upgrade offers any measurable improvement).
Lee, a friend and one-time MINI Peabody tech, came with me – first we went to the local Krispy Kreme where MINIs-Making-A-Wish was helping to launch a toy collection, and Steve, MINIs-Making-A-Wish maestro, was interviewed by the local TV station:
Steve had recently been at Randy Webbs Pulley Party, getting this air intake (and a pulley) fitted (he commented that it was now like driving a new car); so Lee & I headed over to YarrowSport to meet Randy. While we were there we watched a short-shift kit being installed on Marks Pepper White MCS – Mark already had a pulley, computer, exhaust and intake done by Randy at a previous event.
I met “Onasled” again – since the previous Dyno Day he has personally installed a pulley, air intake, computer, header, exhaust and intercooler! Wow! His first dyno run gave 197hp.
Once again Yarrow got creative, adding racing fuel to the car and then super-chilling the intercooler to get a highest reading of 214.6!
Eventually GBMINI went back on the dyno; Yarrow told me that the rig corrects for ambient temperature & humidity differences so it is apparently fair to directly compare the September run with todays run (unfortunately Yarrows printer had no ink!):
We can see on this plot that todays run shows an increase all the way up the rev curve showing a peak torque of about 186 compared with 177 – but the red line cuts in about 200rpm lower, so the peak hp shows only about a 4hp increase.
It looks like there should be about 6-8hp increase (maintained up the curve from about 3300rpm) and I don’t know if the red line is due to operation of the dyno, or a side-effect of the V39 engine update.
So we once again try to conclude some results:
The JCW upgrade upgrade seems to give about 10 lb-ft increase in torque, but the expected hp gain does not show on the above dyno run – apparently due to a lowered red line
A full aftermarket modded MINI can still beat the “210hp JCW”, by about 6hp.
Randy Webb is a great guy who can put together a very high performing package (all the top-performing MINIs at both Dyno Days were equipped with Randys Unichip/Pulley/etc packages.
That intercooler really does need to get cool to give good performance.
Yarrow needs to stock up on his printing supplies!
UPDATE: A close comparison of Onasleds and my plots shows that while his peak hp is better than the JCW, the JCW shows higher hp at lower “real world” revs:
| rpm | JCW | aftermarket |
| 2100 | 61 | 57 |
| 2700 | 86 | 80 |
| 3300 | 115 | 105 |
| 3900 | 137 | 132 |
| 4500 | 157 | 155 |
| 5100 | 171 | 171 |
| 5700 | 182 | 187 |
| 6300 | 185 | 194 |
| Peak | 193.7 | 197.0 |
UPDATE: here is a video of the TV coverage:
M&I / GBMINI 
