Saab 92 Forum : Saab92x.com / Manual Convertible

ERP · 2018-05-07 14:55:52

2015 BMW M4
It was just dropped off this morning. It took 5 days to ship from Ft. Lauderdale to Colorado. One problem is that it was shipped on the far back of the semi's trailer, it smells like burnt truck brakes. I gave it a quick wash and I'm letting it air out, but it might take days or weeks for that smell to dissipate. Some neat features to get used to, like the auto rev matching and on board diagnostics. Time to RTFM.

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Rodman · 2018-05-07 21:26:27

Beautiful, good luck with it.....

ERP · 2018-05-08 10:38:20

Thanks
The kids like it and their car seats fit great in back. Another bonus, even with the roof up the kids are easy to get in and out of their seats because there is no B pillar, just fit them through the window.

racerjim · 2018-05-08 12:33:32

Sweet ride, congrats!

ERP · 2018-05-22 18:48:13

Its been two weeks since it was delivered and I've started diving into the modifications already. I've installed a shorter clutch pedal stop, clear front side reflectors and wheel spacers (12mm f, 15mm r). Also installed the JB4 piggyback tuner. I've always avoided piggyback systems because they were often a dangerous hack to fool the stock ECU. But I must say that I am impressed with the Burger unit. I can change maps from the driver's wiper stock and during WOT the fuel gauge momentarily changes to a boost gauge.

These S55 engines are rated at 425 hp, but they typically dyno near that at the wheels. With the JB4 unit and 5 gallons of E85 added to a tank of 91, this engine will put down 500 whp. Upgrade the turbos and add methanol injection and you can put down 700 whp. I'm not sure I'll ever take it that far, but its nice to know how easy these engines are to improve.

Last edited by ERP (2018-05-22 18:49:54)

ERP · 2018-05-31 22:13:18

The intakes have been installed. They don't provide much of a performance improvement over the stock air boxes, but it sounds fantastic. And that alone is worth the cost.
Those combined with the JB4 on the car meant it was time to dyno. I was able to run a stock, JB4 tune 1 and 2 on the dyno. The dyno tech did the pulls in 5th gear. Which meant I got to stand next to the rear wheels as they hit 165 mph. driving

Here are the uncorrected dyno numbers. Run 1 is the JB4 tune 2 for E85. Run 2 is the JB4 tune 1 for 91 octane and run 3 is the stock BMW program. There isn't much difference in power output between the tunes above 5,300 rpm, which is attributed to the hardware limitations at this altitude.

Here are the 'corrected' numbers for the dyno altitude of 6,200 ft. The correction factor is 29%, which isn't directly relevant to this engine, but they are good for the ego. Based on dynos from other M3/4s at low elevation, Stock (run 3) the max whp should be ~420, and the JB4 tune 2 should be ~500 whp. Its fun to look at, but low altitude cars with the same tune and hardware will not make these numbers.