Just got back from a dyno day with my club - first pulls for my car. I have the following mods that would affect HP/Mixture, etc.
IATS Relocation Kit
100 Cell Cats from Evosport
SS X Pipe
Eisenmann Race Exhaust
My MAFS are fairly fresh (10k miles or so), fresh plugs, 10k on air filters, etc. The numbers as a whole looked pretty good to me, 332 HP with correction, 332 TQ with correction. The part that concerns me is the AF Mixture. It was about 13.8 and definetley on the high side. I was thinking it could be a number of things:
1. O2 Sensors need replacement. To the best of my knowledge they have never been done - sitting at 65k miles
2. Software maps may be off because of higher flow of cats, x pipe and exhaust
3. Dirty MAF's
Any other suggestions? At the end of the run the AF seems to come back in line. Below are 2 graphs that I pulled with SAE correction.
Thanks for the help.
p.s. On a positive note, the TQ band looks BIG and FLAT. Lots of power at 2k all the way to 5500 before it falls below 300.
__________________ Current Toys: 2000 M5 with lots of goodies, 1997 993 Targa mostly stock, 2002 Jeep GC all set for offroad, 2004 Acura TL bone stock
Last edited by TiSiBeast; 17th February 2007 at 23:15.
the other potential source for error was the shop's afr sensor too, unless they plugged into the 02 sensor pre cat, those numbers have potential for error.
Did other car's at the dyno day have more 'normal' looking afr's?
__________________
Mike
91 M5 Alpine White II, Silver Gray 3/90 production
17x8/17x9 M system with PS2, 20mm touring roll bar; Ground Control Coilovers; EAT Chip, CD43; bmw/nardi blackline steering wheel, 3.8 Cam Gears
08 535i / 6 speed
Space Gray; Gray; Sport/Premium/Nav
00 M5 Ti Silver; Imola/black sportiv --Sold
Engine:
Supersprint Headers, Dinan CAI kit and MAFS, Throttle Bodies, Cams, Ported heads, Exhaust, Custom dinan software, Evosport Pullies, Dinan clutch and lightened flywheel; Ignition solutions plasma coils
Suspension:
Dinan Stage 3 with front and rear Strut Tower Braces, Beastpower Sway bar brackets, Dinan Wheels with 275/285 PilotSport, X5 Thrust arm bushings, Stoptech 355mm 4 piston front, 355mm 2 piston rear brake kit, Dinan 3.45 diff
Interior/Misc:
Eurodash, updated steering wheel, Bluetooth retrofit, Sirius Retrofit, hardwired V1, Widescreen Mk4 nav, M audio retrofit, Ice Link, BSW Stage 1 speaker upgrade, bmw towbar
the other potential source for error was the shop's afr sensor too, unless they plugged into the 02 sensor pre cat, those numbers have potential for error.
Did other car's at the dyno day have more 'normal' looking afr's?
Yes, the other cars that I saw were pretty much in line. My buddy's Cobra ran a 475 RWHP at a 12.8 AFR. Like I said, the HP and TQ numbers actually looked pretty good to me, especially considering it was 75 degrees, 8% humidity at 1150 Ft. They just had a probe in the tail, nothing direct from the ODB or the O2 directly.
__________________ Current Toys: 2000 M5 with lots of goodies, 1997 993 Targa mostly stock, 2002 Jeep GC all set for offroad, 2004 Acura TL bone stock
Your numbers are right on for a beast performing well. WRT A/F ratios.. there are many variables that effect this including heatsoak in the engine bay andthe resulting fuel map the engine used. Your power numbers look good.
A software tune may be the next step if you really want to maximize any gains from the CAI and exhaust. Though you can wait for other mods before doing this if desired.
Looks like you have yourself a well built engine.. enjoy!
Check out Post # 138 in this thread. You'll see where I ran an AFR well into the 13's, had it retuned to average 12.4 or so, with great results (357.6 HP). You can compare the old curves as they're on the posted chart. There's probably another 7-8 HP left above 6600 RPM as you can see from the rich AFR. YMMV.
Check out Post # 138 in this thread. You'll see where I ran an AFR well into the 13's, had it retuned to average 12.4 or so, with great results (357.6 HP). You can compare the old curves as they're on the posted chart. There's probably another 7-8 HP left above 6600 RPM as you can see from the rich AFR. YMMV.
Do you have a link to this thread?
__________________ Current Toys: 2000 M5 with lots of goodies, 1997 993 Targa mostly stock, 2002 Jeep GC all set for offroad, 2004 Acura TL bone stock
Check out Post # 138 in this thread. You'll see where I ran an AFR well into the 13's, had it retuned to average 12.4 or so, with great results (357.6 HP). You can compare the old curves as they're on the posted chart. There's probably another 7-8 HP left above 6600 RPM as you can see from the rich AFR. YMMV.
+1. I had low 12's, around 12.2 at high RPM using the tail sniffer pipe. A few hp may be left on the table, but I won't hole a piston from running too lean either.
Regards,
Jerry
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'01 Black/caramel
Dinan Stage 3 suspension, SS jet coated headers, ESS SC kit, open brake ducts, Hamann front splitters, TEC cupholder, U.S.(Euro style) tilt/slide armrest, 6k HID fogs, 6k super white low beams, V1/Stealth1, dual head LI, 2.65 diff w/40% lockup/2x dynamic, compact spare, Euro trailer hitch, Mocal oil cooler, ACS type rear spoiler, Rogue custom SSK and tranny mounts, ST 355 BBK (fronts), BP sway bar brackets, Bluetooth retrofit
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