Make: Mazda
Model: RX-8
Year: 2005
Engine: 5.3L LH6 (Gen 4)
Transmission: F-Body T56
Rear Gear Ratio: 4.10
PCM: E40
Operating System: 2005 Chevy 6.0 SSR Manual (1250154)
Station Compression ~10.1:1
Mods:
Summit Racing Stage 3 LS Camshaft (231/242 113+3, .600/.600 Lift)
Trick Flow? Double Platinum .660 LS Dual Valve Spring and Retainer Kits TFS-2500286P
Trunion rocker upgrade
Chevy Performance 12576341 42LB Fuel Injectors
Cylinder Heads 799 milled 0.010"
LS7 Lifters
Dorman LS2 Intake (copy of older Fast intake and flows like a TBSS)
Summit HDR 5/16 x .105 wall 7.375 pushrods
CX Racing 1-3/4" Long Tube Headers. Ceramic coated.
Monster Stage 2 Clutch and lightweight 18 lb flywheel
Dual 3" Exhaust with MagnaFlows
180 thermostat
Ported 87mm throttle body
Delphi AF10043 MAF Sensor
Fel-Pro 26191PT .048 Head Gasket
RX-8 Fuel Pressure is 59.5 PSI
Airaid custom cold air intake
Had a LS1 swapped 94 RX-7 back in the day and decided it was time for a project car again. Did this budget build and it's been running for 6 months without issues. Even has A/C!
Ive had trouble finding a local turner that would touch a swapped car. Attached is the current tune from someone local. PCM was from a 2005 Envoy but we flashed a base 2005 SSR LS2 file to start with since pinouts the same and allows for easy cruise control hookup.
Decided to purchase HP Tuners and AEM 30-0334 OBDII X-Series Wideband to learn myself.
Problems with current tune:
1. Cold startup is decent but could be better. It starts and dips down low once, but doesnt stall. Idle stabilizes quickly.
2. Hot starts suck and crank a long time. Hunts for idle very erratically 5+ times up/down before settling after 15-20 seconds. Goosing the throttle during those 20 seconds causes a weird sounding intake backfire.
3. Seem to get a lean intake backfire and stutter when applying more throttle in high load, low rpm situations in 5th or 6th gear on highway. The stutter goes away and car accelerated normally.
4. Insufficient O2 switching error code. O2s barely switch at idle. Common with longtubes but I found a thread on here that can supposedly help wake them up.
5. High negative LTFT trims when cruising on light throttle. -12 or higher.
6. Returns to idle slow under ~1500 rpm.
7. MPG seems worse than it should be. Only getting 14 on highway cruising 2000 rpm @ 74mph. Previous LS1 swapped FD RX-7 with similar specs was better.
8. Full throttle pulls can feel inconsistent depending on starting RPMs
9. Enable DFCO.
Would someone be able to take a look at the current tune and see if anything really sticks out that's incorrect? I've never tuned a car before.
Attached my low rpm high load stutter log file.