427 RX-7 Tune input needed...
09-15-2007, 02:54 AM
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427 RX-7 Tune input needed... Greetings all -
I'm looking for some input on my tune so far. I'm new to tuning GM stuff, my background is AEM/TEC and a few other import setups. I started with my old cal which was performed by a local shop when the car was a H&C 347. I've got unlimited access to a dyno now, so I figured I would try my hand at it. The car is a 93' Mazda RX-7 (2650 LBS
). Here are the engine specifics:
(Built by Erik Koenig)
RED Darton sleeved LS1 block, 4.125" Bore
Diamond Pistons
Callies Racemaster crank, 4" Stroke
Ported LS7 Heads (Greg Good), Ti Valves, stock rockers, upgraded springs
Upper 24x duration/.600ish? lift/112 LSA Cam (Erik told me the specifics once, I've since forgot)
Morel Lifters
LS7 Intake
Holley 90mm TB
1 7/8" headers
52lb Bosch Injectors (OEM 07' GT500 injectors), Modded Nasty rails
Meziere EWP
Alternator only, no other acc's
01' PCM
Right now I'm running Mafless. I disabled SES's for the MAF, copied over my Hi/Lo timing tables and removed the MAF entirely. I *think* I'm set at low RPM with the VE table. I did drive around and tune the VE table a bit. LTFT's are -5 to 0. I pulled a couple degrees of timing up top out of my old tune and did a best guess IFR curve. I couldn't find anything published/posted on these 52 lb injectors. I also updated the displacement in the cal.
So I strapped the car down on the dyno, still MAF-less, and did a couple pulls to 6K. A/F's were ~12:1 from 3500 until about 5K when it started to lean out. I tweaked the VE table from 5K onward and it started to fatten up. I thought about messing with the PE table but that just looked like a multiplier (which was probably correct before?). I added to the VE up top which seemed to help some but still lean. I added some more and did another pull, doin' better. Am I on the right track here? I attached yesterday's cal below. The only difference today was +4 on the VE table from 5200 on up. Below is today's dyno. It looks to fall flat from 5800 onward. I tried to lean the mix out by subtracting VE in that region but it made less power. I figured it would run best a little leaner than this. Does there look to a signifigant gain in power left in the tune? 500 RWHP is kind of a letdown after all this time and money. Let's not even discuss the 14 months my car was down waiting for the "magic" engine to be completed.
If I made some bonehead mistakes in the tune though, please point them out. I'm still learning HP Tuners. I think I have a clue but I could be mistaken
. Below is the cal & dyno sheet. Incidentally, torque peaked at 454 Lbs/Ft.
Thanks for any help!
Ryan
I'm looking for some input on my tune so far. I'm new to tuning GM stuff, my background is AEM/TEC and a few other import setups. I started with my old cal which was performed by a local shop when the car was a H&C 347. I've got unlimited access to a dyno now, so I figured I would try my hand at it. The car is a 93' Mazda RX-7 (2650 LBS
). Here are the engine specifics:(Built by Erik Koenig)
RED Darton sleeved LS1 block, 4.125" Bore
Diamond Pistons
Callies Racemaster crank, 4" Stroke
Ported LS7 Heads (Greg Good), Ti Valves, stock rockers, upgraded springs
Upper 24x duration/.600ish? lift/112 LSA Cam (Erik told me the specifics once, I've since forgot)
Morel Lifters
LS7 Intake
Holley 90mm TB
1 7/8" headers
52lb Bosch Injectors (OEM 07' GT500 injectors), Modded Nasty rails
Meziere EWP
Alternator only, no other acc's
01' PCM
Right now I'm running Mafless. I disabled SES's for the MAF, copied over my Hi/Lo timing tables and removed the MAF entirely. I *think* I'm set at low RPM with the VE table. I did drive around and tune the VE table a bit. LTFT's are -5 to 0. I pulled a couple degrees of timing up top out of my old tune and did a best guess IFR curve. I couldn't find anything published/posted on these 52 lb injectors. I also updated the displacement in the cal.
So I strapped the car down on the dyno, still MAF-less, and did a couple pulls to 6K. A/F's were ~12:1 from 3500 until about 5K when it started to lean out. I tweaked the VE table from 5K onward and it started to fatten up. I thought about messing with the PE table but that just looked like a multiplier (which was probably correct before?). I added to the VE up top which seemed to help some but still lean. I added some more and did another pull, doin' better. Am I on the right track here? I attached yesterday's cal below. The only difference today was +4 on the VE table from 5200 on up. Below is today's dyno. It looks to fall flat from 5800 onward. I tried to lean the mix out by subtracting VE in that region but it made less power. I figured it would run best a little leaner than this. Does there look to a signifigant gain in power left in the tune? 500 RWHP is kind of a letdown after all this time and money. Let's not even discuss the 14 months my car was down waiting for the "magic" engine to be completed.
If I made some bonehead mistakes in the tune though, please point them out. I'm still learning HP Tuners. I think I have a clue but I could be mistaken
. Below is the cal & dyno sheet. Incidentally, torque peaked at 454 Lbs/Ft. Thanks for any help!
Ryan
