LAGUNA SECA -SCCA ITE / American V8 supercar race this saturday 6.8.13
06-11-2013, 02:14 PM
#32
Under the Lift
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Lifetime Rennlist
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I was talking to Brian who said his car runs 280ish rwhp with a pretty decent fuel air mixture of near 12:1, and only has 37psi fuel pressure.
I do remember tuning my buddies S4 6 liter who had near 15psi and ran ok, but was still running kind of fat for reasons we still don't quite understand.
anyway, Im at 43psi and can easily drop my pressure down to 37psi. maybe that might clear up some richness at the top end. if I can get the mixture in the 12s from 5500 to 6500rpm, where else can I gain Hp by tuning, even with a shark tuner? timing??
I might have to check out running another brain so I can do a shark tunen and see what the potential is of the 6.4 liter with the stock stuff on top of it.
I do remember tuning my buddies S4 6 liter who had near 15psi and ran ok, but was still running kind of fat for reasons we still don't quite understand.
anyway, Im at 43psi and can easily drop my pressure down to 37psi. maybe that might clear up some richness at the top end. if I can get the mixture in the 12s from 5500 to 6500rpm, where else can I gain Hp by tuning, even with a shark tuner? timing??
I might have to check out running another brain so I can do a shark tunen and see what the potential is of the 6.4 liter with the stock stuff on top of it.
I do have spare ECUs with PEMS installed. If we can get Sharktuner wired (with a wideband O2 installed - I have that too), we could do some real tuning and burn chips for your ECUs. I don't have much time until late August (tied up w/ a home remodel/sale), but we could try Sharktuner again then. Until then, sure, drop the FP a bit.
06-11-2013, 07:09 PM
#33
Race Director
I was talking to Brian who said his car runs 280ish rwhp with a pretty decent fuel air mixture of near 12:1, and only has 37psi fuel pressure.
I do remember tuning my buddies S4 6 liter who had near 15psi and ran ok, but was still running kind of fat for reasons we still don't quite understand.
anyway, Im at 43psi and can easily drop my pressure down to 37psi. maybe that might clear up some richness at the top end. if I can get the mixture in the 12s from 5500 to 6500rpm, where else can I gain Hp by tuning, even with a shark tuner? timing??
I might have to check out running another brain so I can do a shark tunen and see what the potential is of the 6.4 liter with the stock stuff on top of it.
I do remember tuning my buddies S4 6 liter who had near 15psi and ran ok, but was still running kind of fat for reasons we still don't quite understand.
anyway, Im at 43psi and can easily drop my pressure down to 37psi. maybe that might clear up some richness at the top end. if I can get the mixture in the 12s from 5500 to 6500rpm, where else can I gain Hp by tuning, even with a shark tuner? timing??
I might have to check out running another brain so I can do a shark tunen and see what the potential is of the 6.4 liter with the stock stuff on top of it.
However my 265whp-289 torque 4.5L is hitting near 88% duty cycle at 6000 at the end of the straights.....its about 12.0-12.1 on my new wide band too...
If I were to bump up to a 5.0L I would get an adjustable regulator to bring my duty cycle down a bit
06-11-2013, 07:11 PM
#34
Rennlist Member
I can tell you that below 30 PSI, the injectors fail. I don't know how far you can drop below the "rated" pressure of 45 PSI before it adversely affects the spray pattern enough to matter.
I do have spare ECUs with PEMS installed. If we can get Sharktuner wired (with a wideband O2 installed - I have that too), we could do some real tuning and burn a chips for your ECUs. I don't have much time until late August (tied up w/ a home remodel/sale), but we could try Sharktuner again then. Until then, sure, drop the FP a bit.
I do have spare ECUs with PEMS installed. If we can get Sharktuner wired (with a wideband O2 installed - I have that too), we could do some real tuning and burn a chips for your ECUs. I don't have much time until late August (tied up w/ a home remodel/sale), but we could try Sharktuner again then. Until then, sure, drop the FP a bit.
06-11-2013, 07:13 PM
#35
Rennlist Member
I run bone stock fuel pressure regulator...not even adjustable.....its set by the factory at 2.5bar or 36.75psi.... We tested it at about 37psi....I think all pre S4 928's with L or LH jet ran this pressure too.....
However my 265whp-289 torque 4.5L is hitting near 88% duty cycle at 6000 at the end of the straights.....its about 12.0-12.1 on my new wide band too...
If I were to bump up to a 5.0L I would get an adjustable regulator to bring my duty cycle down a bit
However my 265whp-289 torque 4.5L is hitting near 88% duty cycle at 6000 at the end of the straights.....its about 12.0-12.1 on my new wide band too...
If I were to bump up to a 5.0L I would get an adjustable regulator to bring my duty cycle down a bit
More fuel per squirt, you are already a bit fat..you need to lean out what you have now a little. Not too concerned about 88% where you are now, when it needs to be lower anyhow.
06-11-2013, 10:08 PM
#36
Rennlist Member
Thread Starter
I run bone stock fuel pressure regulator...not even adjustable.....its set by the factory at 2.5bar or 36.75psi.... We tested it at about 37psi....I think all pre S4 928's with L or LH jet ran this pressure too.....
However my 265whp-289 torque 4.5L is hitting near 88% duty cycle at 6000 at the end of the straights.....its about 12.0-12.1 on my new wide band too...
If I were to bump up to a 5.0L I would get an adjustable regulator to bring my duty cycle down a bit
However my 265whp-289 torque 4.5L is hitting near 88% duty cycle at 6000 at the end of the straights.....its about 12.0-12.1 on my new wide band too...
If I were to bump up to a 5.0L I would get an adjustable regulator to bring my duty cycle down a bit
so, i dont understand if you are 88% duty cycle at 265rwhp and they are the stock 24lb injectors, that the S4 went to 19lb injectors for the same HP (about).
maybe the S4 is just a lot leaner naturally . of course i bumped up the pressure to 70psi and had 335rwhp with the 19lbers.
I can tell you that below 30 PSI, the injectors fail. I don't know how far you can drop below the "rated" pressure of 45 PSI before it adversely affects the spray pattern enough to matter.
I do have spare ECUs with PEMS installed. If we can get Sharktuner wired (with a wideband O2 installed - I have that too), we could do some real tuning and burn chips for your ECUs. I don't have much time until late August (tied up w/ a home remodel/sale), but we could try Sharktuner again then. Until then, sure, drop the FP a bit.
I do have spare ECUs with PEMS installed. If we can get Sharktuner wired (with a wideband O2 installed - I have that too), we could do some real tuning and burn chips for your ECUs. I don't have much time until late August (tied up w/ a home remodel/sale), but we could try Sharktuner again then. Until then, sure, drop the FP a bit.
Then, i guess we can try a real tune!
Mark
06-11-2013, 10:11 PM
#37
Rennlist Member
Thread Starter
Remember gregs 928 was running (as crappy as it was )at sub 20psi. It was so low i thought my gauge was broken. but raised it up to near 40psi , but still didnt fix the running problem. (im sure its got other issues). its running ok now, but occasionally floods out after its turned off, on restart. Im thinking its a leaking injector or something else.
06-12-2013, 07:48 PM
#38
Race Director
06-12-2013, 10:37 PM
#41
Race Director
If an RD needed any more info...just watch the stupid blocking moves he made earlier......I have no doubts there were a "few" complaints about this driver
06-12-2013, 11:14 PM
#43
You gotta be kidding.....the RSX pushed a stupid pass in PIT LANE.....then understeered wide and FORCED the RX7 off track.....no way...you are wrong
If an RD needed any more info...just watch the stupid blocking moves he made earlier......I have no doubts there were a "few" complaints about this driver
If an RD needed any more info...just watch the stupid blocking moves he made earlier......I have no doubts there were a "few" complaints about this driver
That he was let by a few turns before butt did not let his opponent by?
Just think how sweet it would have been for them to continue to swap positions.
tino
06-12-2013, 11:19 PM
#44
Rennlist Member
He left room to BE passed, and left racing room as well...but failed to account for what you must expect in a late inside pass at an apex..that the passing car (who has right to be there in this case) can either define ANY point to actually turn that they WANT to, or..may push a little. Same result if you don't plan for it.
If you don't wanna be passed somewhere, defend it. Bob screwed up.
The passing car didn't push anyone anywhere, Bob in the RX7 reacted to it quite well, he knew he was there...the RX7 didn't even own the corner as they went into it.
The honda did push thru the turn some when it bounced thru the apex, but go to your CCR, figure 12, page 118 or so.
There was no driving in any pit lane in that pass either. Two wheels on the racing surface is "on course" and legal to pass with.
Even if there was contact..the RX7 would have still been at fault.
Was there another timecode
06-12-2013, 11:34 PM
#45
Rennlist Member
Race much?
If so, what race organization says you have to let someone by, just because you have to be nice..even if no rule says you have to.
Racing is about exploring weakness and taking advantage of it.
The GOOD racers, know the rules like the back of their eyelids..and will exploit them cleanly.
That was done here.
This isn't HPDE. I've been clear on here about the subtle differences between a track day and a race (in any organization), this is one of them.