racecar

With a 233/239 .600 cam, CNC heads, 11.5 compression, and an aluminum flywheel, this motor should have really quick revs, but it feels sluggish when I give it gas. If it had a carburator, I would say that it needs more accelerator pump. It just doesn't want to take the gas. When cruising at 3000rpm in 2nd gear, it should jump at any increase in throttal, but it just feels lazy. If I floor it, yes it goes good from 3000-65000, but it feels flat when I give it a 1/4 throttal or 1/2.
I have worked on the VE table and spark below 3000 to get it to take off from a stop sign, but it just does not have a quick snap your head back feeling. If you push in the clutch and rev the gas pedal, it feels lazy. The injectors are sized right and the PE is good. The wideband O2 numbers are good in closed loop and open. What should I try next???
Thanks

racecar

Any ideas?? Tuners??

jimmyblue

iTrader: (11)

I would suspect something with the throttle, like the PCM
trying to make a "desired torque" number rather than a
straight throttle position that tracks pedal position. I am
not too up on the inner workings of drive by wire but have
seen some logs where the guy thought he was WOT, but
the true throttle position was being moved by the PCM
with RPM and never got fully open. Look at the pedal
position (?) and TPS, see if it's giving you what you ask
for.

racecar

Thanks man, that's a good idea to check out. That's exactly the problem, it's like there is a delay in the throttal opening.

Bink

What AFRs are you running and when is PE set to kick in (TPS%)?? If you are at 14.63 it will seem sluggish.

RedHardSupra

iTrader: (1)

that's not true, i had a car last weekend tuned at a track, and the owner forgot to switch some things, and ended up with a 1.00 PE, and the car felt great, pulled like mad. not that i recommend it, but it will not feel slugish

family sedan

iTrader: (3)

racecar: You sure you have enough spark advance? Try putting more in down low and in the mid range.

Bink

I'm telling a falsehood? I'm a liar??



My car 2001 Z06, 239, 251 on a 106 lsa, heads, headers, lightweight Exedy Dual disc:

AFR = 14:00 - 14:63, rap the throttle - it revs.
AFR = 12.90 - 13:10, rap the throttle - it Barks.

Part throttle response much better @ higher EQs.

FWIW.

macsperformance

iTrader: (2)

From what you are saying....it sounds like an acceleration enrichment vs. TP rate of change problem.

Does the car feel less slugish if you roll (slower) into the throttle?



Chris Macellaro

ringram

Id vote for timing.
Are you getting any knock?
I think you should get it on the dyno and see what spark it likes for max torque.
Otherwise, yes check afr, but I think off throttle response will be down to timing.

Did you scale the effective area table for ETC? It might have something to do with this too.

racecar

Wow, Great input. The AFR runs about 13.4 in closed loop and 12.7 in open. That should work. Any increase in throttal, it has a dead spot for the first 1/4, when you give it 1/2 of the pedal it runs, WOT it goes great.
I have added spark below 3000, leveled out the table on all those columns that were really low. Maybe could add more there, what is safe? anything below 18 or 20 ?
"acceleration enrichment vs. TP rate of change" Chris could you explain where this is at with LS1Edit and what values should I change? Likewise with "effective area table for ETC" where do I find it and what should I try to change it to. Thanks guys.
I just tried some WOT runs on this new motor, WOW is it strong from 4200-6500.
My first race is this weekend. If you guys can explain some of these ideas, I will reprogram before I go out.

Bink

I don't think "eff area" is available in Ls1edit -and it doesn't apply to ETC.

Stock Throttle body?

Is VE table stock except for adjustments made, as you stated, below 3000 rpm to get it to launch??
If so that's your main problem.

macsperformance

iTrader: (2)

sorry my friend...


I did not read this portion of your post.....that changes my response a little bit.

Bink and ringram sound like they are on the correct track. What kind of timing values do you have in that portion of the map? And you stated you worked on the VE.... how much have adjusted those numbers from the original map and what kind of numbers are in the map? Can you post up a screen shot of your spark table and VE table?



thank you
Chris Macellaro

racecar

Thanks guys, I will post spark and VE after the weeekend. Right now I have to replace the cracked rear brake rotors, Install new front brake cooling ducts, adjust the front sway bar, bleed the brakes, all of that tonight, and tomorrow is my first SCCA weekend of the year.

racecar

SPARK AND VE ARE ATTACHED, CAN YOU GUYS CHECK THIS OUT. I WOULD REALLY APPRECIATE YOUR INPUT HERE. THIS IS ONE OF THOSE AREAS WHERE THERE IS NO BOOK, AND VERY FEW PEOPLE WITH EXPERIENCE. THANKS.
The good news is that I ran the first SCCA race last weekend, Started 5th, thought my motor was slow at the start, but I passed everyone into turn one.
Once it gets past 4200 it really gets strong.

racecar

Timing, VE, what do you guys think I should change next??

RedHardSupra

iTrader: (1)

injectors

Bink

Buy EFILive commercial version.
Turn off the MAF and do an AutoVE tune.
You can't finesse it on a track unless part throttle is tuned.

jimmyblue

iTrader: (11)

So did you do anything with the electric throttle? I still
think that having it less than full open, has to cost you
MAP hence torque. You can tune it up for that but seems
to me, you want your foot and not some fancy computer
estimate of what torque you wanted, to control the
throttle.

racecar

Jimmy, There is a max torque setting that I reset to 639, that was the max number that it would accept. When I am driving and it starts pulling, it does not feel torque limited.
You may be right about the throttal body not reacting, but how do you change that on a C5 electronic. That's my complaint, when you free rev it or step on it at 3000 in second, it is sluggish until 4200. You can say that is just the cam power range, but it should have much better revs with no load. I built small block race motors ten years ago with more cam than this, and they had impressive quick revs. This one is flat.