Why won't it run hard on the backside?
04-25-2012, 12:23 PM
#21
I've had one recent experience that may be of interest to you. I tried backing my cam timing up from 108.5 ICL to 110 ICL and the car slowed down a whopping 2+ tenths and 2.5 MPH in the quarter mile. So, I am going to try 107 ICL next. I will let you know how the car reacts. My smaller cam (226/234) is on a 110 LSA though and I have a short runner intake which is also a consideration.
04-27-2012, 01:07 PM
#22
Just did a couple wot pulls for logs.
MAP kpa key on engine off was 97kpa, at WOT it drops to 94kpa at 4k RPM. By the 6350rwhp shift point it was 91kpa.
I think this means I might be able to find a couple HP by going to a 4" intake tract over the current 3" OD pipe and 3" outlet filter. Might need to do a run with no filter in front of the MAF, hopefully its not the 85mm MAF that is the restriction.
MAP kpa key on engine off was 97kpa, at WOT it drops to 94kpa at 4k RPM. By the 6350rwhp shift point it was 91kpa.
I think this means I might be able to find a couple HP by going to a 4" intake tract over the current 3" OD pipe and 3" outlet filter. Might need to do a run with no filter in front of the MAF, hopefully its not the 85mm MAF that is the restriction.
04-30-2012, 08:30 AM
#24
I guess I don't fully understand fluid dynamics. Hard to wrap my head around a pipe with 3.5" ID but a 90* smooth bend flowing less than a 3" ID MAF full of stuff in the flow path. Gotta learn some time I suppose.
04-30-2012, 03:46 PM
#27
This was the first car I've tuned, so it could surely be possible since I do have EFI live and a wideband...but I am thinking it means there is less room for error in the tune.
I do not know entirely what all is involved in a SD tune but I am not opposed to looking into it. Not like I couldn't switch back just by saving my old tune file and the hard parts.
I do not know entirely what all is involved in a SD tune but I am not opposed to looking into it. Not like I couldn't switch back just by saving my old tune file and the hard parts.
04-30-2012, 05:57 PM
#28
That's what I would do, look into it.. get a filter that will just bolt on the Tb, and see if you can get it running right. If you can, and can get it right you'll be better off IMO.
Leaves the option of not running anything other then the filter.
Leaves the option of not running anything other then the filter.
04-30-2012, 06:17 PM
#29
It's definately not your maf, I fed a 441ci motor and went mid 9's N/A with an 85mm maf.
Your car is heavy and turning that big-*** converter while pulling all 3700+lbs isn't helping u.
Have you considered a smaller diameter converter? U'd lose the lock up feature but that will give you the biggest improvement I feel.
It would let the motor scream up to where it wants to be rpm-wise and then you'll see something.
Your car is heavy and turning that big-*** converter while pulling all 3700+lbs isn't helping u.
Have you considered a smaller diameter converter? U'd lose the lock up feature but that will give you the biggest improvement I feel.
It would let the motor scream up to where it wants to be rpm-wise and then you'll see something.
05-01-2012, 08:47 AM
#30
Really not wanting to lose the lock up or do anything to slaughter the drivability of the car. Might do some 3.73 gears in the future.
I see where you are coming from but without the fuel economy and being pleasant to drive around town and on the highway while still running half decent at the track it would kind of defeat the purpose of the ls1/efi swap.
I would consider having the converter rebuilt as a 4k when it goes in to be freshened up.
I see where you are coming from but without the fuel economy and being pleasant to drive around town and on the highway while still running half decent at the track it would kind of defeat the purpose of the ls1/efi swap.
I would consider having the converter rebuilt as a 4k when it goes in to be freshened up.
11-21-2012, 09:29 AM
#32
I just went over the weekend, last time they will be open for the year and the car is finally in a better spot!
Trapped a best of 115 mph and consistent 114 mph all day.
Changes:
upped timing to 27.5*
5 gallons of 94 octane mixed with 14 gallons Shell 91 (had 3/4 tank by the time I was at the track) to insure no burst knock was possible at all
12.7:1 AFR with the tune on pure 91, didn't read what the 94 did to it if anything
upped the shifts/rev limit, shifts at 6750rpm
1100-1400ft DA, slight tailwind
installed smaller orifice PCV valve and an oil catch can to reduce oil in intake
cool air so IAT were reading 68-74* which I think helped a lot
Car ran new best everything but 60ft (crappy track prep):
1.7155 60ft (rolling into throttle a bit) (previous best 1.68)
7.50@93.05 mph 1/8th
11.7916@113.95 mph 1/4
That pass the car kissed the rev limit on the 1-2 so an adjustment of rev limit there should help some more. I honestly think the car just wants to rev further than I am, but I can't advance the cam without pulling the engine so I'm stuck with it for now. Overall I'm pleased. I bet if I shifted it at 6850 or higher it would pick up more. I finally found graphs of similar cams and they seem to peak at 6500-6600 but carry flat to 6800-6900 before falling off slowly.
Trapped a best of 115 mph and consistent 114 mph all day.
Changes:
upped timing to 27.5*
5 gallons of 94 octane mixed with 14 gallons Shell 91 (had 3/4 tank by the time I was at the track) to insure no burst knock was possible at all
12.7:1 AFR with the tune on pure 91, didn't read what the 94 did to it if anything
upped the shifts/rev limit, shifts at 6750rpm
1100-1400ft DA, slight tailwind
installed smaller orifice PCV valve and an oil catch can to reduce oil in intake
cool air so IAT were reading 68-74* which I think helped a lot
Car ran new best everything but 60ft (crappy track prep):
1.7155 60ft (rolling into throttle a bit) (previous best 1.68)
7.50@93.05 mph 1/8th
11.7916@113.95 mph 1/4
That pass the car kissed the rev limit on the 1-2 so an adjustment of rev limit there should help some more. I honestly think the car just wants to rev further than I am, but I can't advance the cam without pulling the engine so I'm stuck with it for now. Overall I'm pleased. I bet if I shifted it at 6850 or higher it would pick up more. I finally found graphs of similar cams and they seem to peak at 6500-6600 but carry flat to 6800-6900 before falling off slowly.
Last edited by thunderstruck507; 11-21-2012 at 09:34 AM.
11-30-2012, 12:30 AM
#40
Fwiw it's not uncommon to see guys turn off every unneeded electrical load possible, makes the alt have a lower load, which decreases drag, and without an alt it keeps the ign. Voltage higher for the run as well... I know people that will even shut the water pump and fans off as they stage the car, and flip them back on after going thru the traps. I don't suggest it but its a more common practice then you'd think.