New tune, new numbers *UPDATE WITH TRACK TIMES*
06-12-2010, 12:57 AM
#1
New tune, new numbers *UPDATE WITH TRACK TIMES* Mods in sig for the chevelle
Tune was started at the beginning of the year but drive shaft failure led to transmission destruction and I finally got back today.
Only took one more pull to finish the tune to 13.2 a/f and 28* timing, no knock. I didn't want to push my luck so I decided against a locked/cutout open glory pull.
Unlocked converter, cutouts closed, car heat soaked from driving 4 hours: 345rwhp/ 325rwtq SAE
peaked at just under 6000rpm and both curves look perfect, tq is very flat from the 4000stall flash to 5250rpm
I'm a little bummed with the results but waiting to run at the track before I worry much...car feels stronger in the low/mid than before. The past 2 times the car was dynoed torque was 340...not sure why the drop this time especially with the addition of the underdrive and 3" exhaust pipe since then.
Some factors that are hurting me: drag radials, heavy wall chromoly steel driveshaft, 12 bolt
The first pull for this tune back when it broke was 360rwhp/340tq but a/f was 14:1.
Tune was started at the beginning of the year but drive shaft failure led to transmission destruction and I finally got back today.
Only took one more pull to finish the tune to 13.2 a/f and 28* timing, no knock. I didn't want to push my luck so I decided against a locked/cutout open glory pull.
Unlocked converter, cutouts closed, car heat soaked from driving 4 hours: 345rwhp/ 325rwtq SAE
peaked at just under 6000rpm and both curves look perfect, tq is very flat from the 4000stall flash to 5250rpmI'm a little bummed with the results but waiting to run at the track before I worry much...car feels stronger in the low/mid than before. The past 2 times the car was dynoed torque was 340...not sure why the drop this time especially with the addition of the underdrive and 3" exhaust pipe since then.
Some factors that are hurting me: drag radials, heavy wall chromoly steel driveshaft, 12 bolt
The first pull for this tune back when it broke was 360rwhp/340tq but a/f was 14:1.
Last edited by thunderstruck507; 02-21-2011 at 01:37 PM.
06-12-2010, 08:37 AM
#2
Good to see you finally got your problem free dyno session! Look like solid numbers to me, I bet it will run strong at the track.
Do you have any track numbers with previous setups?
Do you have any track numbers with previous setups?
06-12-2010, 01:36 PM
#3
14.1 is way too lean, and 13.2 is still too lean, i am not saying for power reasons but for safety reasons
power numbers are not surprising through a unlocked converter especially 3600-4000k stall... also generally the reverse split cams make great under the curve "mid range power" with a slight sacrifice of top end power..... i would just run the car at the track, i bet it performs like 400 rear wheel car
power numbers are not surprising through a unlocked converter especially 3600-4000k stall... also generally the reverse split cams make great under the curve "mid range power" with a slight sacrifice of top end power..... i would just run the car at the track, i bet it performs like 400 rear wheel car
06-13-2010, 12:49 PM
#4
stock stall, old tune: 8.4x-8.5xs 2.0 60 fts
yank 3600, built trans, heavy *** driveshaft, 26xx DA, old tune: 7.89@88 1.79 60ft
I hope to get numbers with the new tune this weekend. Between tune and underdrive I'd like a 7.7-low 7.8 pass@90 to not be too bummed. If I make it for test and tune I would like to run 3-4 passes new tune then load the old one.
For what it's worth my cutouts have averaged a .15et drop and 1mph gain at the strip
Car weighs 3800 street weight with me and a full tank and some luggage, should be right under 3700 with me race weight (I pull my sub, tools, box full with spare starter coil packs wires plugs, and my 12v air pump flat repair kit)
yank 3600, built trans, heavy *** driveshaft, 26xx DA, old tune: 7.89@88 1.79 60ft
I hope to get numbers with the new tune this weekend. Between tune and underdrive I'd like a 7.7-low 7.8 pass@90 to not be too bummed. If I make it for test and tune I would like to run 3-4 passes new tune then load the old one.
For what it's worth my cutouts have averaged a .15et drop and 1mph gain at the strip
Car weighs 3800 street weight with me and a full tank and some luggage, should be right under 3700 with me race weight (I pull my sub, tools, box full with spare starter coil packs wires plugs, and my 12v air pump flat repair kit)
Last edited by thunderstruck507; 06-13-2010 at 12:55 PM.
06-15-2010, 10:00 AM
#5
so I know the numbers are corrected for temp and humidity, but does the hat of the day and minimal airflow from the fans hurt things anyway?
several friends have insisted the car being so hot from the drive and 90*+ temps with soaking humidity still didn't help anything
I'm just hoping to make it to the track Sat night
several friends have insisted the car being so hot from the drive and 90*+ temps with soaking humidity still didn't help anything
I'm just hoping to make it to the track Sat night
06-21-2010, 11:19 AM
#6
car ran better in worse air
1.79 60ft spinning some
7.85@82mph ( I let off, car was doing high 88mph runs that night)
DA was at least 2900 (humidity went up as the night went on and was 2900 with 50% humidity), race weight was at least 3700# because I had 3/4 tank or more (didn't plan on making it in time to race)
1.79 60ft spinning some
7.85@82mph ( I let off, car was doing high 88mph runs that night)
DA was at least 2900 (humidity went up as the night went on and was 2900 with 50% humidity), race weight was at least 3700# because I had 3/4 tank or more (didn't plan on making it in time to race)
06-21-2010, 01:33 PM
#7
Nice track numbers, thanks for the update!
Are you pleased with the current performance? Do you have any more mods planned or are you going to fine tune what you have?
Are you pleased with the current performance? Do you have any more mods planned or are you going to fine tune what you have?
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06-21-2010, 01:48 PM
#8
I am decently pleased, I was hoping for a little better but I guess the Fast intake isn't benefiting my setup as much as some because the cam is meant to handicap intake and the advance it has makes me peak right at 6000rpm.
I am going to work on fine tuning for now, I'm not enjoying the way the car idles up rolling and pulls on the brakes, its like running on a stock stall all over again. So I do need to call my tuner and see what to change to fix that.
The car does seem to pull better under the curve with the new tune. And best I can figure based on DA corrected data I gained right at 18hp with the underdrive and tune.
I want to start saving for ported 243 heads...but I might be better off paying extra on student loans or saving for a good engine build once this one eventually goes.
I am still spinning the Nittos even on the 1.79 60ft passes, so I'm going to look out for a deal on 26"x10" slicks and see if hooking harder helps me much.
Does it seem like my car is running as it should to everyone? DA corrected I'm coming up with 7.56@91.35mph
I am going to work on fine tuning for now, I'm not enjoying the way the car idles up rolling and pulls on the brakes, its like running on a stock stall all over again. So I do need to call my tuner and see what to change to fix that.
The car does seem to pull better under the curve with the new tune. And best I can figure based on DA corrected data I gained right at 18hp with the underdrive and tune.
I want to start saving for ported 243 heads...but I might be better off paying extra on student loans or saving for a good engine build once this one eventually goes.
I am still spinning the Nittos even on the 1.79 60ft passes, so I'm going to look out for a deal on 26"x10" slicks and see if hooking harder helps me much.
Does it seem like my car is running as it should to everyone? DA corrected I'm coming up with 7.56@91.35mph
02-21-2011, 01:40 PM
#9
Ran the car at the 1/4 so I finally have results there:
DA 1842
60 ft: 1.7776 (stabbed 1/2-3/4 and it stuck so I stuck it WOT a few feet out)
330ft: 5.0621
1/8th: 7.8091
trap: 89.55
1000: 10.2091
trap: 101.81
1/4: 12.2473
trap:110.38
I feel like this trap speed is showing low for my mods. My raceweight should be right around 3700# with me in it.
So according to the HP from ET/Trap/weight calcs online, it seems my dyno numbers are fairly accurate. Any red flags to anyone?
Suppose the intake seals on the fast internal or seals for heads to intake were bad causing an unknown leak? Maybe the combo just isn't peak happy?
DA 1842
60 ft: 1.7776 (stabbed 1/2-3/4 and it stuck so I stuck it WOT a few feet out)
330ft: 5.0621
1/8th: 7.8091
trap: 89.55
1000: 10.2091
trap: 101.81
1/4: 12.2473
trap:110.38
I feel like this trap speed is showing low for my mods. My raceweight should be right around 3700# with me in it.
So according to the HP from ET/Trap/weight calcs online, it seems my dyno numbers are fairly accurate. Any red flags to anyone?
Suppose the intake seals on the fast internal or seals for heads to intake were bad causing an unknown leak? Maybe the combo just isn't peak happy?
02-22-2011, 09:21 AM
#10
No opinions?
I am currently thinking a cam swap to something in the 234-238 range, maybe EPS or similar lobes when the ls6 heads go on. My current cam is a milder lobe cam based off the TR230 which is already considered a mild design by modern LSx standards.
I am currently thinking a cam swap to something in the 234-238 range, maybe EPS or similar lobes when the ls6 heads go on. My current cam is a milder lobe cam based off the TR230 which is already considered a mild design by modern LSx standards.
02-22-2011, 10:10 AM
#11
Not bad at all imo. A converter swap to something like a fti 3800 or 4k should pick you up another tenth or 2 and 1-2mph. Also like you said a custom eps lobe or something similar should yield more gains aswell. The tr230 was good in its day, but there are better options out there now.
02-22-2011, 03:22 PM
#13
In your opinion, what would be the reason my car has an injector duty cycle of 94-96% at 6000rpm assuming I have correct fuel pressure at the line? Could I have an undiagnosed vacuum leak (my suspicion)?
I reused the gaskets on the fast intake, which appeared to be stock gaskets from a ls1/ls6 intake.
See thread here if you have time to input:
https://ls1tech.com/forums/generatio...l#post14540801
