Made it to 11s but trap might be low, ideas?
03-06-2012, 07:56 AM
#23
May not be he whole thing but....
15x10 Torque Thrust IIs325/50r15 MT ET street radials (aired to 12.5# but this lap was a hot lap, likely at 13.5# at time of pass)
Drag radials when aired to a comparible PSI to a Bias PLy slick should put down a faster MPH but being that you have a heavier rim, and the PSI is LOW those are contributing factors. If you can't launch with a higher PSI, then you may need to do some work on suspension so that the tires can hold more and thus have a better MPH on the back half. Heavier rims running off the axles effect HP and hence MPH so put something lighter on there, you will see a difference.
Being that its a 4L60e car you should not need that low of PSI in the tire and the converter seems a little tight and given the race weight 3.73 to a 4.10 would really turn up the wick on the N/A runs. Just depends on how much you want to get into it.
Last to mention, Areodynamics and Drag co-effiecent. Your not a 4th Gen Firebird or a lighter C5, your pushing air and thats going to effect the back half mph too.
15x10 Torque Thrust IIs325/50r15 MT ET street radials (aired to 12.5# but this lap was a hot lap, likely at 13.5# at time of pass)
Drag radials when aired to a comparible PSI to a Bias PLy slick should put down a faster MPH but being that you have a heavier rim, and the PSI is LOW those are contributing factors. If you can't launch with a higher PSI, then you may need to do some work on suspension so that the tires can hold more and thus have a better MPH on the back half. Heavier rims running off the axles effect HP and hence MPH so put something lighter on there, you will see a difference.
Being that its a 4L60e car you should not need that low of PSI in the tire and the converter seems a little tight and given the race weight 3.73 to a 4.10 would really turn up the wick on the N/A runs. Just depends on how much you want to get into it.
Last to mention, Areodynamics and Drag co-effiecent. Your not a 4th Gen Firebird or a lighter C5, your pushing air and thats going to effect the back half mph too.
03-06-2012, 08:03 AM
#24
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Was about to ask why you're running 28's with 3.42's, can't beat $200 for new tires though. You should come run at ozark raceway park with us some time, several guys from here run there.
03-06-2012, 08:45 AM
#25
I was running lower pressure based on MT website recommendations. I went back to the track Sunday and ran 17# and the car was more consistent on the burnout and launch. Didn't seem to affect MPH but it did let me get 3 decent 60fts.
1.69
1.70
1.71
Then the track got messy from all the street cars and I never got another clean pass.
It also looked like the pcm was short shifting the 2-3 at 6200-6300. I forgot to compensate the tune for the 28" tires since I run 26" on the street. I need to work out a track tune and a street tune to account for the difference.
1.69
1.70
1.71
Then the track got messy from all the street cars and I never got another clean pass.
It also looked like the pcm was short shifting the 2-3 at 6200-6300. I forgot to compensate the tune for the 28" tires since I run 26" on the street. I need to work out a track tune and a street tune to account for the difference.
03-06-2012, 01:08 PM
#26
Consistancy is important, but further upping the pressure to the point where 60 foot is negativly effected is a good plan to see HOW MUCH you can run before it detracts from the results.
If the car likes low 20's and puts up 1-2 MPH due to the harder tire and cuts the same 60 foot, there is room to work here.
If the car likes low 20's and puts up 1-2 MPH due to the harder tire and cuts the same 60 foot, there is room to work here.
03-06-2012, 02:22 PM
#28
The cam was designed by Geoff for my combo and he said it would peak before my desired 6500rpm shift point but carry on to 6800rpm if I wanted to. I had set the pcm to shift higher by RPM, but it acts like the tire size threw off the MPH and the pcm was shifting off of that for the 2-3 instead.
The cam was installed dot to dot, I can't remove my oil pan with the engine in the car and wouldn't be able to remove the oil pump pickup without doing that. Since there was no way the engine was coming out during the cam/head swap I didn't see the point dropping money on the tools I would have needed and the adjustable timing set to properly degree the cam since I couldn't have changed it anyway.
In fact I had a huge "oh ****" moment when I dropped a cam gear bolt and it bounced into the small passenger corner of the pan and rolled along the pickup tube into the pan. 1 in a million shot. I had to spend 10 minutes with a magnet to drag it over the the driver side and then use a magnet on a flexible rod to fish it out between the block and the pan lip.
The cam was installed dot to dot, I can't remove my oil pan with the engine in the car and wouldn't be able to remove the oil pump pickup without doing that. Since there was no way the engine was coming out during the cam/head swap I didn't see the point dropping money on the tools I would have needed and the adjustable timing set to properly degree the cam since I couldn't have changed it anyway.
In fact I had a huge "oh ****" moment when I dropped a cam gear bolt and it bounced into the small passenger corner of the pan and rolled along the pickup tube into the pan. 1 in a million shot. I had to spend 10 minutes with a magnet to drag it over the the driver side and then use a magnet on a flexible rod to fish it out between the block and the pan lip.
03-06-2012, 02:40 PM
#29
Do you plan to run your car NA and never plan on using nitros? Then If you went from the (YANK)SS3600 to a (YANK)PT4000 like I'm running you wouldn't see as much rpm drop between gears. That would help out your trap speed alot.
03-06-2012, 02:47 PM
#30
I've toyed with the thought of a 50-75 shot but no immediate plans to buy or install a kit.
At the track I can't go 11.5 or they will ban me until I get a roll bar (not happening). So if I did it would be a small shot at the track and maybe a larger one if something else were going down from a roll.
At the track I can't go 11.5 or they will ban me until I get a roll bar (not happening). So if I did it would be a small shot at the track and maybe a larger one if something else were going down from a roll.
10-09-2012, 01:22 PM
#31
Just an update.
I got the 85mm MAF installed (removed stock screen and put one of the Saxon PC screens with larger mesh in), also installed a much larger air filter with a built in velocity stack. Car shows a 2-3 kPa vacuum at peak WOT which if I understand correctly is pretty fair for no ram air.
Retuned the car WOT for the maf changes, 12.6 air/fuel. Also added a degree and half of timing and pulled a degree from where the car hits on a WOT stab so it doesn't get KR on a launch.
Raised shift rpm to 6700rpm, saw a new best peak MAF reading of 49.7 lbs/min on a log run so the car seems to like the extra revs.
Went to a 275/50r15 ET street on a 15x8.5" aluminum slot wheel
new trans fluid and filter
These changes didn't seem to make any difference in the heat, car was running low 12s at 109-110mph in mid 2000 da. I tried to go back the other night now that it was cool (~1700 da) but I unknowingly got bad gas so I was down to 105mph and went home to find out what was wrong. (didn't have my laptop to see that it was pulling over 10* timing)
I am going to try to make it back to the track in the next week or two. Looking for some other budget ideas worth trying.
I got the 85mm MAF installed (removed stock screen and put one of the Saxon PC screens with larger mesh in), also installed a much larger air filter with a built in velocity stack. Car shows a 2-3 kPa vacuum at peak WOT which if I understand correctly is pretty fair for no ram air.
Retuned the car WOT for the maf changes, 12.6 air/fuel. Also added a degree and half of timing and pulled a degree from where the car hits on a WOT stab so it doesn't get KR on a launch.
Raised shift rpm to 6700rpm, saw a new best peak MAF reading of 49.7 lbs/min on a log run so the car seems to like the extra revs.
Went to a 275/50r15 ET street on a 15x8.5" aluminum slot wheel
new trans fluid and filter
These changes didn't seem to make any difference in the heat, car was running low 12s at 109-110mph in mid 2000 da. I tried to go back the other night now that it was cool (~1700 da) but I unknowingly got bad gas so I was down to 105mph and went home to find out what was wrong. (didn't have my laptop to see that it was pulling over 10* timing)
I am going to try to make it back to the track in the next week or two. Looking for some other budget ideas worth trying.
10-10-2012, 03:20 PM
#33
I hope so, I'm running out of ideas and I don't get much in the way of ls1 cars to compare to at our track so I'm left looking on here and I seem to be way out in left field compared to where I think the car should be for the mods.
I can't imagine it being anything too serious since the car has been running and getting the snot beat out of it for years, I would expect a major problem to have caused serious damage by now.
We might be having a local forum dyno day soon on a Land and Sea dyno (which I gather is more like a Mustang and less like a Dynojet) so I could get a graph for the new heads/cam and see if anything looks funny.
It's just hard to believe 100-200lbs and possibly the aero of the car cut .4-.5 and 4-5mph from what a comparable fbody would run. Maybe I should do some research on GTOs, they seem like they would be more comparable for weight and body shape...
I can't imagine it being anything too serious since the car has been running and getting the snot beat out of it for years, I would expect a major problem to have caused serious damage by now.
We might be having a local forum dyno day soon on a Land and Sea dyno (which I gather is more like a Mustang and less like a Dynojet) so I could get a graph for the new heads/cam and see if anything looks funny.
It's just hard to believe 100-200lbs and possibly the aero of the car cut .4-.5 and 4-5mph from what a comparable fbody would run. Maybe I should do some research on GTOs, they seem like they would be more comparable for weight and body shape...
10-10-2012, 03:56 PM
#34
Here is a GTO with very similar mods but I have a Fast intake and mildly ported 799 heads on him but he is a manual. I would really hope the intake and head work would about even out the trans difference. His 1/8th is about the same but similar to an fbody the 1/4 is in the 115mph range:
"Nice and cool tonight. 800-1000' DA.
Spare/jack/skid plate removed.
EPS 230/238 .600/.615 112+2
Vararam, ported TB, stock IM.
Full catless exhaust with PS longtubes.
Monster 3 and McLeod short throw.
Nitto 555R's"
"Nice and cool tonight. 800-1000' DA.
Spare/jack/skid plate removed.
EPS 230/238 .600/.615 112+2
Vararam, ported TB, stock IM.
Full catless exhaust with PS longtubes.
Monster 3 and McLeod short throw.
Nitto 555R's"
10-11-2012, 09:07 AM
#36
Late model, I know it's still not a perfect example.
Here's to hoping I get a clean pass before winter hits...maybe the higher shift points and timing will help a tad. I can also do another tune that is leaner up top (12.8-13.0) and see if it responds better but I've read when you often end up getting e10 fuel the engines can make better power at closer to 12.4 so I compromised on 12.6 since I doubt there is more than a few HP difference between that range.
Here's to hoping I get a clean pass before winter hits...maybe the higher shift points and timing will help a tad. I can also do another tune that is leaner up top (12.8-13.0) and see if it responds better but I've read when you often end up getting e10 fuel the engines can make better power at closer to 12.4 so I compromised on 12.6 since I doubt there is more than a few HP difference between that range.
10-11-2012, 02:01 PM
#38
Probably in November when the track stops running Friday night and starts doing Sunday afternoon.
Too hard to get off work Friday, drive 2+ hours in traffic, race until midnight, then drive 2hours home. Our temps here just started getting nice and cool, might be able to get some 300-800 DA if I'm lucky.
Too hard to get off work Friday, drive 2+ hours in traffic, race until midnight, then drive 2hours home. Our temps here just started getting nice and cool, might be able to get some 300-800 DA if I'm lucky.
10-12-2012, 08:03 PM
#39
I leaned it out one jet size which netted about .25 on an AFR point and picked up MPH. I also pulled 1 degree and picked up MPH. Earlier in the night I tried more timing at 29 and lost MPH.
Between the two, I picked up 1 full MPH and those were really small adjustments.
10-15-2012, 09:17 AM
#40
Yeah, I am going to play with it a little more next time I go. I found I didn't have to richen it to get it to take more timing, just had to go to the cells that were getting hit from a wot punch or downshift and pulled 1.5* out of them so it didn't get KR on the hit.
I'm going to try leaning it out to closer to 13:1 and go a few degrees each way to see what it likes. Right now it's at 27.5*, up from the previous 26*.
I'm going to try leaning it out to closer to 13:1 and go a few degrees each way to see what it likes. Right now it's at 27.5*, up from the previous 26*.