91parkave

iTrader: (4)

But air does pass through. Regardless it'll act as a vacuum at speed. If my car wasn't in the body shop right now I'd show how mine is spaced and the gap

rottonj

iTrader: (4)

I cross referenced the Impala police radiator GM 15140592 found on Rockauto, and it seems to be the same radiator in the GXP. Part numbers are sometimes fucked up so if anyone has found something different please post your findings. Thanks

Found this also, it may help?

RADIATOR,(CORE SIZE 29 3/8 X 14 9/16 X 7/8)(ACDelco #21576).

spawne32

iTrader: (2)

Yeh, 7/8" core, same size as the Koyo rad i replaced it with.

05GXPjake

Well damn, would you say the Koyo is any better? Or would you attribute any change to simply being newer? thanks!

spawne32

iTrader: (2)

Well, TYC/Koyo ive always had fantastic results with, quality has always been impeccable. I tend to stay away from things like vista pro and readyrad unless its like a last resort kinda thing where I have to change a radiator on the spot with a parts store part. But as rottonj pointed out to me, the koyo rad is a fraction of a hair smaller, not core thickness, but overall core length and width. I dont know if that makes it better or worse or not, its possible the end tanks are slightly larger, or the trans cooler is a slightly different shape, who knows at this point. I don't think it attributes to the running hot though. We were discussing the fact that the idiot gauge on the dash can make it seem like the car is running hotter or cooler then it actually is. The range on my idiot gauge goes from 198 or so about a 1/8" below the middle line, to about 210 at the middle, and roughly 215-217 slightly above the middle line. His is a bit different. It's possible its all sensor related as well, as I have replaced my ECT sensor with a new acdelco one at the time of the rebuild, very well possible the calibration is slightly off.

Regardless of that, 210-217 is NOT overheating by no means, its just alot hotter then id like to see for a highway cruise where airflow is constant over the radiator. That signaled to me that airflow is an issue under the hood, as is the overall cooling capacity. I just got done pulling a half gallon of coolant and put in a container of purple ice, and water, trying to dilute it down to about 60/40 and see if it makes a difference.

rottonj

iTrader: (4)

Yes, mine reads slightly different, but after thinking about it I was reading thru the torque app and a cheap dongle, and yours was from HP software which could be more reliable. Mine right in the middle the reading is 202.4 degrees. Yours also has all new sensors, where as mine are all original at 110k. I think It is probably pretty close to the same, although mine drops to 194 when back on the highway . That is the part that puzzles me with yours, I think it could be the headers generating much more heat and it is having a harder time trying to get it cooler. The coolant additive I think will help, gonna try some on mine too to see if it makes any difference.

spawne32

iTrader: (2)

well, tonights runs were less then stellar at the track, started out with a pathetic 14.3 @ 97mph, and i was furious, so after datalogging two runs I discovered some major issues. First issue that we all unfortunately have to deal with, is traction. I can tell you that, even rolling into it on every run, I spun so bad that on one run i spun to the 1000 ft marker. Second thing i found that was attributing to my bad trap speed, was ignition timing related to high IAT's. So since we all suffer from heatsoak, GM's factory IAT compensation tables are setup where they can actually pull up to 14* of timing from the high and low octane tables based on air temperature. By the time I get to the tree at the track, my IAT's are already heatsoaking and running close to 130-140 even though as soon as i crack the throttle they begin to drop. HPT does not show ACTUAL timing, it only references timing based on the base table and factors in knock retard. So i was showing 28* of timing advance, and zero knock, but in reality that actual timing was 16*.

I went back into the tune file and started playing with the IAT compensation table, at first I set the entire table to -2 where it would have normally had -10's and 12's and 14s etc. So the max it could pull at any time was 2 degrees. The car immediately jumped up to just a hair under 100mph trap speed and cracked the 13's for the first time. However had up to 6* of KR the entire run. Then i went back and began smoothing and lowering the actual base timing tables to something between 23-25 degrees. Was able to lower the KR some, and the final two passes of the night wound up being 101 and just a hair under 102mph, with a 1/4 mile time of 13.8 @ best and a 60 ft of 2.19.

Obviously, not the best results, but there is plenty of room here to get faster now that I know what i have to deal with. I'm gonna need to work on correcting these base timing tables so that they are knock free WITHOUT having any timing being pulled based on IAT alone. Tires, obviously going to be a major issue, the all seasons were worthless. I smoked those ******* into a cloud and they still wouldnt hook. In fact the one run was so bad that i started to lose control of it at about 60mph on a shift when they started spinning and had to let off. lol I was miserable at first when I saw the numbers but I am happy now knowing that it did trap over 101mph with KR and with a shitty timing table, I know now that if i can correct that table specifically and get results from a wideband which i will be ordering real soon, that next time im at the track in a few weeks 103-104 are not out of the realm of possibility.

spawne32

iTrader: (2)

91parkave

iTrader: (4)

I would revisit your timing again after you get fueling right, that being said you really need trash the factory maf and tb now that your cammed. Go with innovative or the afx wideband. As there the only ones that come to mind with free air calibration. Once your intake is on and you figure out what your doing with what tb and maf you go with I'm sure you'll pick up quite a bit. Also what was the da for your run? If you compensate for your da you might feel alot better about your time

spawne32

iTrader: (2)

Don't have the weather data available yet to run the DA, waiting for them to put it up on the site, but it was about 75* on that last run with 65% humidity. DA was pretty high and everyone was running pretty shitty. My buddys 12.6 GTO in the cool weather ran that 13.2 @ 106 right next to me, he also was pretty unhappy about the times. I'm convinced once I sort out the timing situation and get that fueling spot on it can easily pick up 2-3mph. I had KR all over the table once I removed that IAT compensation table, and when I went back and looked at what it was trying to command, the high octane table is ridiculously high even for the part throttle areas. MAF, TB, intake etc are all on the to do list for the next 2-3 months. I got my ICT low profile valley cover in today and the katech adapter, thats ready to swap on, and a splice harness for the LS3 TB, however it uses all white wires on the pigtail rather then colored so I need to find an actual pinout reference to know which one goes where.

91parkave

iTrader: (4)

Ls3 is the exact same as the ls2 pinout. Im running the gold blade ls3 tb now. Hell of a lot better than the ls2. All you need to do after that is change your etc scaler and your golden.

I wouldn't say the timing table is high at least for a 5.3 with 243 heads its not. You should see the 5.3 trucks timing table as much as 50 degrees in very light Armas areas. Which helps with gas mileage but of course the more air you pull in the less timing you'll need.

spawne32

iTrader: (2)

Yeh i have the cross reference diagram, but i need the actual pin positions on the connector now because all the wires are white on the splice harness.

91parkave

iTrader: (4)

There you go

spawne32

iTrader: (2)

perfect thanks!

91parkave

iTrader: (4)

Just triple check against this for your pinouts

rottonj

iTrader: (4)

Well you have not owned this car for long and this was its maiden track voyage, this is what baselines are for. You have a good idea what is going on and how to fix it so you will see progress next time. If this car is to see a good amount of track time, it will really need sticky tires. We both live in the Northeast, and while those tires will provide traction for the elements drag racing is not their designed purpose and your traction problems will worsen when you add more power. I wonder if any gains could have been had by adding a couple of gallons of high octane fuel(100+) to try and help with the KR? We talked about the rear spring GTO spring blockers type mod to keep the rear from squatting . I really think if its that hot under your hood you could benefit from the hood rear bolt hinge shim to release some heat. Keep at it, you will get there for sure.

spawne32

iTrader: (2)

Well like i said before, the 1/4 mile time wasnt what i was looking at so much as the trap speed. With a high DA and 6* of KR, 101.4 was perfectly acceptable to me by the end of the night, and there just wasnt enough time to get in more runs to smooth that timing table out. I was expecting to trap about 103 but i knew i was going to have issues with traction and the 1/4 time. It easily has 103mph in it, once i clear up that knock retard. For every degree of ignition timing that i can bring back into the fold, ill gain .5-1mph additional. Also take note that im pulling vacuum at WOT too, the manifold is just not flowing what the car is capable of pulling, hitting 94-95kpa above 5500rpm isnt cutting it. So think once i get this tune sorted out, and the manifold swapped on with the LS3 tb and eventually the maf swap to enlarge the intake. I'll easily be trapping over 105, with a 1/4 time dictated entirely by how hard i can come off the line.

rottonj

iTrader: (4)

I think there is just as much to be gained with traction and lowering that 60ft time, drag radials probably would have had you closer to your desired ET I would think. I know some run 17 inch wheels and they clear the brakes using 275 on there(don't quote me, do some research lol). Do you know somebody you could borrow a set from? It wouldn't be cost effective to grab a matching set of fronts unless they could be had super cheap. You are going to need them for sure.

spawne32

iTrader: (2)

rottonj

iTrader: (4)

Damn, was all that smoke from the burnout from your buddy's GTO or your car?