Car not performing!
Car not performing! Ok, I stepped back and took a deep breath and now me and my Camaro are friends again, although he is very upset I bought a set of heads and intake for my LS1 TA. Anyways, Im a little disappointed with my last visit to the track. After a AI H/C/I swap and dyno tune and making 392 whp, I ran a 12.68@108, 1.78 60ft. Another run was 12.65@108, 1.82 60ft. I was running slicks on some steel wheels I think at 25psi, hooked pretty good. I wasnt launching that hard, under 3k rpm. I got lca, relocation brackets, panhard bar. I got weld in subframe connectors, but they arent on the car. I was thinking it should be faster, way faster. Im running a Hughes 3k stall, Im wanting to upgrade to a 3600 or bigger. Could my stall be hurting times? Would it help a lot to upgrade?
I think I only gained like 2mph even after the HCI and dyno tune, not sure if the tune is even nuts on. I was thinking about obd1 to get a better look at whats going on with the pcm but I need to pass emissions. Another option would be a 24x swap, but dont know if thats really necessary. Both options would require a completely new tune on the pcm, there is $500+ right there. When it was getting tuned, he had software but was only able to monitor a handful of things, basically enough to get the job done. Ideas, suggestions? If you need any more info, let me know. I also asked this same exact question on a different forum.
I think I only gained like 2mph even after the HCI and dyno tune, not sure if the tune is even nuts on. I was thinking about obd1 to get a better look at whats going on with the pcm but I need to pass emissions. Another option would be a 24x swap, but dont know if thats really necessary. Both options would require a completely new tune on the pcm, there is $500+ right there. When it was getting tuned, he had software but was only able to monitor a handful of things, basically enough to get the job done. Ideas, suggestions? If you need any more info, let me know. I also asked this same exact question on a different forum.
Last edited by ascastil; Mar 12, 2013 at 11:15 PM.
So your tuner had very limited datalogging info?
That doesn't sound good to me.
Since it made a decent number on the dyno for an emissions setup I would wonder about something like the dyno was not loading the engine as hard as the car does and the timing was set aggressively and that now on the track with the extra load it is going into knock retard and pulling several degrees of timing the whole pass. To see that though you are going to need some way to scan it.
Had it not made a good number on they dyno I would be looking at valve adjustment and ICM, so if the KR thing turns out to be OK maybe revisit those.
I know two guys here in WI who had cars there were just "soft" after heads/cam swap not a miss or anything obvious just didn't have the power they should have, and they both said the cars were completely transformed by swapping the ICM even to a used spare that had been sitting in the toolbox. The one guy had put a brand new ICM on while doing the HC swap and it was the new one that was weak out of the box.
Can you give us more info on the stall? Not some 12" POS is it?
a 3K stall is certainly not ideal but if that alone was the issue I think we would still see more MPH.
That doesn't sound good to me.
Since it made a decent number on the dyno for an emissions setup I would wonder about something like the dyno was not loading the engine as hard as the car does and the timing was set aggressively and that now on the track with the extra load it is going into knock retard and pulling several degrees of timing the whole pass. To see that though you are going to need some way to scan it.
Had it not made a good number on they dyno I would be looking at valve adjustment and ICM, so if the KR thing turns out to be OK maybe revisit those.
I know two guys here in WI who had cars there were just "soft" after heads/cam swap not a miss or anything obvious just didn't have the power they should have, and they both said the cars were completely transformed by swapping the ICM even to a used spare that had been sitting in the toolbox. The one guy had put a brand new ICM on while doing the HC swap and it was the new one that was weak out of the box.
Can you give us more info on the stall? Not some 12" POS is it?
a 3K stall is certainly not ideal but if that alone was the issue I think we would still see more MPH.
I bought a datalogger and I believe one of the VERY FEW things that it does monitor one of them is timing. Maybe ill go do a wot pull and see what it says. I'm at work now and I'm on my phone so when I get home ill list everything that's on the car in more detail, including the stall. Thanks so much. I spent so much money on this car and want it to run right. Knowing we need to see what's going on with the pcm, what is your opinion on a 24x swap? I know its pricey, but is that something that I may have to do if I want to see the full potential of my car?
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Ok mods on the car as follows:
AI 200cc heads, ported mani, 228/234, 610/610, 108 cam
Block freshened up, nothing fancy, 15k miles
Long tubes, dual exhaust, no cats
Rebuilt tranny, Hughes 3000 stall. Its not a huge diameter converter but cant seem to find the diameter listed anywhere
3.73 rear
Crappy dyno tune
Well me and my neighbor went out and did a wot pull and it read 41* advanced on the timing, cruising if I remember was around 30* advanced. I have a feeling that is a very bad. Not sure of the DA of the track when I got those times, it was back in December.
AI 200cc heads, ported mani, 228/234, 610/610, 108 cam
Block freshened up, nothing fancy, 15k miles
Long tubes, dual exhaust, no cats
Rebuilt tranny, Hughes 3000 stall. Its not a huge diameter converter but cant seem to find the diameter listed anywhere
3.73 rear
Crappy dyno tune
Well me and my neighbor went out and did a wot pull and it read 41* advanced on the timing, cruising if I remember was around 30* advanced. I have a feeling that is a very bad. Not sure of the DA of the track when I got those times, it was back in December.
Last edited by ascastil; Mar 13, 2013 at 10:07 PM.
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Verdad Gallardo 41degrees WOT is enough to destroy the engine, 30 at cruise is likely too low depending on exact conditions.
Far as the converter 12" is stock size, a proper performance street/strip converter is most commonly 9.5".
IMO "rebuilt tranny" unless done by someone proven with this tranny can mean completely ruined, such a small percentage of hops are capable of handling this thing well.
Far as the converter 12" is stock size, a proper performance street/strip converter is most commonly 9.5".
IMO "rebuilt tranny" unless done by someone proven with this tranny can mean completely ruined, such a small percentage of hops are capable of handling this thing well.
Maybe you got your numbers swapped? 41 degrees cruising is about right. 30 degrees WOT means, hopefully, you have 6 or 8 degrees of knock retard. If you have 30 degrees @ WOT, above 2400 RPM, and no retard, your tuner stepped on his pecker. I doubt you would have made that kind of power with only 30 degrees. Betting on knock retard.
I would have bought a Vigilante converter.
I would have bought a Vigilante converter.
Well, I know 2 things as of right now. My car isn't running worth **** and my tuner ripped me off. Where do I go from here? I can't monitor **** with this pcm, nobody even tunes them anymore.
The chamber in the AI heads doesn't need a lot of timing, think the highest WOT timing in the tables on my pcm is like 29 degrees and the pcm adds a couple beyond that but it still only sees low 30s. Several of us have reported this with the AI 200cc head.
I know some other chamber designs can like more timing so I am not completely dismissing what Ed said, just saying it is not always the case.
41degrees at WOT can destroy the engine, hope the damage isn't done.
Also I am not sure if your scanner reports commanded timing with or without the KR accounted for.
Where are you? Maybe there is a local with better scanning equipment you could bribe with a 12-pack?
I know some other chamber designs can like more timing so I am not completely dismissing what Ed said, just saying it is not always the case.
41degrees at WOT can destroy the engine, hope the damage isn't done.
Also I am not sure if your scanner reports commanded timing with or without the KR accounted for.
Where are you? Maybe there is a local with better scanning equipment you could bribe with a 12-pack?
That's just wrong. I have seen AFR heads (**** poor chamber) like that much. Is that what you have? AI chambers are very good, and don't like/need as much. GM heads, if done correctly, normally like 36 to 38.
Just to reinforce what has already been said:
I have AI 200cc heads and 12.0:1 CR, and it makes best WOT power at 29 degrees timing in the spark table.
Datamaster will report ~4 degrees more than that; however, 41 degrees reported is cause for alarm with those heads. You need to get it into the hands of a competent/equipped dyno tuner.
I have AI 200cc heads and 12.0:1 CR, and it makes best WOT power at 29 degrees timing in the spark table.
Datamaster will report ~4 degrees more than that; however, 41 degrees reported is cause for alarm with those heads. You need to get it into the hands of a competent/equipped dyno tuner.
Just to reinforce what has already been said:
I have AI 200cc heads and 12.0:1 CR, and it makes best WOT power at 29 degrees timing in the spark table.
Datamaster will report ~4 degrees more than that; however, 41 degrees reported is cause for alarm with those heads. You need to get it into the hands of a competent/equipped dyno tuner.
I have AI 200cc heads and 12.0:1 CR, and it makes best WOT power at 29 degrees timing in the spark table.
Datamaster will report ~4 degrees more than that; however, 41 degrees reported is cause for alarm with those heads. You need to get it into the hands of a competent/equipped dyno tuner.
And why is that, Ed? I know some of the GM programs add timing in PE mode, but I've not seen it in an LT1 program. I only tune my own stuff and only know the parts that Tunercat lets me see.
Similar deal. Just believe the scan tool. As long as you know what numbers make the most power, that's all that matters. Right?