Tuning tips for ported manifolds and TBs

[JJFormato]

Tuning tips for ported manifolds and TBs.

A few tuning tips for manifolds and ported TBs. We have found these specs to help bring out the most from the manifolds and TBs in LS2/3/4/7/9 vehicles. Throttle response
will be greatly improved and the vehicle will have much more of a "torquey" feel through the bottom end and mid range. There is a very remote chance that those of you with ported TB's may set codes, but in the event that you do: these codes should be addressed see HPT1:
It is not detrimental to delete these codes whatsoever. If you have a tuned vehicle and are adding a ported intake and TB, many times you may need to retard timing in order to get the most power out of the vehicle. The denser the air charge the less spark that is necessary in order to achieve best power and the less likely to knock. We also highly recommend thoroughly cleaning all the oil out of the intake ports of the cylinder heads in order to run a more aggressive tune, as any oil in the induction greatly increases the likeliness of spark knock.

If you are using HP tuners here are a few tables we would suggest you or your tuner modify.
Codes and airflow parameters :
Engine Diagnostics> General> Diagnostic test P101.106,121 and P0068 (screen shot HPT1) disabling certain airflow vs TPS parameters/ tests
Engine> Spark Control> Spark Advance> High Octane (screen shot HPT2) High load low RPM timing addition better for lower end Tq
Engine> Fuel Control> power enrich > PE enable (screen shot HPT3) Lowering Thresholds for PE fueling in the RPM and set enrichment rate to 2.0
Engine> Spark control> spark retard> Burst Knock> Base vs cyl air delta (Set burst knock to 1 and 2 in last cells or 0 thru in FI applications)
Engine> Airflow > Electronic Throttle> Area opening limits (Screen shot HPT4) set to 100%:

We always recommend tuning the Speed density map if the vehicle has one as well as the MAF table to get the best overall tq from the vehicle. Of course getting the RIGHT
amount of spark in there can make all the difference in the world; more is not always better. If you are filling the cylinder worse (big cam) at a lower RPM more timing CAN help.
If you are filling the cylinder greater at higher rpm (FAST manifold) less timing generally is best.

[TurboLX]

Originally Posted by JJFormato

Tuning tips for ported manifolds and TBs.

A few tuning tips for manifolds and ported TBs. We have found these specs to help bring out the most from the manifolds and TBs in LS2/3/4/7/9 vehicles...

Codes and airflow parameters :
Engine Diagnostics> General> Diagnostic test P101.106,121 and P0068 (screen shot HPT1) disabling certain airflow vs TPS parameters/ tests

I wouldn't recommend completely disabling P0068 operation. This is a critical safety check for the electronic throttle control that is supposed to detect a runaway condition in the event of a failure. If you just max this table out, you are disabling the safety feature and opening yourself up to a HUGE potential disaster if something goes wrong.

The proper solution should be to measure the newly increased actual airflow and use that data to repopulate these tables, including some safety margin. The same holds true for the older P1514 threshold tables on the C5s.

Again, it's not a question of whether it functions OK under normal conditions, but whether you can detect and react to a failure before things get out of control.

[JJFormato]

On early TB porting and tuning of the LS2 I have NEVER seen any "runaway" issue but in the event that a code would set or a threshold of airflow vs TPS was exceeded it would reduce engine power, closing the throttle and retarding timing. This is the complete opposite scenario and I have seen it whenever airflow and or map does not correlate to TPS. I am not saying that your scenario is impossible but I have never seen nor heard of it. Sounds as though you have solid credentials and I will heed your advice.
I wonder what situation would cause a "runaway" issue?
Jeremy

[TurboLX]

Originally Posted by JJFormato

On early TB porting and tuning of the LS2 I have NEVER seen any "runaway" issue but in the event that a code would set or a threshold of airflow vs TPS was exceeded it would reduce engine power, closing the throttle...

That code is P0068 on the newer cars (P1514 on older cars), and is set when the measured airflow exceeds the values in the tables you show above. You should be able to confirm this by setting them lower on purpose and driving the car. You will hit the diagnostic limit very easily and enter reduced engine power mode, which is the PCM's natural response to what it thinks is a hardware failure.

The object here is to set the diagnostic limit high enough to allow normal WOT behavior, but not so high that it doesn't catch a legitimate failure and intervene.

I wonder what situation would cause a "runaway" issue?

In this case, they're detecting that someone has molested the factory TB. What happens if you double the available blade area without proper PCM recalibration? You'd get far more airflow (and engine torque) than expected by the driver along with the corresponding vehicle acceleration. We don't always want to go WOT, especially when in a crowded school parking lot. Catch my drift?

It can also be a symptom of a sludged up or mechanically jammed blade/shaft that isn't closing properly. OEMs cannot risk the potential lawsuits associated with the phrase "it just took off on me without my foot on the gas," so they employ this safety check in the software to detect such failures.

Properly tuned, you won't ever have a runaway condition. It's just one of those "what if.." deals that the OEM must prove they can catch. Turning this off in the aftermarket is almost begging for liability issues.

[phils C5 vette]

[seevi]

Originally Posted by TurboLX

That code is P0068 on the newer cars (P1514 on older cars), and is set when the measured airflow exceeds the values in the tables you show above. You should be able to confirm this by setting them lower on purpose and driving the car. You will hit the diagnostic limit very easily and enter reduced engine power mode, which is the PCM's natural response to what it thinks is a hardware failure.

The object here is to set the diagnostic limit high enough to allow normal WOT behavior, but not so high that it doesn't catch a legitimate failure and intervene.


In this case, they're detecting that someone has molested the factory TB. What happens if you double the available blade area without proper PCM recalibration? You'd get far more airflow (and engine torque) than expected by the driver along with the corresponding vehicle acceleration. We don't always want to go WOT, especially when in a crowded school parking lot. Catch my drift?

It can also be a symptom of a sludged up or mechanically jammed blade/shaft that isn't closing properly. OEMs cannot risk the potential lawsuits associated with the phrase "it just took off on me without my foot on the gas," so they employ this safety check in the software to detect such failures.

Properly tuned, you won't ever have a runaway condition. It's just one of those "what if.." deals that the OEM must prove they can catch. Turning this off in the aftermarket is almost begging for liability issues.

[Mez]

I recently installed a ported FAST 92 on my LS2 with a head/cam/headers engine. See the mod details in my signature below.

With the stock ported intake manifold, I was able to set ignition advance to 26-27 degrees at WOT and over 5200 rpm with no KR. After the installation of the ported FAST 92, I had to back it down to 20-21 degrees. I initially increase the PE thinking it was fuel related but that did not help. I am now running about 12.5 A/F ratio at WOT.

I understand less advance is required when the intake track is less restrictive thus more air is reaching the cylinder creating a denser air/fuel mixture, which makes for a faster flame travel on ignition. How else would the FAST create more power?

My question is this: How many degrees are other guys having to reducing their engine's advance when they switch to a FAST 92 intake?

I have not Dyno'd the car after the FAST install but before, it was making about 430 rwhp. The car seems faster now but I would have to dyno it to make sure.

I've tuned it myself using HP Tuners and a PLX WB02. My LTFT % error is between 0% - 3% everywhere.

Thanks.

[seevi]

Originally Posted by Mez

I recently installed a ported FAST 92 on my LS2 with a head/cam/headers engine. See the mod details in my signature below.

With the stock ported intake manifold, I was able to set ignition advance to 26-27 degrees at WOT and over 5200 rpm with no KR. After the installation of the ported FAST 92, I had to back it down to 20-21 degrees. I initially increase the PE thinking it was fuel related but that did not help. I am now running about 12.5 A/F ratio at WOT.

I understand less advance is required when the intake track is less restrictive thus more air is reaching the cylinder creating a denser air/fuel mixture, which makes for a faster flame travel on ignition. How else would the FAST create more power?

My question is this: How many degrees are other guys having to reducing their engine's advance when they switch to a FAST 92 intake?

I have not Dyno'd the car after the FAST install but before, it was making about 430 rwhp. The car seems faster now but I would have to dyno it to make sure.

I've tuned it myself using HP Tuners and a PLX WB02. My LTFT % error is between 0% - 3% everywhere.

Thanks.

Here's a before and after time chart of an LS2 with a ported intake manifold. High RPM timing is reduced.

[Mez]

Thanks. This shows about a 1-2 decrease in timing.

Is this a ported stock manifold?

I went from a ported stock manifold to a ported FAST92 and had to reduce ignition advance by 6 degree.

One other thing: When I purchased the new FAST 92, I had it ported by the vendor. Upon inspection, I noticed it was basically gasket matched to my Lingenfelter CNC ported heads. So the porting went into the manifold about .75-1.0 inch where it narrowed back down to the as-molded FAST 92 port then widened back out further back.

So I fabricated a slightly wedge-shaped template and using my Dremel I ground each port so they had identical straight taper profiles. I ended up with a very constant taper on the walls of the manifold to the cylinder head (if that makes any sense to you all).

Could I have by pure luck created an insanely efficient intake port that fills the cylinder so effectively that the engine needs 6 degrees less ignition advance? Or is 20 degrees advance normal for an engine with my combination of mods? I suppose a Dyno test would help shed some light on the subject......

[Z06high]

I occasionally get a P1516 code since installing a ported tb on my LS7. I cannot determine any particular circumstance in which this occurs and it has never caused any problem at all other than the CEL which I just delete with a code reader. The codes have sometimes come in a close time proximity and then gone weeks or months without occurring again. Any ideas on what is causing this?

[seevi]

Originally Posted by Mez

Thanks. This shows about a 1-2 decrease in timing.

Is this a ported stock manifold?

I went from a ported stock manifold to a ported FAST92 and had to reduce ignition advance by 6 degree.

One other thing: When I purchased the new FAST 92, I had it ported by the vendor. Upon inspection, I noticed it was basically gasket matched to my Lingenfelter CNC ported heads. So the porting went into the manifold about .75-1.0 inch where it narrowed back down to the as-molded FAST 92 port then widened back out further back.

So I fabricated a slightly wedge-shaped template and using my Dremel I ground each port so they had identical straight taper profiles. I ended up with a very constant taper on the walls of the manifold to the cylinder head (if that makes any sense to you all).

Could I have by pure luck created an insanely efficient intake port that fills the cylinder so effectively that the engine needs 6 degrees less ignition advance? Or is 20 degrees advance normal for an engine with my combination of mods? I suppose a Dyno test would help shed some light on the subject......

Yes, my intake was stock and match ported by Charlie at RPM Motor. He did not removed the internal column supports. What I
noticed first was the 12% increase in cylinder airmass.

[KGB6]

Originally Posted by seevi

Here's a before and after time chart of an LS2 with a ported intake manifold. High RPM timing is reduced.

Greetings Seevi,
Is the PE/COT Spark Advance Table set to all 0s?

[seevi]

Originally Posted by KGB6

Greetings Seevi,
Is the PE/COT Spark Advance Table set to all 0s?

[FASTBLUEZ06]

I am installing my Stage 2 ported intake manifold and throttle body this week and having East Coast Supercharging do the tuning on my bolt on LS7 C6Z... They use EFI Live. When I bring my car there... what should I tell them to look for when tuning my car with the Manifold and TB installed? Just reduce timing at high RPMs?

Thanks,
Bryan

[Slowhawk]

Originally Posted by FASTBLUEZ06

I am installing my Stage 2 ported intake manifold and throttle body this week and having East Coast Supercharging do the tuning on my bolt on LS7 C6Z... They use EFI Live. When I bring my car there... what should I tell them to look for when tuning my car with the Manifold and TB installed? Just reduce timing at high RPMs?

Thanks,
Bryan

I'm pretty sure they know what to do.

[FASTBLUEZ06]

Yeah i'm def not doubting their tuning at all, I am just worried I am goin to be stuck with some of these CELs that are being mentioned in the thread... O well, we'll see how it goes.

[JJFormato]

Originally Posted by FASTBLUEZ06

Yeah i'm def not doubting their tuning at all, I am just worried I am goin to be stuck with some of these CELs that are being mentioned in the thread... O well, we'll see how it goes.

Bryan, I would not worry at all about it setting in CEL's. Most of the time that we see them set is from an unconnected vacuum line left undone somewhere, and corrected when reinstalled.
If you do have any issues at all, please let us know, but it would certainly be the exception rather than the rule. Jeremy will be up in Gettysburg PA. again at the end of August to coincide with Corvettes of Carlisle.
Thanks and if you have any questions at all please don't hesitate to call.

Dan
Fasterproms

[Bill Curlee]

Excellent post!

BC

[phils C5 vette]

i dont think those are a pictures from a C6 Corvette PCM in HPT.

Looks GTO to me

correct me if im wrong

[BOTTLEFED440LSX]

Originally Posted by FASTBLUEZ06

I am installing my Stage 2 ported intake manifold and throttle body this week and having East Coast Supercharging do the tuning on my bolt on LS7 C6Z... They use EFI Live. When I bring my car there... what should I tell them to look for when tuning my car with the Manifold and TB installed? Just reduce timing at high RPMs?

Thanks,
Bryan

Bringing this back from the dead, but what were your gains with the ported set-up?