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]

I'm glad to continue the discussion. Let's just keep it to a single thread OVER HERE.

[JJFormato]

TTT for anyone looking for advice.

[Pewter1]

What about on a 98 with an LS1 with ported 92mm and ported 90tb i am having idle and surging issues as well right now it idles at 1200-1300 so it run about 45 without touching the gas.....I think the 98 PCM is different, as far as idle parameters?

[JJFormato]

Originally Posted by Pewter1

What about on a 98 with an LS1 with ported 92mm and ported 90tb i am having idle and surging issues as well right now it idles at 1200-1300 so it run about 45 without touching the gas.....I think the 98 PCM is different, as far as idle parameters?

We are referring to a 98 vette correct?

Do you have a catch can / with breather? If yes, then there is a vacuum leak and the PCV system is incorrectly routed. Which is part of the problem but not the whole problem. C5 tb's have PCV port in the tb itself, and have a design circuit for PCV flow. On a C6 and many aftermarket tb's there is no port or a provision for the stock style PCV system. If C6 tb, do you have a port between your MAF and the tb going into the valve cover?

The PCV system is drawn by vacuum from the port just behind the tb flange on the intake manifold itself - passenger side. From the vacuum source this goes to the valley cover or valve cover, depending on year. From the crank case it attaches at the passenger side valve cover port. The right front side of the motor (to the tb port on a C5 and into the maf-to-TB coupler on a C6. hope this helps. Its also a good idea to look at a stk car.
There are many tuning issues that it could also be, but i didnt want to fill up 5 pages of scenarios.
Make sure what we just said is good and go from there.
Thank you
Jeremy