Ported Intake Manifold

[InFiD3ViL]

I definitely can feel more power from when I installed the Ported Rod Mod intake. I can now feel some tire spin on the 2-3 shift at WOT, which I never had before...My trans is a mess...Not really, just sloppier than I would like. Very inconsistent. I have 172k on the trans, so I can't ask for much. I will state that some BIG changes are coming to my car and trans. Haven't nailed down all details yet.

Only issue is that I am noticing she is running VERY LEAN on idle now, since after the ported rod mod install. I don't have a wideband, but I do monitor STFTs, and at idle I am usually between +15 - 20%. I did not retune after install. WOT pulls seem to be more in normal range, but as I said, I'm only monitoring trims, so accuracy isn't great. Confirmed no vacuum leaks, at least as far as I can tell. Idle speed is perfect. I will add I try to stay off of her too heavy since I noticed the lean issue. Lucky if I drive it 50 miles a month right now.

[acammer]

Originally Posted by InFiD3ViL

I definitely can feel more power from when I installed the Ported Rod Mod intake. I can now feel some tire spin on the 2-3 shift at WOT, which I never had before...My trans is a mess...Not really, just sloppier than I would like. Very inconsistent. I have 172k on the trans, so I can't ask for much. I will state that some BIG changes are coming to my car and trans. Haven't nailed down all details yet.

Only issue is that I am noticing she is running VERY LEAN on idle now, since after the ported rod mod install. I don't have a wideband, but I do monitor STFTs, and at idle I am usually between +15 - 20%. I did not retune after install. WOT pulls seem to be more in normal range, but as I said, I'm only monitoring trims, so accuracy isn't great. Confirmed no vacuum leaks, at least as far as I can tell. Idle speed is perfect. I will add I try to stay off of her too heavy since I noticed the lean issue. Lucky if I drive it 50 miles a month right now.

Some additional trim at idle is not unexpected, and one of the most "affected" areas by airflow changes through the engine. The beauty of a closed loop fueling system is that you can make some minor airflow changes like that without taking things too far out of calibration. What you'd ideal monitor to have an idea on where the AFR has gone would be the long term fuel trim PLUS the short term fuel trim (LTFT+STFT) as that's a wholistic value on what sort of trimming the ECM is doing. STFT alone doesn't tell the whole story, that's a very fast changing value. When it trends far enough off center for long enough, the LTFT will step in and make a correction that will bring it closer to center. The ECM learns and remembers those LTFT corrections, which has the effect of bringing those STFT in line quickly.

Of course, what I just described above depends on the tuner still using LTFT - which not all do. Many will remove the LTFT completely, and operate just with STFT. This is done because LTFT has the ability to impact the AFR under power enrichment (full power). It also adds a small amount of complexity to the tuning process. It's a bit of a debated topic, with good logic and support for either approach.

All that to say, what you're seeing sounds fine. Enjoy the new power. Really feel it come on in the 3500-4500rpm range? That's where I noticed the rod mod added the most when I had one. It's across the whole curve, but we've seen as much as 35ft/lbs increase in torque through that particular range, really stand the curve up earlier and stronger!

[camguynj]

[QUOTE=camguynj;11360905]Thanks Andrew, good to know.

Update - I did wind up replacing the gaskets on the ported IM from GPI as two of them appeared to be compressed flat even with port wall. I also lined the IM with ThermoTec 13575 aluminized heat barrier.

FWIW I noticed that after a faint dusting of snow the snow was still on the hood cowl over the IM after the car was off a few hrs and nowhere else. I’m assuming the IM temp was lower than elsewhere in the engine bay due to the heat barrier I also have the IM clam shell removed.

[Arogg]

I have this rod mod / ported intake in my cart for a while now. I really want to do it before my track day in April. My only concern is that i dont necessarily LOVE my trifecta tune but it has served its purpose up until now which was keeping my SES light off for inspection. If im gonna do this, id like to get retuned but not sure what route I want to go for that. Dyno tuning in my area is either non existent or when they see my car, they want like 1000 bucks to tune it. My buddy with a 5.0 just got his headers installed and dyno tuned for 800. Unfortunately, where he went, they wont touch a GM product lol

[camguynj]

Originally Posted by Arogg

I have this rod mod / ported intake in my cart for a while now. I really want to do it before my track day in April. My only concern is that i dont necessarily LOVE my trifecta tune but it has served its purpose up until now which was keeping my SES light off for inspection. If im gonna do this, id like to get retuned but not sure what route I want to go for that. Dyno tuning in my area is either non existent or when they see my car, they want like 1000 bucks to tune it. My buddy with a 5.0 just got his headers installed and dyno tuned for 800. Unfortunately, where he went, they wont touch a GM product lol

I had the same concern about needing a retune on my cammed n/a LS3 so I asked GPI. They said no as the ported rod mod really doesn’t change IM pressure it just delivers air at an increased velocity constantly throughout the rpm range.

[Arogg]

Originally Posted by camguynj

I had the same concern about needing a retune on my cammed n/a LS3 so I asked GPI. They said no as the ported rod mod really doesn’t change IM pressure it just delivers air at an increased velocity constantly throughout the rpm range.

Yeah, i asked the same. In general, i really just want a better tune lol. I might just buy the intake now and worry about a tune when I do more work. Its affordable enough but house hunting with a kid on the way has SERIOUSLY put a dent into mod money

[Leadsled]

Originally Posted by Arogg

I have this rod mod / ported intake in my cart for a while now. I really want to do it before my track day in April. My only concern is that i dont necessarily LOVE my trifecta tune but it has served its purpose up until now which was keeping my SES light off for inspection. If im gonna do this, id like to get retuned but not sure what route I want to go for that. Dyno tuning in my area is either non existent or when they see my car, they want like 1000 bucks to tune it. My buddy with a 5.0 just got his headers installed and dyno tuned for 800. Unfortunately, where he went, they wont touch a GM product lol

My original tune for my car was about 650-700 the first go around. (Cam setup) My re-tune was for gutting the cats and ported TB. The second time around I was only charged $200 which gave me about 4 pulls.
My point being the first tune should be the most expensive tune until you add something like power adders (N02/turbo/SC). No need to punish you for trying to have more fun.
I drive 3hrs one way to my tuner also

[George-CZ]

So I finally got around to it.
Installation went surprisingly smoothly.
The bigger problem was finding the order and torque of the bolts.


I was curious about the difference and it came right after the first start.
I had driven the car with the OEM intake all day before so I had a starting point for comparison.
The car was right from idling - stronger, a much bigger pull was felt.


I have to admit that the guys from GPI did a very good job.
Now I will adjust the tune and it will be absolutely perfect.

[Joe.G]

Is Steve going to adjust your tune? Let me know if you notice difference after re tune, I didn't retune after the swap.

[George-CZ]

Originally Posted by Joe.G

Is Steve going to adjust your tune? Let me know if you notice difference after re tune, I didn't retune after the swap.

Yeah, we agreed to do it.
He sent me the values he wants to record and now it's just a matter of my free time that I have to take to do it.


Do you want a private message or is it enough here in the thread?

[Joe.G]

Here is fine, I was just curious if it's worth it, Steve told me not really needed.

[George-CZ]

Originally Posted by Joe.G

Here is fine, I was just curious if it's worth it, Steve told me not really needed.

I directly asked him for it.
Maybe it won't be necessary.
But at least the control can be done.

O.K. I'll keep you informed.

[camguynj]

Originally Posted by George-CZ

I directly asked him for it.
Maybe it won't be necessary.
But at least the control can be done.

O.K. I'll keep you informed.

GPI told me a retune is not needed as the ported rod mod doesn’t change IM pressure, it just provides an improved constant air flow velocity throughout the rpm range

[Bluebagger06]

Originally Posted by camguynj

GPI told me a retune is not needed as the ported rod mod doesn’t change IM pressure, it just provides an improved constant air flow velocity throughout the rpm range

Im not so sure about that , I have looked at everything 5 times over and dont know why i get CEL light on my car with the ported rod mod, Its P0106,0086 codes and if you rev it up it goes into reduced power mode!! Even broke one of those pos intake bolts from taking it off and on so much, New GM gaskets, MAP sensor , have a new MAF sensor coming tomorrow , along with smoke machine to verify i dont have a leak or cracked intake, I have others telling me it needs a tune! Andrew suggested the smoke tester!