I am looking for real experiences from those who have had a Rod Mod done to an LS3 intake manifold.
Opinions are not even worth reading.
Facts and real experience are what I am looking for.
Let us know how it worked for you.

 

I had a GPI ported Rod Mod on the LS3 in my Chevy SS sedan. On a stock motor they add about 10-12 hp. Before that I had a FAST LSXR first with long (black) runners, then with medium (grey) runners. After switching to the ported Rod Mod, I had to add a ton of fuel in the 3000-5000 rpm range while tuning it. The problem with the Rod Mod is that the runners while great for stock and mild cams, are simply TOO long to carry power above 6500 rpm without falling off a cliff. Since the only way to make real power NA is to increase engine speed, I found it was holding me back once I installed 3.91 gears, 4500-4600 245mm converter and GPI SS4 NFC cam. I now run a long Holley Sniper and the difference is obvious above 6300 rpm (shift point is around 7300)

For stock or mild LS3 cams, ported Rod Mod is an EXCELLENT choice, I would never even consider the FAST LSXR, the Rod Mod is the better all around unit. Understand though that while a 102/103 Throttle Body will fit with a tapered adaptor, it upsets the airflow enough to not show ANY gains. Stick to a ported 90mm Gold LS3 TB--that is a nice combo.

 

I had a GPI ported Rod Mod on the LS3 in my Chevy SS sedan. On a stock motor they add about 10-12 hp. Before that I had a FAST LSXR first with long (black) runners, then with medium (grey) runners. After switching to the ported Rod Mod, I had to add a ton of fuel in the 3000-5000 rpm range while tuning it. The problem with the Rod Mod is that the runners while great for stock and mild cams, are simply TOO long to carry power above 6500 rpm without falling off a cliff. Since the only way to make real power NA is to increase engine speed, I found it was holding me back once I installed 3.91 gears, 4500-4600 245mm converter and GPI SS4 NFC cam. I now run a long Holley Sniper and the difference is obvious above 6300 rpm (shift point is around 7300)

For stock or mild LS3 cams, ported Rod Mod is an EXCELLENT choice, I would never even consider the FAST LSXR, the Rod Mod is the better all around unit. Understand though that while a 102/103 Throttle Body will fit with a tapered adaptor, it upsets the airflow enough to not show ANY gains. Stick to a ported 90mm Gold LS3 TB--that is a nice combo.

 

Thank you for responding Jay.
This is exactly the type of information I was hoping for.

 

If you want every last little bit go for it
If youre hoping to feel something, pass.

 

For anyone still questioning a rod modded LS3 intake, theres a before and after chassis dyno comparison between a stock vs rod modded manifold in the vid below (starting around the 14:00 mark).

Basically a cam/bolt on LS3.

I run one on my stroked LS3 427ci and like posted above, the stock long runners are great for gobs of torque down low but like stated above, peak early (6650rpm on my setup).

 

What do you run currently on your setup! Interested, since I will be doing my SS4 NFC soon. Are you staying with a 90mm TB and a Hi-Ram?

 

The GPI ported Rod Mod is a great choice for adding horsepower to an existing or slightly tuned LS3 engine. It can deliver up to 10-12 extra horsepower, which can make a marked difference in performance. However, for more modified engines that require higher RPM, the long run on the Rod Mod can become a limitation, causing power to drop above 6500 RPM. This can be a problem for those with higher gear ratios and performance cams.
To solve this problem, some users have turned to other loading systems, such as Holley Sniper. This can provide better airflow at higher RPM, allowing more power to be generated. However, for those with an original or lightweight LS3 camcorder, the ported Rod Mod is still a great option. It pairs well with the ported LS3 Gold LS3 90mm throttle body, which can further improve performance. In general, the choice between the Rod Mod and other intake systems will depend on the specific needs and modifications of each engine.

 

Is that just for NA builds or boost builds as well?