Chevy tuned port limitations

batln12 · 10-23-2022, 02:53 PM

Does NHRA have any limitations in stock eliminator on what fuel rails are required on an 89 350 Iroc with tuned port. Can the fuel lines be modified to braided lines vs steel?

Doug Hoven · 10-24-2022, 09:08 AM

I'm sure someone will correct me if I'm wrong, but I believe you have to retain the stock fuel rails. However, you are allowed to change the fittings to accept a different fuel line. I say this because it's what I've seen on a bunch of fuel injected cars.

Signman · 10-24-2022, 10:04 AM

It would be best to download a copy of NHRA Rules read for yourself and send questions to your division tech director.

https://www.nhraracer.com/content/ge...000&zoneid=132

Replacing fuel lines with steel braided is encouraged. No mention of size.
There is no mention of requiring the stock fuel rail.
Can adapt the stock rail to braided lines.
Can install larger injectors there cannot be any machining of the lower plenum for fit replacement fuel rail would need to be a stock replacement.
Can install larger fuel pump and regulator must be controlled by ignition switch.
Can install fuel cell stock tank must be removed.

jamie2370 · 10-26-2022, 09:24 AM

When I built mine, I had my chassis guy weld an fittings on all 4 corners of the rails. No factory crossover pipe either. Removed and plugged all the holes. Basically each rail had it's own inlet and outlet. Not connected to each other.

batln12 · 10-30-2022, 12:39 PM

Thanks for all the comments. Has anyone removed the IAC manifold on the bottom of the throttle body? It seems there is no use for coolant to the throttle body or Idle air control solenoid.

10-23-2022, 02:53 PM	#1
batln12 Junior Member Join Date: Mar 2017 Posts: 2 Likes: 1 Liked 0 Times in 0 Posts	Chevy tuned port limitations Does NHRA have any limitations in stock eliminator on what fuel rails are required on an 89 350 Iroc with tuned port. Can the fuel lines be modified to braided lines vs steel?

10-24-2022, 09:08 AM	#2
Doug Hoven Member Join Date: Feb 2018 Location: Jersey Posts: 212 Likes: 193 Liked 855 Times in 164 Posts	Re: Chevy tuned port limitations I'm sure someone will correct me if I'm wrong, but I believe you have to retain the stock fuel rails. However, you are allowed to change the fittings to accept a different fuel line. I say this because it's what I've seen on a bunch of fuel injected cars. __________________ 1189 F/SA Defunzalo Racing Enterprises

10-24-2022, 10:04 AM	#3
Signman Senior Member Join Date: Oct 2003 Location: Lower Slower Delaware Posts: 535 Likes: 22 Liked 269 Times in 99 Posts	Re: Chevy tuned port limitations It would be best to download a copy of NHRA Rules read for yourself and send questions to your division tech director. https://www.nhraracer.com/content/ge...000&zoneid=132 Replacing fuel lines with steel braided is encouraged. No mention of size. There is no mention of requiring the stock fuel rail. Can adapt the stock rail to braided lines. Can install larger injectors there cannot be any machining of the lower plenum for fit replacement fuel rail would need to be a stock replacement. Can install larger fuel pump and regulator must be controlled by ignition switch. Can install fuel cell stock tank must be removed. __________________ Frank Ferrucci I/SA 1271 "Be Thankful for the Gifts You are Given"

10-26-2022, 09:24 AM	#4
jamie2370 Member Join Date: Dec 2014 Location: Perry, GA Posts: 331 Likes: 11 Liked 239 Times in 90 Posts	Re: Chevy tuned port limitations When I built mine, I had my chassis guy weld an fittings on all 4 corners of the rails. No factory crossover pipe either. Removed and plugged all the holes. Basically each rail had it's own inlet and outlet. Not connected to each other.

10-30-2022, 12:39 PM	#5
batln12 Junior Member Join Date: Mar 2017 Posts: 2 Likes: 1 Liked 0 Times in 0 Posts	Re: Chevy tuned port limitations Thanks for all the comments. Has anyone removed the IAC manifold on the bottom of the throttle body? It seems there is no use for coolant to the throttle body or Idle air control solenoid.