When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey so my current setup is a lsx 454
I just installed a holley hi ram intake with a direct port setup, my old setup was a mamo ported msd with a direct port setup.
the intake swap picked up power and torque everywhere I will post pics of the graph,
on nitrous I made 870whp on a 200shot through the msd and dropped down to 830whp but with a massive torque gain on a 250 shot.
I will post both graphs,
We started with nitrous express recommended jetting for a 250 shot, 29n 22f at 8-10psi on the fuel side,
it ran crazy rich around 10:1afr, we did another pull dropped fuel pressure to 7 psi, still crazy rich,
we ended up doing 4 pulls on the last pull we were down to 5.5psi on the fuel and still around 10.8:1 afr and continued to lose power,
I have checked all my jets to make sure they are correct, I pulled nitrous solenoids off and checked inlet screen, me and my tuner are not sure where the restriction could be coming from, or are we losing that much power just from the rich condition
let me know if anyone can help, I plan on flowing the system tommorow to ensure I'm getting the proper amount of nitrous through the jets.
The jets supplied are usually just safe starting points. Normally on a 5-10psi fuel system a 10 jet spread is a good starting point. What sucks with a direct port is that's a lot of jets to by to get all the shots tuned in. Being that rich I'd more than likely try swapping the jets you already have. Example, 250n with 200f jets or 300n and 250f jets. Bump the pressure back to 10psi and start over.
The jets supplied are usually just safe starting points. Normally on a 5-10psi fuel system a 10 jet spread is a good starting point. What sucks with a direct port is that's a lot of jets to by to get all the shots tuned in. Being that rich I'd more than likely try swapping the jets you already have. Example, 250n with 200f jets or 300n and 250f jets. Bump the pressure back to 10psi and start over.
Yes that's what I was going to try today was drop my fuel jet to a 20 or 19 and see how it goes,
Originally Posted by brandon@nitrousoutlet
What size feed line?
I have a -6 feed lines feed line is the same that was used with previous intake as well.
I used a 29 N2O and 19 fuel at 10 psi on my N.O. Direct Port (Ported 102mm Fast) which put A/F around 12.75:1. Ran 9.44 at 145 in my 3800 llb car hitting limiter on both 1-2 and 2-3 as still sorting out shift points....
I used a 29 N2O and 19 fuel at 10 psi on my N.O. Direct Port (Ported 102mm Fast) which put A/F around 12.75:1. Ran 9.44 at 145 in my 3800 llb car hitting limiter on both 1-2 and 2-3 as still sorting out shift points....
thanks for the info I just put some 20 jets in the car, I'm going to wait for it to warm up a little outside and go test it out!
02-06-2019, 11:13 PM
Need help lost power with bigger shot 
