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LS7 Fast Fuel rails and MSD atomic intake manifold
I can see that if you have the LSXR FAST intake (what I currently have installed) and you want the FAST billet fuel rails you actually order the LS3 billet rails for it.
I am planning on installing an MSD intake manifold and need to know if the fuel rails I have on the FAST will work, or if I need to order a different set?
To simplify... Do the stock LS7 fuel rails fit on the MSD or do you have to buy LS3 rails?
I'm sending the intake off to Nitrous Outlet for the direct port plumbing and FAST fuel rail modification this week. The rails I'm sending are the rails that were used with my FAST 102 intake. We will see how it goes. They weren't hesitant at all about the job so I don't foresee an issue.
Searching the part number to list here it appears that the LS3 and LS7 rails are both the same rail from FAST, this is the same for both their "OE style" fixed and billet rails. I found some misleading information from a supplier on their website which is what confused me on the billet rails. To go a step further I looked up the part numbers for the LS3 and LS7 factory rails. Even from the same years these rails are different. 12633513 LS7 and 12633511 LS3. No idea what is different. If FAST could make a cheap fixed rail that fits both, why would the factory not do so as well.
To add more mystery to the mix, FAST sells a kit with spacers listed as "LS3/LS7/L76/L99 Fuel Rail / Fuel Injector Spacer Kit for LSXR™ Intake". Now why in the hell would you need that if many others like myself have mounted the FAST LS3/LS7 rails on the stock shorty injectors with no spacers. With spacers I would think the mounting tabs that come with the rails would not even be able to bolt to the manifold itself as they would sit almost a half inch high.
In these pictures the rails are sitting on the LS7 style shorty injector. From my test fit, these rails will not fit this intake at this height without some mill work to the back of the rails. We shall see how it turns out. I will keep the thread up to date. I think they said 2 weeks to get it back to me.
I'm sending the intake off to Nitrous Outlet for the direct port plumbing and FAST fuel rail modification this week. The rails I'm sending are the rails that were used with my FAST 102 intake. We will see how it goes. They weren't hesitant at all about the job so I don't foresee an issue.
Searching the part number to list here it appears that the LS3 and LS7 rails are both the same rail from FAST, this is the same for both their "OE style" fixed and billet rails. I found some misleading information from a supplier on their website which is what confused me on the billet rails. To go a step further I looked up the part numbers for the LS3 and LS7 factory rails. Even from the same years these rails are different. 12633513 LS7 and 12633511 LS3. No idea what is different. If FAST could make a cheap fixed rail that fits both, why would the factory not do so as well.
To add more mystery to the mix, FAST sells a kit with spacers listed as "LS3/LS7/L76/L99 Fuel Rail / Fuel Injector Spacer Kit for LSXR™ Intake". Now why in the hell would you need that if many others like myself have mounted the FAST LS3/LS7 rails on the stock shorty injectors with no spacers. With spacers I would think the mounting tabs that come with the rails would not even be able to bolt to the manifold itself as they would sit almost a half inch high.
In these pictures the rails are sitting on the LS7 style shorty injector. From my test fit, these rails will not fit this intake at this height without some mill work to the back of the rails. We shall see how it turns out. I will keep the thread up to date. I think they said 2 weeks to get it back to me.
thank you for the info. What are they charging you for the service and parts?.
I never got Nitrous Outlet to make it right. I ended up going this route and you would not have to mill the rails for it to work. They are just the standard LSXR Rails that were ordered with the FAST intake I used to have. https://www.corvetteforum.com/forums...l-details.html
I suppose everyone's definition of "simple" bolt up is different. I had to drill new holes in the rails to line up with MSD mounting locations and also fab some mounting brackets but aside of that it isn't bad. None of the FAST rails will line up without drilling new mounting holes. It is pretty easy. I didn't feel that it was that bad. I just went through trouble as I trusted a company to do this for me and they didn't come through. The injector alignment was way off which was unacceptable was well.
09-24-2016, 02:40 AM
LS7 Fast Fuel rails and MSD atomic intake manifold
