1G vs. 2G fuel rail...physical difference?

[Mistaspakles]

Is there a physical difference between the 1G fuel rail and the 2G fuel rail? I forgot which one I have. I did the 1G Intake Mani/Head Swap but I don't remember if I had the fuel rail replaced. Is there a physical difference by just looking at them to tell which is which?

 

[doug]

The 1G one is about a 1/3" shorter. I personally can't tell the difference unless I hold them side by side.

 

[Mistaspakles]

Can I get a measurement of fuel rails from 1G guys and 2G guys, in terms of length? Thanks.

 

[Mistaspakles]

Ok, someone with a 1G fuel rail emailed me and said his was 13.5 inches. Another guy with a 2G fuel rail said his was 13.75 inches. Is this right? I thought the 1G rail was significantly shorter than the 2G rail.

 

[doug]

I haven't actually measured, but that sounds about right.

 

[GVTalon]

The visual difference is in the ends. A 2G rail positions the bolts for the fuel line and the pressure regulator verticle while the 1G the bolts are more horizontal.


o= Bolt
O= Hole in fuel rail


1G---> o O o




2G--->
o

O

o


Sorry about the cheesy diagram

 

[WhipmastaFlex]

im running a 1g fuel rail on my 2g after i karate chopped mine trying to loosen a stubborn bolt and cracked it in half... ouch... anywho, if you look at the 2g rail, you can see two pieces that run parallel to each injector, which the dinks at mitsubishi told me are to prevent "injector roll", which apparently is a problem i, or anyone i talk to about "injector roll", have never heard of. the 1g rail does not have these... i was told that due to the lack of those pieces on the 1g rail it would not work on my 2g, and i would have to order a new fuel rail for $185... i just went to the local JY and pulled the rail and lines, used the 1g adapters and she bolted right up

 

[turboglenn]

For what it's worth i've used both on both engines. currently, i have a 2g rail on a 1g 6 bolt motor. I can't wait to get another aftermarket rail though

And as stated above the 2g rail is slightly longer, but not by much. Whne doing an aftermarket FPR install on them the 2g kit comes with a slightly tighter bend in the adapter right off the rail to clear the timing cover, but a 1g would most likely work as well, just might rub on the T-cover though

 

[1LE]

Either should work, if your FPR will bolt up. I originally had a 2g 7-bolt fuel rail on my 1g 7-bolt engine. I now have a 1g 6-bolt fuel rail on it so that I can use the bolt-on Buschure AFPR...

 

[BoostedTalonTS]

A side from the 2g rail being a little bit longer, it also has a larger ID when compared to the 1g rails... not much (forgot what the exact ID reading was on the caliper) but it is slightly larger then the 1g rails.. Plus it allows the plugs to fit better when you rewire your 1g with 2g style injector plugs


EDIT: It is better to use a 2nd gen fuel rail with 2nd gen injector plugs. If you were going to use a 2g rail with 1g injector plugs, the 2g rail must be modified in order for the 1st gen plugs to fit.

 

[94tsi]

As far as flow difference, is there any difference in the 1g and 2g rail?

 

[turboglenn]

A side from the 2g rail being a little bit longer, it also has a larger ID when compared to the 1g rails... not much (forgot what the exact ID reading was on the caliper) but it is slightly larger then the 1g rails.. Plus it allows the plugs to fit better when you rewire your 1g with 2g style injector plugs

I didn't know wither of those. The 1 & 2g stock FPR's are the same diameter where they go in the rail ( ot the eye at least when held to each other). So you have to grind a 1g rail to plug in the 2g injector plugs? I had to grind my 2g rail to fit the plugs on my 720's. I wonder how easy 2g plugs on 1000cc injectors and 1g rail would work together?

 

[92awddsm]

I didn't know wither of those. The 1 & 2g stock FPR's are the same diameter where they go in the rail ( ot the eye at least when held to each other). So you have to grind a 1g rail to plug in the 2g injector plugs? I had to grind my 2g rail to fit the plugs on my 720's. I wonder how easy 2g plugs on 1000cc injectors and 1g rail would work together?

I had fic 750's, 1g rail, and 2g plugs and never had to do any grinding for anything to fit. I would tell you about the fit of 1200cc injectors and 1g fuel rail but I switched to an aftermarket rail. I wish I had done some test fitting beforehand so I could better answer these questions. And as far as afpr is concerned, you are always better off tapping the rail to 3/8 npt and using a screw in fitting and running the remote afpr. The bolt on an adapters and regulators are more restrictive due to the inlet size. These can be overrun as easily as a stock regulator with a good fuel pump.

 

[BoostedTalonTS]

ok let me clarify here...
The 2g fuel rail's ID (NOT just the opening for the FPR) is larger then a 1g fuel rail... The FPRs have the same diameter as the machined recess for them IS the same ID on both rails. Looking further in then that recess is when you find that the actual ID of the 2nd gen TURBO fuel rail's fuel capacity is greater, for 2 reasons: Larger ID and longer length = more fuel capacity vs the 1st gen rail.
As far as the injector plugs go, the 2g fuel rails need to be modified in order to use the 1g style injector plugs. The 2nd gen style injector plugs will work on either fuel rail (I used the 2g fuel rail in my 1st gen first then later upgraded to the 2nd gen plugs after seeing what a PITA is was to remove the 1st gen plug's retaining clips w/ the 2nd gen fuel rail installed).

 

[rich3389]

Can I bolt a 1g FPR onto a 2g rail? Or is the bolt spacing different?

 

[turbosax2]

2g on left, 1g on right.

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As you can see, the 1g bolt pattern is wider than the 2g's, so a 1g fpr will not bolt on a 2g rail. However, you could probably elongate the holes on the 1g fpr in closer and fit it on the 2g rail. The portion of the fpr that goes into the hole in the rail is the same on both.

 

[DSMunknown]

Something also to note - the 1G 1990 rail is different from the 1991-1994 model. IIRC the earlier version will not be able to be installed in the 2Gs because the inlet flange comes into contact with the head (or is it the TPS?). I was having an issue with fitment of an AN fitting when switching to an AFPR (seen here), but after a 1G rail install, I have about 1/8-to-1/6 of an inch clearence for the cam gear cover to fit on.

 

[Gamble97]

ok let me clarify here...
The 2g fuel rail's ID (NOT just the opening for the FPR) is larger then a 1g fuel rail... The FPRs have the same diameter as the machined recess for them IS the same ID on both rails. Looking further in then that recess is when you find that the actual ID of the 2nd gen TURBO fuel rail's fuel capacity is greater, for 2 reasons: Larger ID and longer length = more fuel capacity vs the 1st gen rail.
As far as the injector plugs go, the 2g fuel rails need to be modified in order to use the 1g style injector plugs. The 2nd gen style injector plugs will work on either fuel rail (I used the 2g fuel rail in my 1st gen first then later upgraded to the 2nd gen plugs after seeing what a PITA is was to remove the 1st gen plug's retaining clips w/ the 2nd gen fuel rail installed).

I think the 1g ID is bigger than the 2g.

 

[420a-t]

Hmm, I just bought a 1g rail with an fittings on it. Will I run into problems if I have a 6-bolt head?

 

[Gamble97]

Why would you have problems. The rails 1g and 2g are interchangeable. It's the length that can be an issue with the stock regulator.