So i bought a v-1 s trim i'm going to run 8 to 10psi and a guy at a mustang shop said that if i run 42lb injectors that i don't need the fmu..Has anyone heard of doing this and is it ok to do...Also the guy said i can run 42lb injectors on a stock fuel rail has anyone ran bigger injectors then that on a stock fuel rail?
fmu vortech?
- Thread starter JT929240
- Start date
Yes....can be done an is quite popular. It's not quite simple as just swapping out the injectors though. You'll need a larger fuel pump to suply the fuel (I recommed a 255lph unit) and an ECU tune (via SCT/Diablosport chip) to pull it all together. A set of 42lb/hr injectors will slip into the stock rails just fine.
Just use the fmu setup.
It's works pefectly fine.
The ECU tune is over the top with little benefit.
Most pushrod experts would set your fox up with the Fmu, it's the newer guys work on prodomintely 96+ cars that like to do the tune. Don't forget there are shop owners out there that are also salemen, a tune with a chip is like $750 and up.
It's works pefectly fine.
The ECU tune is over the top with little benefit.
Most pushrod experts would set your fox up with the Fmu, it's the newer guys work on prodomintely 96+ cars that like to do the tune. Don't forget there are shop owners out there that are also salemen, a tune with a chip is like $750 and up.
I don't disagree that it will run fine with the FMU set up, but an FMU will get you in the ballpark at best. Some will hit it closer than others, but if he want's optimum drivability, economy, emmisions and over all performance, and ECU tune with properly sized injectors is the ONLY way to go. I've seen half a dozen cars (pre-'96 included) pick up as much as 20hp on the dyno with the correct ECU tune, that promote the above listed qualities to boot.
What he's got to ask himself is, are all the above benefits worth the additional cash layout to him.
I've seen tunes by reputable shops pick up -5hp (that's negative 5).
There really isn't much a stock mustang computer can't handle.
It's all about how well the combination of parts is setup.
Properly done, a chip should yield pretty much nothing.
Unfortunately sometimes a chip is used to bandaid things that are screwed up, giving the illusion that it actually did something.
For the pump he should for sure make sure to use the high pressure 255 pump.
GSS340.
And i agree, inline pumps in conjuction with an in tank are nothing but problems.
FMU
The inline pump will have its own fuse, relay, wiring, etc. Just more stuff to go wrong. If you go with the 255 intank pump, make sure it is the high pressure model ( gss340 for Wlabro). FYI fuel supply calculation will be on crank hp not rear wheel ex; the 42# inj should handle 480 - 500 fwhp. For street and daily driving, my fmu set-up works great and the wideband AFR let's me know that the fmu is working right (10.5 - 11.0) under boost.
The inline pump will have its own fuse, relay, wiring, etc. Just more stuff to go wrong. If you go with the 255 intank pump, make sure it is the high pressure model ( gss340 for Wlabro). FYI fuel supply calculation will be on crank hp not rear wheel ex; the 42# inj should handle 480 - 500 fwhp. For street and daily driving, my fmu set-up works great and the wideband AFR let's me know that the fmu is working right (10.5 - 11.0) under boost.
Mike is right, why use two pumps when one will do the job?
Inline pumps sometimes are a bottleneck for the in tank if you use the Gss340.
Besides if you use 2 mediocre pumps (like a standard 255 and a t-rex), and one stops working, you are left with too little fuel and no way to know it. That's not good.
BTW, a gss340 is only about $100.
That saves you extra work on the external and $200.
Inline pumps sometimes are a bottleneck for the in tank if you use the Gss340.
Besides if you use 2 mediocre pumps (like a standard 255 and a t-rex), and one stops working, you are left with too little fuel and no way to know it. That's not good.
BTW, a gss340 is only about $100.
That saves you extra work on the external and $200.
That wouldn't work.
The pumps would have no problems keeping base fuse pressure.
It's under maximum load you have to worry about, and i'm not sure you would want to be watching the fp gauge driving a car at full throttle with 12 pounds of boost.
The t rex is pretty much an outdated expense that just really isn't needed when you have the proper in tank pump.
Cobra912
Active Member
I ditched my FMU, gotta a tune with my 42's, and run both a 255 and t-rex without issues. I make 475 to the wheels and have never had an issue with drivablility or anything else. I also didn't have a problem with the FMU so either way you decide to go would be fine. I needed a tune anyways so that's why I ditched mine.
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