Talk to me abut 4th injector

goofy · Jan 9, 2017

I am looking at a 2015 viper that is set up with larger inter cooler, fuel pump upgrade and a 4th injector. Currently they have only ran 110 race fuel. I am not interested in running 110 so would drop the boost and run 91 but how does that exactly work? All injectors still work? Still run good running at 91 and lower boost. Just feeling it out. Maybe just look for a standard 180 kit? It does have a pro logger to adjust boost

madsledder · Jan 10, 2017

How much boost is it running? Does it have a head shim?
Could look at the evo reflash for a little more on stock compression since it has the forth injector.

madsledder · Jan 10, 2017

Or just do a head shim if it doesn't have it. Then its still setup.

goofy · Jan 10, 2017

I don't know what boost they were running but basically wanted to know if I drop boost to say 7 lbs and run 91 octane will it run fine with all the upgraded stuff? It's got a lot of upgrades for high boost but don't really want it. It's just a good deal. Only 300 or so miles.

up-high · Jan 10, 2017

Might as well buy some 110. Boost is addicting. If it's set up to run high boost it will be fine at 7 lbs on 91(ask the owner to be sure). You won't leave it at 7 very long. Viper rods have a problem with high boost(heard this on the internet so must be true).

Octanee · Jan 10, 2017

Well If I remember right, the nytro ran like 7 psi on pump gas did they not? and the viper has the nytro engine, so it should be all the same gig. If you want good horsepower on pump gas, the head shim is a must, race gas costs lots, a little time to put in the head shim and on pump gas you'll be up and beyond on pump gas vs that of race gas with stock compression.

Motorbreath_ · Jan 11, 2017

up-high said:
Might as well buy some 110. Boost is addicting. If it's set up to run high boost it will be fine at 7 lbs on 91(ask the owner to be sure). You won't leave it at 7 very long. Viper rods have a problem with high boost(heard this on the internet so must be true).

That's only the 2016 models.. and only a few were affected. Kind of like Russian roulette.. 14 and 15 models can handle boost no problem.

goofy · Jan 11, 2017

I need to understand the head shim thing I guess. So the deal is you have someone do a head shim and you can run the same boost with 91 Oct vs 110 oct? Ya not interested at all running 8 dollar per gallon fuel. I run a nytro with turbo 7 lbs of boost and I love it. Not saying more isn't better!

Octanee · Jan 11, 2017

goofy said:
I need to understand the head shim thing I guess. So the deal is you have someone do a head shim and you can run the same boost with 91 Oct vs 110 oct? Ya not interested at all running 8 dollar per gallon fuel. I run a nytro with turbo 7 lbs of boost and I love it. Not saying more isn't better!

Well the head shim lowers compression, So IIRC, the nytro is 7 psi ish on pump gas, and is ~180 hp? 190? then you go with a head shim, ~270 horse @ 15#? on pump all day every day.

aj1180 · Jan 20, 2017

The head shim would be a good idea but if you want a cheaper fuel than 110 run 100 ll av gas. I run 50 av/50 92 at 12-14 lbs of boost and have never had a problem without a head shim. 100 ll is 5 bucks a gallon vs around 3 for 92 so 5 gallons will cost you an extra 10 bucks per tank. That's cheap insurance and you can turn it up!!!!

madsledder · Jan 21, 2017

Ihad issues with av and pipe senser on my bb cat. But I ran it anyway. Not sure how the o2 senser will take it.

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Talk to me abut 4th injector

goofy

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madsledder

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madsledder

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goofy

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up-high

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Octanee

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Motorbreath_

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goofy

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madsledder

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