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180 wanabe

Nistune Flex /injectors

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Having recently done a RB box conversion I am looking at doing a flex tune upgrade on my car in the not too distant future.

 

Currently running a nistune with a set of nismo 740cc injectors and a walbro 460

 

Turbo setup is a precision HP5130 and I am running un1cams +springs

 

Car is currently making 310hp @ the wheels on a "safe" 98 tune

 

I know everyone is going to tell me to throw out the 740s and go top feed etc, however I was wondering if anyone on here has seen how far the Nismo 740s can be pushed on E85 with a bit of help from a fuel pressure regulator ?

 

Not wanting to go top feed I guess the other option is to go some five O 1200cc side feeds which seem to work ok for the SR20 but are rubbish when it comes to RB engines.

 

I'm thinking that Dose pipe might be the man with the most nistune flex experience who is active on the forums so any input would be appreciated :)

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Get a decent reg and run the 740cc at 3.5 bar and milk them a little.

 

I managed to get a set of 740cc on the stock reg making 240kW and they were at about 96% duty cycle or so lol.

 

Could even run the 740cc at 4 bar but the idle might be on the shit side and also the cruise area might suffer a little.

 

Also remember when running high base pressure you need a fuel pump that can flow base pressure + the intended boost on top. So say 4 bar base, and 1.5 bar boost you need a fuel system that can support 5.5bar of fuel pressure and flow fuel still.

 

The Walbro 460 is perfect for this :)

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Any thoughts on the five O 1200cc in a SR20? I did a search and found one of your posts saying they were rubbish in a RB but fine in a SR. Planning on going flex tune so they will be running on 98 at least 50% of the time as the closest united is about 15k away from me.

 

I also value reasonable idle quality, cruise is something I would also want to be decent as I do a trip to Brisbane and back from the Gold Coast one a week to see the GF.

 

Sounding like the 740cc will have to replaced if I want the above 2 things.

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Stay away from those Five O injectors, I made that mistake.

 

Had 2x just seize up on me too.

 

740cc with high base pressure OR straight up top feeds. I do like the ID1300 stainless body ones :D

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I got around the 245KW peak power with 740s on e85 with a T518z... injectors were close to maxing when the turbo did come on in the mid range apparently ( from my vague recollection of what was said at the time)

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I got around the 245KW peak power with 740s on e85 with a T518z... injectors were close to maxing when the turbo did come on in the mid range apparently ( from my vague recollection of what was said at the time)

 

Were you runnig stock FPR ?

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Most i got from 740cc injectors and caltex eflex so abit head room than united was 280kw

Nismo fuel reg on 4bar base and same pump rewired walbro 460

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I got around the 245KW peak power with 740s on e85 with a T518z... injectors were close to maxing when the turbo did come on in the mid range apparently ( from my vague recollection of what was said at the time)

 

Were you runnig stock FPR ?

 

Yeah stock FPR, Walbro 460 pump

 

Thinking about maybe going a nismo FPR so possibly screw a bit more out of it but keep it stock looking as that setup is now going in a street s13 with a GTX2860R

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I think that the saving grace for my 740cc injectors will be that the car will probably never be running on straight E85.

 

Given I want it set up as flex fuel and I will be running 98 most of the time, even if I was to fill up 40l with straight E85 with say 10l of 98 in the tank as I never run the tank dry I would end up with around E70.

 

Any idea on how much extra headroom E70 gives over 85?

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I wouldn't bother with trying to tune for e70.

 

740cc at 4 bar should get you over the line. The DW injector calculator says at 4bar they will get about 850cc.

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I like your setup Wanabe, very similar to what I have except I have larger cams. If you decide to go E85 Flex with your 740's keep us updated because I'd be interested in knowing how it goes.

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I wouldn't bother with trying to tune for e70.

 

740cc at 4 bar should get you over the line. The DW injector calculator says at 4bar they will get about 850cc.

 

I would get the car tuned on straight 85 and up the pressure as you suggested to try and milk the 740cc injectors that little bit more.

I could not see myself filling up exclusively on E85, more than likely it would be a tank of 98 and then a tank of E85 then back to 98 etc.

 

Running a few numbers through a blend calculator http://www.georgebelton.com/E85Calculator.php

 

People say that the S15 tank is supposed to hold 65L and the fuel light comes on when you have 10L left in the tank.

So if I was filling up when the light came on and then putting 50L of E85 in the tank, that would get me around E71 on the 1st fill.

The next fill being 50L of 98 would bring the tank contents to E12.

Fill up with another 50L of E85 and the contents should be around E73

 

Basically, the tank contents would alternate between E73 and E12 each fill if I kept alternating between 98/E85.

 

Having a look at the Nistune feature pack documentation on page 12/13 http://nistune.com/docs/Nistune%20Feature%20Pack%20V1.pdf it shows the ethanol scaling tables/fuel trimming and ignition trimming.

 

My understanding is shit will get maxed out when running E85 "fuel/ignition" and then backed off in increments depending on what the flex sensor is detecting in the tank. So if the car has been tuned on straight E85 and a couple of tanks later is running E73 it should lean out the mixture a tad, buying a bit more injector duty cycle headroom/insurance.

 

My understanding of why you don't want to be maxing injectors is

 

1, @100% they are just open pouring in fuel and not properly spraying.

2. Having spare duty cycle means they can throw in extra fuel incase of a boost spike and save the engine from running lean/damage

3. Heat ?

 

Came across this site https://www.plmsdevelopments.com/customers/paul_180sx.shtml kind of a build blog on a guys 180sx. Ended up getting 274rwkw with 740cc injectors @ 90% duty cycle. There is no mention of what pump was in the car or if a FPR was used.

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correct Nistune allows you to bend the blend curve too.. it's just way too good and powerful for the price point. so many features :)

 

it will lean and pull timing out as it blends between both e85 and 98 maps. amazing it is, adaptronic just does a dirty linear blend without the option of adjusting the curve yourself so the afrs are a bit on the funny side when you've got a blended tank but that's where the wide band o2 feedback comes handy.

 

probably had the base pressure bumped up.

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