how much fuel pressure?

CMF_maat

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my micra goes into get tuned in the next couple of days and the mod list is as follows...

custom headers
highflow cat
2" exhaust
ga15de TB
advanced timing
import cg13de
hks pod with CAI
adjustable fuel regulator
and last but not least a Apexi SAFC NEO

so my question is what fuel pressure should i look at running when they put it on the dyno, or will they work all of that out by reading the air fuel ratio reading from the dyno or is should i set it before i take it in?

thanks in advance..

matt
 

smidge

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14.5psi to a bar

1 bar = 1 atmosphere

1 atmosphere = the amount of air pressure on us at sea level

which means if you're running one bar of boost its got twice as much pressure as NA
 

CMF_turbo march-rolling shell

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if you have an safc, you shouldn't need to touch the fuel pressure. the less fuel pressure you can run,.. the better. the only reason you need an aftermarket adjustable reg is if your injectors are maxed out at 100% duty cycle. if they are, then you up the fuel pressure to give you a little more fuel through the injectors. just set it on stock, or close to, and if need be, i'm sure the people tuning it will adjust accordingly.
 

CMF_maat

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thanks for the advice guys..

now as promised heres my dyno sheet,

and before people start saying oh thats not much power for the mods keep in mind the car was in full street trim ie heavy mags etc and the dyno is not in shootout mode like some tuning places do giving a bull**** figure..

anyways after the tune i couldnt wipe the smile off my face the car drive un beleivably well now pulling had all the way to 6grand :)

enjoy

http://i173.photobucket.com/albums/w80/maats_pics/dynosheet.jpg
 

CMF_deNs

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If it puts a smile on your face when driving, then that's all that matters :)

Trying to understand your setup though - the adjustable fuel regulator is for fuel pressures, and the AFC is for changing the air/fuel ratio?

Just looked up the pricing of the AFC NEO.. that's just scary. That's a huge amount of money to put into an N/A setup. Could easily justify spending that kinda money towards FI but dunno about spending so much on N/A.

---dens
 

CMF_maat

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but im considering cams later on down the track thats why i chose it so we'l see what happens..
i had a run with my mates BA falcon today and from 0 to 100 i showed him who was boss :D

it jus powers on, i got so used to the flat spots before it was tuned that now its like :O ............. :D fark yeah hahahaha
 

CMF_MicGreen

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maat, which gear did you have at the dyno? 3rd or 4th? was that lower axle kilometers per hour? because the 4th gear ratio is most nearest to "straight gear", not the 3rd... i'm just saying, that you should have more power in numbers with those modifications...

i just have custom made 4-1 extractor and a cat-back exhaust and K&N 57i-kit and i have the same power... and how much do you have torque? i have 119Nm and it's about 87,5 lb-ft... and my car dyno was made with 4th gear, and the power i got when hitting the rev limiter and the speed was 180 kilometers per hour...
 

CMF_MicGreen

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Yom WROTE:

"MicGreen WROTE:

the 4th gear ratio is most nearest to "straight gear", not the 3rd... "</div>

Correct. But don't forget about the final drive in the differential gearing.
Click to expand...

hmmm.. can you explain some more, please? :) what's the final ratio for?
 

CMF_Yom

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From when you select a gear the drive still has to be sent to the CV shafts somehow. So there's more cogs, and therefore more gearing.

This extra gearing between the gear speed and the axle speeds is the final drive ratio.

But that probably makes very little sense. :p
 

CMF_MicGreen

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Yom WROTE:

"
This extra gearing between the gear speed and the axle speeds is the final drive ratio.
Click to expand...

but isn't the final drive ratio same with every gear?

but how does the final drive ratio effect when you are going just trough one gear? because you have to push pedal to the medal just with this one gear... you can just shift gears without touching the gas pedal, because there is no tyre resistance when your car is at the dyno-roll...

and if you want to know the torque of your car, you have to use nearest gear to "straight gear".. if you for example use first gear you'll get a huge torque, but that's very far from the right torque...
 

CMF_MicGreen

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maat WROTE:

"my micra goes into get tuned in the next couple of days and the mod list is as follows...

custom headers

highflow cat

2" exhaust

ga15de TB

advanced timing

import cg13de

hks pod with CAI

adjustable fuel regulator

and last but not least a Apexi SAFC NEO

so my question is what fuel pressure should i look at running when they put it on the dyno, or will they work all of that out by reading the air fuel ratio reading from the dyno or is should i set it before i take it in?

thanks in advance..

matt
Click to expand...

errrr... just wondering also the 68 hp with those modifications... should that be 68 kW? you should have 75hp without any modifications in cg13de (-minus losses which are due to transfering the power from engine to the wheels)

i mean i have with my modifications 60kW at the wheels, that means about 82hp at the wheel...
 

CMF_Yom

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MicGreen WROTE:

"Yom WROTE:<BR><BR>"<BR>This extra gearing between the gear speed and the axle speeds is the final drive ratio.<BR><BR>"</DIV><BR><BR>but isn't the final drive ratio same with every gear?<BR><BR>but how does the final drive ratio effect when you are going just trough one gear? because you have to push pedal to the medal just with this one gear... you can just shift gears without touching the gas pedal, because there is no tyre resistance when your car is at the dyno-roll... <BR><BR>and if you want to know the torque of your car, you have to use nearest gear to "straight gear".. if you for example use first gear you'll get a huge torque, but that's very far from the right torque...
Click to expand...

Yes, it is the same for every gear. Some operators seem to like to know what it is and figure out from there which gear offers the most accurate 1:1 ratio. Seems a waste of time to me but I thought I'd bring it up considering the arguements we always get on this forum about dyno charts... :p
 

CMF_deNs

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MicGreen WROTE:
errrr... just wondering also the 68 hp with those modifications... should that be 68 kW? you should have 75hp without any modifications in cg13de (-minus losses which are due to transfering the power from engine to the wheels)

i mean i have with my modifications 60kW at the wheels, that means about 82hp at the wheel...
Click to expand...

To be honest I was thinking the same thing. I was thinking of these dyno readouts specifically, and it seemed a little low. I know you can't compare dyno to dyno exactly, but that's a pretty big dif.

---dens
 

CMF_maat

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you may have a higher number but my car was in to get tuned, that graph isnt really a power run its more just setting up the AF maps, if it were to be in shoot out mode itd be higher,

tell you what ill take it to Xspeed and get a power run done..
their dyno is well known for making massive numbers and we'l see the difference :)
 

CMF_deNs

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1300cc WROTE:

"3 years later...............
Click to expand...

..and your point in posting that was? If you want to find out the results - contact him directly, because I think he might have sold that car off quite a while ago. He certainly doesn't post on here often/at all anymore.

---dens
 

CMF_fred

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there come to a point in increasing fuel pressure that the injector turns from a 'mister' to a 'squirter' that's probably around 47+ psi. You want a nice misting spray for good combustion.
 
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