Jump to content
SAU Community

Recommended Posts

Hi guys i got an r32 GTR with a Garett t04z turbo, 60mm wastegate, 260 poncams and Vipec ECU.

And i got it tuned but there isnt enough fuel available, i could only get 260awkw at 13psi with the injectors maxing out.

I got a Sard 280ltr pump, Sard 700cc injectors and standard fuel rail and lines.

What could be the problem?

as above tai... i'd be looking at things in the fuel system before the injectors that are holding them back... 480 cc injectors can flow 260rwkw

as stevo suggested but also fpr, fuel filter and pump relay

Im not really sure, but my brother (whos tuning the car) said the injectors are at 95% duty cycle via what it says on the Tuning software.

I find it odd as i had 240awkws at 15psi using stock injectors and stock pump? now i've upgraded and only slightly done better?

Theres lots of fuel in the tank, lines seem to be unhindered, as i never touched it since my stock setup.. might have to check the fuel filter. Is there a way of knowing if its blocked?

Just that its running at 95% at the top end of the rev range, and cannot boost or tune further until this problem is resolved.

Thanks for the help guys :P

Tai

Did they leave the standard fuel reg on, pump side just under the inside of the fuel tank cap?

I believe they did, I remember the pump i brought had the gold colored reg thing still attached to it, and they removed that one and used the one that was already on the stock pump i think?

there is no reg attached to the pump. and no reg in the fuel tank so i'm not sure what 666Dan is talking about?

what is the AFR? you can make any injector max out at any power level if you don't mind AFRs around 9:1! lol. more info needed to sort through this one I think.

I believe they did, I remember the pump i brought had the gold coloured reg still attached to it, and they removed that one and used the one that was already on the stock pump i think?

They should have retained the brass one for sure, the stock one is a plastic piece of crap :P

Richard, my pump had a reg on it....purple plastic thing right up the top of the outgoing fuel line, I got a nice replacement one with the GTR pump.

there is no such thing in an R32 GTR. there is an anti drain back valve on the pump. but there is only one fuel pressure reg in the whole system, and it's on the return end of the fuel rail.

I'll have to find out more info, but just got off the fone with my bro he said the AFR's are around the 12-13 (safe) all the way throught the rev range on the 13psi its at now, but once boosted more it wants to lean out.. so its set on 13psi.

He's tuned heaps of cars alot more powerful than mine, so i don't doubt him.

OK...well there is one in the R34, I had to call Nissan to check what it was and they said it was a primary fuel reg on the feed line (it's definately on the feed in my car)

I even just checked the workshop manual, complete break down of the fuel pump side, shows the two halves of the pipe but doesn't show the reg thing in line....bloody Nissan left it out *shakes fist*

So stock fuel reg?

Here's what ive added to a stock fuel system in a gtr, compare your parts;

-Intank 044 bosch

-SARD f.p.r.

-SARD injectors (same)

Just by doing that it did 355kw atw at something like (from memory, probably wrong) 70% duty cycle. I remember the fuel system had a shitload more in it

As BB said, more info

OK...well there is one in the R34, I had to call Nissan to check what it was and they said it was a primary fuel reg on the feed line (it's definately on the feed in my car)

well there is some gold dangly thing, but it's not a reg like the other one is. it has no pressure feed. and it's on the supply line. so if anything it restricts flow (and if it was doing that it would LOWER pressure in the feed after it). but most likely it's anti drain back valve.

candy33, i would get your brother to check that he has setup the injectors correctly on the ECU, he could be confusing a value of 95 on the fuel map as being 95% duty. what is the master value set to? (XXms)

on this image where is it showing 95?

post-32350-1229061099_thumb.jpg

basically with the sard pump, stock lines, stock wiring, stock reg and sard injectors you should be able to support 350kw+. so something is wrong. either the software is not accurate and you don't really have 95% duty, or you do have 95% duty, but don't need to (ie your AFR is stupid rich), or something is not installed correctly.

I will get you more info soon guys.

Yes its running stock fuel reg, fuel rail and lines.

My brothers have built and tuned several other GTR's using the stock fuel reg, fuel rail and lines for near 400awkws, so i can't seem to see how that could be my problem.

He did say that my turbo ramps up really quick with about 80% of the power coming in the vicinity of a thousand rpm, which could be the cause of it not keeping up.

But yeah i'll stop speculating and do more investigating.

Thanks guys

candy33, i would get your brother to check that he has setup the injectors correctly on the ECU, he could be confusing a value of 95 on the fuel map as being 95% duty. what is the master value set to? (XXms)

on this image where is it showing 95?

post-32350-1229061099_thumb.jpg

Thanks for that Titan, i will find out for you asap.

Cheers

well there is some gold dangly thing, but it's not a reg like the other one is. it has no pressure feed. and it's on the supply line. so if anything it restricts flow (and if it was doing that it would LOWER pressure in the feed after it). but most likely it's anti drain back valve.

Maybe regulator was the wrong wording, yes it's a flow restrictor. Most people just bugger the thing off as it's got no place in a real car :)

I was thinking in terms of it restricting fuel supply into the lines, the injectors not getting the pressure behind them as they're draining the post restrictor fuel off too quickly, as a result low line pressure is seeing duty cycle increase as it's having to be high to meet the challenge.

First things first

Stock fuel reg, rail & lines are fine for massive power, so its not a problem there in that sense

So if the injectors are maxing out, something is impeading flow.

I would look at

1. Pump voltage - is the pump getting the required volts (stock wiring is NO good).

2. Fuel Filter - is it a decent flowing one? Is the fuel filter perhaps blocked?

3. Fuel Hose - has it been changed at some point? Is it large enough etc etc.

4. Fuel Pump - is it mounted correctly? Is there 110% certainty there is nothing potentially blocking the pickup?

5. Fuel lines - Are some of them bent/kinked perhaps which would possibly cause problems?

6. Fuel pressure - Has this been checked and confirmed to be correct?

Check those things, and also the other stuff about the "95" value actually being 95% Duty.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
×
×
  • Create New...