First Dyno Session - 420 whp

[Darius]

I know it has taken me far too long to get my car tuned by a professional on a dyno. Up to this point, I had only done street tuning on flat, vacant, country roads with good success for being a novice/intermediate tuner. I never knew how much the car put down though.

So we strapped it to the Superflow dyno and Steve Kan (http://www.kantuning.com) started going through my settings to make sure there wasn't anything out of the ordinary. The first question he asked was, what kind of injectors do you have (referring to my lag settings)? I told him Deatschwerks and I input the lag numbers they provided with the injectors (650cc). Steve said the car couldn't get the AFR up to 14.7 at idle because the lag settings were not accurate for the injectors. He input lag settings from a Mitsu injector, which is what the injectors originated as, and he was able to get it to idle properly. However, changing the lag settings has a direct correlation to injector duty. I didn't know this was was so dramatic until he was only able to extract 420 whp at 16 psi on a T04Z. For this power level, the injector duty was at 85-90%. He tried manually increasing the injector duration, but the AFR did not drop at WOT so he was confident that it was running out of fuel either via the injectors or fuel pump.

I have a Supra TT fuel pump and at 16 psi boost, it should pump 250 lph (4166 cc/min=694 cc/min/injector). IMO, the pump has plenty of head room above 420 whp. I have contacted DW about the injectors and how I was surprised and obviously disappointed in not being able to even hit 500 whp before the injectors maxed out. Has anyone else had experience with DW injectors not flowing what they are "rated" for? I'm hoping someone from DW can maybe chime in on this to help explain.

I will post a video later.

[l0nestar]

... and this is a perfect example why you should avoid DW and 're flowed' injectors.

[Booztd 3]

Agreed

Those injectors are s***....along with 'venom'

I helped a customer troubleshoot a Z32 with a surging idle (would fluctuate between 750-850 rpms over a time period of about 10-15 seconds)

After trying everything with no desired result, we switched over to an OEM injector and the problem dissapeared

[robbie2883]

you can spell it how ever you want...but in the end it's all pronounced douche for a reason! LOL all joking aside i've never had much luck with their injectors...both on my cars or customers cars.

[eh?]

Which color injectors were they?
I had success with mine they were purple 740's did 420 whp on 14psi with a 62-1 @60% idc.
I think it's a low reading dyno or something else.
Isn't 420whp on a t04z/16psi kinda low?

[Darius]

I heard that SuperFlow dyno's are the most conservative (lowest reading), but I don't know how dramatic the number difference is from say a Mustang or Dynojet.

These are not their newer injectors. Mine are the dark red 650's from a few years back. And yes I think that is low for a T04Z @ 16 psi.

I suppose I'm stuck with what I have until I go E85 this coming winter. Then, I'm looking at using 1200cc top feeds and the fuel pump/plumbing has yet to be determined.

[Darius]

Here is a video. This was only at 13 psi.

http://s118.photobucket.com/albums/o118 ... 0521-1.mp4

BTW, how do you embed video into a post?

[RRRRB]

i have DW 850's, not impressed with the idle..

Where does that turbo really start coming on at? im thinking of ditching my 3076R

This is just a shot in the dark.. but where was the exhaust venting during the session?? if it was in the room like it looks like that could also cause a lower reading

[Darius]

i have DW 850's, not impressed with the idle..

Where does that turbo really start coming on at? im thinking of ditching my 3076R

This is just a shot in the dark.. but where was the exhaust venting during the session?? if it was in the room like it looks like that could also cause a lower reading

The T04Z is the big brother to the GT35R and doesn't spool until about 4500 rpm. I'd say stick with the 3076R unless you like turbo lag.

Very observant of you hahaaha! My car kept blowing the exhaust ducting off of the tail pipe, so they put a clamp on it to hold it in place. Then, my car shot a fireball through the exhaust it and destroyed their exhaust fan LOL! There were 3 other guys that had to tune after me without any forced air ventilation.

[RRRRB]

haha, Seems RB's are famous for the fireballs.... i like it

What did your torque curve look like? how high did you rev it?

I wanna see the dyno graph

do you know if fuel pressure was holding? if it was dropping off then looks like your out of pump..

[gawdzilla]

i am pretty sure it is your fuel pump. the supra tt pump is known to require a lot of amperage to hit it's claimed flow numbers. what wiring are you running for the fuel pump? if you did not upgrade it to 10ga wire, i would say the pump is not running at it's full potential.

i had the same problem. put a fuel pressure gauge on. i used a mechanical gauge and taped it to my windshield. fuel pressure would drop at WOT in higher gear pulls and the injectors aren't getting enough fuel. no matter how much you open up the injectors the A/F stays the same. if you're running stock base pressure you should be just under 60 psi fuel at 16 psi boost. when I had the supra pump, the FP would hit the desired 1psi fuel per 1psi boost increase, but they would not hold. pressure would drop off partway through the pull, and require much more inj duty cycle than necessary.

i have had ok experience with deatschwerks injectors, and i would not put them in the same boat as venoms. at least they are flow tested and matched in consistent batches. i believe the downside to them is their spray pattern is less than ideal, which can lead to inconsistent idling results.

check your fuel pump before blaming the injectors. my supra tt maxed me out at about low 400 whp as well.

[Darius]

I got a dyno plot e-mailed to me but the file types couldn't be opened by any Windows office program. I'll try to get a different file extension from the shop.

gawdzilla - It could be the wiring to the fuel pump since I have not upsized it yet. But when I was having odd idling and lean/rich issues last summer, I had the fuel pressure gauge on the windshield like you suggested and it seemed to hold pressure just fine up to 23 psi (66.5 psi). Plus, I was running 23 psi on my own tune before going into the dyno and wasn't leaning out. Once Steve changed the injector lag, he was not comfortable with running IDC's greater than 85-90%. Apparently it was running on 100%+ IDC, which makes me still think it is injectors instead of fuel pump.

[RRRRB]

When you refer to lag setting are you refering to the voltage offset tables?

[Darius]

He changed the voltage correction table for sure. I'll have to go back in and look to see if he changed the latency values too.

[RRRRB]

23psi on pump gas? or E85?

Just doesnt make sense that it would limit injector by adjusting that ... 23psi you were certinly using more fuel

[240sxwanted]

Darius, what are your specs? referring to the motor

[Darius]

23psi on pump gas? or E85?

Just doesnt make sense that it would limit injector by adjusting that ... 23psi you were certinly using more fuel

I was running 23 psi on pump gas. That's why I say there is more fuel than those injectors can push out because I was pushing it out at 23 psi before I put it on the dyno. Now the injectors may have been operating at 110% injector duty, but that's my point

When you change the latency settings, it directly correlates to the injector duty. So it increased the injector duty cycle even without changing the injector pulse width because it is all relative.

Specs...short hand is forged 8.5:1 pistons, GTR rods, T04Z with .84 housing if memory serves me, 6boost divided manifold, Greddy IM, Supra TT fuel pump, LS2 coils, 3" IC, and air conditioning. Anything more you want?

[RRRRB]

Anything done to the head?

[S14-NEO]

hey Darius, do yourself a favor and throw a volt meter on your pump power supply...take it for a run and watch the voltage going to the pump, it should be in the area of 13 - 14 volts with the car runnning......im running the same size injectors as you but they are RC engineering and im also running the denso pump...i had to rewire my pump in order to get that sucker to flow properly...by doing that it completely changed my tune to the point i had to get it retuned after i upgraded the power supply going to the pump...before i did the upgrade the voltafe going to the pump would drop off to 9 volts or below under hard acceleration.. after i rewired it i got alternator charging voltage of 13-14 volts....its worth looking into

[Darius]

Anything done to the head?

Oh yah, duh. I forgot. Cams, Ferrea +1mm valves, and port/polish on the exhaust side.

S14-NEO - I'm definitely wiring in a relay to power the pump directly from the battery this weekend. It'll make my new tune irrelevant, but I can tune it myself just fine on the street as long as the injectors can keep up

[RRRRB]

what kinda timing where you running on 23psi and pump gas?

[Darius]

17-19 degrees.

[meet07]

hey Darius, do yourself a favor and throw a volt meter on your pump power supply...take it for a run and watch the voltage going to the pump, it should be in the area of 13 - 14 volts with the car runnning......im running the same size injectors as you but they are RC engineering and im also running the denso pump...i had to rewire my pump in order to get that sucker to flow properly...by doing that it completely changed my tune to the point i had to get it retuned after i upgraded the power supply going to the pump...before i did the upgrade the voltafe going to the pump would drop off to 9 volts or below under hard acceleration.. after i rewired it i got alternator charging voltage of 13-14 volts....its worth looking into

I forget b/c its been about 3-4 years since ive been in the 240sx gas tank but isnt there small wires that go from the lid to the fuel pump? And if so how would you wire in a thicker gauge wire to the tank?? I wanna say that the factory wiring was soldered on the lid.....Ill be wiring a relay on my wimpy 255 so this doesnt happen to me on the dyno.

[Darius]

Yes it has wimpy wiring from the lid to the pump and I'll be replacing that as well. Soldering ain't no thang...oh wait this is on a gas soaked assembly. Might be exciting for a couple seconds.

[RRRRB]

wow im only at 11 degrees at 21 psi and pump gas on my 3076R

[Darius]

Why is your timing so retarded? Are you seeing knock? Doesn't it run hot during pulls, like glowing red hot?

[RRRRB]

i stopped adding timing when the torque increase was getting to become very minimal... i was seeing good increase in torque and horsepower when adding timing... once it started diminishing i stopped ( usually indicates that your nearing MBT) "maximum brake torque"

how are you safely tuning to 17-19 degrees without a dyno?

[Darius]

Knock sensor output.

[RRRRB]

isnt that sensing alot of noise due to built engine?

[Darius]

Yah with every engine they pick up false knock but it's not much. You just have to know what is knock and what is noise.