robertb

I dyno'd my car yesterday, I'm up to 184 HP/135 Torque, not too shabby for an NA. Is anyone making 200HP (NA) with fuel injection. If so, what is your setup?

I've got a streetported S4 block with S5 rotors and the S5 intake manifold, 550 injectors in the secondaries, a K&N cone and the Racing Beat full exhaust setup (which is not a true dual).

I'd spend the money for a standalone EMS where I could control timing and fuel, but I don't want to if it's not going to get me to 200HP. Another option would be to switch over to a carb but since I'm so close I don't want to have to start over. Any ideas?

NZConvertible

Since you don't mention having any way to control these injectors, you're probably running way too rich and will be loosing power as a result. Just adding more fuel does not make more power, it does exactly the opposite. Swapping the stock injectors back in will probably get you 5-10hp closer to your goal.

Even if you do have some kind of fuel control, those injectors are a waste of time because even at 200rwhp you'd be safely within the capacity of the stock injectors.

Travis R

I think you could definitely see gains with a stand alone and a wideband O2.
Is that 184 to the tires? If so that's already pretty darn good.

robertb

Yes, 184 rwhp.

robertb

I'm using a mazda ECU with a 'SuperChips' chip in it. This didn't help much, with a stock N327 ECU I had 183 HP/136 Torque

I checked a fuel calculator at Rotary Performance's site and the flywheel hp potential at 80% duty cycle for the 460s is roughly 212. If I'm making 184 rwhp, that's roughly 216 fwhp. I have no idea what the duty cycle is on the chipped computer but I was running rich. The a/f ratio was monitored but not recorded in the dyno results. With the superchips computer the a/f ratio was about 10.5 and dropped to the 9s. With the stock N327 the ratio was mid 11s.

mwatson184

11:1 is way to rich for an N/A. You want to be somewhere around 13:1, you have a lot more power you can unleash with some tuning. Impressive numbers, mind listing your mods?

Marques

sub9lulu

iTrader: (7)

pix too

C. Ludwig

iTrader: (27)

NZ is absolutely right. On my ITS car the logged fuel curve is actually very flat. It tails a little rich over 7000rpm but only about a half point. In this case a fuel pressure regulator is an easy way to make adjustments since it will raise or lower the entire curve.

On stock ports, stock injectors, and stock ECU we're down to 25psi of fuel pressure and are still in the 12.5:1 range. The fuel pressure regulator begins to be erratic at anything ender 25psi so we're looking for another solution to take yet more fuel out.

mwatson184

You might need a larger return line to get the pressure under 25psi...unless 25psi is just the bottom of the adjustability range of the FPR you are using. What FPR are you using?

C. Ludwig

iTrader: (27)

Aeromotive pressure regulator and -8 return.

Marcus_F

RobertB, would you post your timing specs and if you're running a CD ignition (which one). Thanks

JerryLH3

iTrader: (11)

If the chip is dropping the A/F that low, you'd do better with the stock ECU. I imagine you could come pretty darn close to 200 hp with an aftermarket system. Even a piggyback like an S-AFC would give you more control and improve the numbers.

superpimp35

i think i should hit the 200 mark, what do you guys think..
s4 block & manifold
1/2 bridge
no emissions
mind train header
ported tb and manifolds
msd 6a
rb alum fw
safc
sx fpr w/ -6 lines ran in parallel (no more fuel rail in series)

i know i need to get a stand alone, but i just dont have the money right now....

BlaCkPlaGUE

The porting and standalone is your key right there to hitting that mark, im sure that it will hit 200. Most of us can't becuase we either don't have the porting, or we don't have a standalone, or both.

*EDIT*

whoops, lol, the msd6a is an ignition booster right? Not a standalone.. lol sorry about that

staticguitar313

iTrader: (2)

i'll be hitting 200+rwhp on my s4 na block, when i slap turbo parts on it!!! the only thing thats holding me back from doing it is that i dont know how to route all the emissions and vac stuff to the turbo intake manifold etc.

NZConvertible

That calculator is way too conservative.

This is what I don't get about people doing injector swaps. The only reason for upgrading the injectors is if your mods (or planned mods) force the peak injector duty cycle beyond 80-85%. There is no other reason for doing it. Yet I can think of only one or two people on this forum who've ever posted about measuring injector duty cycle, so everyone else upgrading injectors is just guessing, often incorrectly. I can buy a DMM that measures frequency and duty cycle for NZ$40, so I'm sure you can pick one up for US$20-30 and find out for sure what's really happening. Then you'll know who's fuel injector calcs are wrong...

Then that chip is a rip-off and a con just like nearly all supposed "performance chips" being flogged. You should stick a stock ECU back in, get some form of fuel control and get it properly tuned. You won't be disappointed with the results.

Dcrasta

How about trying it with the stock injectors maybe the enrichment will be closer to what you need for good power production..

robertb

Here are the list of the modifications:

Street ported S4 Block with S5 rotors and intake plenums
Racing Beat's full race exhaust (not the true dual setup)
K&N cone
550 injectors for the secondaries
17 lb steel flywheel
Unorthodox underdrive pulley
Pineapple Racing 6 port sleeves
Electric Fan (mariah design shroud/I think the fan is a black magic unit)

The jpeg of my dyno chart is too large to be uploaded. How can I paste it into a message?

RETed

I call your bullshit...
Can you post your dyno sheet?


-Ted

robertb

Here's the chart for the superchips computer:

robertb

Here's the chart for the stock N327 computer:

robertb

Timing was stock and so is the ignition system, except for whatever the Superchips computer is doing.

RETed

I still find it hard to believe that you're running your set-up with no way to control fuel.
There should be a dip (or at least a noticable transition) for the fuel injection crossover that doesn't show up on your graphs.

Who did the rebuild and porting?

Your ignition break-up on the top end is skewing your peak hp numbers, and I'd bet it's more like 180 and not closer to 185.
Are you running worn plugs?

EIP Tuning?
You know Brad Scott from Ellicott City?


-Ted

NZConvertible

If you have bigger secondaries and no fuel control you should definitely see a change at ~3800rpm as you suddenly went 10% richer. Are you sure those were 550cc/min injectors you used?

robertb

The charts show a 3rd and a 4th gear pull. The higher numbers came from the 4th gear pulls. I definitely have no way to control fuel. I suspect the superchiped computer has reprogrammed maps but this does not explain the even transition for the stock N327 ECU.

I did the rebuild myself. The porting was done by Bret de Pedro of RP Performance in Manassas and myself. Bret did the exhaust and 4 of the intakes. I bought a mazdatrix template and ported a little more on the aux ports. All housings and side plates are from S4 NA pieces. I didn't use the turbo rotor housings like some do.

The plugs have less than 15K on them and I cleaned them up not too long ago.

This was the first time I went to EIP, I don't know anyone there personally.