Hey guys.

My class limits my ECU so I can't adjust ignition or fuel map based on RPM.

I have one hour on the dyno tomorrow to tune my car with a fuel pressure regulator.

I've read this to get an idea for how to tune with a FPR: https://aeromotiveinc.com/advanced-t...fuel-pressure/

However it's my first time tuning EVER on a dyno.

In addition to the steps in that article, do you guys have any tips?

FYI: I'm posting this in the road race auto x section of HT because the all-motor guys would just tell me to get Hondata -_-

 

They are right just get a hondata and be done with it.
If you dont know how to tune get a reputable tuner who knows honda engines.
I dont know anyone who uses anything else.

 

The article pretty much covers it. You're adjusting FPR (as a crutch) to change what you're seeing WOT. Hopefully you're not making too big of a change and the ECU will compensate when in closed loop.

 

I think what Dil is saying is that he cannot run an aftermarket ecu in H4. His only adjustment for tuning is raising his fuel pressure and or advancing timing via the distributer (I may be wrong). Dil, personally I would try advancing timing a degree or two at a time, see if you pick up power if you do, go until it stops increasing power. Then add fuel pressure 1 or 2 psi at a time to see if it picks up power and stop once it levels out. Keep a keen eye on your afr and knock especially if you start to heat soak it on the dyno. Just make small changes and watch your graphs, if they can overlay he graphs for the instant comparison, you should be able to dial it in a bit faster. FWIW, go for more torque under the curve rather than peak hp at the expense of torque imo.

 

THIS. ALL OF THIS.

Thanks man. So, you're saying tune ignition BEFORE AFR? I also don't have EGT so I won't know if I'm knocking until check engine comes on.

How would you watch for knock? AFR I aim to follow directions from what the article says.

Top-end power is what i've been told I would gain, not torque. If I had cam gears and a proper ECU maybe?

Thank you all for the help guys I really appreciate it.

 

No problem =-) I would run base fpr first and see if you pick up power with just ignition. If you don't pick up anything, set It back to base timing and do the fuel pressure 1-2psi at a time, see if you pick up anything. If so then go back to ignition timing and advance a degree or 2 at a time to see if you pick anything up additional. One of them or a combination will change the power. For ignition/afr tuning pull the plugs after each run and look at them (check out this article for reading plugs for ignition tuning for afr/iginition timing: https://www.dragstuff.com/techarticl...ark-plugs.html). That will give you the best guestimate on how things are during combustion. If you see signs of detonation (audibly or by reading the plugs) knock the ignition timing back 2-3 degrees and give it another 1-2psi of fuel pressure. If they are saying go for the best wot hp number give it a shot and see how it feels. Are you running a WBo2 or narrow band? Oh and once you find the optimal position for advance on your distributer, make a centerline mark with a scribe so that you know where it is (ignition timing) and don't need the light on the crank to check it.

 

I do not have a wideband I have the stock narrowband. My car is OBD1 so it only has one primary and that's it.

Do I increase fuel pressure 1-2 PSI at a time at idle or WOT?

Seems like it'd be hard to do at WOT.

And I have the FPR. Wouldn't I automatically just want to do the FPR first then play with ifnition later?

 

Does the dyno have a wideband to use while you’re on it? If not, you’re playing with fire.

WOT pressure is the same as the pressure with the vacuum line disconnected, so you can set it at idle speed then reconnect the line.

 

This^

The narrow-band wont cut it and you could grenade w/o enough fuel. Cough cough.. I have a nice new PLX M300 WB02 fs in the for sale forum if you need one. I don't need it with the K-series as the primary is already a WB. Do you have a timing light to make sure you are going up in small ignition increments? Even with the wide band, still pull the plugs and look at them to make sure you don't get one cyl leaning out (injector flow rates are not usually100% even, the wb only reports an average of all cyls).

 

Thank you all for your help. I got the car on the dyno on Friday and picked up some power. Here's the tuning process I used. Maybe you all can provide some feedback:

1. First I measured fuel pressure at idle with the stock FPR still installed. I did not disconnect the vacuum line to the FPR when doing this. I regret doing this since I set idle fuel pressure with my AEM with the vacuum disconnected.
2. I did two base runs with the stock FPR installed and measured AFR vs RPM and HP/Tq vs RPM
3. I turned the car off and installed my AEM FPR
   1. I used the installed orifice (black)
   2. I used teflon tape and the provided gasket when installing the plastic return line fitting
   3. I used the provided gasket when bolting to the fuel rail
   4. The FPR comes with two allen screws and two washers. The fitment is not perfect, but you can make it work.
   5. I attached the return line
4. I started the car with the vacuum line disconnected and set fuel pressure to stock using my B&M filter-mounted gauge
5. I did a dyno pull and AFR was way high (too lean)
6. I began increasing fuel pressure to the rail 1-2 PSI at a time
   1. Each time I adjusted fuel pressure I disconnected the vacuum hose
7. After each adjustment I did a dyno run
8. Once the power stopped increasing after FPR adjustments, I increased fuel pressure by 1 PSI above optimal power to prevent lean conditions
   1. I will likely be running xylene, acetone, or some other octane booster to prevent pinging in the future
   2. I am considering cleaning my injectors as well
9. After I made peak power with my FPR adjustments, I attempted to advance ignition 1 degree
   1. It made no additional power or torque anywhere on the curve
10. I put ignition back to stock and left it alone.

Car seems to run fine and it didn't blow up....yet

Thanks again guys!

 

are you happy with the power? that's the big thing...

was the AFR okay on the stock system with the stock pressure?

Why did you guys only bump timing 1 degree? I don't think that was enough movement to really make a difference. My H2 B20 motor had the cam timing adjusted and was running 10* advanced (I'm pretty sure). I generally don't argue with the tuner though... so refer to my first question!

 

I'm very happy with the power honestly. At least the gain in power. Long term I have other plans but not enough time and money before championships.

AFR was great on stock system with stock pressure but was slightly rich as would be expected.

I bumped timing 1 degree because I figured it would be enough. That's interesting tho! I would consider bumping ignition in the future then.

I was the tuner I can't argue with myself unless I'm feeling schizo that day

 

Glad you found some ponies. How did the plugs look on the last run?

 

They looked ok. No white crap or black crap they looked pretty clean. I had a track day on Saturday and the car ran great.

 

Awesome! Did your data match an increase in peak power?

 

Have not looked yet. I don’t have any runs on tracks with a comparable setup to compare. Always tweaking with this thing...