[jlm]

spent a day at SPI trying out some things and dyno-jetting (20 runs).

base line was 179 hp, same as last recorded at Helix on the Mustang, except the car now has the AMD One-chip. (we weren't able to switch back to compare, but I didn't expect much hp changes)
SPI uses SAE corrected wheel hp readings. (For example, 198whp SAE, would be 207 whp uncorrected, 204 whpDIN)

the point of the day was to try out the piggy-back Apexi fuel management controller. This baby lets you transparently add or subtract to what the ECU has determined is the appropriate pulses/sec for the injectors and you can do this at 600rpm increments over the rpm range. Testing the result is done on the dyno, measuring power and wideband O2 fuel/air mix. We aimed for 12:1 in the >5k range. My car has the 19% pulley, 61mm throttle body, Super sprint header, ACT Cat, 2-1/2"exhaust, intake, AMD One-click as the major tweaks.

we were able to get to a very repeatable 188whp, SAE.
Interesting point 1: we had to add fuel in the 5-7k range, eventually maxing out the injectors' capacity, implying larger injectors, suitably Apexi'd back as needed. It looked like 195hp could be reached. Boost readings were about 20psi read at the intake manifold with the Autometer gauge
Interesting point 2: we swapped out the custom intercooler made for the Twinchargd car and instantly got a repeatable 198hp, here max boost was 18psi, presumably lower boost due to the colder air, and more power due to the colder and denser air. Hubie tried to get 200hp for the record book, but even adding 25% with the Apexi had no effect. again, larger injectors are called for.

conclusions:
the Apexi tuning extracted 10hp, and is a very useful gadget; (highest reading 188hp)
with larger injectors, there is more power to be had;
with better intercooling there is another 10hp; (highest reading 198hp)
with larger injectors and better intercooling, perhaps another 5-10hp.

As far as the Twincharged car, a bit more info.

the cost is high because the components add up:
custom intercooler, four new injectors, Turbo and exhaust manifold, Apexi, Boost relief valve, as well as the interconnecting tubes and fittings. This package is meant to be applied to an otherwise stock car (maybe exhaust) and will add 100hp (given that stock is 150whp)
The design intent was to make a fairly simple bolt-on, which is why he kept the blower. Ditching it and going full blown turbo would make much more power, but then there are water pump issues and a lot more mechanical tweaking.

[gowest]

I'm not sure which Apexi unit you are using, if it's the S-AFC-2, I think it's adj. in 250 rpm intervals and up to 12 points. It's good to hear you got that kind of power but I wonder what it would do for a MCS with intake, header and exhaust mods only? AND, would it be better/worse or about the same as one of the better ECU mods on the market? Class rules prevent me from doing both.

[jlm]

S-AFC-II, 500 rpm increments. on top of the stcok ECU, you have to more correction; the AMD seemed to come much closer, as Hubie noted, compared to what he found on his stocker.

[bluemcs]

John -

Questions....questions.....questions! (:

If you were adding fuel in the 5-7k range was it because the AMD fuel curve was running too lean?

What were the final A/F ratios in this range given that the pulse width was maxed out?

Every A/F curve I have seen has shown 11/1 or lower in that range. I don't understand why the Apexi couldn't find any more fuel? Maybe its designed so that the pulses are maxed out early and mixture is being solely determined by the pressure regulator. I can't believe that anyone would design it like that.

Was he taking A/F measurements from the tail pipe? Did you make adjustments assuming a .5 richer measurment at the bung?

The other thing that would be really interesting would be to track the fuel pressure over the rev range to see just how much the stock pressure regulator is adding.

The only problem in my mind with adding bigger injectors, aside from the cost, is that I don't know if the stock ECU could control them. Therefore the Apexi becomes a permanent part of your fuel control system. Additionally, could they be brought back far enough to meet state emissions?

Also, what kind of torque did you get and what did it do to the shape of the curve (for both HP and torque)?

[Andy@Ross-Tech.com]

jlm,

Wow! Very interesting results. Weren't you able to swap back to stock programming? Was it just a time issue, or was the One-Click not functioning?

Did SPI express any interest in selling their IC on its own?

[macncheese]

Another gadget for the batmobile!


--
Cheese

[Mugami]

Good to hear john.. once Hubie sends the Diagram im installing the S-AFC2 on mine and will be heading to dyno tune it as well. Which i should be doing soon.. Currently im running the 15%, intake and Cat back exhaust. ill report in what i find after that. I'm hoping Base is still the 157 whp i had when i dynoed the car last year at the Battle of the Imports. We shall see. Later i will be switching to the 19% pulley and Lightwieght flywheel then its back to the dyno to retune.

[jlm]

I have an extra bung welded to my header just before the cat into which we screwed the O2 sensor.

Hubie went up to +25% at the top trying to get the downward trend out of the hp curve from 6-7k. He was able to richen the curve, but no more than 12:1 or so. The limitation of the injectors was diagnosed when extra Apexi bumping had no effect; that and the fact that Hubie had a similar problem on his Twinmobile, solved with bigger injectors. 85% of max is the typical practical limit for driving an injector, so going bigger will get away from that constraint. My opinion is the 19% (and the TOO blower mod), giving me 20psi boost, puts me in a new category from previous A/F plots

If I had had my way, I would have monitored intake temp, maybe EGT. As it was, we used wide band O2 and plug readings. The intercooler part was surprising, especially considering the vehicle was at rest.

gadgetry abounds! I'm going to put in an AES wideband gauge in the cockpit as well, might as well use that bung.

[bluemcs]

Ahhhhh, I forgot about the TOO SC. I figured the high boost was just the gauge. Yea, Hubie found the boost limit for the stock injectors and you seconded the motion.

The IC results are indeed very interesting. Was he pushing a LOT of air through it? I would think that the Apexi and the IC producing more HP and torque especially in the summer with lower boost is the way to go. The real world differential during the summer months should be higher than 10hp.

Sign me up!

[Andy@Ross-Tech.com]

jlm,

Why don't you pick up one of these and tell me how it works before I take the plung.



http://www.hopupracing.com/spinteme.html

Thanks to Cheese for the link.

[jlm]

FYI: my torque reading was 161ft-lbs and 188hp; I don't have the graphs to post; maybe later.

At Helix, my previous best was 153ft-lbs and 178hp.

[Hubert]

Hi John,

If AMD can offer the same sort of performance for better fuel consumption compared to your previous ECU setting, does that mean the AMD is just running relatively lean and hot (or your old ECU running relatively rich)?

Why don't you ask AMD to provide you with a map with a/f ratio at 12:1 in the >5k range, instead of buying the extra Apexi? Simply more handy to have the Apexi in hand for further experiments?

What's the TOO blower mod?

Are these dyno runs based on the stock cylinder head without any porting and polishing?

[jlm]

yes, the AMD seems to run leaner, and that was good, just not good enough. Remember, we found out the need to run even leaner in the >5K region prceisely because we could tweak ans see with the A'pexi. and we need to do more with new injectors. very handy.

stock head and cam.

The blower was modded bt TOO at Endyn; he closed the two small. extraneous triangular openings at the output, ported the int and out and re-coated the lobes. He is also working on my spare engine, head and block, but it is delayed, eaitng for custom pistons.

www.theoldone.com
look in thr BBS, Technical-Ask TOO for a mini thread where he has some head pictures in progress.

[Mugami]

Hey john .. since im still waiting for hubie to send me the diagram.. do you think you can beat him to the punch and show what wires in the ecu i need to tie into. So i can wire the S-AFC2 up correctly.

[Hubert]

I suppose you won't need the AMD now with the Apexi?

What is the your current rev limit? Around 6900? I've seen the rev limit calc here before based on the supercharger rev limit, but I couldn't find that post.

[Mugami]

on the contray im still planing on getting the AMD one click. even though the S-afc2 takes care of a/f things like timing and other stuff the reflashing does will still be needed. Its that or the New uni-chip that Randy is or has come out with. The SAFC2 is just to fine tune the car not as a replacement for the work done by AMD and the others.

[Hubert]

oh...after setting up the Apexi to get the car run at the desired a/f ratios, what happens when summer comes? Is the Apexi going to let the car run rich because of higher air fuel mixture temps? And the injectors would have to work harder still?

[Mugami]

If i understand you question Hubert..
The apexi alters the incoming signal going into the ecu so that even thou the real A/F is what you desired the ECU is seeing what it wants. Therefore if due to temp and Mass of air the ECU will still be adjusting the injectors to what it believes the ideal rate is. So the APEXI doesnt set them to one fixed rate and thats it. If it did that would scare the devil out of me. simply because if you tuned the car on a good hot and humid day of summer. to the edge of performace. Then on a nice cool fall or spring day you went for a romp you would blow the engine up.

One thing in JLM report that does have me worried is that with his car they did find the limit for the injectors. Just how many with the pulley exchanges 17%-19% might be running a tad to lean on top due to injector unable to supply the right amount of fuel and not know it. This could show up as reliability problems blamed soaly on the pully and not someone preparing the engine to handle it. Accorrding to Hubie from SPI they estimate the stock injectors limit is 220hp

until we meet on the road
Have fun, Be safe and Keep MOTOV8N

[Hubert]

Thanks for your input Mugami

I've seen several dyno plots here and on NAM that the engine tends to run rich at 10:1 or 11:1 at higher revs, and then John's car is running lean before adjustment and he has to add fuel to get to 12:1 at higher revs. Does that mean the AMD is making the car run relatively lean at over 12:1? I've read a book before saying than max performance comes at above 14:1, so adjusting to 12:1 should reduce performance and increase reliability of the engine? But the result says additional 10hp. What's wrong with my logic? Please advice

I take that as 220hp at the wheel? If it's 220hp at the crank, then what's happening in all these heavily modded Minis above 240hp?

[Mugami]

There are alot of different theories on this. Now im not a book man so fact and figures like you've read i cant verify can only give an opinion. in the past there has been a slogan going around of "Lean is Mean, But Fat is where its at! " and of course there are differences on whether the engine is Force inducted or Normal Asperated. As JLM stated he wish he was taking Exhaust Gas Tempetures. From my understanding of this is that theres two points in know what that is.. 1) once you get a temp of 12000 egt im most cases your melting the pistons. 2) at one point this temp which is relative to the expansion of air of the combustion. Gets so high that the fuel begins to Desil or predetonate on its own causing loss of power. by richening up the mix it will prevent this and give better power.

As for the 220hp .. he never spec at wheel or crank.. but my guess would be crank. remember jlm car was only doing 188 at the wheels..and for all the heavily modded ones.. hopefully like JLM they have gone to oversized injectors to correct the problem. Then again remember most street driving you dont get into that range and stay there for long unlike racing. So its not that much of a problem but it still exists

Hope my opinions help in some ways. Now im expecting the experts to come in and point out faults in my logic and all which is encouraged from my time in making cars go fast i didnt have all the technology thats out today. which has clarified on what we thought was happening to what was really happening. So im off the mark at times. other times im right on the money.

Until we meet on the road
Have fun, Be safe and Keep MOTOV8N