The Great 4AGE Hand Grenade Debate

[Flannelman]

THIS IS NOT A DRILL.

As I have stated in other threads on here, I am attempting to build an engine that tests the theory that the standard Silvertop ECU is capable of controlling an engine with close to if not exceed 200hp. Many, or as I suspect all, will disagree.

First off, my current setup stands at 170-175hp flywheel (99.7kW measured at the treads). It can haul a consistent 15.2sec @ 91mph 1/4, and thats walking it off the line (no launching). An increase of 22kW and 1.2sec reduction over standard. (78kW and 16.3sec)

Now its time to up the game again.
Ive spoken of the angle milling process being done to a 20V head which has been competed.The new chamber size stands at a measured 31cc. It is also in the process of having multi angle valve and seat faces being cut. Once complete, its being sent away for HPC ceramic coating of the valves and chamber.

Next piece is some Blacktop pistons. These have had the exhaust cut outs modified to give more space due to both the angle change and height reduction. They will be sent away for HPC ceramic crown and Teflon skirt coatings with the head. The intakes are close to the limit of clearance, but even with VVT function, don't need modifying.

The new meat in the sandwich is going to be a TRD 0.8mm head gasket held down by ARP head studs.

To clarify the math...
Chamber CC...............31cc
Head Gasket..............4.3cc
Blacktop Piston Dome....-5.5cc
Total........ 29.8cc
Compression Ratio (chamber cc + swept volume) / chamber cc
29.8+396.8=426.6.
426.6/29.8=14.315.

Call it 14.3:1.

Got your attention? Good.

Detonation control is no doubt the first and foremost concern, and I am taking it seriously myself. I didn't expect the compression ratio to be found this high or so easy but now I have its time to run with it.

To control heat, I have gone for a Davies Craig Electric Water Pump. It gives me greater control over engine temperature. Running a few degrees coolant temp will add to detonation resistance, as will the ceramic coating.

New JE Piston rings are going to be used with the above pistons. The top ring gap is going to be investigated due to the higher temperature they will be exposed to. This commands a bigger ring gap as the higher temperatures cause the rings to grow. Without this, the threat of them butting together and destroy a piston ring land is higher. A common problem that many blame detonation on.

Aiding combustion is a new and improved distributor cap and rotor. The cap can now support 8.5mm MSD leads and the rotor is getting attention in closing the gap between the inner spark jump points to the leads. An MSD system is also waiting to replace the one I fried during previous testing (a lead fell off....) This much fire power in the combustion chamber is needed for a secondary aid in reducing detonation and further increase torque.

Snow Performance sell a water/methanol kit which will be installed and switched using the VVT. What this does is give a "fail safe" system as VVT wont work unless the Snow Performance system is active. The principal of VVT is changing the dynamic compression ratio by altering the intake valve closing point. Advancing the intake increases dynamic compression giving the increase in torque that aids the 20V heads natural air supply. With this compression ratio and VVT off, dynamic compression should be low enough (and the presumed lazy advance curve of the stock ECU) should keep any adverse combustion at bay without the need of water/methanol. Its going to need a play with timing to get it right.

Another extra is a simple exhaust excavation system. It uses exhaust gas flow to generate a vacuum based on the Venturi principal which will be plumbed into the crank case via a simple non-vented catch can. This vacuum helps ring seal, oil control and subsequently increases power as the rev rise.

Theory goes on the new parts are
Compression, +5% torque everywhere (7.5% power @ 7500)
Water pump, up to 5hp
Snow Performance , 1% increase with every 10F loss in intake temp. can go as high a intake reduction of 100F (10%) extra torque can be possible by the expansion of water on the piston. It also reduces peak cylinder temperatures and pressures.
Exhaust excavation system, anywhere from no gain to 10hp. All depends on the amount of vacuum the system can create.

170hp + 7.5% (12.5hp) = 182.5 + 10% (18hp) = 200.5hp

This makes no allowance for the water pump or exhaust excavation system, but also looks at the best possible outcome from the two known factors that are proven to be the case.

Any thoughts? Questions? Will it even hold together! What about too much pressure and blowing a head gasket? Has enough being done to stop detonation? Will the stock ECU finally call mercy?

Best way to restart a forum is do post up something like this!

[matt dunn]

Running on Avgas or similar may help too. Maybe an ethanol blend, but would take a bit of figuring out the Eth %,
as too much Eth% and the fuel required goes up, which on the standard ECU wont be adjustable.

Have you adjusted the fuel mixture under load by playing with the AFM spring settings inside the AFM?
I have always though there will be good gains by adjust the mixture to be correct under load rather than too rich which I think they run,
remembering that at WOT they run open loop so the O2 sensor wont correct it.

[Flannelman]

Present fuel is Gull E10.
There are some charts that refer to boost plus compression, and using someone in the car club running 30psi in a standard compression (but not so standard engine) WRX as an example, it works out to the equivalent of 15:1 N/A. He uses it too.

The AFM has been played with, I think by me about 12 years ago. All I do know is when its on the dyno the A/F ration is always in the 12-13:1 range. Far leaner that the 10:1 I have seen on stock ST 20Vs

[whynot]

With this trying to retain the factory ecu are you open to butchering the ecu internals to get the desired fueling and timing? Not so much a piggy back ecu solution but more tinkering with the internals to change its behaviour.

I have heard of people changing the clock speed in the 4afe ecu to lift the rev limit but it does effectively lower the map resolution. It should apply to the 4age ecu too.

I have wondered how far a stock 4age ecu could be pushed. Even if there is a way to effectively make a budget turbo setup retaining the stock ecu.

We should be able to take advantage of the fuel trimming the ecu does with the o2 and afm but what can be done with the timing? Some kind of stand alone ignition trim board? I suppose you could change the base timing but that would be less than ideal.

I have wondered if a mechanical distributor could be adapted and fitted with a vacuum diaphragm to retard or advance the timing while still retaining the factory ignition curve but modified a few degrees.

Anyways a few thoughts to stir the conversation.

[Flannelman]

So far, providing fuel isn't an issue as of yet. When it does, I plan to use an Aeromotive in tank pump and an adjustable fuel pressure regulator. This combo (not forgetting surge tank set up) will enable a little more head room by upping the fuel rail pressure. All else fails, there is some 440cc injectors I can try.

Ignition, I haven't heard of ECU surgery but I have seen a product by MSD called 6al-2 programmable. This, with a MAP sensor, could be used to alter the ignition timing. The MAP sensor could take boost too. However, tuning it won't look like a normal ignition table as it will be a true "piggy back" deal. +1 to +4 may be its ignition map on the back of the ECU commands. Start with ignition base timing in full retard and let the MSD pick up the slack.
At the moment I just play with the base timing and call it a day. I also tune by ear, not a timing light so I can't say exactly what it is, just what it does. 700km to a tank and have as much as a B16 on tap is my only proof of it being as good as it can get.

[Flannelman]

Oh, while I remember. Im trying not to alter the ECU as that would spoil the test. Once the above plan becomes a reality (with installed parts at least) then the ECU will be looked at. For what Im told by the Dyno operator, peak power won't change much. Mid range and throttle response is where the gains are made.

Ive said it before on here that spending 3K on a Link and tune for 95kW on a stock Blacktop doesn't make sense. Ive managed to get +99kW with the standard ECU and spend less to get it. With what I saved was spent on suspension and brakes making the car that much better overall. Thats smart money.

If there is any lesson to be learnt here is work on the basic engine combo first. If the ECU is factory MAP, then choices become somewhat limited as most ditch the factory ECU. This makes it hard as ignorance steps in with the "it can't be done" attitude. No one has taken the time to try new things. Something most of us have done, and all who use this forum are looking for.

Sometimes, all it takes is logging off Facebook, switching off YouTube or any other time wasting trap and go find a new challenge and start doing it.

[whynot]

I'm all for tinkering and trying things for myself.

I had seen the programmable msd gear. It's still expensive for just controlling the ignition. I wonder if it could work with the stock ignitor and coil setup or would the ecu get upset because the ignition confirmation signal is not been seen when expected? It's also likely the confirmation signal is just to trigger the tachometer and will not care in the least.

I managed to piggyback a 3sfse ecu onto a Gen 1 3sge ecu and engine to get the Canbus communications through to the body computer and dash on a late model Toyota. Everything worked fine and surprisingly there was no problems with running two ecus in parallel on the same engine. So I'm picking we have not yet began to reach the limits of what we can get away with on these ecus

[Flannelman]

For me to run an MSD unit I had to get a tach adapter. The standard ECU didn't like the modified RPM signal. I tapped into the coil wiring to get the MSD trigger which means its the ECU controlled side of the ignition. Only bad point is the standard Tachometer no longer likes to run. I have an after market one on its way... its taking its time.

When doing some dyno time with a camshaft I was experimenting with, I did a Stock V MSD comparison. On the test cam it ran 90kW and MSD running it ran 92kW. They were back to back runs (less than a minute apart) so all should have been in favor of the stock due to heat soak.



The 98.8kW run was a 280 degree regrind cam with a stock plenum. All were in 4th gear.

Crazy work on the twin ECU hookup! I have to admit when it comes to electrical circuitry of a computer I have no experience, so its mostly why I'm leaving it alone. Anything else is fair game tho!

[whynot]

There is an easy way to get the stock tacho working again. You just need to get a 12v relay and remove the moving parts out of it. Then just connect it to the ignitor just like the factory ignition coil was wired in. This will generate the voltage spike the tachometer and ignition confirm signal is looking for.

I did this when I fitted a msd 6al to my factory wiring and ignitor setup, everything worked fine after that.

I noticed some improvement with the msd box too. Can't say how much kw but it did run smoother. With a msd CDI system you can also run resistor less plugs and not cause interference. I use ngk race plugs now with recessed electrodes to help minimize potential hot spots in the chamber. The plugs are way cheaper than normal plugs too.

[Flannelman]

Nice move on the Tacho. Bit late for me, Summit just sent my new one yesterday.

Do you have a part number on the NGK Plugs? They sound like the go for what Im hoping to do.

[whynot]

Those ngk plugs are R5671A-(heat range). Im running R5671A-8 you might want the 7's.

Have you considered making a tuned exhaust system? There are some gains to be had by getting the exhaust system right not just making it straight pipe and bigger.

Out of curiosity would you perform a compression test with vvt on and off? Would it even work at cranking speed? I would like to know what the difference in compression is.

[Flannelman]

Thanks for the plug numbers. I shall look into getting some.

I have looked into the exhaust side of things. I spent a lot of time making a system based on DynoSim 5 computer software. Surprisingly, the torque curved it modeled compared to reality was very accurate. The actual numbers were not.

I have since made some changes, the greatest being a return to a full FGK setup with a 2.5in collector. It simply gives low end torque that no ordinary system on the software can seam to replicate. Perhaps the closest I get is by using very, very long primary, secondary header and collector lengths. However according to the software I shouldn't be getting the 5-7K "ramp up". In the software, I can only get one or the other, (top end or bottom end torque) not both like I have now. Oh well, its there as a guide, not a rule. What I can do on the car is change the collector diameter off the end of the header easier. I have thought of going down to a 2in just to satisfy my curiosity, although I somehow doubt it making any substantial difference.

If there was any header I would like to fabricate its using a reducing diameter to speed up flow right at the merge points of 4-2 and 2-1. Increasing velocity here should increase vacuum on the opposing header. The logic is using the Venturi Effect. Increasing gas speed past any pipe opening increases the vacuum created in the opposing pipe. Its at odds with stepped headers, or even the "go big" idea. Any gains from these is more from increased total volume of the system, thus keeping overall pressure inside the exhaust down and a gain in power is seen over standard fitment.

I guess I got burned last time building something that didn't work out. So, to build a set of headers again is going to be an emotional struggle.

As for compression testing, I can't say I have thought of it. Would applying 12V across the VVT solenoid activate it while cranking?

[whynot]

I remember touge_ae101 got an exhaust designed for his ae82 race car. It had a 2 stroke style expansion chamber roughly where the resonator went. The placement and size was critical but I believe it was worth the effort.

I suspect vvt could be triggered but it would take a bit to build oil pressure. Either that or fit an adjustable cam gear and set it to the two positions to achieve the same result. To much effort by that point though.

What Intake arrangement do you have? Stock Silvertop airbox?

[Flannelman]

I cut and shut a stock one. It is as big as physically possible to fit behind the engine. I did testing by opening the stock silvertop one and using a brush to hold the vane open in the air flow meter.
Testing at the dragstrip dropped times from 15.6 to 15.2. Now there is no difference other than increased sound and fuel usage.

I have read touge_101 build page.

What I do have to question is kW readings on a dyno. I post 1/4 mile times as its a little harder to fake.
I know for a fact that on dyno in palmy my car made 98kW when it made 87 here in New Plymouth. Ive also seen a car run 130kW in Palmy yet only 100kW in NP. It comes down to knowing your dyno and backing them up at either a strip or track times. If anyone claims to have 40-50kW more than what Im running but can't back it up by running 1.5-2sec quicker in the 1/4 shows something is up with the dyno numbers.

It goes back to the DynoSim software, same shape curves just different numbers. To do true comparisons, its got to be same day, same dyno, different cars.

[Leon]

Talking of exhausts on 4AGE's, I had a quick look around at headers for my stock(ish) silvertop AE92 rally hack, since for the first time in 16 years it isn't running a stock(ish) exhaust system.

It's like $850 ish for what looks like headers that fit the bill well from MRP, or about $1500 to get a custom set built. Gulp.

This looks like an interesting thread though, as I've also concluded that I can't justify to myself sinking the mayyyyyybe $4k or so to go link + dyno + cams to make my silvertop perform like a stock B16A from 1989

[Flannelman]

Financials are always a problem for what is the burning question of "what do you want." Achieving anything from a 4age always gets offset with buying something else first. I faced that problem when the Levin needed new suspension. The car isn't worth much anymore, so why spend 2k+ on a car that I can replace with another for 2K.

Taking this view is thinking that a car is an investment on selling it. This is not an investment. Its a risk based on demand, like buying and selling houses. My view is that my car takes me to work (unless I want to push bike 2 hours one way) so it is responsible for my full paycheck. This thinking makes my car an asset so it must be maintained to keep the asset being just that.

I could spend 40K on a Toyota RC86, drive and enjoy it. In the next couple of years, second hand ones could be got for low 10K numbers. But the process starts again. To muddle the problem, 10K sank into a 4age and its body could be just as fun to drive, but also more emotional as I made the car more to what I want it to be rather than the generic canvas that all new/unmodified cars are.

It is your choice how to spend your time. If any, I hope to motivate people to spend it doing what you love. Owning a car for 16 years means I love my car. It is my first car so no amount of money is too much to attempt to get what I want from it. That emotional connection isn't going away any time soon either. I could sell it, upgrade to something with more power potential. But, I don't roll that way. I will make what I have, better.

As an update, I reinstalled my MSD unit using a new Street Fighter ignition box, modified the rotor and distributor cap for 8.5mm MSD leads. Only issue is spark leakage under low RPM/high load. The spark is earthing out on the spark plug tube. I suspect its earthing down the spark plug so need new ones. I will do this before looking into replacing the silicon sheath with the standard hard plastic one. Unless someone has any other idea to putting on the lead without destroying the lead/boot like I am?

[Leon]

Yeah, I'm in at least $30k into my $2k Corolla so far If not far more than that, I try not to think about it. My Toyota GT86 was wayyyyy cheaper at $30k (depending on your point of view).

[Bling]

Blacktop extractors are a good set aren't they? Unless you already have those on your silvertop.

[Leon]

I do indeed already have those

[Lith]

I have read touge_101 build page.

What I do have to question is kW readings on a dyno. I post 1/4 mile times as its a little harder to fake.

Not everyone drag race, but touge_101's car is VERY fast and he is a very smart lad - he won't be faking numbers, just looking for gains.

Why do you insist on using a standard ECU? It seems like cutting off your nose to prove you don't need to have a nose to still have a face. Also, why did you create a new thread? I could swear you did an identical one ages ago.

If you are really serious about gains on the standard ECU then have you considered using a higher octane base fuel (so you don't have to worry as much about timing) and a wet nitrous kit? It's unlikely you'll be able to go much better than that.

Alternately, calculate the injector size difference required, bump your compression, set your base timing slightly wrong and run methanol