Gasoline Direct Injection

[Twisted6]

Has anyone considered this technology and retro-fitting it to the SHO? We already have the benefit of an OHC 4-valve head, which relocates the spark plug to the center of the combustion chamber. DI technology has been around for about 80 years, but just recently has technology gotten to the level to take full advantage of it. In a DI setup, the fuel injector is relocated right into the cylinder bore, it requires a specialized injector that is much higher pressure (2,200 PSI) and can also withstand the temperatures and pressures within the cylinder. To achieve this pressure they also require a specialized high pressure fuel pump and a fuel rail with usually, at least, 1/8" thick wall tubing to withstand that kind of pressure.

Outside of the fuel system, it requires specialized pistons, moreso a U-shaped relief where the fuel injector sprays into. DI systems typically operate in three different modes:

Ultra-lean burn: At idle or light-running conditions, fuel is not injected during the intake stroke, but rather towards the end of the compression stroke. This applies a very small air-fuel mixture right at the spark plug and since the remainder of the cylinder is filled with nothing but air, this keeps the fuel and flame away from the cylinder walls, reducing cylinder temps (Which would normally increase in a port injected system trying to run this lean).

Stoichiometric: For moderate-running conditions, fuel is injected during the intake stroke at 14.7:1 AFR.

Full power: For heavy acceleration, fuel is still injected during the intake stroke, but slightly richer.

By removing the injectors from the intake manifold, you allow air to flow uninterrupted through the manifold. Some OE manufacturers add bumps and trips to the top and bottom of the intake ports to create a tumble effect for increased part-throttle response.

Another major benefit of DI is the ability to run much higher compression ratios while retaining the use of pump gas and the ability to run boost on high compression.

Would TwEECer be able supply this kind of control through the EEC-IV or would a standalone EMS be needed?

 

[lowc]

imo i think that tryin to get this type of setup in these cars would cost way more than the benifits would pay out to do this your talking about completly redesigning the heads and intake system and like you said also the pistons

 

[SHOtime2511]

Cool stuff but not realistic on these old motors.

 

[somedude_001]

Cool stuff but not realistic on these old motors.

+1 you really need to consider a cost/benefit here. say you converted it to DI. what is the gain? slightly improved fuel economy. If you are building a big power engine drop your compression a bit and add boost. Or if you are happy with 400whp and 30mph then a stock engine is fine with fuel upgrades.

FYI our fuel injectors do not obstruct air flow at all.

 

[Twisted6]

imo i think that tryin to get this type of setup in these cars would cost way more than the benifits would pay out to do this your talking about completly redesigning the heads and intake system and like you said also the pistons

No redesign to the heads needed, here is a 4-valve head setup for port fuel injection, like ours:

Now, a 4-valve head setup for gasoline direct injection:

The valves are removed in that picture, but the only difference is the hole drilled for the GDI injector.

The pistons have a U-shaped or donut-shaped relief, in addition to the valve reliefs, where the stratified air-fuel charge remains, right at the tip of the spark plug.

It is less about fuel economy and lower emissions and more about power potential and expanded powerband. Has anyone driven a Mazdaspeed3/6? It is like a jet, pulling hard at any RPM, while yes it is turbocharged, the direct injection has a huge part in that, eliminating all turbo lag. To give you a rough idea of what kind of gains can be had from GDI:

Mazda MZR 2.3L (NA, no GDI): 160 BHP
Mazda MZR 2.3L (Aftermarket turbo kit, no GDI): 245 BHP
Mazda MZR DISI 2.3L (Stock turbo, GDI): 274 BHP

GDI is a foundation for which all other modifications are built off of, so price versus horsepower in just completing this is an unfair assessment.

Ok, to tackle the piston issue. The new 3.5L EcoBoost has a bore diameter just .5mm larger than the 3.2L SHO. When I was shopping for my engine back in March, there were already complete EcoBoost engines for sale on Ebay. Considering how Ford is pushing the EcoBoost to have it swapped into anything and everything, new and old, I wouldn't be surprised to see it parted out as much as the SHO engine currently is in short order. Don't know the wrist pin diameter yet, Mitchell On Demand hasn't yet got that information up, but we will see.

Besides using the EB's pistons, Wiseco has already come to market designing performance GDI pistons and from what I am finding, the price of a complete one-off set of GDI pistons and ShoNut's low compression or high compression pistons, is pretty much the same price. I've already decided I was getting pistons anyway.

Delphi sells their Multec GDI injectors in a wide variety of lengths to fit many applications.

The largest hurdle I see is in the ECU, which is why I was wondering how powerful the EEC-IV was when paired with TwEECer, if it could control those multiple fueling schemes.

If nothing else, a fun idea and a challenge to see if it works, and I love a challenge. Which kind of explains why I kept the Pontiac 301 V8 in my other project vehicle.

 

[93rev2sev]

Isn't fuel pressure at the injector some ungodly high number?...

Like 2500PSI?

 

[popsracing]

There is the issue of getting lean or rich pockets within the cylinder, this would take considerable time in designing a proper retrofit but it's possible. Keep in mind direct injection is speed density. It's similar to tuning a diesel.

 

[Twisted6]

Isn't fuel pressure at the injector some ungodly high number?...

Like 2500PSI?

Yes, they use a specialized high pressure fuel pump, it's not in the tank though.

 

[Phoenix]

If you feel the urge to retrofit something , use a carb on a custom intake with the distributor attached to the cam sprokets.

Its been done and it looks badass.

I think DI has more benefits on the antipollution rather then HP.

 

[STL. SHO]

I think the FI setup on our cars works great from an enginering point of view,I think its as close as we can get to DI without spending tons of$$$$ on fab work and parts as others have said.Id leave well enough alone.

 

[hawkeye18]

Possible? Absolutely.

Feasible? Less so than herding kittens.

Bringing Steve Irwin back to life would give you a better ROI.

 

[pjtoledo]

Isn't fuel pressure at the injector some ungodly high number?...

Like 2500PSI?

try 20,000 PSI
the fuel has to be injected, and fully atomized, and evenly distributed in a scant few thousandths of a second.

one of the big advantages of DI is during scavenging. no fuel is lost, hence emissions are greatly improved

Perry

 

[SHO_ROLLER_2]

+1 you really need to consider a cost/benefit here. say you converted it to DI. what is the gain? slightly improved fuel economy. If you are building a big power engine drop your compression a bit and add boost. Or if you are happy with 400whp and 30mph then a stock engine is fine with fuel upgrades.

FYI our fuel injectors do not obstruct air flow at all.

Wouldn't be happy......nope..........no sir.


I need better than 30MPH

 

[HotRodKid]

the only way to make a sho V6 direct injection is to toss the heads in the recycle bin and build new ones.

The tweecer isnt gonna help you any either, none of the stock ECU will, its just not made to control a DI system. Neither are any of the stand alone systems.