Leon

Modern turbos have very little turbo lag, it's essentially unnoticeable. You may be thinking of boost threshold, and what ovenfood brings up is a good point; what about cam threshold? It take time for an NA engine to "get on the cam." As far as the blow-off valve sound, I'm not sure if you fully understand how turbocharged engines work. A "blow-off" valve should not be vented to atmosphere, but instead should be used as a recirculation valve on throttle drop in order to prevent surge and keep the compressor wheel spinning, in a nutshell. Incorrect, and a terrible generalization: "a larger engine will always be able to make more power than a smaller engine." Like I said in my first post, forced induction is the replacement for displacement. Use the ideal gas law as a model for the air entering the engine during one engine cycle; PV = nRT. P is pressure, V is volume, n is # of moles, R is the universal gas constant, and T is temperature. (1) Solve for V (volume); V = nRT/P. Note that density is mass per unit volume; rho = m/V. (2) Therefore, V = m/rho. (3) Substituting for V in the ideal gas law; m/rho = nRT/P. (4) Solve for density (rho) with m/n=M; rho = MP/RT. Therefore, with M and R being constant and holding temperature constant, doubling intake pressure doubles intake density. (5) Look back at the density equation (2) and double the density, so V = m/2rho. (6) Put the right side of the equation back into the form of (2) and you get 2V = m/rho. This means that when you turbocharge an engine, you are effectively increasing displaced volume. Double the intake pressure and you effectively double displacement, e.g. take a 2L engine and put in 14psi of boost and you now have an effective engine displacement of 4L. I do enjoy letting the nerd out once in a while... When we talk about two turbocharged engines, the comparison remains the same, increasing intake pressure increases effective displacement. So you can say that theoretically, "a larger engine with running the same amount of boost as a smaller engine will almost always be able to make more power" but where does that really get you? Can't you just slightly increase the boost on the smaller engine and get to where the slightly larger one is? Using the 3.1L vs. 2.8L comparison, and let's say that the 3.1L runs 10psi of boost. In order for the 2.8L turbo to match the 3.1L at 10psi, it would have to run 11psi. The performance difference is essentially negligible as there are other factors in ultimately making power and going faster besides the amount of "boost." For example, the 2.8L can spin faster than the 3.1L, holding everything else constant (lower mean piston speed at equal engine speeds). Will that alone make up for the discrepancy, I don't know and I don't feel like doing the calculations to possibly find that out. The price difference, however, is not negligible. I'll take the 2.8 turbo over the 3.1 turbo, thankyouverymuch! My 2 cents.

There is a replacement for displacement and it's called forced induction. I would have a very hard time justifying 3.1L vs. 2.8L if both are to be turbocharged.

You already have the 3.9 diff as well so add a lighter flywheel and you're good to go. The car should feel and go pretty quickly with an otherwise stock setup.

Great video! More?

You'll get much more bang for the buck out of a numerically higher diff ratio, lighter flywheel and bigger exhaust than trying to cobble bits together that will degrade performance unless more thought and money is put in.

And filthy with a combination of rust and penetrant!

Bingo. Higher altitude makes for less cylinder filling, which means less cylinder pressure (and temperature) therefore reducing the tendency to knock.

I'll try to break this down, it's getting late. There's always a happy medium or compromise, and in this situation it's fuel mixture homogeneity vs. pumping losses. At some point, one overwhelms the other and you get diminishing returns in mixture uniformity while further increasing head losses. The injectors do atomize fuel better initially due to a much greater deltaP than carbs, but the location of the injectors matters as well. If they're far away from the valve then you still need to rely on the intake to mix the air and fuel properly. I would tend to agree that in general, carbs need more help in getting the mixture uniform when compared to EFI. Yes, take diesel engines as an example, they're all direct injection. Even though air is all that flows through the intake, it is still beneficial and actually more important to impart spinning/twisting forces pre-combustion chamber in order for the mixture in the cylinder to be better distributed. You don't want the incoming air charge to be shot straight into the cylinder with some air getting a bunch of fuel and the rest getting too little. You want it spinning and swirling turbulently as the fuel injector does its work. Port design is much more at play here, with intake design taking a back seat here. However, in order to change the angular momentum of the incoming air you do sacrifice volumetric efficiency through pumping losses. This is more evident at high rpm where higher flows mean higher head losses. Also with the air charge coming in at a higher momentum at high rpm there is less of a need for swirl and tumble to get the job done. For more info, you can look up the terms swirl and tumble as they pertain to IC engines. More time for the air and fuel to mix is good, but heating your intake charge is a double-edged sword; it benefits fuel atomization while being detrimental to volumetric efficiency (air temp goes up, density goes down). As rpm increases heat transfer effects decrease, so ITBs with injectors far from the valve will have better atomization and mixture distribution at high rpm with the sacrifice of low rpm efficiency. The magnitude of the sacrifice would have to be empirically quantified on a dyno, where the same engine would be tested with different injector locations. Injector placement is an oft-overlooked but important piece of the puzzle, finding the "sweet spot" takes testing. The main reason for having staged injectors is when using larger injectors that cannot adequately and precisely control the smaller pulse-widths required at idle. I suppose there are some secondary mixing effects from this, but I would consider it negligible for all but the most detailed builds. One injector per cylinder placed correctly should be able to deliver a good, well-distributed mixture given that the demanded pulse-width doesn't go outside the injector's realm of predictable operation throughout the engine's speed range. Hope that made some sense. You're getting caught up in describing flow as laminar or turbulent when it doesn't really matter as you won't get laminar flow from an engine anyway. You get high speed pulses tossed in the exhaust which would never come close to being laminar flow. Your last sentence sums it up pretty well, but laminar or turbulent is the least of your worries even in the scavenging portion. There are greater effects to take advantage of than trying to hit an unattainable and unnecessary goal of achieving laminar flow in your exhaust, or intake for that matter.

We should have some jackets made with "Spindle Pin Club" and your skull and cross-pins on the back!

Laminar flow has been thrown about a bit in this discussion. If you calculate out the Reynolds Number from the flow in the intake tract, I doubt you could ever get laminar flow, unless the tract is very smooth and large in diameter. Therein lies your contradiction, you want to have laminar flow yet you want velocity relatively high. These are conflicting goals. By the way, a large port is not detrimental either as long as you match the intake geometry accordingly. Turbulent flow is not necessarily bad and laminar flow is not necessarily good, at least in the case of internal combustion engines. The turbulent flow in the intake is beneficial to mixture homogeneity which is in turn important in maintaining consistent and more complete combustion. Mandrel bends in the exhaust have nothing to do with laminar flow and everything to do with minimizing pumping losses by having a bend of consistent radius and diameter. A crush bent radius will have a smaller effective diameter than the rest of the straight piping which would increase frictional losses in that bend. My 2 cents...

Turns out that I definitely misread direct ignition control as direct injection control when I was reading over the TEC3 stuff!

The swap is definitely for someone that knows what they're doing. I think one of Electromotive's TEC systems handles DI as well, as do other fairly expensive standalones. The Audi V8 is a great suggestion, those are nice engines and it would definitely be a more do-able swap. You've got me thinking now. Just need to figure out a manual transmission that would work with the engine, as I'm not very familiar with Audis. I did have an '89 100 however, it was an interesting car.

As an aside, those of you who have drastically altered combustion chamber shape have to keep in mind that MBT (max best torque) timing will change. I'm sure if one has spent the money for head altering that dyno time will be in order, so remember that a faster burning chamber will require less timing advance to get best performance.

Sounds like I really need to invest in an air compressor!

You just broke physics!

A few that come to mind: California, Scaglietti, 456 GT, 412, Mondial, 365 GT, 330 America, etcetera... The GT6 is a great design, but I'd consider it more of a hatch/fastback. This should get you started.

There have been plenty 4-seat Ferraris before this one, albeit no Ferrari shooting brakes since the '70s. I agree that it doesn't quite fit with Ferrari's modern image, but on its own it's a good looking car in my eyes. Again, I'm a big fan of wagons, hatchbacks and shooting brakes. Speaking of shooting brakes, there have been some great designs in the past including some of my favorites: BMW M-Coupe Volvo P1800ES MGB GT

Just checked and the '07 RS4 engine does have direct injection, in which case you can run a standalone ECU, it will just be more expensive. I think an aftermarket ECU is still the way to go here, as Douglas points out, if you decide to tackle this one.

Voice your concerns to the guy and get the price dropped down. If you can grab that engine for $1k or so then why not. If the guy doesn't want to budge then let the car sit there until he's tired of looking at it and try again. If he's any sort of car guy, I'm sure he'd rather see the engine put to use instead of getting crushed. I don't know if that engine has direct injection, if not, then why not go with a standalone ECU and your own wiring harness. It will likely be cheaper and easier than adapting the Audi ECU to run the engine in another car. Two R8s? It's not like he needs the money. Good luck!

It looks great! I love the "shooting brake" styling and didn't expect Ferrari to come out with something like this. I'm not a big fan of the headlights and front end, but it's a minor gripe. Although I really like the M-Coupe as well, so I'm a bit biased to the styling. Honestly, in the end I'd prefer the M-Coupe to the overpriced, overly-luxo Ferrari any day, unless someone wants to let me drive the Ferrari.

So everything is stock, except the MN47 head and flat-tops? Good luck running pump gas with that setup, as your compression is definitely over 10:1 and probably getting close to 11:1. Since you are running a stock cam, you will definitely detonate unless you swap out to a longer duration cam that can bleed off cylinder pressure at low speeds. IMO, it's worthless to go with flat-tops and an MN47 without doing anything else. You'll see minimal gains and you'll have to run race gas. So your choice is to either run race gas and hope that the stock ECU handles this combo (which it probably will given that your cam is stock) or swap out cams to get more performance out of it and maybe run pump gas. However, the latter will require custom fuel management. Or, you can always go with the easier and more economic choice, forget the MN47 and put on a P79/P90 head. You'd have a late-ZX engine which will run on pump gas and the stock ECU.

Especially with the stock cam. This is a situation where we need as much info as possible to make any judgment. If it's an overbore with everything else stock then the stock ECU handles it just fine. If you have an MN47 with flat-tops and a 290 degree cam then you really want a standalone ECU.

Attaboy! 98 pins? I am not envious. Hearing protection is key, but it makes it harder to judge the volume of foul words coming from my mouth into the neighborhood. It protects my ears, but not my neighbors!

The puller definitely helps, but if you have the will it can probably be done by sheer brute force. Blue's method worked well, pounding one side and then the other slowly moving the pin one way and then the other. Eventually, they slide out, and by eventually I likely mean hours of torture! Use heat, a lot of heat.

I've used rubbing alcohol and paper towels with great success.