488 GTB 7500 rpm Rev Limiter

My example and point is that turbocharging an engine doesn't necessarily mean it has to have less rpm capability, not that I thought Ferrari would turbocharge a 458 engine.

 

Of course you can turbocharge a 458 and retain the 9k bhp peak, but that is apples and oranges in this context. What I'm saying is that you can't retain efficiency, and thus keep emissions within regulations. With a different setup, you could make more power and keep the engine more efficient. As for durability and maintenance, you'd have to make cams with a lot more aggressive lobe ramps to avoid "blow-thru" in the combustion chambers and minimize reversion + a higher spring pressure to keep the valves under control. If you build a high revving efficient turbo engine, the lobes, the rollers and the springs will be under a much harder load than a lower revving engine. Turbocharging a 458 is no measure of how different the engine would have to be, if it had to retain its power and its efficiency at a higher rpm. You could build an efficient turbo engine that would rev to 11k but it would need a seriously stout and demanding valvetrain to work well with little lag and low boost threshold.

 

It's not apples to oranges as turbo engines -do- work extremely well with naturally aspirated camshaft profiles.

You do not need more aggressive ramps to avoid "blow-thru". May need higher spring pressure depending on how much overhead is built into the valvetrain to begin with.

Fwiw I used to think the same way and started testing different camshaft profiles on my turbo V8 builds. More overlap resulted in more power, every time, even on setups that had 2x turbine drive pressure than intake manifold pressure. The more power it made naturally aspirated the more it made turbocharged.

Point is, if you already have a valvetrain stable to 9k it would require minimal changes for it to remain stable to 9k turbocharged.

Boost threshold I agree can be an issue as if turbo sizing is consistent with another 1000rpm of powerband it will result in slower response unless it has variable turbine geometry.

 

Perhaps the real reason for the lower redline is that the 488 needs to know its place in the model hierarchy.

Right now it is as fast as the F12.

But I am quite sure that the Ferrari engine design team will produce even greater performance and greater RPM in future V8 turbo designs.

 

Note: Cali T is 2 hp less than 458. FF and 488 about the same. F12 king of the hill at 730.

 

Interesting to read, it seems to me you both have great experience and knowledge!

Just out of curiosity, how do you handle the additional heat generation (piston, valve train...) if you build a turbo system on such a high performance Ferrari V8 NA engine? New materials? Only bigger coolers? Both? Others? In the tuning scene I've seen so many heat damages (next to bearing damages)...

 

I just drove the car on the race track so no turbo lag is felt.
I also test drove the California T on public roads and felt no lag.

 

Generally speaking, heat management is very important. Depending on how much fuel and air one squeezes in there, it will need different approaches. I've never modded a 458 engine, but if only doing a low pressure system, charge coolers is all there should be needed. If you go big, one has to look into materials and coatings. Titanium intake valves, inconel exhaust valves, piston coatings, larger coolers for engine, oil and charge air is needed, but it all depends on what you wish to do. Most do a conservative turbocharge system on their 458's when they turbo them, and not much is needed. These engines are built well, so often mods are done more out of getting a better package i.e, new pistons not because the OE pistons are bad, but because lower compression is of an advantage and so forth. There's no super easy answer to your question, because it depends on the setup. The more power you wish to make, the more you'll need to do. A 1200 hp engine running race fuel, will need to be built from top to bottom and so will a lot of the other systems in the car. A 75-100 hp addition, will take far less. In that case, a proper mapping and adequate cooling is usually all there is to it.

 

Sounds serious, I like to read what you write.

Why do I ask for the durability; I am a burned child with regard to the issue of durability in engine tuning, no matter if turbo or conventionally.

Let's have a look on all the modification Ferrari did for its 488 engine (F154 CB) in comparison to the Cali engine (F154 BB): more stroke, new cylinder heads, new camshafts, bigger cooling water ducts (!!), new pistons, strengthened conrods etc.. Here we are talking about an increase of approx 100hp. Therefore (and because I have many great powerful engines see die ) I'm always slightly skeptical when I read "without any major problems" or "100hp only with chip tuning". And now imagine the installing of a turbo systems on an engine which was not designed for turbocharging. Force effects are amplified x times, the same with the heat development.

 

DK308, good post!

Daniel, when properly tuned, turbocharging is not adding a huge amount of additional stress on an engine. Peak power can increase by hundreds but peak cylinder pressure does not increase proportionately, average cyl pressure increases.

Another bonus of a turbo engine is constant downforce on the piston. (this is no matter of course with any properly designed engine)...but, when naturally aspirated you have compressive force on the piston/conrod during compression/power only and conrod attempts to pull itself apart due to inertia at TDC of the exhaust stroke/start of intake.

Turbo engine is pressurized on intake due to manifold pressure, compression/power of course and also exhaust due to turbine drive pressure.

To optimize a combination with the intent of turbocharging it's no surprise that so many components were changed for the 488.

Turbocharging a naturally aspirated engine in stock form is not generally ideal as compression ratio would usually be reduced to some degree. (not reduced a lot as used to be done) but as DK308 stated, proper tuning and cooling upgrades is all it takes on a mild system.

 

You seem to state that you know more about turbo engine design.

These threads are about Ferraris. I ve owned three. Ferrari races in F1
What engine do you sell? Do your engines compete in f1?

,Ferraris sell for hundreds of thousands of dollars. No offense but who are you? I'm a real buyer

 

I don't sell engines or any performance products. I'm an enthusiast and owner like you, and I've been brought up around high performance cars and offshore race boats. I like to get my hands dirty and I've been involved with some fun projects over the years (TT Lambo, TT Fcars, some American stuff, go-fast boats etc.) My wife and I are both in the medical field, so none of us deal engines or high performance products for a living, and never will. All I was doing here, was to talk about turbo engines in general in relation to the 488 discussion, how they work and how they are usually built etc. I apologize if it came across as I was trying to sell anything, I just like to partake in the discussion as everyone else. There are sponsors advertising here, and they pay good money to do so, and those are the ones can/should be selling products on Fchat, I'm personally against non-sponsors advertising here.

Best.

 

Fwiw I found the Cali T to have quite a bit of turbo lag based on my experience driving it

best

 

is 8k official yet ?

 

Hey Arnie, great drive yesterday, hope you can join us for one soon

 

I don't get why some people are still questioning this.

 

Lag would 100% exist in turbocharged, it's just whether you could tolerate or not. The best way to feel the lag is cruising at about 20m/h and suddenly floor the pedal, then release it again. But there is no point to do this.
Turbocharged with little lag was first made famous by Porsche by using 2 small turbos instead of 1. So the boost could be set minimal from single turbo when low rpm or non aggressive pedal, then maximum when certain rpm or aggressive drive. I think Cali T would have less lag because the boost is set lower at all time as the max hp and torque is lower than 488. Just like Porsche Turbo and Turbo S.

 

I love turbo engines. You can easily mod them with a tune for a lot more power.

 

So do car-makers. Everytime they introduce new models, they don't need to invest on new engine or new material anymore, like you say, it can be easily mod to get more power, long way to go. This is a huge $$$ saving.

 

I would rather have more power then less. One reason I got rid of the 458 and went with the 650s is a new z06 gave me a good spanking. You can say it doesn't matter, but it does to guys that do not want to have a slower sports car at 3 times the price.

 

You should go for Nissan GTR Omega Alpha. Forget the 650S, this will smoke the P1. And in few months, another tuner will create another monster, definitely faster than the Omega again. It never ends. But for passion, look at 360CS for example. It could be slower than BMW X5M, but everybody wants one. Passion lives forever.

 

LOL, I already have one of those also. I have a 1500 hp GTR.

 

+1,500.