Engine limitations for F50

There are many ways to increase the power of an engine without resorting to forced induction. different cams, exhaust work, different pistons, ECU mapping, larger injectors etc.... . There is a NA F50 that has over 600hp to the wheels, that is a 100% road legal car. That car has been ported and polished, full exhaust (including headers) higher compression ratio pistons slightly higher redline, remapped ECU etc.. The F50GT has all of that just too much extreme end, the redline in that car is over 10k.

 

Are you asking what the upgrades cost on the F50 road car, or the costs associated with bringing the car to F50GT specs? Because those costs are worlds apart . To give you idea doing an exhaust upgrade on the standard road car will run over $17K(including headers). The 600 rwhp F50 has 125K in work done to it. If you want 800 wrhp (NA) in an F50 you may as well buy one of the three F50GT1s. Its good to know we have other Tool fans on the board (no pun intended). We had an Fchat get together at the last Sacramento show.

 

The F50 uses only 2 spark coils...and a performance upgrade to a 12 coil-on-plug system would improve performance, emissions, and gas mileage for less than $2,000.

If you are only using your F50 on the track, then replacing the cats with straight pipes makes sense...inexpensive hp on tap with no loss of reliability in the car.

Programming the F50's cool Motronic 2.7 engine computers could be done on your home PC with a chip burner and $10 worth of blank EPROMs.


Other options (best detailed by Tool above) are available, and you could stroke the motor, advance ignition timing, and advance the cam timing for more hp, too.

More fuel, more timing, more air, more spark...can yield more hp. Pretty basic. Lots of untapped power in that motor long before you get to forced induction.

 

Are you sure about that? I was under the impression that it was a static ignition setup on them.

 

You have to open up the air pump.

Consider that your average 1.0 litre sport bike is making 150 HP stock (measured at the rear wheel) and when rebuilt using absolutely stock components can achieve 175 HP/litre (perfectly blueprinted, blaanced, muti-angle valve job,...). The 600cc-ers are pushing 200 HP/litre (120 HP at the wheel)--and these are street bikes! you can buy for <$10K.

The F50 heads are on the same order of flow as these high end motorcycles, so that end of the breathing is accessible. A port matching both ends and polish of the exhaust (only) will bring the heads into order. Titanium valves will lighten the load on the valvetrain (said to be good for 50HP) and enable access to higher engine revs.

Given access to race gas (as the only fuel) one can bump the compression a full point (not street gas capable any longer)

And then one needs to modify the air intake system for lower restriction, and modify/replace the exhaust system not for lower restriction, but for bigger resonances so the intake velocity stack augments the power curve of the headers,...

So, basically, the block, liners, crankshaft, and con rods are preserved, and everything else is either replaced, modified, or massauged.

Consider the dollar amount given in earlier in the thread ($125K) this includes at least 40 dyno runs, and tests of several different headers (cut, fab, weld) and intake velocity stacks (different sizes) to get the whole thing working correctly over the power band.

 

Adding::

They probably lightened, polished and did some aerodynamic work on the crankshaft (often called knife edging but the counter weights really take on more of a wing profile than a knife edge).

 

Pretty nicely preped as delivered! Extra power is all in the top end and a CR bump, the bottom is nicely done with Tefloned piston skirts and the likes
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The F50 engine comes very well equipped from the factory with a 5 valve cylinder head, individual throttle bodies, a relatively high compression ratio, titanium connecting rods, etc. It will be very difficult to make significant gains without losing drivability and turning it into a race car that runs off race fuel. For a street car, the best option would be a tuned exhaust and leave it at that.

The modifications we are working on for the 550 motor are similar to the features incorporated into the F50 engine. For example, the induction system.
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How are you going to determine if a shorter velocity stack is going to work better or worse than a longer one, or a larger diameter one, or even a narrower diameter one, longer or shorter taper, exponential taper or elipsodial taper; without putting the parts together and measuring the outcome?

In order to find the combination of intake velocity stacks {height and taper} and exhaust headers {primary length, primary diameter, secondary length, secondary diameter, collector parameters, muffler alterations} you have at least this number of things to try and see which ones work best. A careful and planned atack on the parameter space on the dyno can minimize the number of tests from hundreds-to-thousands to several hands full.

On the other hand, you could just throw a bunch of part together, run it on the dyno (once) find x amount of increase and call it a day. But, here, you will never know how much you are leaving on the table--a little or a lot. For a GT1-like race car, they are not in a position where leaving a little or a lot on the table is acceptable.

 

While RPMs get a lot of the credit, the power is comming from making the intake resonances and exhaust resonances coincide with the RPM powerband. That is, RPM are necessary, but so are the intake and exhaust tuning requirements. The 600cc-ers road bikes are achieving 200 HP/litre at the wheels (225-ish at the crank). The race bikes wil a full on massauge of the parts can achieve 250 HP/litre at the crank (maybe a tad more). This is port matching, exhaust polishing, exotic valve job, tuning of the ECU for race gas, and new header and exhaust components.

The OP was only looking at 160 HP/litre at the crank, 225/1.6 ~= 160 so in theory one could drop from 16K RPMs/1.6 = 10K RPMs and make 160 HP/litre. One gains a lot of lack-of-friction dropping from 16K PRMs to 10K RPMs.

In order to make 160 HP/litre (up from 110 P/litre), the intake system is going to have to be able to deliver 160/110 ~= 1.5 times are much air at the same pressure drop (0.5-0.8 PSI) as the "road car" at 10K/8K ~= 1.2X as many RPMs. Thus, the intake system is going to need significant work. Injectors will need to be in with the plan.

The exhaust system is just going to need to be returned to the new power band and cam timings, and diddled with until it augments the new resonances of the new intake system and exit through an essentially restriction free duct to the atmosphere.

While an enginie such as this is "barely doable" catagory (no catastrophic part strength issues) it is way beyond the means of your typical hot-rod shop--what one might call a 40-hour motor suitable for leMans, it is in no way streetable. 120-130 HP/litre might be streetable with a little luck.

 

How?

Well, if the O.P. or anyone else is serious, the "how" is to model the gas dynamics of the stock engine, which will require actually disassembling a stock engine and taking lots of measurements - both static and dynamic (like flow at various lifts/etc.).

The software is multi-kilobuck to multi-tens-of-kilobucks per seat, but that's how it's done.

Jim

 

Granted, but even here, the multi-kilo-buck SW only narrows down the possibilities, you still have to test the real parts on the dyno to know for sure. That is Computational Fluid Dynamics--even done to F1 standards--is not ready for direct translation from simulation to production.

So, you either pay several handfulls of kilo-bucks for the SW, or several handfulls of kilo-bucks for the stainless tubing and welding, or both. Being good only minimizes the expense, but does not eliminate it.

{I'm currently doing 1D CFD simulation of a new F355 exhaust system and am considering some articulating velocity stacks for both low and high end gains simultaneously.}

 

Complete agreement with Mitch and Jim on this one.

We all know where the restrictions are but what constitutes ideal is a long way off.

There are a few weak points in the bottom end of the F50 engine that will show themselves quickly if wound any higher than it is in stock configuration. These are fairly easy work around redesigns but exist none the less. For a race car this is an acceptable compromise, for the street the owner would tire of engine pulls quite quickly.

Ferrari didn't make a habit of leaving a lot on the table when it came to building their Supercars. Surely more can be gained but it comes at a cost in longevity, they built a race car redesigned for the street with this model. Only ONE gasket in the entire engine!

A great mental exercise but I doubt there would be a line to widdle up an F50.

 

The answers to all this is boost, and ECM reprogramming.

 

Boost and Slipper skirt pistons make for short lived company
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Of course there would be gains by removing the potatoes in the tail pipe but it would most assuredly fall far short of the criteria you set in your original post of a 50HP/Ltr increase.

Really it all depends on the seriousness level of a given project. Mitch and Jim gave perfect examples of how a project of this level must be approached if one is to expect a high level of success. Prior to such an exercise one must set ground rules and expectations regarding needs for the car to be Federally legal, low RPM torque, driving in stop and go traffic, noise restrictions, ect.

As a rule, Ferrari left little on the table with the SuperCars when it is viewed as a package. There are a lot of Chip Tuners that will say they can give incredible increases with a simple remap. How many hours do you think Ferrari and Bosch spent on a dyno developing the package they offered? Change the ground rules and eliminate the need for Cats in the exhaust, reasonable noise restrictions, ect....everything changes and then you start looking for the next weakest link.

I have experimented with these exhaust changes and intake mods on the F50 and there are gains to be had albeit far more modest than the 50HP/ltr goal unless a complete redesign is done. My point is the bottom end of the F50 engine is nothing short of art when viewed as a street car of that era. Few have seen what Ferrari built in the bottom end, there were not many corners cut down there! The conversation could go on for pages if not for your ""with a caveat of not sacrificing reliability"" quote and a list of compromises one is willing to accept.

Compromise.... Both the F50 and the 430 are chain drive valve trains. One designed as a Super Car, the other as a Production Car... there are differences when the Bean Counters get involved.

 

I build racing engines for a living.
The engine is -as Mitch stated-and quite succinctly, is an air pump.
To achieve tghe gains you are asking requires a redesign from a USA/EPA certified smog engine, to a Comp motor. This entails a complete redesign of the combustion chambers, and extensive flowbech work on the heads, AND the intake, AND exhaust to achieve a TUNED tract to account for the laminar air flow characteristiccs being altered as well as the reversion shaock waves...thids is all vovoo and nobody is going to give away hard earned secrets on the internet. The time and expense in undertaking such an endeavour is not a"about how much" affair..its a this is how far we've gotten, this is how much we've spent...how much farther is needed rquired?
And yes, constant and repetetive dyno tuning is required...a max horsepower point is useless...a wider band of torque, earlier, longer, overlapping with increased HP, with less advance(twist on thje crank) is much more desireable results.
When you have tons of advance, tons of fuel, usually you have a poor flame front with lots of detonation spots in the quench zone. This is bad.
less advance is less stress, more power, better flame front propogation, better velocity of the pulses/reversion shock waves, etc...
The real question is: What are you trying to achieve?
The Ti rods ith ethe 50s are most likely made by PANKL, the also own Carillo, there is a steel rod which is better suited today for this app, than is Ti..Ti is ONLY for no holds barred racing, and is silly waste of money for anything short of unlimited budget, maximum frequency teardown, "works" style racing...

 

My intake mods were done to correct a design issue but it gave me time to study and think 'what if...'. The snorkle on the GT appears the correct direction but I never studied the laminer air flow on that body. With the radiator exit as it is on the 50 and my studies done on the LM style F40 bonnet, searching for clean air for the rear wing..... I have reason to think there might be better suited methods.

My focus on that 50 was longevity as it was the final stage of a complete engine rebuild.

 

You hit the nail on the head!

I fully agree with you,Mitch, and Dave.

To the OP...buy an F50, show me your credit line and then we will get serious...as for this fantasy quest in theory I've got to make a living and posting anything further will be $400hr..lol

It took a full year of developement just to get this engine ready for insertion into a race....constant dyno testing at the expense of many blown engines and a complete redo that left virtually nothing of the engine intact/untouched. Even after all of this it was still a continual engine developement involved after each race and we still didn't achieve something that was consistantly reliable.
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