Dyno results on the 348

I'll see your bet and raise you.

How about,

348 with all the final Fabspeed mods vs 355 with the same Fabspeed mods. The headers, free flow cats/cat delete pipe, x-pipe exhaust (you guys have got to be developing that one), and the ecu tune. Similar mods vs similar mods. Same dyno same day. Hp vs hp at each rpm (2,3,4,5,6 & 7000rpm) up to the 348's rev limit.

Think you guys can pull that one off Evan, Chris? Surely there is a local 355 with all your bells and whistles on it that would be game for the dyno show down.

 

The 355 head and intake arrangement wins hands down liter for liter. The 348 is not exactly choked, but it just doesn't have the CFM that extra valve per cylinder the 355 has nor the [beautiful] ITB arrangement on the 355.

355 challenge programmed motors with proper exh manifolds are seeing some 430ish bhp or so aren't they? 340-350ish at the wheels?



What can I say, the 355 is sort of my not-yet mistress lover. I want one, but I cannot bring myself to buy one haha.

 

I sense a challenge. Hmm, maybe time for a 348 head upgrade with larger valves. We can make them flow every bit as much as a 355. We just don't wanna spend the money. Also we need to push the 358 motor a bit. Higher octane fuel, higher revs and more advance. I think we might be in for another Dyno day, Bruce! I swear there's 400 ponies in this engine yet.

 

Has anyone ever done any head work that really flow significantly better. Larger valves, porting etc. I've seen a few examples of gasket matching and port polishing but that still doesn't offer the advantage of larger valves

 

Those 348 heads can flow a ton of air, the ports have a lot of potential as they flow pretty well right from the get go. Larger ID intake valve seats and larger intake valves, some bowl work through to the throat and it will pick up a ton no doubt putting it into 355 territory. That said, a 355 head can have some work done too. No one is going to convince me that a 348 head can ever outflow a 355 head meaning I could never see a 'built' 348 engine ever eclipsing -liter for liter- a 355 engine. The 355 ports are just poetry.

 

While I admire the 5 valve 355 heads, they were intended as a surrogate for VVT which the 360 and 430 models have. VVT would negate the necessity of 5 valves, which to me adds unnecessary complication to the head design with all those extra parts. At the time it was pretty cool, but now they're a novelty.

I still want to do my 348 heads just to see what the gains would be, but I need to work out a budget. At some point the cost per pony gets prohibative.

 

+ F355 !!! ...................... ​

Partially correct .. ......... the 360 and the CS use the same 5 Valve heads as the F355 ............. the 360 only has variable cam timing on the 'exhaust' side ....... on the intake, the 360/CS have that big 'variable intake manifold', along with the same 'fixed' intake cam timing as the ALMIGHTY F355 ..............

 

Don't forget those wonderful hydraulic lifters!

 

+1 .........

 

Yes.

Fchatter TheItalianJob did some head work on his 348 heads over three years ago, but I don't think he ever finished the project. I pinged him a week ago for an update, sadly haven't heard back.

He flowed the stock heads before the work began and it made decent numbers. At .300" of lift it flowed 194cfm and at .400" it flowed 212cfm. Mind you this was with teeeeny tiiiiiiny 30.5mm intake valves. Here is the rub. Stock 348 intake cams have an advertised lift of 362, so there is no point in flow numbers at .400+ unless you are gonna get a custom grind. Well, Daniel also flowed the ports at .360". The stock ports and intake valves flowed 209cfm. Then he put in 34mm intake valves, and I'm guessing some port work, and the flow numbers at .360" when up to 241cfm. Before you ask, I have no idea what the velocity was.

So there's powa to be had in them thar heads.

 

If you can produce something which increases torque in the, say, 3500 - 6000 range without sacrificing anything else I would be very interested indeed!

 

Its called a 12 cylinder Ferrari

 

Maybe, but I don't want to sacrifice the looks or handling either.

 

i dont think its a surrogate for VVT. the 360 is a five valve head also... the F50 had them also which was based on what the F1 cars were running at the time if memory serves.

5 valve heads are still cool, like the yamaha FZR crotch rockets... just be thankful they didnt do a 6 valve heads like on the trident cars

not much wrong with the F355 motor other than valve guides and some disposable factory headers?

the drivetrain is nearly 20 years and old without force induction, VVT and direct injection. at 108hp/liter its still amongst the highest normally aspirated motor out there.

 

The 3rd intake valve was used to perform the same function as VVT does now - essentially getting more fuel into the cylinder at higher rpms. I beleive that it doesn't even open until the rev range is high. They do that now with variable timing of the intake valves. Also you can tune in a little Helmholz effect (ah, not that again!) once you can control the valves. Yes, the 360 continued the 3rd intake, but only b/c Ferrari didn't use VVT on both valves. BMW followed the same path with VVT. First the exhaust was variable, then both.

Dropping the 3rd intake makes sense from the standpoint of economizing the valve train on the road car. You cannot compare race engines where the budget has no limit and every ounce of performance is desired or a small displacement, high revving mortorcycle engine that has very little reciprocating mass.

Ultimately, a VVT 4-valve engine has the best performance design for the street in terms of performance and reliability. At some point I wonder if a 3-valve design might not be better, especially for large displacement engines.

We can get more out of the 348 engine, but at what cost. That has always been the Stooge objective. For me it's with keeping the car in a stock configuration and smog legal. I personally think my mods so far are at or near the limit. I never wanted to go into the engine for this initial stage. Now its time to consider other options. Head work, engine management, forced induction, (God forbid) nitrous are but a few.

Again not taking anything away from the incredible 355 engine. That is a work of genius given the 1994 era. Mostly. We can nit pick the small stuff, but it still sets the bar for that generation of performance car engines. 5 valves, by-pass exhaust, individual throttle bodies!!! Wow. For the time. I wish Ferrari had taken some of that technology and used in on the 348 in its latter years. No we have to do it.

 

Love seeing some good data posted for any type of modification work. Props to your team for sharing this.

I'm certainly not a forced induction expert, but if someone was looking for just 50-100 HP more from either of these engines, would it be outlandish to think that this could be done in a low boost scenario with a couple small turbos? I know there would have to be an ECU worked up, but if someone had a plug and play ECU worked out, alternate injectors, and conservative turbos with a pre-fab piping system, could this be done without internal engine mods or is there an existing barrier (ie. compression) that prevents a mild turbo setup from being an option on stock internals?

I seem to recall from previous discussions that the ECU is the killer for this, but if a company were to get one of these dialed in, it would seem like this would be a killer product to go with an essentially bolt on performance line up?

 

Man I think you are way off based on what the VVT really does. Variable valve timing on the Fcars or bmw Varnos is not really for increasing flow rates by any significance. It dosent open the valve with more lift or add duration but advances or delays the cam timing to control lob centers, overlap and phasing.

the much more sophisticated units like the “No limit budget” on mass produced econoboxes of honda vtecs, Mitsubishi. work of genius? the Toyota which also had 5valves , VVT and itbs all for 25k usd for the common folks in 91. last time ive checked (a buddy in LA has one in his track car) it didnt need headers and valve guide, belts replaced. these cars had the variable valve train that does indeed increase flow by essentially having an extra pair of camshafts by skipping to a different lob to give u more flow. They are switch on later up the rev range, yes you guessed it for emission purposes. Most purpose built race motor of this era took the variable valve timing off the motors because low speed drivability and emission aren’t a priorities. for reference a S2000 unit is 120hp/liter motor, it revs higher and with much higher recipocating mass and higher piston speed due to the longer stroke compared to a 355.

Now if you want to really go back it, I was first aware of this VVT feature on the 86 alfa spider. It was use to reduce the overlap for emissions and increase pressure off idle to run with the old style hemi chambers for drivability. Puts it this way the VVT in the 360 or 430 and BMW are primarily used for emission reasons and to enhance low speed drivability with aggressive cams I reckon. newer infinite type VVT coupled with modern management and direct injection definitely has advantages today.

still nothing wrong with both the 348 or 355 output in my book.

cheers

hf

 

I simplified my VVT comments. Being able to control valve timing allows one to tune all sorts of things, but mostly to refine the air fuel timing and ignition for power, fuel efficiency and smog output. The 355 didn't have it but the 3rd intake can replicate what an intake cam VVT would accomplish on a simple scale. This also allows the intake cam profile to be more flexible since you can always open the 3rd intake value as an option. The possiblities are many, but Ferrai obviously had their own plan and I certainly cannot tell exactly what and how it works or even when. And leaving an intake cam open slightly longer can add more fuel.

Another quandry is the balancing valve we 348s have between the plenum halves. We have a single small butterfly. Check out the 360 and 430's. They came back to single TBs per side and greater equalizing valves. I know its for managing torque and sort of is a primitive surrogate for what unequal length intake runners give you.

Still love the 355 engine, but am dedicated to deliver similar or better output in our 348 mills, certainly at rev ranges where one can use it.

 

+1 ... I do recall Ferrari referring to what they did on the 355 intake valves as VVT ...... I actually read it on the F355 description plaque, when they had the Ferrari exhibit at the Peterson Automotive Museum. I would like to use that same VVT acronym and more accurately identify the 355/360/CS intake valves articulation as 'Varied Valve Timing' ....... instead of 'Variable Valve Timing' ........

 

How does the 3rd valve on d a 355 replicate variable cam overlap, lob centers and timing again? What the 3rd valve may do it have a different lift, duration or lob center from the other intake 2 valves...hardly variable valve timing. For instance if u had two different intake cam lobs on your 348 motor would you label that as a VVT ?

 

You will have to bring that argument to the factory, as they are the source of this VVT 'nomenclature' ..... none of us here believe the 355/360/CS have 'variable valve timing' on the intake ....... as I have mentioned above, it should have been called 'varied valve timing' ...... the two outer valves open before the center valve and the center closes before the two outer valves .....

 

Of course, and a good point to illustrate the difference between real VVT and the simulation provided by the 3rd intake valve. The only way this might seem practical is to use the 3rd valve to allow for more overlap between the intake and exhaust. Basically, you just open the 3rd intake. The cam is ground one way, but you can use the 3rd intake to sort of finesse some more intake valve when you think you need it. Say you want greater lift and/or duration in the primary intake valves, but are worried about clearance and duration on the stock cam, which you figures works just fine for normal operation. You toss in another intake valve for the "adjustor". Ecco as the Italians would say. Think of it like a mini shot of F/A at the right time. Imagine a 360CS that might have all of its valves adjustable, even this third "tweeker" valve. Heady stuff!

And yes, if you had another cam profile on our 348 engines and could flip it into another cam mode, yes, I'd say that was VVT, but really it's either or and not really "variable" IMO.

 

Finesse more intake valve when you need it? You mean like at idle?

worried about the clearence with the extended duration? wouldnt the 3rd valve the one in the middle be the closes one to the piston anyways?

opening the 3rd valve may have its merits but what you are saying dosent make much sense to this layman. Ok i give, mercy you win. if you say its a VVT then a 355 has VVT. This is Ferrarichat after all !

gothspeed good point..yes, varied valve timing would be more apt

cheers