Question re raising compression '95 f355

Well on current pump gas they already detonate. I'll add not only with current pump gas but also what we had in 95, whatever differences those may be. You'll need different fuel or a different advance curve and with that you may just give back whatever you gained with the bigger CR.

Yea, I think you'll want a lower RPM range. Ferrari had intended to make it a higher redline than it was but they ran into a whole host of durability issues during testing and lowered their sights to 8500. Rods being one of those issues. I would for sure talk to Carillo or Crower about a set of their titanium rods.

 

Does anyone actually make aftermarket rods for our cars or would it be a custom order?

 

Is there anyway I can remove the rev limiter? I want to hear this motor scream the factory intended at 9000+. Lol.

We have 100 octane fuel here but it is pricey.

 

As Brian said, it'll only cost you a few rods and collateral damage. Make sure you record the sound for us, including the kablam!

 

No off the shelf stuff. All custom order but I know Carillo has made rods for many Ferrari motors. I have installed a bunch of them. My own 328 has Crowers in it.

I will not do a rebuild with Ferrari rods. Too many blocks with holes in them out there. After the old sodium filled valves the rods are the next worst part.

 

I would consider doing this but only with an aftermarket ecu with flex fuel capability to run it primarily on E85. Tune would auto adjust to be very conservative on 93 if E85 wasn't available. (say on a road trip)

On 93 and stock ecu's you might be able to bump the compression slightly with a cam change as later IVO will reduce DCR but it will be trail and error unless cat cams or someone else has results from using those parts. (and really I wouldn't install the cams unless they are proven anyway)

If there's room to reduce piston weight significantly the stock rods may survive but agreed that you may as well upgrade them at that point.

If it peaks at 9500 you are looking at close to a 10k shift point. At that rpm I wonder if your timing belt change interval would be reduced to months? What rpm do the Toda engines turn?

 

Timing belt life was what ultimately made Ferrari turn down the RPM.

With more aggressive ramps and springs that will just get worse.

 

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Damn Ferrari rods.





That's a good one. I have that picture too.

 

What the heck is that from?

 

Re the porting.

It is reasonably well known the early heads breathed a little better. The splitter between the ports where they divide for the 3 valves is thinner and more knife edged. Beware if you go in that direction. Ferrari quit doing that because they kept finding water down there. Lots of heads oozing H2O into the intake ports.

 

I think it was one of those big Japanese modular ship engines. I bet it made a big noise.

 

How do they compare to the stock specs? Run the specs through a dynamic compression calculator, if it's the same or less than stock you should be ok (or as ok as you are with a stock car). However, you don't need to increase the compression to get the benefit of the cams if there's enough airflow in the stock heads and intake setup...Based on what Toda gets/advertises with stock heads, there's still quite a bit of headroom there...You can also play around with the cam centerlines to tune the cams to the compression you have. With less compression, tighten them up a bit (105 already looks pretty tight) which will narrow the power band but make it higher. Widen with higher compression to flatten the power band a bit but get more top end and low end power.

I wasn't aware there were any other cams available. What's the cost?

 

Bumping the compression from 11.5 to 12.0 buys about 8 HP if the cams are left as is.

Given 10 more degrees of intake opening and a few more degrees of overlap::
a) the power band will move up the RPM band by 800 RPM, that is it will come in 700-800 RPMs later and sign off 700-800 RPMs later.
b) you loose 25-30 lb-ft of TQ before the engine comes on the cam
c) you gain about 30-35 HP if you accept 9000 RPM rev limit (about 425 HP)
d) you may have lost enough TQ down low to tolerate the compression bump without detonating.

e) if you go with titanium valves you loose enough mass in the valve train to gain another 25-30 HP from the reduced reciprocating weight and the lower spring pressures.
f) if you can find titanium shim under bucket tappets you can gain another 15-20 HP.


(a) indicates this is not a very street friendly build point.

Also note, with this much overlap, header "timing" is significantly more critical to avoid the "dreaded" flat spots. My simulations show 2 potentials at 1200 RPMs (right off idle) and 1800 RPMs. The flat spot at 1200 will DEFINITELY interfere with the 1050 RPM idle point.

 

While lightweight valvetrain components are worth pursuing in something that will turn more rpm, 25-30hp from titanium intake valves and 15-20hp from ti shims is not anywhere close to happening. Power gain would be less than five and closer to zero assuming no valve control issues to start.

The springs are not a high source of drag (they return a portion of energy spent opening on the closing side)

 

I tend to agree raising compression can give you a better powerband. However with dialing back timing you loose the peak HP with pump gas and that will only get worse.

Lighter valves = excellent
Lighten up the flywheel clutch assembly =priceless
friction coatings also
Loose weight, even my dr tells me that for years

I do have question, who makes good titanium vales for the 355? I have a spare motor apart right now thats an experiment.


By no means I am a pro on the f car motors I was a mountain motor guy. We found decreasing reciprocating mass on the valvetrain and friction coating got us in the rpm range of much smaller engines

 

Sure, on a mountain motor when a steel valve weighs as much as an f355 piston ti valves will dramatically increase rpm potential due to control. With a 5 valve head, relatively small valves and lift numbers, controlling a steel valve is not an issue. (As we see with the stock f355 rpm potential).

Same shape same airflow. If valve control is not an issue ( and it isn't with stock components ) power gain if anything would be very small.

 

Seems like your looking for torque, not power. You won't get it from a 355 engine. The displacement is just too small.

Torque is what makes a car fun to drive. That is what smokes the tires etc. unless you wanna drop a Z06 engine into your Ferrari, your stuck with what you have. Sorry. The 355 is pretty much maxed out as you have it.

 

HP is more fun,that's what makes the car accelerate. Gear a low torque, high hp motor properly and the rear wheel torque is the same as a mountain motor making the same hp, simple physics.

Only two ways to increase hp: more torque or more rpm. Cams can get you more rpm, compression more torque. You can usually do both as more aggressive cams will tolerate more compression without detonation.

If you are afraid to rev the motor and want more low end torque, you have the wrong car.

 

Only 1 way to find out

Get to it and takes notes for us