Lots of threads about 348 engines being modded, but I was wondering if anyone has modded a 355 engine. If so, how much power did you got out of it and what did you do to it?
The most interesting stuff is the parts Toda makes. Problem is price. You could either build a Toda engine or buy another 355.
The 355 is pretty strung out "as is" Headers cleaner intake and some ecu mapping Or go toda and double the price of your motor You can also sqain-coat everything, titanium valves and a lightweight flywheel. Personally headers and ecu tune is what I do for the street
Headers, GruppeM intake, better exhaust and piggy back computer for computer tune. That will set you back $10-12000 and give more power and better throttle response over stock but expensive for the gain.
Reason I ask is that I have the opportunity to have a 355 engine rebuilt and installed in my 348 along with a 355 gearbox. Was hoping with ecu and mods I could get 425bhp plus. Either that or just mod my 348 engine.
Well I'm with Tim on this. I could see maybe checking port work/valve job if it's apart, new headers,tuning, induction seems pretty nice. Considering it's specific output in stock form I think you would be better off spending the money to make the car as light as possible. What I would like to do more is just lighten the car but keep it stock appearing. Carbon front/rear bumpers and hood, carbon seats, alloy engine cradle, lightweight battery, CCB? Carbon wheels? I think my car already feels pretty damn good for 3200lbs but would be even better at 2900, even leaving the engine as-is.
I agree. The $/hp ratio is very high and it quickly becomes a grenade. A number of the existing parts went through quite a bit of development to make them reliable at the stock output. The block basically started as a 230 or so HP with all the same bearing sizes and rods as the 250 which made about 20 HP per cyl. The stock 355 makes nearly 50 hp per cyl with the same parts and they substituted steel with titanium on the rods.
My challenge (raced in GT4) has apparently an engine tuned by michelotto (although I couldn't get any info from michelotto). Rumour has it it's good for 440 hp. I haven't put it on rolling road. Bespoke manifolds, no cats, bespoke ECU
Thats seems to be the "safe" limit I have seen a few at that rating. I'll be putting both of my 355ch on a dyno soon maybe we can share figures in private
There is 10-15 HP in the exhaust, There is 25-35 HP in the intake system, All without raising the RedLine, or changing internal parts, and with the air cleaners still in place. This DOES require new airboxes. Now, if you are willing to do porting, and Ti valves and solid lifters, another 50 HP (on top of the above) is available.
I've been talking to a few Ferrari specialists here in the UK. Apparently, most of the 355's they've dyno'd are only around 350/360 bhp. I recall one friend who had only 330bhp on his 355. My car is 1420kg (3130 lbs) at the moment. Don't really want to get carbon body panels, unless I find some 348 GTC ones which is very unlikely.
What kind of dyno? They are calculating back to 350/360 crank hp? Both on the same dynojet my current 95 made 327rwhp and trapped 114mph in the 1/4 mile. Previous 99 was 295rwhp, 109mph in the 1/4. Seems like there is a big variance between cars. 2.7/5.2 and other variables now that they are over 20 years old.
No idea on the type of Dyno, but the general consensus is that the 355 is not putting out as much bhp as Ferrari states. I've decided to scrap the idea of modding a 355 engine and will just get a 355 gearbox and mod my existing 348 engine.
I believe there's a good amount of room for improvement on the 355 engine but the costs associated are prohibitive. For what it would cost to get 450hp out of the motor you could probably go out and buy a used 5.0L coyote Ford Mustang and throw a twin turbo kit on it to get nearly 1000hp out of it. That said, I'd love to see someone spend some time engineering modern parts to suit the 355's motor as someone is doing in the 348 thread.
To me, the problem is not lack of HP, it is lack of torque and low end throttle response. Ultimate hp numbers don't mean much because it comes in at an rpm that we don't use 99% of the time. On the street where we mostly drive we seldom go beyond 5000rpm and that is not where the power is, I would be more interested in getting the power to come in earlier so it is more usable. I removed my Fabspeed headers and bought a set from Bruce Wright that was smaller diameter tubing for more low end power. My top hp may be slightly less but I have more power where I drive most of the time. My car has very good low end below 5000rpm with the addition of the headers, Goth's exhaust, GruppeM and piggyback computers that remapped fuel and timing.
I don't know about it being prohibitive with regards to increasing the performance, but I will agree that it would get expensive quickly if you remain normally aspirated and are aiming to pick up significant amounts of power. As someone else noted above, it's the lack of low end torque that is the biggest issue, but that's a problem that can be solved with about 7 PSI of boost, provided you have the octane to prevent detonation.
I totally agree. Any day I rather have the best usable power-band then all out HP. If the 355 could have the 348 motor below 4000rpm we would have th emost insane car ever. Mark I am watching your turbo build and think with todays info and turbo bits is the smartest way to go for power. I have a spare bullet in my garage that I am dying to go with a very small turbo that spools up really low rpms.
I know that everyone loves a smallish turbo to build boost, but I think that really misses the boat in many ways. The biggest secret to great spool-up and throttle response is getting the turbine as close to the exhaust port as possible. I would rate this as a higher priority than turbine size, and would actually go a little oversize on the turbine to achieve this goal. There are many benefits to a loose turbine which include more power per PSI of boost. Everyone is looking at PSI as being a measure of potential power, when in fact it's a measure of resistance in the system. All things being equal, flow = HP much more linearly than boost in PSI. A light pressure turbo system can make pretty big numbers when not being choked by a tight turbine. Just my 2 cents.
That is likely going to be tricky for a number of reasons, much of which relate to how far I have gone with the removal of many parts and the fact that I am using a single very large turbo. You will however be welcome to steal any of the ideas that I come up with. Who knows, maybe later I will run tightly packaged twin turbos, but for now, it's a single unit.
The cost to do a valve job on the F355 engine is about what it takes to buy a 5.0 Coyote and put twin turbos on it.
