Dyno results on the 348

Fair enough. Exhaust note and regular NA/forced induction pros and cons aside, it sounds like on stock internals at least, the cost/benefit ratio for a mass produced turbo just isn't there.

I still think a cost effective, plug and play ECU replacement would have appeal, and open up a whole new frontier for things like traction control, diagnostics and more flexible tuning. If you go down that road, definitely keep me posted!

In the mean time, thanks again for your hard work and sharing your R&D and data with us.

 

Well, you notice I never said it made sense or that it was VVT after all. That's because it was Ferrari's marketing department, I think, who came up with this analogy. More intake valve volume is great, but you have to get all those gases out of the cylinder too. Having a small 3rd intake to fudge your mixture works for the car. This is where the 3rd valve adds to the mixture in a way that a variable cam could. Can't do anything to the timing of course, but knowing you have the 3rd valve available allows for grinding the cam with it in mind. Don't need it now, however, with VVT technology. Which is probably why you don't see it on street cars any longer. That and omiting it reduces costs and complexity.

Anyway, I am looking forward to having an option for replacing or supplementing the Motronic board. So, Fabspeed, get on it! I'd lve to be able to hook up my laptop and refine the map for my specific mods. Or you guys can do it.

 

Oh who cares about the stupid vvt, 3rd lobe, variable timing, bla, bla, bla. We drive 348s, and 348s have plain old overhead cams. So it's point less to talk about all that stuff. We are modifying 3 4 8 s! So like Chris said let's stay on topic please.

Now.

The ecu tuning is going to be crucial to getting more power out of our 348s. The Motronic 2.7 is not an adaptive ecu at wide open throttle. Someone please correct me if I'm wrong. It does not adjust for extra air, and sticks to the mapping that came from the factory. Like Fabspeed, I ran to the engine running lean during the dyno pulls, especially on one particular mod I'm working on. It was so lean that the a/f ratio stayed above 14:1 from 1800/7700rpm. The Motronic did not adjust for the extra air begin ingested. So to keep from melting pistons I put things back to the previous mods. That and, it's my opinion the stock fuel injectors aren't up to the task of making more than 330hp before the air fuel ratio gets to far out of whack on the stock mapping. The stock injectors are only 18.4/lbs, 193cc units and early 348s have 3.4bar/49.3psi fuel pressure regulators, while the later 348s have 3.8bar/55.1psi FPRs. At 49.3 psi the injectors will act like 19.55/lb, 205.46 injectors. However if you want 330hp, with a .45 brake specific fuel consumption, and an injector duty cycle of 80% you will need injectors rated at 20.6/lb, 217cc. By bumping the fuel pressure to 55.1psi/3.8bar the stock injectors will act like 217cc units, which is why I think the factory did just that. But that is where the party stops, and the limit I have reached. Now before anyone suggests upping the fuel pressure any more, if you do that then you run the risk if having idling problems and problems at low rpm. Also, I have been told the fuel pumps have internal pressure relief valves the will bleed of excess pressure to protect the pump. So in my opinion bigger injectors and tuning are going to be key.

I'm eagerly waiting to see what the boys at Fabspeed come up with.

 

If it was gonna make more horsepower, wouldn't it do so until the injectors reached their limit? IE, upper rev range?

 

It does, it did, and they have.

So far I've topped out at 332hp, and when you look at my air fuel ratio on the "dyno day" thread you can see it's a bit lean. From the numbers I calculated I now understand why. Besides, you where there the day I tested the mod and saw what the a/f ratio was. Heck, we even cranked the MAFs down to 150 ohms, and then all the way to 0 and it didn't do jack. The daggon a/f ratio was at pretty much stoichiometric until 5500-ish/rpm and then went "down" to 14.3:1 all the way out to the rev limiter. The injectors where tapped out and the Motronic didn't adjust for the extra air no matter what we did. I stuck around and talked with Shawn and he was saying a lot of the cars he tunes make the best power with an air fuel ratio closer to 12.5:1 in the upper rpm range. The better the volumetric efficiency the more fuel you are gonna need. There was no way for us to add extra fuel, nor tune it, that day so I have no way of knowing what it was fully capable of. All we found out was that it was running WAAAAY lean and it lost power, BUT, it lost it linearly. The torque curve wasn't affected nor was the power curve, it made less power but the curve was the same. Now the air fuel ratio, that was a problem.................the car wanted Redbull and it got watered down Koolaid with no sugar.

We are getting the 348 to breath MUCH better, so it's only logical more air needs more fuel to make more power. That is the next hurdle, and yet one more reason why the 348 doesn't make the power it is capable of.

 

Pretty obvious hotrodding 101. Piggyback won't do it. Non-OEM ecu is needed. Nitrous solves all problems and you can pass smog. No fancy headers, cats or any of that stuff.

 

Hey Ernesto. Got new chips.

 

I must admit, adding a 100 HP shot of NOS sounds entertaining... but what will break is the question?

To solve the fueling problem is not entirely out of the question. Granted the stock injectors are limited to only so much there are always ways to work around limitations of the stock ECU, however not all of these solutions are desirable and it seems to make more sense to just run fuel and ignition from a secondary ECU and allow the factory ECU to think it is still in charge of everything. This is how you pass smog on an OBD-II car and still have a computer that will provide proper fueling and timing. The computers (prior to the newer post OBD-II) generally cannot tell that they are not providing spark timing and fueling to the car because they don't monitor that the injectors/ignition actually were fired by the ECU.

 

Probably nothing if it is done properly and correct safety measures are in place to shut the system down. As I understand it, the danger comes from running lean and adding O2 to the mix, causing detonation. Scary prospect when you consider the normal electrical gremlins that plague these cars.

Even with everything else working, you'd still have the cost of engineering a balanced system for both sides.

 

Big problem with Nitrous....limited to the size of the tank. HP wanted now and always!

 

Exactly. This one point is what has always steered me away from nitrous. It just doesn't last long before a refill is needed. Then again, the counterpoint is how often does one really need full power on a street car and for how many seconds at a time?

 

All true. Even in a stock low power 348 you are breaking the law in 6 seconds. So a 10lb NO tank will get you 3 mins of full throttle. Unless doing the Texas mile or on a racetrack you aren't going wide open throttle that much. In fact I think too many owners baby their Ferraris and never see redline! MarkPHD who posted above even talked about his 355 and oil smoke. Yes you could have an valve issue and yes you could have overfilled the oil and yes it could be something else but it could also be the fact that you have not driven this car in a long time and it needs some proper exercise. Anyway there are solutions to the Nitrous issues and ways to easily design a competent safe system but that is for a different thread. And welcome back Mark!

Back to the 348 power seekers can gain more power capacity (more fuel) possibly by taking a tip from the Nitrous fans. Plumbing in 2 stand alone fuel injectors downstream of the throttle bodies on a rudimentary fuel mapping is a down and dirty way to go. It can be done super cheap with sub $25 injectors and home built megasquirt for about $100 bucks! The question is how good is the 348 plenum in flowing a wet mixture?

 

+1 ....... if I had nitrous .... I would be tempted to use it, even in parking lots ....

 

Yeah but 348's have so little power they need nitrous in parking lots.

 

Ouch!! lol

 

12-cylinder snobbery!!!!!

 

I tend to break the law less in my F355 than I do in my other vehicles. It's hard to deny it was you speeding when you have the only Ferrari 355 on Guam and a 35 MPH speed limit.

Don't fret, mine will see plenty of WOT, but I was doing a proper shakedown this week following the maintenance and downtime. It's running well with the exception of that oil smoke, which is inconsistent at the moment. I'll get it figured out. I don't think it's harming anything yet... and thanks for the warm welcome back.

It's probably better to just run a proper fogger system, albeit more expensive, you can be assured that the mix is not likely to go lean on you. Installation of a fogger system is pretty straight forward.

If there was room, and there really isn't, I think it would be interesting to see how a twin screw supercharger on the 348 would fair. The problem with boost is the already high compression of these motors. Not an issue with real race gas, but with pump gas it's an issue.

Mark

 

Again,

The fuel and tuning issue needs to be solved. A few months ago I talked with Andy about his ITB setup, and what his a/f ratio was. He said he was around 11:1, which is pretty rich, and why I think his car is belting out 6' foot flames. Andy is running a stand alone ecu so he is able to actively tune his engine. This isn't the case with the stock Motonic 2.7. It can be done with an emulator, but you have to crack open the box an swap out the EPROM, tune is actively, burn a new EPROM and put it in. Then the mapping is fixed again. If you make more adjustments you have to.........open up the Motronic again, pull the EPROM............... So the Motronic 2.7 is not a tuner friendly ecu. Not forgetting to mention WHO can tune it???

Be it n/a, boosted, or squeezed, when the engine is getting more air in MUST get more fuel, and the stock ecu is not adaptive. So before we can get the 348 to see it's full potential this issue needs to be solved. I hope the boys at Fabspeed can crack this nut.

 

Ernie as FBB pointed out could you not use a nitrous injector to inject fuel only and inject into each intake kinda like my shower injectors on my race bikes? At least during your test you could see if all the ecu work would be worth it. Maybe your only gonna get 10 hp once your ratio is correct. Just a thought but I'm sure you have considered such stuff.

 

The thing is Grant, I have absolutely zero interest in nos on my 348, none at all. I am aware of how easy it is to hook up nos. I use to hang out with some street racers that would go rent a car, take out the full coverage insurance, and hook up a 150 shot just for kicks. After they had their laughs they would remove it and turn the rented car back in. Yeah I know it's easy to hook up a bottle. I also am aware of how fast you can destroy a motor with it. Again, I have absolutely no interest at all, and I suspect neither does pretty much everyone else, Fabspeed included, in hooking up nos to a 348.

As for the tuning, I think there is plenty more power to be extracted from the 348. I guess we are just gonna have to wait and see just how must power Fabspeed is able to unlock once they are finished with their ecu tuning of Dave's 348.

 

While this is not a discussion on nitrous, I have done a lot of it. You can safely nitrous cars with no issue when done properly. The best part about nitrous is it is reversible and does not effect stock configurations. I would guess that there are much fewer cars that blew up due to nitrous vs. The number of poorly conceived power additions like cams ,porting etc. Where the initial and long term results were far less than ideal. In racing we can race stock crate motors a long time. When people go up in class and souped motors they blow up often. Adding power to the 348 is great. Just don't end up a "did not finish".

 

Amen to that....eagerly waiting.....

 

Amen to that....eagerly waiting.....