Remaps.......

[Randy]

I can vouch for the fact that there is quite a lot of untapped potential in a 4200. Mine is now running very nicely and I matched a Tubi equipped 360 in a large scale roll-on acceleration test on the motorway this evening. Once they are allowed to breathe properly these engines pump put the power even with standard hardware.

There are some pretty big compromises made in shoe horning that engine in the front of the maser. I can see sorting out the exhaust would take the proverbial cork out for starters. These cars run MAF sensors so, up to a point, the engine will correct itself for the additional airflow.

 

[Randy]

I always use the highest octane I can get as it lowers the combustion temperature which helps longevity.

There won't be a tangible difference in combustion temps, that's not why you want to run super. Higher octane means = more resistant to knock, thats the bigger gain. To make matters more confusing though the supers that are commonly available don't find the octane in the same ways. These days most have a small additive pack and then a reasonable amount of ethanol which is a mixed blessing. You heard that shell v-power is the best... It is; they *** 5% extra toluene as opposed to ethanol and this has a much higher calorific value than ethanol which is good (for fuel consumption and for your stock mapping).

Or you could do what I do and buy neat toluene and make your own octane adder

 

[hodroyd]

Randy,
That's interesting..!! I always use Shell V-Power in my 42 and IMHO it is a very good fuel, if I can't get it, such as when in certain places in Europe, I stick a bit of Redex in to keep everything clean. The ECU should adjust for the fuel used, but the better fuel works for me very well.
I don't understand this comment that the cats will get sucked back in to an engine, they are on the exhaust side and would be pushed out, not in, If they somehow get sucked back in you already have a massive engine failure going on..!!
Cheers
R

 

[mjheathcote]

I guess that the octane boosters that you can buy are therefore basically toluene?
Regarding this sucking back of broken cats, I too find this puzzling, surely the exhaust valves are only open on the upward piston stroke?

 

[Randy]

I guess that the octane boosters that you can buy are therefore basically toluene?
Regarding this sucking back of broken cats, I too find this puzzling, surely the exhaust valves are only open on the upward piston stroke?

Normally some combination of toluene and xylene, but hideously over prices! I pay about £1.80 per litre for toluene buying 200ltr at a time and I'm sure it can be bought much cheaper than that. The octane boosters you buy are like 7-8 quid for 500cl bottle

 

[BennyD]

I can understand the higher octane being a useful knock resistor in a turbo engine because of the variable combustion pressures due to the turbo pumping in pressurised air (and heat). However, I can't see that being as much of a problem with a n/a engines because the combustion pressures are much more consistent. I was always led to believe that lower combustion temperatures were the benefit of higher octane fuel. I stand corrected.

 

[hodroyd]

As far as I am led to believe, the higher octane is a cleaner and faster burn, so the engine does not have to work as hard to achieve the desired result. I don't think it actually get's hotter, it just works better for better combustion.

 

[CatmanV2]

Octane is only a measure of resistance to detonation. Can't see any reason why it should be cleaner or faster, or why the engine would have to work less hard.

As long as the fuel you're using is not detonating at the maximum compression of your engine / ECU combination, then increasing the octane of the fuel will have no effect at all.

You may be able to adjust your ignition timing via an ECU remap to retard spark further, give more compression (up to the maximum that the physical dimensions of the engine will allow) and gain some power there, but that's about it.

C

 

[MASEQP09]

OK I've asked the dealer the question as promised and they have said the reset can only be done by plugging in the 'Maserati Computer' which I guess is the SD3/Leonardo...

Thank you Mowlas

 

[hodroyd]

There are a number of myths about the octane ratings of gasoline. In actuality, octane ratings only tell you one thing: the amount of resistance to detonation the gas has. But what does that mean?
That just means that gas with a higher octane is less likely to detonate before the spark plugs fire. Sometimes gas does that, like if your car’s engine has a particularly high compression ratio. You won’t get the maximum amount of power from the high performance car if you use regular, but you’re not going to damage your car. For the small percentage of people who have high performance/high compression cars, premium gas will help you squeeze out that top shelf performance.

So that sort of tells you what the experts think..??

 

[CatmanV2]

[/COLOR]So that sort of tells you what the experts think..??

But *only* if your ECU / engine combination can take advantage of it....

C

 

[hodroyd]

Of course, we all have Maserati's, not Ford Fiesta's, so we are talking presumably about high performance cars and the use of fuel..??

 

[Randy]

Of course, we all have Maserati's, not Ford Fiesta's, so we are talking presumably about high performance cars and the use of fuel..??

Its worth considering how the ECU would go about correcting for the fuel that's put in the engine. Your engine is dumb to the octane number on fuel but it does know, through the use of the knock sensor, if there is knock. If the engine detects knock it will retard the timing to get rid of it and you will loose power in the process. No manufacturer would calibrate an ECU with an ignition curve that's likely to cause knock on the fuel its been specified to use. So, if the car has been calibrated on 95 then there is no value in putting in 98 but if the car is calibrated on 98 then you will loose power by running 95 (and also potentially cause some damage to the motor). Basically, knock control isn't used to maximise the power of the engine, its a safety device there to save the engine if the fuel is wrong/old etc.

 

[mjheathcote]

So no advantage to using super plus, certainly in the 42/GS, that is calibrated for regular. Not sure for other models.

 

[CatmanV2]

So no advantage to using super plus, certainly in the 42/GS, that is calibrated for regular. Not sure for other models.

I don't think we can *know* this unless we know that the ECU can set timing to induce knock on 95 RON.
If that's the case, then we could *assume* that 98 RON may allow the ECU to retard ignition a tad more to take advantage of the increased compression and eke a tad more power out.

*But* without seeing the code of the ECU or some test results, I'm at a loss as to how we'd state this with certainty. Of course, I come frome a background of scientific research and data as opposed to desire and smoke and mirrors

C

 

[mjheathcote]

I doubt that the ECU adjusts itself to the fuel, knock yes, but a higher octane fuel, really doubt it to be honest.

 

[CatmanV2]

I doubt that the ECU adjusts itself to the fuel, knock yes, but a higher octane fuel, really doubt it to be honest.

Dinglydinglydinglydingdingdingdingding!

Until someone shows me, I wont be buying Super unleaded!

To be totally honest, I owned a Ducati Monster for a while. It suffered with terrible carb icing. Super unleaded fixed that, but *nothing* to do with the octane rating....

C

 

[Tim82]

In my experience in the world of Honda's, most cars leave the factory with them leaving a fair bit of room for improvement. They run rich, and arnt set up to give their full potential, more a trimmed back factory level of potential. Hondas were easy to tune, Plug a laptop with a piece of equipment called flashpro and let your tuner do its magic on the dyno. A stock type r would produce anywhere from 197bhp to around 210. A simple remap changing AFR values, cutting some ignition, leaning out the fuel ect would produce around 225 on some. Nothing unsafe, just readjusting values that have been set up poorly by the factory on the ecu.

The same could easily be done to our masers if you had the hardware to map your ecu. Id have no doubt DMS know what theyre doing, a smooth linear increased power delivery and increased throttle response with improved fuel economy is a basic thing to be able to achieve in the tuning world. I wouldnt be surprised if 450hp at the flywheel could be produced seeing as at stock they produce an advertised 390bhp which like any engine means its lowest value as you cant advertise a car to have 410bhp and when dynod actually produces a lot less. So they go with the lowest possible outcome, as all engines differ slightly.

If i was bothered about figures (which with the maser im not to be honest) then id go have a remap without doubt but i wouldnt pay more than about 400 quid for perhaps 2 hours on the dyno of tweaking

 

[Tim82]

Oh and as for fuel octane, if youve mapped your car when it had 95 octane in it then filling up with 97 or 99 will give you no power increase. If you mapped your car with 99 octane then youd get more power than mapped on 95. If you mapped your car on 99 then filled up with 95 you'll have less performance and risk the run of engine knock.

 

[hodroyd]

This is a subjective argument that will rattle on and on. I prefer 98 because the engine feels more reactive to throttle demand and at the top end of the rev range the engine sounds and feels great. I have used 95 on the odd ocassion and the car feels slightly less agressive, or that may just be me..?? 98 has a cleaner burn and is not as subject to pre-burn as much as 95 is, so only in my opinion, 98 is the better fuel, but again is more expensive. I don't buy cheap tyres, or oil etc., I just like my car to have the best I can provide..!!