Hurricane 270 tune difference compared to 300 header tune?

[hpmaniac]

Side note, i was running the Header tune this year and it would still be correcting fuel up to 110% @ 53 lbs key on with the bigger pump.

This just tells me the base tune is off a mile, In the automotive world and cars i tune we like less than 10% correction. Not sure how this system works though but That is a BUNCH of correction. what are you for actual afr on a pull at say 8800-9200 rpm? Nm i see 11.8

 

[fatchance]

The tunes are developed for Cookie cutter components. Start adding to the system to increase air flow, charge temps and more fuel and you are working outside the prescribed range of the tunes. This is why it's so important to Data log to maintain safe parameters.

 

[hpmaniac]

The tunes are developed for Cookie cutter components. Start adding to the system to increase air flow, charge temps and more fuel and you are working outside the prescribed range of the tunes. This is why it's so important to Data log to maintain safe parameters.

I have everything hurricane so it will be interesting to see how much my closed loop has to adjust the tune. Header arrives Friday, installing Friday night and testing Saturday. Ordered a couple helix to try as well. Straight 40 and a 38 42 also a straight 36

 

[Turboflash]

1. From my experience running my sled on Ulmer's track dyno for 2 days, I can say that the ability of our ecu to adjust fuel delivery for changes in iat is pretty minimal. So that would help explain why data logging is showing 14% or more fuel multiplier. I'm betting most of us have noticed that very cold ambient temps, the sled tends to run crisper (leaner) and the opposite on warm days. That tells me the internal iat compensation circuit is not really precise.
2. I would tend to agree that maybe the base map is not right if that much more fuel is needed to hit target afr.
3. One other possible component of this is observed or set fp versus actual fp. I don't have data logging (yet, PEFI doesn't have it until next season) but I have compared fp on my afpr gage with 2 new gages and they're not the same. The gages vary about 1.5-2 lbs from one to the other. Which one is right? Doesn't really matter as long as my afr is right. I don't have a certified calibrated fpr.
4. I may be wrong on this but I also think our gas itself could also affect tune and needed multiplier. For example running gas with ethanol vs. without. I think other additives in gas could affect it too.
5. As fatchance says, mixing components probably does affect it too. There are manufacturing tolerances for each component.

 

[sideshowBob]

On the data logging discussion here is a couple logs showing before and after I raised my fuel pressure from 45 to 50 to lower my AFR from 12.4 to 11.8. These logs were done under similar conditions and identical clutching and power train setups.
Its interesting to note that when I raised the fp and richened the sled up it also picked up rpm. I have since added more primary weight and have the shift rpm down to 8800 - 9000. Looks like my sled likes to be a little on the rich side.

45psi fp, 12.4 :1 afr, and 8900 rpm

Now 50psi 11.8:1 afr and 9250 rpm

 

[hpmaniac]

Some people forget we have a very accurate dyno on our sleds. make a change same day same weather with engine tuning and gain rpm you just built more HP. Surprising it picked up power moving to 11.8, normally a boosted engine will make peak power near 12.2 12.4 if everything is happy.
For mountain riding i hear many people complain they loose power or the sled feels like stock power, i would bet money it is caused from not enough intercooler when climbing at lower speeds or from snow blocking front vent. I am adding the second cooler at throttle body. Water meth injection would be the answer as well but not much room for a tank. It would work amazing with closed loop because you are adding a secondary fuel source basically.

 

[Turboflash]

In addition to you increasing fp by 5 psi, fuel multiplier is still 112.8. But your afr is a safe 11.8. Tells me the base map must be even safer.
On first log, makes me wonder if fuel compensation was "all in" at 122.6 since afr was too lean; and when you increased fp up 5 psi, the multiplier came down because it had more fp to work with and afr became richer. I wonder what the base map is looking for as far as afr? What would afr be if multiplier was near zero?
To me this is why I would use an adjustable fpr even with closed loop.
Without closed loop active, I get to decide what afr I want, and adjust fp to get it. Works for me.

 

[hpmaniac]

I found some old hurricane dyno sheets from the 270 and 300 tune and afr was around 11.56 to 11.7

 

[sideshowBob]

I found some old hurricane dyno sheets from the 270 and 300 tune and afr was around 11.56 to 11.7

Yes I have those dyno sheets and was one reason I wanted to bring the AFRs down below 12:1.

 

[1nc 2000]

Any of you guys hitting the boost cut out at half throttle acceleration? Right around 23 psi boost.

 

[KnappAttack]

This just tells me the base tune is off a mile, In the automotive world and cars i tune we like less than 10% correction. Not sure how this system works though but That is a BUNCH of correction. what are you for actual afr on a pull at say 8800-9200 rpm? Nm i see 11.8

You have to remember that 998 guys are a greedy bunch, and they are running hardware beyond what the tune was developed on. I dont care what brand tune a guy runs, when you put on bigger mufflers, ram air intakes, bigger intercoolers and other hardware that the tune wasn't developed for, they are going to go lean and change with the wind. You should see how lean some of these things run, and then people decide not to use closed loop and data log...

The stock injectors are out of fuel using "300 HP" tunes with good hardware. I know some guys running 3" mufflers and intakes on 280 PEFI sleds and they are extreme lean. They get by with it by throwing in some race fuel to keep them alive. The PEFI setups are not supposed to be using any intakes or mufflers larger than their own 2.5" trail muffler that does not flow much. The little turbo is out of air right along with the injectors being out of fuel in the so called "upper 280-300 HP" levels. I'm not sure there is a true 300 pump gas setup out there on a real engine dyno myself with stock injectors and turbo, (Tommcat had 297 real engine HP I believe on a stage 4 PEFI setup he dynoed, and I think he even had cams in that engine, they are claimed to be 320HP on pump gas stock engine from PEFI).

These ECU's are not much to write home about for consistency day to day either. They are severely lacking in different areas compared to good automotive stuff out there. Basically the ECU is a POS in comparison. We chase them day to day with the changes and there no consistency in them. They are all over the board and no two sleds are the same.

 

[sideshowBob]

My sled has a different muffler and intake then Hurricane designed the tune with ...you can't expect the tune vendors to be responsible when you have messed with their original product.
I think there are always a few other variables with our tuned sleds.
How accurate are the O2 readouts that are adjusting the closed loop fueling?
How accurate are the FP gages we are setting our fuel pressure with?
When running a tuned sled no matter how good the original tune vendor is ,[and IMO they are very good], we are venturing into no man's land when we expect these sleds to be all and do all for everyone.
This is why I think data logging is critical and If in doubt be conservative by running good fuel with Boostane. We have to thank guys like Yamamarc and KnappAttack for driving this message home years ago....they probably have saved more then a few engines.

 

[sideshowBob]

Any of you guys hitting the boost cut out at half throttle acceleration? Right around 23 psi boost.

23 psi boost?
With a header?
My sled runs max 19 to 20 psi boost max.

 

[KnappAttack]

23 psi boost?
With a header?
My sled runs max 19 to 20 psi boost max.

Tim is talking about the 50% part throttle where the boost is up around that 23 lbs and hitting the boost cut. In some instances it will hit the boost cut. Typically when using big/more intercooler and its colder out the can do this. Again, parts and changes outside the parameters of what the tune was designed for, in Tims case he's running the secondary intercooler so it going to be more pronounced and happen more frequent in those certain conditions.

Every greedy 998 bastadd wants to push the limits just we bit more than the next guy you know......

 

[1nc 2000]

23 psi boost?
With a header?
My sled runs max 19 to 20 psi boost max.

Not wide open, half throttle mine hits boost cutoff on acceleration.