Stock/Arrow/Torrie

[SRT BILL]

Question, When changing from stock PCM to the arrow and back to stock is the effect of the new calibrations immediate. I believe I've read that there may be a relearn process that takes some driving to fully complete the change over. Could this be the reason for the apparent lower looking Arrow numbers?

[outnumbered]

Question, When changing from stock PCM to the arrow and back to stock is the effect of the new calibrations immediate. I believe I've read that there may be a relearn process that takes some driving to fully complete the change over. Could this be the reason for the apparent lower looking Arrow numbers?

I don't think in this particular case, as the Arrow tune was the first one on the dyno. It's been in the car for the last 4000-5000 miles

But to your point, when going from stock to the Arrow tune, yes, my throttle had to learn the new settings.

[Sub Driver]

A custom tune is always better than a canned tune. Not surprising that a custom tune makes more power than the arrow.

[7TH_SIGN]

Remote tuning is just as good as the tuner being there physically.

I'm not surprised the least in regards to how much the Torrie tune made. Actually I expect those numbers 590-600whp.

My surprise comes from how low in power the Arrow PCM made. That's a big difference in power between the two and if you were to line both tunes against each other you would see the Torrie tune put a couple car lengths on the Arrow.

I actually was going to go with the HP Tuner however couldn't get a confirmation on remote tuning availability so I went with the Arrow.

[outnumbered]

Remote tuning is just as good as the tuner being there physically.

I'm not surprised the least in regards to how much the Torrie tune made. Actually I expect those numbers 590-600whp.

My surprise comes from how low in power the Arrow PCM made. That's a big difference in power between the two and if you were to line both tunes against each other you would see the Torrie tune put a couple car lengths on the Arrow.

I actually was going to go with the HP Tuner however couldn't get a confirmation on remote tuning availability so I went with the Arrow.

You won't be disappointed with the Arrow. The sound alone is worth the money. In addition, the throttle response, as well as the hp bump are noticeable. I do not think the Arrow retards timing as dramatically as stock. It's definitely a good investment. Remember, you will ultimately spend more on the HP Tuner, for the tuning and dyno time.

[7TH_SIGN]

You won't be disappointed with the Arrow. The sound alone is worth the money. In addition, the throttle response, as well as the hp bump are noticeable. I do not think the Arrow retards timing as dramatically as stock. It's definitely a good investment. Remember, you will ultimately spend more on the HP Tuner, for the tuning and dyno time.

Thanks man. Yeah I have no regrets going with the Arrow PCM but your gains on the HP Tuner I definitely envy lol. I'm a very hungry person when it comes to horsepower. The reason I went with the Arrow PCM is because of the lack of response and customer service for the HP Tuner (I'm not a tuner and leave that to the pros). I called multiple vendors of the unit and emailed them as well. Never could get a call back or even an email response and when I am going to be relying on remote tuning service where communication is vital for setting up dyno sessions on multiple individuals schedules I just don't have the time to deal with that. I would call and email Andy and he would answer every single damn time lol. He was awesome to deal with and why I went with the Arrow PCM. The best customer service always wins my business.

When its time for TT I will be upgrading to a Motec or Infinity so either way the Arrow or the HP Tuner would have to be retired.

Get some vids of your Carbon Snake when you get a chance!

[Steve M]

Question, When changing from stock PCM to the arrow and back to stock is the effect of the new calibrations immediate. I believe I've read that there may be a relearn process that takes some driving to fully complete the change over. Could this be the reason for the apparent lower looking Arrow numbers?

The relearn process you are thinking of is the throttle relearn, which is a basic calibration process that you either do with a WiTech for the Arrow PCM or with the HPTuners scanner. That relearn process is a one time only thing, and has nothing to do with power production...if it isn't done right, the car simply won't run (it'll go into limp mode). There are some other adaptives that do some learning (like fuel trims), but those only affect part throttle operation.

Calibration changes to WOT fueling (which is what we're talking about here) are immediate. WOT on these cars is open loop, so what is commanded is what you get. Anytime I make a calibration change that affects WOT fueling, I don't have to drive it for 500 miles for it to learn anything...it just does what it's told, and does so right away. Swapping in the Arrow PCM would be no different.

[Vipes]

Yeah no thanks. A remote tune for your car on a dyno? Let's hope nothing melts down on the hwy or driving around town.

Arrow tune is built by Arrow. For the Arrow engine. In all scenarios

So if you go across country do you have to fine tune based off altitude, weather conditions and engine load?

If anything a remote tune is usually better vs a canned tune. I'm still skeptical about calling somebody up, listing your mods on the phone and having them mail you a tune based on a baseline of somebody else who had similar mods to you. Everybody seems to have great experiences with the arrow tune but I'm used to another car/life where canned tunes usually didn't end well. A remote tune would be the same as a local custom tune but it just takes a little more time between pulls to send the results out to tune then back to upload them into the car and repeat.

[Bruce]

Doesn't the HPTuner support a parameter called something like decel fuel trim? If so, why can't Torrie just dump more fuel by adjusting this parameter and get the decel pops back???

[Steve M]

Doesn't the HPTuner support a parameter called something like decel fuel trim? If so, why can't Torrie just dump more fuel by adjusting this parameter and get the decel pops back???

It's deceleration fuel cutoff (DFCO), and the flag is either set on or off. If on, there is no popping, if off, it keeps a little bit of fuel in it, which causes popping. It still pops with HPT, just not as much as it does with the Arrow calibration. I'm almost 100% certain Arrow advances the cam under decel to enhance the popping - HPT does allow cam control, but the one table available doesn't affect the cam under decel or idle conditions. I've asked them to look for an additional parameter or table that would allow this, but additional Viper development is extremely low on the priority list due to the amount of time required to reverse engineer this particular PCM. Proprietary source code + a single, limited production platform = extremely limited profit potential for HPTuners.

You might be able to add fuel to the cells in the MAF table that are being referenced during those conditions, but I'm not sure if it would just get trimmed out...I might give it a look this summer to see if it is possible, but since there is zero performance benefit to it, it's not real high on my list of things to try.

[outnumbered]

It's deceleration fuel cutoff (DFCO), and the flag is either set on or off. If on, there is no popping, if off, it keeps a little bit of fuel in it, which causes popping. It still pops with HPT, just not as much as it does with the Arrow calibration. I'm almost 100% certain Arrow advances the cam under decel to enhance the popping - HPT does allow cam control, but the one table available doesn't affect the cam under decel or idle conditions. I've asked them to look for an additional parameter or table that would allow this, but additional Viper development is extremely low on the priority list due to the amount of time required to reverse engineer this particular PCM. Proprietary source code + a single, limited production platform = extremely limited profit potential for HPTuners.

You might be able to add fuel to the cells in the MAF table that are being referenced during those conditions, but I'm not sure if it would just get trimmed out...I might give it a look this summer to see if it is possible, but since there is zero performance benefit to it, it's not real high on my list of things to try.

Torrie turned it off on mine. But like you said, not as pronounced as the Arrow.

[dewilmoth]

It's deceleration fuel cutoff (DFCO), and the flag is either set on or off. If on, there is no popping, if off, it keeps a little bit of fuel in it, which causes popping. It still pops with HPT, just not as much as it does with the Arrow calibration. I'm almost 100% certain Arrow advances the cam under decel to enhance the popping - HPT does allow cam control, but the one table available doesn't affect the cam under decel or idle conditions. I've asked them to look for an additional parameter or table that would allow this, but additional Viper development is extremely low on the priority list due to the amount of time required to reverse engineer this particular PCM. Proprietary source code + a single, limited production platform = extremely limited profit potential for HPTuners.

You might be able to add fuel to the cells in the MAF table that are being referenced during those conditions, but I'm not sure if it would just get trimmed out...I might give it a look this summer to see if it is possible, but since there is zero performance benefit to it, it's not real high on my list of things to try.

I know everybody raves about the decel pop, but I can't imagine dumping unburned fuel down the exhaust does much to help the already high door sill temps. If there's no performance benefit, I don't understand the draw.

[donk_316]

No actual data shows higher temps on the cats.the only time it would be an issue is for people running stock cats. Hiflo cats or no cats then it isn't an issue anymore.

I haven't swapped my exhaust yet and I haven't noticed any increase in sill temp with the arrow.

[7TH_SIGN]

All this talk about decel pops. I get to experiance it on my catless exhaust this Friday when I get the Arrow PCM installed.

That being said, I'd rather have 40whp extra over exhaust note.

[donk_316]

AND calling it "decel pops" isnt even correct. Decel popping makes me think of old glasspacks or chery bombs mufflers. This is a decel burble.

The F-type burbles on decel. This is the sound that the Arrow makes. It doesnt "pop" or "snap"

I had the HPT in the "shopping cart" and backed out and went Arrow. Just not super comfortable with that just yet.

[Dman]

19hp from exhaust and Arrow PCM.

Seems like false advertising to me.

We have major vendors saying 60hp at the wheels.

I don't know how you explain away that much power difference.

I think anyone who spent that kind of time and money on those mods and got 19hp would be livid.

This would suggest all you should do is get he Hap tune and anything else, including exhaust is a bit of a waste of money for so little hp return.

[The_Ruski_Driver]

19hp from exhaust and Arrow PCM.

Seems like false advertising to me.

We have major vendors saying 60hp at the wheels.

I don't know how you explain away that much power difference.

I think anyone who spent that kind of time and money on those mods and got 19hp would be livid.

This would suggest all you should do is get he Hap tune and anything else, including exhaust is a bit of a waste of money for so little hp return.

Exhaust makes all the difference in sound and gives you power under the curve. The cats on these cars are where the majority of the restriction is. Personally, I plan to run HI-flows so I don't have to breath in the awful smell for 5HP

[Dman]

Exhaust makes all the difference in sound and gives you power under the curve. The cats on these cars are where the majority of the restriction is. Personally, I plan to run HI-flows so I don't have to breath in the awful smell for 5HP

That's fine, under curve yea, we're talking peak advertised numbers. When we have SRT and our major vendors saying these parts provide 60rwhp, and attest to it in dozens of dynos and installs, and you get 19rwhp. That's with full exhaust. Um, if any aftermarket vendor were advertising 60rwhp for mods and we dyno'd and saw 19rwhp, the thread would go apocalyptic and the aftermarket vendor would join the ranks of Hennessy.

I'm NOT a dyno warrior, I have always compared mods by 1/4 mile MPH numbers myself, vs going and strapping onto rollers, but a 40rwhp shortfall on the same dyno is .... A LOT.

[outnumbered]

19hp from exhaust and Arrow PCM.

Seems like false advertising to me.

We have major vendors saying 60hp at the wheels.

I don't know how you explain away that much power difference.

I think anyone who spent that kind of time and money on those mods and got 19hp would be livid.

This would suggest all you should do is get he Hap tune and anything else, including exhaust is a bit of a waste of money for so little hp return.

Dave, just for clarification, all my pulls had a full Belanger exhaust. So where the dyno states "stock", that is on the stock tune WITH a full exhaust. I don't know what the car made stock (without the exhaust)

[Dman]

Dave, just for clarification, all my pulls had a full Belanger exhaust. So where the dyno states "stock", that is on the stock tune WITH a full exhaust. I don't know what the car made stock (without the exhaust)

Gotcha, just seems the car must've been rather weak upfront, or something going on. With SRT putting out their dyno video showing 538rwhp as a typical rwhp number, showing 540rwhp with full exhaust .... almost seems like something was awry and the Arrow didn't correct for it, but Torrie nailed whatever it was and you got the performance you should be getting. I know a gen5 here dyno'd 534, they rolled it off the drums and installed the ARH full exhaust and back on the dyno the next day for a 571rwhp pull. Arrow install took it to 589rwhp, all corrected. Same dyno all in 24 hrs, pretty good comparison. But it could be a fluke, the thing with vipers is there are so few with particular mods it seems we're always in new territory with things. I know we see Torrie generally gets more HP from posts I've seen, 30+ more rwhp is cray cray. I think if I do another viper, which is likely at this point, I'd try Torrie's tune. I've had great results from Lund remote tunes on my mustangs for years, and Torrie has the same type stellar reputation and results.

[outnumbered]

Gotcha, just seems the car must've been rather weak upfront, or something going on. With SRT putting out their dyno video showing 538rwhp as a typical rwhp number, showing 540rwhp with full exhaust .... almost seems like something was awry and the Arrow didn't correct for it, but Torrie nailed whatever it was and you got the performance you should be getting. I know a gen5 here dyno'd 534, they rolled it off the drums and installed the ARH full exhaust and back on the dyno the next day for a 571rwhp pull. Arrow install took it to 589rwhp, all corrected. Same dyno all in 24 hrs, pretty good comparison. But it could be a fluke, the thing with vipers is there are so few with particular mods it seems we're always in new territory with things. I know we see Torrie generally gets more HP from posts I've seen, 30+ more rwhp is cray cray. I think if I do another viper, which is likely at this point, I'd try Torrie's tune. I've had great results from Lund remote tunes on my mustangs for years, and Torrie has the same type stellar reputation and results.

I had a great experience with him in the past. Unofficially, I had the record (from what we could tell) for a naturally aspirated SRT10 Ram. Torrie took it to 601 at the wheels. Obviously that was with a good cam and a good set of heads from Greg Good. But it all had to come together with a tune, and Torrie delivered.

[The_Ruski_Driver]

So to get this Torrie tune, we would need to have access to a Dyno? you guys have a dyno in your garage?

[Stealth]

These results do seem a bit strange. FWIW, my '14 GTS has been running the Arrow PCM, Stock CATS and Corsa CAT-back exhaust on 91 octane for 3,000-4,000 mi. with no known adverse effects (my car has 7,000 mi. currently). As I have noted previously, my feeling is that the Arrow tune is the tune that would be preferred by the factory as the OEM tune, except for regulations, etc. The car just seems to run better and sound better, with better throttle response. I have never felt a "night and day" difference in power just based on the Arrow PCM.

[Malu59RT]

So to get this Torrie tune, we would need to have access to a Dyno? you guys have a dyno in your garage?

You have to rent a dyno from a local performance shop. Prices range from $175-$300/hr around here, although it has been a while since I've checked.

[outnumbered]

So to get this Torrie tune, we would need to have access to a Dyno? you guys have a dyno in your garage?

If you are anywhere close to Charlotte NC, I can help make it really easy for you.