More questions about XFlash/XEDE
Noize, I'm glad you're happy w/ the XEDE. It definitely has more features and room to grow than the Xflash but I don't need the extras, I just want a very fast and reliable Evo. I was definitely under the impression that I can make similar power w/ either once tuned. In fact if you look at the readme's on top of this forum one of the graphs compare XEDE to Xflash, the 2 curves look very similar. Also, from looking at one of the other comparison graphs the Xflash makes very repeatable power 
I think I recall a post where Vishnu was able to unlock the boost control function of the XFlash and get essentially the same results as the Xede AT MODERATE BOOST levels. I also recall Shiv stating that the Xede was useful in high boost applications (ie. Stage 2) because of its greater resolution and ability to control bigger injectors etc, etc.
I'm running the stage 1 with Xflash mainly because of these posts. I'd like to see some overlayed plots of Stage 1 w/Xede vs. Stage 1 w/XFlash vs. Stage 1 with XedeFlash. Would be interesting to see the results.
I have no doubt that the Xede is probably able to make a little more power under the curve thanks to its higher resolution, but don't think that the extra few ponies it makes (or bumps it smooths out) would be noticeable to the butt dyno, nor justifiable to the wallet. Who knows, somebody prove me wrong and I'll gladly buy an Xede if it's all that and a bucket of chicken!
I'm running the stage 1 with Xflash mainly because of these posts. I'd like to see some overlayed plots of Stage 1 w/Xede vs. Stage 1 w/XFlash vs. Stage 1 with XedeFlash. Would be interesting to see the results.
I have no doubt that the Xede is probably able to make a little more power under the curve thanks to its higher resolution, but don't think that the extra few ponies it makes (or bumps it smooths out) would be noticeable to the butt dyno, nor justifiable to the wallet. Who knows, somebody prove me wrong and I'll gladly buy an Xede if it's all that and a bucket of chicken!
IMO only when combined with the XedeFlash does the Xede shine over Xflash for obvious reasons that the flash has over the Xede. If it were just between Xflash vs. Xede and you were pretty much not going to make additional mods the Xflash is the ticket and it will only get better once the Xflash Tuner comes out. From what Shiv has stated about the future of XFlash is you will have muliple map switching capabilities and some adjustment controls to timing and fuel, not to the extent of the Xede though. The results of the Xflash is great and comes without the annoying ticking the Xede's relay emits. It all boils down to what the end users goals for their Evo is. I'm just glad the guys at Vishnu are giving us options.
Last edited by n00dle; Mar 19, 2004 at 03:58 PM.
The relay tick is super quiet and does not bother me at all. The tranny and tires are much louder.
For all of you that are running a Stage 1 with an XFlash, please tell me what kind of boost readings you are getting close to redline. Mine would drop off to 15psi, but this is likely because I am catless. I'd get an unbelievable midrange kick, but then it would taper off a little. With the XEDEflash, I'm holding boost a lot longer, and the values drop off to only ~18psi to fuel cut.
I'm not trying to flame the XFlash, but I had it before I had the XEDEflash, and I like the XEDEflash a lot better. In all honesty, a good deal of that might be due to the fact that I have a Shiv custom tuned map with the XEDEflash, and that makes the car a total freaking monster.
The main point to me was that my boost dropped to ~15psi with the XFlash (catless) by 6000rpm, whereas I'm still atound 20psi at 6000rpm with the Xedeflash.
I raced a Z28 friend before and after the custom tune, and I pulled him before the dyno day with the XFlash, but at about 6000rpm, I'd stop pulling as hard. After Shiv tuned my car, I can walk him all over the highway, ESPECIALLY at higher rpm. YMMV with the XFlash vs XEDEflash.
Until you've driven both, though, don't make a concrete judgment. I'd take a Stage 1 XEDEflash over a similarly priced Stage 1+ XFlash in a heartbeat... Wait a minute.. I already did.
For all of you that are running a Stage 1 with an XFlash, please tell me what kind of boost readings you are getting close to redline. Mine would drop off to 15psi, but this is likely because I am catless. I'd get an unbelievable midrange kick, but then it would taper off a little. With the XEDEflash, I'm holding boost a lot longer, and the values drop off to only ~18psi to fuel cut.
I'm not trying to flame the XFlash, but I had it before I had the XEDEflash, and I like the XEDEflash a lot better. In all honesty, a good deal of that might be due to the fact that I have a Shiv custom tuned map with the XEDEflash, and that makes the car a total freaking monster.
The main point to me was that my boost dropped to ~15psi with the XFlash (catless) by 6000rpm, whereas I'm still atound 20psi at 6000rpm with the Xedeflash.
I raced a Z28 friend before and after the custom tune, and I pulled him before the dyno day with the XFlash, but at about 6000rpm, I'd stop pulling as hard. After Shiv tuned my car, I can walk him all over the highway, ESPECIALLY at higher rpm. YMMV with the XFlash vs XEDEflash.
Until you've driven both, though, don't make a concrete judgment. I'd take a Stage 1 XEDEflash over a similarly priced Stage 1+ XFlash in a heartbeat... Wait a minute.. I already did.
Xede with XedeFlash vs. Xflash is not a fair comparison. Stage 1 with the Xedeflash will reap the benefits of the flashes capability to increase revs and remove boost cut. Whereas the Xflash can't reap the same benefits of the boost capabilities of the Xede.
Xede without XedeFlash vs. Xflash would be a better comparison. Both have their own unique benefits and shortfallings.
For the potential buyer the line has to be drawn somewhere, because it's easy and tempting to rationalize that extra $100 for XYZ.
Xede without XedeFlash vs. Xflash would be a better comparison. Both have their own unique benefits and shortfallings.
For the potential buyer the line has to be drawn somewhere, because it's easy and tempting to rationalize that extra $100 for XYZ.
Last edited by n00dle; Mar 20, 2004 at 12:16 AM.
Originally posted by n00dle
Xede with XedeFlash vs. Xflash is not a fair comparison.
Xede with XedeFlash vs. Xflash is not a fair comparison.
True. Your argument for the Xede plus the XedeFlash is good and one would be foolish not to get the Xedeflash for a $100. But alot of folks are looking at the entry price point for each option. Xflash is what? $395 vs. Xede $900 ?
That's a big difference and makes the Xflash bang for the buck.
(the prices may be off cause the Vishnu site is down right now)
That's a big difference and makes the Xflash bang for the buck.
(the prices may be off cause the Vishnu site is down right now)
Last edited by n00dle; Mar 20, 2004 at 12:26 AM.
What I don't get is... why can't we use a MBC/EBC with the XFlash? Theoretically, that is what the XEDE is doing. It's using it's own boost control instead of the ECU. So couldn't we use XFlash, and a boost controller? Or is there something so special about the way the boost tables are setup that it can't be emulated with a stand alone boost controller?
I could have sworn that XFlash and XEDE were running the same boost values anyway, as noted by the stickies in this forum. But I guess that was a XEDE without the XEDEFlash...
n00dle makes a good point though.. the XEDE + XEDEFlash is more than double the price of the XFlash. Right now, that's a lot more than I can afford. I can afford the XFlash + cam gears, but that's still cheaper than the XEDE.
Noize, not that I am doubting you, but I am just curious how much of this "power increase" you feel from going from XFlash -> XEDE is actually the capabilities of the XEDE, and how much is because you have a custom tune now as opposed to the baseline XFlash you had before.
I could have sworn that XFlash and XEDE were running the same boost values anyway, as noted by the stickies in this forum. But I guess that was a XEDE without the XEDEFlash...
n00dle makes a good point though.. the XEDE + XEDEFlash is more than double the price of the XFlash. Right now, that's a lot more than I can afford. I can afford the XFlash + cam gears, but that's still cheaper than the XEDE.
Noize, not that I am doubting you, but I am just curious how much of this "power increase" you feel from going from XFlash -> XEDE is actually the capabilities of the XEDE, and how much is because you have a custom tune now as opposed to the baseline XFlash you had before.
You can use an external boost controller with the Xflash, however you'd be better off having Shiv tune the Xflash with the boost controller set. I'd be weiry of adding a boost controller and raising the boost or sustaining boost when the Xflash isn't efficiently programmed for it via mail ordered flashes. That and you start getting closer the cost of an Xede and start seeing it's benefits, value, etc. 
Last edited by n00dle; Mar 20, 2004 at 12:49 AM.
See, I currently have an EBC and a SAFC. I dynoed 270 on a dynojet, with peak horsepower at like 6500-7000rpms. It's not "shabby," so to speak. But it seems like XFlash would get the job done better. I guess I'm confused about how the XFlash controls boost... when I see the boost lines, it looks like it jumps to 23-24psi on spoolup, then tapers down to like 18 as it goes to redline. This tapering of the boost - is this something that is uncontrollable, or is it something desired? Does it taper because the ECU doesn't let you boost that high, or is it simply because the 16G stops being efficient at that point?
Only Shiv or Brett can answer how and what the Xflash does or doesn't do.
Despite the product description they've provided alot of people are still not clear on the specifics.
As for boost tapering...
I believe it's a function of the stock ECU. Several publications and Mitsu have stated that peak is 19.5psi, but ECU controlled tapered down to 16psi. I'm curious if those with standalones like AEM experience this tapering. If not, then it gives greater credit that the factory ECU is controlling that aspect.
Despite the product description they've provided alot of people are still not clear on the specifics.
As for boost tapering...
I believe it's a function of the stock ECU. Several publications and Mitsu have stated that peak is 19.5psi, but ECU controlled tapered down to 16psi. I'm curious if those with standalones like AEM experience this tapering. If not, then it gives greater credit that the factory ECU is controlling that aspect.
Last edited by n00dle; Mar 20, 2004 at 12:57 AM.
I did some searching and this is what I came up with..
That clears things up a little, but still doesn't make clear if boost is tapering because the ECU can't control it, or is it because that's the optimal solution for boost control?
Oh boy... this is how it starts
Okay, back to the XFlash: It controls boost a bit differently than most I imagine. First of all, it provides a two stage boost level. Higher boost up to 4800rpm, which provides quite a midrange torque whallop without having to get very aggressive on timing and fuel mapping. Above 4800rpm, boost immediately levels off to almost stock levels (within 1/2psi of stock in most cases). At these higher engine speeds, we close to extract the extra power through running moderate boost pressures with more aggressive fuel and spark mapping.
Second, it also allows for a small time-dependant overboost much like the factory ECU code. But with a different overboost amount as well as a different overboost duration.
Why do we tackle the problem differently at different engine speeds? Because we think it provides the best result. Both in terms of output as well as safety margin. One of the nice things about having a load bearing dyno is that we can load up the car at different engine speeds and find the "ideal" combination of boost, fuel and spark advance at every RPM point along the way.
The whole idea of holding boost constant to redline means that we essentially give up control/tunability over one of the three tuning parameters which, needless to say, is a compromise. Especially in octane limited conditions where you need all the tuning flexibility you can get.
So that's the answer from the horse's mouth. By no means gospel, of course. But it's working for us and, so far, XFlash customers have been quite satisfied. So have I, for that matter. For actual XFlash dyno results (using the baseline XFlash map with no additional tuning), check out
https://www.evolutionm.net/forums/sh...threadid=59672
Or any of the other threads on our forum about the XFlash.
Regards
shiv
Okay, back to the XFlash: It controls boost a bit differently than most I imagine. First of all, it provides a two stage boost level. Higher boost up to 4800rpm, which provides quite a midrange torque whallop without having to get very aggressive on timing and fuel mapping. Above 4800rpm, boost immediately levels off to almost stock levels (within 1/2psi of stock in most cases). At these higher engine speeds, we close to extract the extra power through running moderate boost pressures with more aggressive fuel and spark mapping.
Second, it also allows for a small time-dependant overboost much like the factory ECU code. But with a different overboost amount as well as a different overboost duration.
Why do we tackle the problem differently at different engine speeds? Because we think it provides the best result. Both in terms of output as well as safety margin. One of the nice things about having a load bearing dyno is that we can load up the car at different engine speeds and find the "ideal" combination of boost, fuel and spark advance at every RPM point along the way.
The whole idea of holding boost constant to redline means that we essentially give up control/tunability over one of the three tuning parameters which, needless to say, is a compromise. Especially in octane limited conditions where you need all the tuning flexibility you can get.
So that's the answer from the horse's mouth. By no means gospel, of course. But it's working for us and, so far, XFlash customers have been quite satisfied. So have I, for that matter. For actual XFlash dyno results (using the baseline XFlash map with no additional tuning), check out
https://www.evolutionm.net/forums/sh...threadid=59672
Or any of the other threads on our forum about the XFlash.
Regards
shiv
That clears things up a little, but still doesn't make clear if boost is tapering because the ECU can't control it, or is it because that's the optimal solution for boost control?
This research is tiring me, but at least it's getting somewhere!
1.7bar is nearly 24.7 psi. I think that's more than I'd ever need to run on the stock turbo. Dangit. I need to call Shiv and clear things up.
Shiv,
For the eventual stage 2 users, the XEDE/Xflash is the only way to go, correct?
For the eventual stage 2 users, the XEDE/Xflash is the only way to go, correct?
Correct. The reflash, by itself, can't read as much load/boost as the system is capable of producing. Needs the XEDE to expand its Y-axis
shiv
shiv
??.. so xflash has limitation of up to stage 1?
Not quite. The load axis on the factory fuel and timing charts only goes up to ~1.7bar of boost. This applies to any reflash. I have run our Stage 2 car with the reflash only but it was in a pump gas application which limited boost to less than 1.6 bar. If you ran much more boost, one would have to make sure that the mapping at 1.7bar is still adequate/suitable for the fuel/spark requirments at the higher boost pressure since that is what it is going to get.
Regards,
shiv
Regards,
shiv
1.7bar is nearly 24.7 psi. I think that's more than I'd ever need to run on the stock turbo. Dangit. I need to call Shiv and clear things up.
More... I need to get some shuteye. Yet I'm still doing research...
So it looks like he is purposely dropping boost because holding it to redline is causing detonation... so basically, I don't want to run a EBC with the XFlash, just because it'd be a lot easier to control boost from the ECU (or XEDE).
Hi guys,
XFlash is a bit different when it comes to boost control. With it, we do what we do with the XEDE. That is, we allow for a mild overboost in the midrange, between 4000-5000rpm which improves torque substantially. But at high RPM, we still employ a gradual boost taper like stock, but not as steep. This allows us to run reasonable advance numbers which makes the car consistent, run after run. We've found that trying to hold boost steady to redline makes the car awfully ping prone and inconsistent-- espeically in lower octane conditions like in CO, CA, AZ, WA, etc,. Peak boost, in stock cars, is a momentary 22-23psi, quickly reducing to 19psi, where it tapers gradually down to 18psi by fuel cut. This basically allows us to keep a healthy distance between operation and knock throughout the entire RPM band. I have dyno graphs of a couple of cars we've done in the last week which I will put on-line as soon as our scanner starts working. It illustrates the effects of the revised boost control quite nicely. In all the cars tested (all completely stock Evos), hp rose from 195-197whp to 218-222whp on the baseline map-- no custom tuning. Torque had similarly impressive gains. Consistently. This made me happy
Cheers,
shiv
XFlash is a bit different when it comes to boost control. With it, we do what we do with the XEDE. That is, we allow for a mild overboost in the midrange, between 4000-5000rpm which improves torque substantially. But at high RPM, we still employ a gradual boost taper like stock, but not as steep. This allows us to run reasonable advance numbers which makes the car consistent, run after run. We've found that trying to hold boost steady to redline makes the car awfully ping prone and inconsistent-- espeically in lower octane conditions like in CO, CA, AZ, WA, etc,. Peak boost, in stock cars, is a momentary 22-23psi, quickly reducing to 19psi, where it tapers gradually down to 18psi by fuel cut. This basically allows us to keep a healthy distance between operation and knock throughout the entire RPM band. I have dyno graphs of a couple of cars we've done in the last week which I will put on-line as soon as our scanner starts working. It illustrates the effects of the revised boost control quite nicely. In all the cars tested (all completely stock Evos), hp rose from 195-197whp to 218-222whp on the baseline map-- no custom tuning. Torque had similarly impressive gains. Consistently. This made me happy
Cheers,
shiv
So it looks like he is purposely dropping boost because holding it to redline is causing detonation... so basically, I don't want to run a EBC with the XFlash, just because it'd be a lot easier to control boost from the ECU (or XEDE).