Can we have a real thread about speed density?

[twdorris]

If you're measuring absolute pressure, I don't see why you would need barometric compensation.

I agree. Dave's only thought on this when I mentioned it was maybe the lower atmospheric pressure outside the exhaust was actually improving VE through the motor for the same manifold pressure. But he certainly agrees that it seems like a far stretch.

Thomas Dorris

 

[Ceddy]

IAT is scaled correctly.

I've heard Baro has a very small effect on exhaust back pressure with SD, but nothing else needs to taken into account.

I think the guy with issues may be mistaking something else for Baro differences.
Just wondering if anyone had seen anything similar.

 

[twdorris]

I think the guy with issues may be mistaking something else for Baro differences.

I agree.

Thomas Dorris

 

[belize1334]

Not that it matters terribly, but this discussion has swayed me. If I do convert to SD it will be with ECMLink v3 instead of DS-Map (Jackal or werewolf). The reason is simple. Despite the overwhelming cost savings of DS-Map and an Ostrich, as a physicist I simply cannot fathom why anyone would ever even CONSIDER using a definition for VE that wasn't referenced to MAP.

What is the purpose of VE afterall? It is an empirical correlation between the conditions in the manifold and the mass of air consumed by the engine. Since the manifold conditions are represented by the thermodynamic measures of pressure and temperature. The "known" variable is density. To get from density to mass, the empirical measure must therefore be volume. It makes sense then to define it in terms of a fraction of some other known volume, namely displacement. But the only pressure in site is MAP so why anyone would even mention ambient pressure is a mystery to me.

This business of a main VE and then a pressure compensation table is too cumbersome. What is it's purpose? If VE is defined wrt MAP and ranges over typical values of 80% to say 105% in the power band, then a table of VE should be sufficient, when combined with the ideal gas law, to calculate mass of air per rev and allocate fuel accordingly.

Maybe I've mis-understood how the Jackal system works, but my knee jerk reaction at this point is to pull the plug on buying an Ostrich and save up a little more cash for V3. I must say I'm a little disappointed too 'cause I was really looking forward to MAP based tables.

 

[dsm-onster]

Hense my spokens. . .

Ideal gas law is what I sleep with every night

So in both systems VE will need to be changed. What's the difference then? I'm not being sarcastic. What IS the advantage of boost as load? I hope you're not suggesting that you can go on to infinite g/rev with the same boost. Because ds-map's target market is not going to have that option. At some point they are going to have to up the boost for bigger power.

I still maintain that you have to alter timing tables for a stroker motor even if you're using boost as "load". That is the point of my post. It's about timing to make cylinder pressure not ve tables and load references. So there's really no advantage as I see it. I'm wanting to be educated: please do that. Though I have just bought V3, I'm definately not arguing for one side or another.

 

[Baron4406]

I have become a Jackal convert even after having a very bad experience with SD a few years ago (Maft-Pro). I was actually gonna set my project up with DSM-link (now its called ECM-Link) but I was honestly swayed by the DS-Map guys and the support on their board. However I refuse to participate in the "Link" bashing over there simply because I tuned cars with it years ago and thought it was the best thing I had ever seen tuning wise as far as ease of use and effectiveness. Maybe I can speak better about this because I have been tuning cars since the days of changing jets, but be glad you have several great, affordable systems to tune with-it wasn't like that few years ago. BTW yea Jackal is "free" but to run it i had to get an Eprom ECU, Wideband,Map sensor, IAT plus the harness and an Ostrich.

 

[belize1334]

I understand that Jackal is very inexpensive to implement and that many people have had great success getting their cars well tuned using it. I just don't understand their implementation of the VE table. Maybe it's my confusion and their actually doing it in a more logical way than it appears to me. I'm gonna see if I can get the people on the DS-Map board to explain it to me and maybe that'll clear things up.

 

[dsm-onster]

I'm sure they will "clear up" how much better it is than link, too. Something about sliders and dumbing down the consumer. Nevermind the records it holds.

 

[Scientist]

I haven't started my car on Jackal yet, but was considering Link for my platform.

I've gone from getting link (when it was in v2.5 and get a GM MAF in blow through) to moving to E-manage Ultimate (SD mode), to considering Link V3 to now going the jackal route.

Most of it was cost for me. my car is a JDM 88 Galant VR4 which came with a Dual board Ecu with no EPROM.

So it was like this for me: Map sensor + iat etc not included in price.
DSMLINK: Source an EPROM ecu + get it socketed + link installed....Most expensive route
E-MAnage: Utilize the ECU i have now, Software I've been familiar with....Cheaper than link
Jackal: Source EPROM, SOcket it, Ostrich + Loggin cable....even cheaper.

I have a bit of experience building VE tables (E-Manage Ultimate Airflow output map) but i was determined to determined to run my car on Map sensor. If a member on this forum didn't screw me over on an EPROM ecu with link already installed I probably would have gone the link route. A friend of mine told me about his experience with jackal. He was doing it with a chip burner and showed me how quickly he gets around to dialing his VE maps consistently every time. He logs a run from the base map and calculates how much his VE map needs to change to reach his target AFR in his fuel map. 2-3 chips later his car is dialed in with repeated target afrs.

I can somewhat understand where Twdorris comes from with the talk of switching between MAF and SD, But that would only matter to me if I was interested in running a Map sensor on my car. Both software packages look rock solid. And coming from a Greddy E-manage and ECU flash world, look to be easier to sort things out.

@Belize1334...I don't see the problems with the VE Table...You only tune ONE of the tables out with jackal which is the SOFT VE to get it to match whatever AFR value you have in the Fuel map. You are reading too much into it

 

[belize1334]

I just want to follow up on my previous statement (scroll up a little and you'll see it). It was not and is not my intention to imply that the guys over at DS-Map have an inherently inferior solution or that they don't know what they're doing. My statement was meant to convey my personal feeling on how such a solution should be implemented and to express concern that things I had heard led me to believe that DS-Map was doing it differently and that perhaps that meant that it wasn't right for me. I don't want anyone to get the impression that I was insulting their system or it's developers. This was not my intent. I am aware that my post came off as highly critical and I apologize. Bashing has no place in a public forum.

 

[99gst_racer]

BTW yea Jackal is "free" but to run it i had to get an Eprom ECU, Wideband,Map sensor, IAT plus the harness and an Ostrich.

Exactly. It's just about a "free" as ECMlink. Both have software you can download for free, and both require you to pay for hardware to make it work. But being that you have to source out your own equipment to use Jackal, that somehow categorizes it as a "free" tuning solution.

 

[Baron4406]

Just go to the DS-Map board and look at the threads. The community there welcomes any question even "dumb" ones. The mods will even real time chat with you if your having problems, its amazing.
BTW Jackal is soon gonna be old news, they are almost finished with Werewolf which is Jackal on steroids.

 

[jrohner]

BTW yea Jackal is "free" but to run it i had to get an Eprom ECU, Wideband,Map sensor, IAT plus the harness and an Ostrich.

If your going to include that stuff into the 'price', you might as well include the price of the laptop pc. Heck why not include the price of the car while you're at it?

If you add that stuff to the price of link, just think of what it 'costs' then. ~~~

If you're going to run SD anyways, the only cost of Jackal is an Ostrich and a logging cable. I bought by Ostrich on ebay for $100 used; can't beat that. Plus the Ostrich can be used on other cars too.

 

[snowborder714]

Let's keep the ECMlink/Jackal debate out of here, please. People can do their own research and make their own decision on which way to go. I hate seeing every tuning thread end up in this direction

 

[knochgoon24]

I like SD. It make my car go zoom.

Seriously. The Evo 8 ecu and my 2g MAF weren't getting along anywhere as near as nicely as I though.

 

[belize1334]

Ok,

This will be my last post on this topic. Mainly, I want to set the record straight. I've just spoken to Nick Sanders who wrote the original code behind the SD calculation in Jackal. I have reviewed his explanation of how SD works in that system and compared it to what the ECMLink SD page has to say and they perfectly consistent. They both determine density from pressure and temperature and then extrapolate the volumetric efficiency by comparing the expected airflow to the actual airflow determined empirically from the AFR reading.

The two systems differ significantly in other regards but they are identically in how the VE is determined and ultimately implemented. They are both built on a solid foundation of thermal physics vis-a-vis the ideal gas law.

 

[knochgoon24]

And that's why I'm confused about why the Evo guys think two 2D tables multiplied together provide a 3D VE table that's "good enough". There were a lot of guys really resistant to the idea.

I've also now put 2,000 miles on my SD setup. The car just rolled past 238,000 miles today.
It's going to get a lot of miles this summer. I drive 25 miles each way to/from work. Plus I have a few nice long road trips planned.

 

[Baron4406]

If your going to include that stuff into the 'price', you might as well include the price of the laptop pc. Heck why not include the price of the car while you're at it?

If you add that stuff to the price of link, just think of what it 'costs' then. ~~~

If you're going to run SD anyways, the only cost of Jackal is an Ostrich and a logging cable. I bought by Ostrich on ebay for $100 used; can't beat that. Plus the Ostrich can be used on other cars too.

Think you took my post the wrong way. I was gonna mention Jackal isnt "free" but still very reasonable compared to what you have to add to the price of the supporting mods. Belize actually did alot of the legwork and made a reasonable conclusion, for all the bashing of Jackal on here it he found out that the way they implement changes in VE are the same....except one is free and the other costs quite a bit more.
After I read my post and your response I actually saw I might have been a little hard on Jackal, well consider you have to tread lightly on this forum if you aren't "linked up".

 

[snooopy365]

I like SD. It make my car go zoom.

Seriously. The Evo 8 ecu and my 2g MAF weren't getting along anywhere as near as nicely as I though.

I accutaly running evo8 ecu and 2G Mas in a 1G car, and it works well.
So what exactly isn`t as nicely as you though it would be?

 

[jrohner]

And that's why I'm confused about why the Evo guys think two 2D tables multiplied together provide a 3D VE table that's "good enough". There were a lot of guys really resistant to the idea.

Yeah, the 2 2D tables suck IMO; it just doesn't work good on a setup like mine -- small turbo running high boost. When I up the boost I have to retune the RPM VE map, as VE goes down a lot with RPM as you up the boost more and more due to high exhaust backpressure. Basically I have to have different RPM VE tables for different boost levels unless I want to fudge the fuel map to get fueling right (which I wouldn't like to do).

 

[the_mork]

I accutaly running evo8 ecu and 2G Mas in a 1G car, and it works well.
So what exactly isn`t as nicely as you though it would be?

It works just fine for the most part, as long as you're just looking for the car to run. The problem comes in when you're trying to dial it in closely. Because MAF differences aren't linear simply changing the MAF scaling gets you close but provides somewhat inconsistent fueling in certain areas. Changing the MAF comp tables can get you closer but the whole thing has to be redone and it is an incredible pain in the ass.

 

[knochgoon24]

I messed with getting the 2g MAF to hit exact values under boost, but it got tired of fussing with it. After switching to SD, it holds a solid 11.5AFR right where I want it. I just couldn't get the MAF to be consistent enough.

The butt dyno also says tip in is better with SD. Spool is also right where I want. In general, it was easier to get SD to work than the 2g MAF.

 

[danl]

The 2d tables work well if you know how to tune them. I'd still prefer 3d but I am using the 2d speed density in both my evo 9 and my 1g dsm. Currently what I am doing is zero out the rpm vs ve table. Then tune the kpa vs load table. Just get the car to drive well from 0-100 load. Then get it to boost well but keep it low, like within 1000 rpm's of when you get full boost. So now you should have the kpa vs load tables tuned from 0-410% load or whatever. At some point in full boost as the RPM's rise you may go lean or rich. Adjust the VE table to account for this. On my setup I start loosing VE at 6000rpm so I will dial out some VE so it won't go rich into redline.

Using this method I have my evo driving better than stock. The DSM is driving better than a DSM has a right to do and it is on 2000cc/min injectors. Runs fine on gas or E85.