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Tec II or SDS efi ??


Guest scca

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Old laptops can be had for $150 and can easily run old DOS version of TEC II software . I have studied the TEC II a fair bit it offers good datalogging useful if operator knows how to interpert the graphs .

 

The fuel and ignition tables can be tuned more over an entire boost range . Howeveer it is a pain in butt to tune . The TEC II has some fancy idle features for big cam engines, and can control a VTEC solenoid or Boost solenoid .

 

For 80% of the people the SDS is all that is needed . The SDS idles super smooth and has good enough air fuel control for a turbo motor .

 

Conditions were I would step up to Tec II or Motech

1. If I was a real serious racer and pushed my motor to the limit.

2. If I had a high compression turbo motor and tried to run on street gas .

4. If I built a huge cam motor that ran crappy on the street with carbs, and I need the sophisticated EFI to make it run and idle half decent .

5. If I had dollar bills growing on my tree in the backyard .

 

Just because it's simple doesn't mean it's a bad thing . For you carbie guys it is way easier to tune than a carb and the results are fantastic, no more it bogs a bit but it's real fast .

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Electromotive is just up the street from me smile.gif Vastly more complicated and expensive but it IS darned capable! I don't know much about the SDS but if it's 9/10ths of what the Electromotive is power-wise and that much cheapersimpler I'd think it would be the smarter way to go. Heck, just look at the cost of SOFTWARE for the TECII!! It's darned awesome software though and the datalogging can really help you tune it (sigh). Got a copy here but I've not yet had time to load it up and check out all the features. Last I saw it years ago it was AWESOME and blew the DFI stuff into the weeds - just the graphing alone was enough for me to lust after it.

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quote:

Originally posted by clint78z:

Old laptops can be had for $150 and can easily run old DOS version of TEC II software .

(snip)

 

Thank you for bringing that up, Clint. You don't have to use a $3000 laptop. Hopefully I won't incur the wrath of the SDS fans, but here goes...

 

I have NEVER seen having to have a laptop as being a disadvantage. On the contrary, having the laptop brings with it the very significant advantage of being able to RECORD DATA while you are tuning. You don't have to guess about whether you were rich or lean at any given point on the fuel map - you can look at the data, and very quickly know where and by how much you need to adjust the fuel map. You just can't do this with the SDS. IMHO, you have to do an awful lot of guessing if you are trying to tune without datalogging.

 

Also, it's very nice to have all of the relevant parameters displayed on-screen at once in a logical manner, instead of having to thumb through the hand controller one parameter at a time until you find the thing that you want.

 

As far as the TEC being 'vastly' more complicated, I just don't buy it. Let's see..

 

The TEC has an 8 x 8 (i.e., 64 points)ignition timing map, based on RPM and MAP. The SDS has to set timing every 250rpm, and also has 64 ignition timing retard settings based on MAP.

 

The TEC has an 8 x 8 fuel delivery table to allow tweaking the basic fuel curve based on rpm and map. The basic fuel curve is set by two parameters (idle and WOT, if you like). The car will run with just these two parameters set, and the fuel table all set to zero.

The SDS has 64 fuel delivery tuning points based on MAP. It also appears to have rpm based fuel points every 250rpm.

 

These are the basic things that you need to tune to get your engine to run, and in each case the SDS has as many or more parameters to tune than the TEC.

 

Granted, there is an 8x8 table for tuning the general purpose output (SDS has a single RPM switchpoint), and an 8x8 for the desired air/fuel ratio for the EGO Feedback (SDS has a single AFR), but you don't have to set any of these to get the car to run, and you can very easily set them to be all the same so it looks like the SDS if that's what you want.

 

The TEC does have more total tuning parameters available than the SDS, but I would argue that the number of parameters that HAVE TO be set to get a decently running engine are about the same, or less. The additional stuff, like being able to tweak your EGO feedback, or control an idle control valve, is just icing on the cake. That stuff won't keep you from getting your car running.

 

Now, I realize that there are probably techniques that can be used to simplify the tuning process for the SDS, and that it's a bit cheaper, but there are techniques that can be used for the TEC, too. And I can't emphasize enough the advantage that comes from being able to datalog.

 

I don't mean to offend anyone. I don't think that the TEC is the be-all end-all of EFI systems, and I do think that the SDS is a capable piece. I just get tired of hearing the TEC get bashed for being 'too complicated', especially since I don't believe that it is.

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i have been investigating aftermarkit efi systems for about 2 years .last spring in san felipe baja i saw tec 11 on race buggys with honda b16 engines or toyota 4ag .i myself dont like it because ecm is with ciols in engine compartment and running in california underhood in a street car insummer it gets hot.the sds is probably good enough for %90 of most uses.i down loaded the sample haltech software to play tune up master but i dont know DOS but i did get to some of it after 2 hours.the fel pro system has a fre sample too.i think most problems come from installation and peoples ability to fabricate harness and solder wires together and route to make it reliable.i am thinking of haltech or sds when i can afford it.

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Guest Anonymous

I don't have a laptop, nor do I want to leave a laptop in my car all the time to be able to adjust the system.

I'm not building a race car on a $50 million budget, I'm building a toy car to race rednecks for money in(or whatever!), and I don't have sunrise to sunset to spend fiddling with overly complex fuel and ignition systems.

A tec2 with a few options and a laptop will add up to more than I paid for my car, and probably more $ than I have in my car total!

 

No thanks, stick with the sds bulk deal please.

 

 

------------------

Morgan

http://z31.com/~morgan/s30

http://carfiche.com

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Yes it was me who bashed the TEC II I admit it and the reason is I still don't fully understand it . After researching things quite a bit between DFI, SDS, TECII . I have read the TEC II manual multiple times and read some tuning articles . What really gets me is the IOT, TOG and Volumetric effeciency tables . That is 3 things just to set the amount of fuel injected correct . In the DFI and SDS you just ask do I want more or less fuel at that rpm and load point . The SDS has a lean rich knob for manual adjustment and then you simply correct it later . Another thing that bothered me is the A/F ratio listed some people say they are setting it for 14.3 at full boost, this doe not make sense to me . Hopefulley you can clear this up for me TimZ, mabey it is easier to do once you get into it .

 

Graphing can be a very good tool in tuning, I have to use Excel to graph my DFI stuff .

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Tim and Clint,

 

you both make excellent points. SDS is not the "equal" of TEC-II and the SDS folks tell you that on their web page. Specifically, there are features, like datalogging, that SDS does not have. On the other hand, folks try to compare the programmability of both and probably conclude the SDS is not as good because it is "Simple". That absolutely was the premise of their design. The "Simple" is in the user interface, not the quality or complexity of the system.

 

Tim, IMO, you are making the classic tech-head mistake. I have several computer engineers that report to me and I have to constantly remind them, berate in some cases, that the average computer user is computer illiterate and should not be expected to understand and use a computer like they (we) do. I believe you are an engineer and the TEC-II internals and knowledge of fuel and ignition systems are second nature to you. On the other hand, how long has James been putzing with his TEC-II and I still do not think he has it down and he is working on his doctorate biggrin.gif

 

Ironically, probably half the folks who have a programmable system, do not have a clue of what to do with it and would be better of with a "set it and forget it" system like JWT. Thats the primary target market for SDS, but again, not to be confused with its capabilities.

 

Bottom line is, most folks need nothing more than a JWT and which programmable system someone chooses should depend on their needs, funds and honest assessment of their ability to understand and take advantage of these systems. These systems are as good as the owner's understanding of fuel and ignition management and ability to tune programatically.

 

I useually do not try to tell folks which system they should choose. What I do say, though, is that as a fromer SDS user who had success, it is a quality system that works. Do your homework and make your decision.

 

------------------

Scottie

71 240GN-Z

http://www.mindspring.com/~vscott911/gnz.html

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Guest Anonymous

Not to throw another wrench in all of this, which I have found very informative, but what about the Wolf EMS system? www.wolfems.com

I like what I see on the web page but must admit I have not gone any further than that.

 

Any experiences?

 

Craig

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Well, I'm afraid I have to agree. I had the DFI system and worked with it for well over a year - had a laptop in the car almost everyday. I'm not a rocket scientist but I'm not stupid either - I just could never get the car quite right. My biggest issue with the DFI was graphing all th edamned data and it's crappy samplig rate (grr). Excel is nice but try graphing things like a 6200RPM input along with a 0-1 volt A/F ratio - doh!

 

TEC II appeals to me because some of it's features like MAF, knock sensor, and it's apparent ability to correct it's fuel maps after you've given it target A/F ratios. Wow, something that learns!

 

The SpeedPro looks cool too - wide band O2, knock sensor (I think), and sequential as an option. The waste fire on the TEC might be nice too BTW.

 

I dunno guys. I want EFI but I don't want to become an engineer. I'm having the SAME issue with my RX7 BTW (sigh). At least we can all support one another here, finding any sort of support for the DFI was hopeless 3 years ago....

 

Heh, at least this time I don't feel quite th epioneer! I'm not going to go EFI just yet so you all will be ahead of me. I look forward to hearing what comes of it smile.gif I've been looking at EFI systems for about 4-5years now and not getting too far. It's nice to have some company at last!

 

P.S. Over on the RX7 forums they're debating the Wolf in the ECU group pretty heavily. It might behoove us to check out some of their postings and what they've learned? http://www.rx7club.com/cgi-bin//Ultimate.cgi?action=intro&BypassCookie=true

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TimZ you did not step on any toes and I hope I did not bash the product you own too badly . Discussions here are great and everyone usually learns more .

 

I think where the SDS exceeds above all other packages is that it actually tells you how to tune your car rather than explaining the features of their system .

 

A good coversation I hope to learn more, for those who don't know TimZ he is very knowledgable and taught me alot about EFI .

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quote:

Originally posted by clint78z:

What really gets me is the IOT, TOG and Volumetric efficiency tables . That is 3 things just to set the amount of fuel injected correct .

 

Well, sort of... I would have to agree that they could have done a much better job of naming their variables. IOT and TOG just don't mean much to the normal person. What they are doing here is setting an 'ideal' baseline fuel delivery function. IOT defines the amount of fuel injected at idle, and TOG defines the amount of fuel at full throttle. The amount of fuel at any throttle opening in between is a straight-line function between these two points.

the engine will run surprisingly well with just these two values set properly, and it's pretty easy to use the datalogging function to do some part-throttle runs to see if you are going rich or lean as the manifold pressure increases. Also, their new software does have a 'wizard' to help you come up with reasonable initial settings.

 

Since no engine is really 'ideal', though, the VE table is there to allow you to fine-tune the fuel delivery for any given RPM/MAP. Again, you can use the datalogging functions to see exactly where you are rich and where you are lean.

 

quote:

In the DFI and SDS you just ask do I want more or less fuel at that rpm and load point . The SDS has a lean rich knob for manual adjustment and then you simply correct it later.

 

Part of my problem here is that I've never tried the SDS, but how do you know what RPM and load point was which? Granted, this is easy enough for part-throttle cruise and low boost where you can hold things steady with the brakes, but at high boost/rpm, things go by really quickly, not to mention the fact that you have to spend a lot of your mental processing load just keeping the car under control. With the TEC, I just start the datalogger, make my run, stop the datalogger, pull over the the side of the road and look at the data.

 

quote:

Another thing that bothered me is the A/F ratio listed some people say they are setting it for 14.3 at full boost, this doe not make sense to me . Hopefully you can clear this up for me TimZ, maybe it is easier to do once you get into it .

 

Well, that doesn't make much sense to me, either. Generally, you want to target a richer mixture at full boost. The rule of thumb for this is ~12.5:1 to 13:1 at full boost, and 14.5-15 at cruise.

Sometimes other values are used, due to inaccuracies of the EGO sensors (i.e., it reads 14.3 when it's actually 12.5)- maybe that's where the 14.3 number came from.

 

Just to reiterate, you don't have to setup the AFR table to get the engine running. I generally don't use the EGO feedback until after I have the VE table dialed in.

 

Anyway, Scottie is probably right about me making the tech-head mistake - my biggest complaint about the TEC is that is isn't capable enough ;P. And he is right in that if someone doesn't have a good understanding of how to read the graphed data, then maybe the datalogging won't do them much good.

 

Just wanted to let you know that there is some support out there for the TEC, also, if you should decide to go that way.

 

------------------

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I am sure I would like the TEC II after a while and I think after a while I would like it after getting used to it . That is a good explaination of the setup of the TEC II, I think I almost understand it cool.gif

 

The SDS has points based on RPM idle to redline you simply enter in values . Then you enter in you numbers for vacuum 0-1bar or whatever sensor you use . From those values it makes a flat 3D grid for a fuel table . This is not ideal but way better than a carburator . The tuning proceedures really walk people through these steps .

 

I hope we are not scaring guys away from EFI, if you take the time to learn the basics of EFI then tuning is way easier than a carburator .

 

So make the correct choice

 

If you are good at concepts and ideas and are good at math and reading graphs and want to spend a little extra for nicer features such as graphing and more tunability TEC II is a good option, be prepared to put your thinking cap on .

 

If you have trouble with alot of number crunching, and would like a nice upgrade that can be tuned in a couple of weekends and you are off and running the SDS is probably the way to go . The system does run remarkabley smooth and will get the job done .

 

I am a little more budget minded being Canadian since my dollar is worth belly button fluff !! I got my DFI system for $450us used, so I must suffer with limited datalogging capabilites .

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