Tweecer datalogging - necessary?

Discussion in '1994 - 1995 Specific Tech' started by Monsterbishi, Mar 9, 2006.


  1. Monsterbishi

    Monsterbishi Member

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    ok, am just considering buying one of these as a stopgap until we decide what aftermarket ecu to run, and for the life of me, I just can't justify getting a RT model, purely because I consider the datalogging function to be not terribly helpful when I think about it -

    1. There's no knock sensor on the ecu to monitor
    2. IDC/IPW is easy enough to calculate without the need for a log
    3. the factory o2's aren't accurate at all, and tweecer wouldn't support wideband o2's would it?
    4. This leaves MAS/MAF voltage - which also doesn't really need logging

    All our tuning is done on a Dyno anyway, with external sensors - so the logging becomes more or less irrelevant since all the dyno info is stored and printed out for us.

    Is there something I'm missing? We used to datalog our Mitsubishi's all the time, but that was purely because we could monitor the factory knock sensor...
  2. final5-0

    final5-0 Mustang Master

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    Funny thing to me is ...... I can't imagine tuning without it:rlaugh:

    Like most other things, I guess its all about perspective :shrug:

    Here is mine :)

    Say you want 36 degrees for total spark advance and you want it between 2500 to redline. On a stock tune, I can assure you the values you see will be that and more the first time you call for that in the base spark table :bang:

    Datalogging can give you a baseline
    and
    Then give you verification your adjustment was right or wrong compared to that baseline.

    One could use this line of reasoning with other parts of the tune :D

    Where I find the dl feature is a godsend is in diagnosing and solving drivability issues. Tuning to me is way more than WOT on a dyno and I guess here is a good example.

    I'll attempt to answer your four Q's

    1) I don't see the relevance to the Q so perhaps you could fill me in

    2) Don't have a clue what you're talking about ... clue me in please

    3) You can install a bung for the wb and input it to the Tweecer. Nice feature as it now becomes 1 in 16 possible options to data log and it would then be in sync with the other 15 data categories.

    4) I don't even know how to respond to this Q as the maf transfer is the most critical part of the tune. It is made up of thirty points. Each point has a maf voltage value that represents KgHr air flow. To know the maf voltage is useful IMHO.

    I've seen your other posts on this forum and I know you have a good deal of import experience so I feel you and I are just looking at this from different directions.

    The PMS peeps say they don't need datalogging as well.

    In no way am I trying to say datalogging is a must :nono:
    BUT
    For me, I like having the data and find it very useful :nice:

    It works for me :D

    Almsot forgot :)

    With datalogging, you can get your tune to 98% without the need for a dyno.

    Grady
  3. Monsterbishi

    Monsterbishi Member

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    Hmm, aux inputs would be handy, would you know whether they're capable of measuring a knock sensor output, variable resistance, etc - or is it just voltage output based sensors? sorry about the acronyms, I assumed they would be the same across brands :)

    IDC(Injector Duty Cycle)
    IPW(Injector Pulse Width)

    When tuning on a modified factory ecu, we usually only monitor one aspect of the MAF frequency output, which is when it over-runs (hit's 5v) once at that point it's usually time to upgrade to a bigger maf and adjust the scaling across the board to suit - curious to see a 30-point spread on a factory ecu too.

    Generally when tuning, the knock sensor is one of the most important sensors to us, since in all honesty, I'm appalled every time I see a post on here about people bumping the timing up and only backing it off once audible detonation is heard - once audible, that means it's right at the bad end of the stick as it were.

    Spark advance isin't something we'd normally datalog either, since the tables are fixed, generally we like to export them into something like Excel so 3d graphing is easier, make any changes we want, then import them back into whatever we're using.

    Cheers for your reply, I may just throw the extra $ in for a RT model then, heh, car hasn't even arrived yet and I'm already having a ball :)
  4. mricci

    mricci Member

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    The only tuning device i have heard of for not a ton of money with a knock sensor is the megasquirt, but it just seems like way to much work for me to see why someone would want a megasquirt over a tweecer or pms.
  5. blksn955.o

    blksn955.o Founding Member

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    With the extreme importance of our eec needing the best/closest MAF transfer the logging lets you see the data to make those fine adj. Without it how would you know for sure how far off you were? SInce the factory has an 3+/- % of error that is going to be realy hard to get perfect without seeing the data.

    yes the o2's are a narrow band but since we can see them and use them in regards to the KAMFR (Keep Alive Memory Fuel Reference) so make sure things are close...preaty important.

    Knock sensors...we dont even have them and most cars that do have them are a PITFA. Think about the F-bodies that once they go...all sorts of poor performance happens. In reality IMHO the knock sensors goes out the door when you start looking at eng. harmonics loud exh. larger exh. pulses, superchargers, solid valvetrains that all can mess with the knock sensors.

    You can calc. the inj. DC and PW based on what size inj. it is...but what about the engine's needs and how the eec is comanding them along with the inj. slopes...its not a straightforward thing again you will need the data to see what your combo needs.

    Simply put the R/T lets you see the changes and look at that collected data you tune from that data for the engines needs. To tune without it with a tweecer is guesswork...even if it is based in solid math you have no way to know that the math is correct.
  6. Monsterbishi

    Monsterbishi Member

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    I could be wrong here, since the car isin't even in my hands yet, but the factory ecu does have its limitations with regards to the limits it can handle in the rpm department, something which a pms/tweecer wouldn't be able to remedy.

    For what it is, the megasquirt offers all the essential features for a budget hi-po system, once we ditch the aode, we'll be going motec, since that's what I'm familiar with from our old cars.
  7. blksn955.o

    blksn955.o Founding Member

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    P.S. the 94-95 eec is load based and bases that load on the MAF. The reason the MAF is so important is with timing and other thing it can put you in a diff. table and if you didnt know to get the transfer (and sea-lev. load scaling correct) you would and could be running in circles wondering why spark was messed up.

    fixed spark tables? do you normaly not have access to them, have the spark set at a max "locked out" setting all the time, or what?

    the 94-95 spark tables are sad stock 26* total timing, SSSSSLLLLLOOOOOWWWW advance, and a good thing to have access to tune.
  8. Monsterbishi

    Monsterbishi Member

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    We usually bin any narrow band o2's in the cars we build - they're only any use for light-throttle cruise tuning, which is the complete opposite of why we open the hood in the first place :)

    Knock sensors are your friend, it's all about where you position the sensor(very important), what freq. spread it responds to, and how smart the ecu is, most top-shelf ecu's can easily determine the difference between knock and noise, as it were since engine noise always follows a repetitive pattern.
  9. blksn955.o

    blksn955.o Founding Member

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    what kind of setup????

    sounds preaty nuts....several tweecer users have turbos, turbo strokers, strokers, turbo strokers that pass CA smog....if your new to the whole tweecer game (from your name guessing a DSM type background) you may be thinking alittle to CRAZY with the need for a standalone system....I am not saying you WILL NOT NEED it. Just the ford eec has its limits but is also preaty good.
  10. Monsterbishi

    Monsterbishi Member

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    So only 16 degree's advance beyond the base? Yikes, our Mirage was running 37 degree's of advance@8000rpm/19psi - no wonder the 5.0 only makes 35hp/litre

    This is all good info, one of these days I'll remember to buy another cartridge for our printer so I can store it...
  11. blksn955.o

    blksn955.o Founding Member

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    agree 100% but it can realy help with drivability issues if you dont have a WB...most tweecer users have a WB or plan on getting one and use it for WOT tuning and to confirm that commanded A/F. Once the load gets to WOT narrows are just along for the ride:rlaugh:

    on a good setup yes knock sensors are good...just most of the setups do preaty well without them. I wanna hear the details of this thing....it sounds NICE, or at least one fun toy.
  12. blksn955.o

    blksn955.o Founding Member

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    It should still be here...just do a search under you screen name if you want to come back to it.

    that and search under final5-0's name...he is preaty much the yoda of the 94-95 eec stuff.
  13. Monsterbishi

    Monsterbishi Member

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    At this point we're looking at going to around a NA build, 10:1 compression, and a much higher rev-limit, I'm still getting my head round a lot of the terminology used with these engines, like with cams, heads, etc we're accustomed to buying based on spec, lift, duration, etc - where a lot of aftermarket cams I see mentioned around here lack that info. And your cylinder heads selection is huge, for us, porting stockers is pretty much the only approach we've ever done.

    Yeah, DSM's (Well, we just call them Mitsubishi's over here) is pretty much all I've done for the last 6-7 years, our last car was a '95 4wd Colt sedan w/400whp

    A lot of what we'll be doing to the car will be based on the tuning used on what we call 'V8 Supercars' europe call them 'V8 Touring Cars/TOCA' so single exhaust too :)
  14. blksn955.o

    blksn955.o Founding Member

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    I just noticed your from NEW Z. :eek: .

    one thing you may want to look at with the build...I am sure your not going with a stock production block or at least hope not. High rpm's (like reg. 7k+ rpm) or at or over 500hp will kill a factory production block. Makes it nice to pull the two halves and see the expensice inside:D .

    10:1 comp is not that much...I am running 10.5+ and a power band of around the stock rev. limit of 5,800-6k. A 94-95 eec will let the car run past the tables entry points its just there is no more fine adj. past that. I believe the tables are "locked" but repeat what was given from say 6250 or so till 16,000 so if you want a total timing of 37 from 3k to 7k it is possible but you cannot run say 35* at 3k-6k and then from 6500-7k run 37.
  15. blksn955.o

    blksn955.o Founding Member

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    what do you use for single...3.5-4in tube? or just run a turbo downpipe and call it a single exh.:D


    My vote would be a single or twin turbo mustang....lots lots lots of power and you dont have to rev it to 7-8k.
  16. Monsterbishi

    Monsterbishi Member

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    We're not fussed about whether the stock block lets go, since ultimately it's being binned in favour of a ford motor that you folk wouldn't be familiar with, which is the 4.0 turbo motor from a Australian BA Ford Falcon XR6T - that's another story though.

    We're aiming for 400whp without forced induction, if we can't do it on a 10:1 setup, then we'll just keep going up until we do, the key is shifting the power up to higher in the rev range, and making the power spread wider - this build is a complete diversion for us, we've come from a Drag racing background, using Japanese 4wd turbo cars:

    [​IMG]
    http://memimage.cardomain.net/member_images/9/web/321000-321999/321156_43_full.jpg

    So switching to a american rwd NA car which we're building to go round corners - is about as much as a change as I could handle :)
  17. Monsterbishi

    Monsterbishi Member

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    Turbo'ing it would be far too easy for us, this project is all about stepping out of the comfort zone :)

    We're going to start with a single 3", and we'll let the dyno show us if bigger is better...
  18. blksn955.o

    blksn955.o Founding Member

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    a stroker 331 or 347 with some good afr or TFS heads with a matched intake and cam should be 400rwhp N/A without revin it to the moon. If you wanna go bigger a 351 based storker like a 393-4xx will be a monster.

    sounds like a cool project.

    one site I would say go search some combos would be www.hardcore50.com you may like to see what some people are running for setups.
  19. blksn955.o

    blksn955.o Founding Member

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    Also look at a screen name called Killercanary (sp?).

    he has gone 12.0x with a factory stock shortblock AFR heads, FTI cam, elb. intake, some other stuff, susp. and in a 94-95 vert. You dont have to rev. the motor to 7-8k just hook what you have, and have a good combo.
  20. final5-0

    final5-0 Mustang Master

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    I had to pick up a friend at the airport so I cut my reply kinda short. I figured out the IDC & IPW thing during the drive. :)

    After reading the posts between you and Greg I have a better idea from where your coming from and what you wanna do.

    I can see how for a dedicated track car, the datalogging might be as useful since you got other options as you talked about.

    The typical street or weekend strip car owner is the perspective I have with the Tweecer's use.

    The Tweecer is not perfect but so far, it has been a tool that has allowed me to:

    Gather data
    Tune for drivability
    Tune for WOT

    I like not having to depend on a dyno or someone else for my tune.

    Good Luck with the new Stang and your project :D

    Grady

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