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Thread: Need help understanding VW classifications

  1. #1
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    Default Need help understanding VW classifications

    Since my attempted threadjack elsewhere fell on deaf ears, I would like to know if anyone can help me understand the following:

    Why are the following cars which will gain power from the ECU allowance classed at a lower weight per HP than similar cars that will NOT gain power from the ECU allowance?

    The Golf IV is: 20.4 lbs/hp in STOCK form at spec weight
    The Golf III is: 20.4 lbs/hp in STOCK form at spec weight
    The Golf II is: 21.7 lbs/hp in STOCK form at spec weight
    The Golf I is: 23.1 lbs/hp in STOCK form at spec weight

    Doesn't the above seem bass ackwards?

    If all of these cars were classed using the same process, how did the older/lower tech/fixed engine management cars end up with worse weight/hp numbers than the newer cross flow headed/ ECU enhanced cars?

    Assuming CIS single side headed cars could make the same power as the later cars, is there a logical reason why, at a minimum, all of these cars are not spec'd at the same 23.1 lbs/hp?

    Shouldn't the cars that can take advantage of the open ECU be xx percent heavier per stock hp than carb and CIS cars that can't?

    The better I can understand the process, the fewer letters I'll have to write!
    Eddie
    ex RX3 and GTI driver
    "Don't RallyCross what you can't afford to Road Race" - swiped from YH and twisted for me
    "I have heard that any landing you can walk away from is a 'good' landing. I bet this applies to flying airplanes as well." - E.J.

  2. #2
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    There's no way you'll get a Mk4 down to 2350 so its a moot point anyway.

  3. #3
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    I'll say the same thing here then.

    I do think something doesn't fit in the classifications. However I also think you will see more gains on the Rabbit than you realize. Dump the toilet bowl exhaust manifold for a Techtonics header. Bump the compression to 9:1 (it is probably around 8ish now, despite a claimed 8.5), go to a dyno and get the fueling right.

    Why will you see more gains?
    .5 is a higher % increase in compression ratio, and increasing compression ratio has diminishing returns as the starting point gets higher. You will get more gain here than the other cars.

    The exhaust manifold on your car was also on the early Golfs. Simply changing to a dual outlet gains 5hp. This means you may see up to an additional 5hp from a header than a Golf with dual outlet (that's more than 5% of stock right there).

    Electronic fuel injection does not make extra hp magically appear. The newer two cars have a cleaner airflow path at the MAF, but with stock throttle bodies, intake manifolds and valves is that even a restriction? (I really don't know this). If you take steps to adjust the fueling of your CIS for optimum power on a dyno - this will make more improvement than almost anything else. More than once I have seen 15-20hp gains at high rpm points simply by fixing the factory lean setup (although this was on CIS-E cars - same pricipals apply, just a differnt method to adjust fuel).

    If I can put together a 25% gain on my motor, I do expect that you could extract a 30% gain out of yours - however it is one thing to do the math on a keyboard, and another to acheive it, maybe I am off base.

    I hope to have a better idea of what a well built A1 1.8 can do in the next month or so.
    Chris Schaafsma
    Golf 2 HProd

    AMT Racing Engines - DIYAutoTune.com

  4. #4
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    Chris,

    Comp is 8.9:1, Techtonics header, the cylinder head was prepped to the edge of IT rules (by Techtonics (they used to offer that service)), the cam is on the strong side of the mfr spec'd tolerances. Multiple exhaust approaches were dyno'd before the current one was settled on.

    The engine is a top tier IT build, which adds to the frustration of seeing the later cars run away.
    Eddie
    ex RX3 and GTI driver
    "Don't RallyCross what you can't afford to Road Race" - swiped from YH and twisted for me
    "I have heard that any landing you can walk away from is a 'good' landing. I bet this applies to flying airplanes as well." - E.J.

  5. #5
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    If you'd send me dyno sheets with air/fuel data, it's more information for the ITAC to put into the mix as we try to grow our understanding of how the pieces all fit together.

    K

  6. #6
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    Default IMHO open ecu is not worth much

    I think you over estimate what the open ECU wil do.... Most of us have already reprogrammed chips and have been running them... So 95% of the gain that is avaible has already been taken advantage of.
    The restriction for the newer cars is air flow related and not fuel. An open ECU will not gain you more air flow just better control of the amount of fuel added to optimize burn.... which you can already do with a re-programmed chip.
    But getting an extra 5% is what some people will do.

    Just my humble opinion - I am also not an expert at engine managment.

    B
    Beran Peter
    ITB #0 NER
    VW Golf

  7. #7
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    Quote Originally Posted by Knestis View Post
    If you'd send me dyno sheets with air/fuel data, it's more information for the ITAC to put into the mix as we try to grow our understanding of how the pieces all fit together.

    K
    I've lost them, but I will be going back for some tuning with a wideband, and once I've got a new sheet, I'll get it to you.

    BTW - Thank you for your work in this matter.
    Eddie
    ex RX3 and GTI driver
    "Don't RallyCross what you can't afford to Road Race" - swiped from YH and twisted for me
    "I have heard that any landing you can walk away from is a 'good' landing. I bet this applies to flying airplanes as well." - E.J.

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    Quote Originally Posted by Beran View Post
    I think you over estimate what the open ECU wil do.... Most of us have already reprogrammed chips and have been running them... So 95% of the gain that is avaible has already been taken advantage of.
    The restriction for the newer cars is air flow related and not fuel. An open ECU will not gain you more air flow just better control of the amount of fuel added to optimize burn.... which you can already do with a re-programmed chip.
    But getting an extra 5% is what some people will do.

    Just my humble opinion - I am also not an expert at engine managment.

    B
    OK, so let's assume, for the sake of argument, that the net advantage for a cross flow head is zero. Let's also assume that the net advantage of ECU tuning vs. CIS tuning is zero. Should the starting point be this out of whack?

    The Golf IV is: 20.4 lbs/hp in STOCK form at spec weight
    The Golf III is: 20.4 lbs/hp in STOCK form at spec weight
    The Golf II is: 21.7 lbs/hp in STOCK form at spec weight
    The Golf I is: 23.1 lbs/hp in STOCK form at spec weight

    To use your Golf III as a reference, your starting out with a 13% better power to weight ratio than the Golf I. Now I realize that my 25 year old Golf I has superior handling, superior braking, stiffer chassis, better aero, better head flow, and better injection, but do you need that much of a head start on the power?
    Eddie
    ex RX3 and GTI driver
    "Don't RallyCross what you can't afford to Road Race" - swiped from YH and twisted for me
    "I have heard that any landing you can walk away from is a 'good' landing. I bet this applies to flying airplanes as well." - E.J.

  9. #9
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    It's part of the academic conversation rather than an excuse or rationale for how things are, but remember that additional mass has to be accelerated laterally, too.

    What you need to do, Eddie is distill your bigger question down to a specific request to the Comp Board, re: the MkI GTI. I'd recommend it be in terms of re-examining the assumptions and calculations used to define its race weight, or something along those lines. On-track performance is immaterial so you can streamline your case.

    The ITAC can't simply "un-whack things."

    K

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    Quote Originally Posted by Knestis View Post
    It's part of the academic conversation rather than an excuse or rationale for how things are, but remember that additional mass has to be accelerated laterally, too.

    What you need to do, Eddie is distill your bigger question down to a specific request to the Comp Board, re: the MkI GTI. I'd recommend it be in terms of re-examining the assumptions and calculations used to define its race weight, or something along those lines. On-track performance is immaterial so you can streamline your case.

    The ITAC can't simply "un-whack things."

    K
    Therein lies my problem. The car makes weight, when stone cold empty of fuel (and fuel starving in the corners- I need to address that ), but as a 240lb driver, it takes a LOT of effort to do it. I'd ask for a weight break for the MKI, but I couldn't use it, so no point in trying to make that happen.

    The other option is to ask that weight be added to the later cars, and I really don't won't to screw my VW brethren who are having a tough enough time with some of the other makes they are facing.

    My pursuit here has not been so much to "un-whack things" as it has been to illustrate how important it is that any new ITAC philosophies must be applied equally. I simply want to know what the ITAC was thinking when they went to the effort to lighten the MKI, but not enough to keep it on par with the MKIII and MKIV.
    Eddie
    ex RX3 and GTI driver
    "Don't RallyCross what you can't afford to Road Race" - swiped from YH and twisted for me
    "I have heard that any landing you can walk away from is a 'good' landing. I bet this applies to flying airplanes as well." - E.J.

  11. #11

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    How about moving the Rabbit to ''C'? Haven't I asked this before? Is it worth a letter?

    JimW
    Greensboro, NC
    Jim Wray
    #4 ITB Wraycer Wrabbit
    Greensboro, NC

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    Eddie,

    If you were allowed, you can get more weight out of the car.

    I could run my Golf 2 at 2180 with about 5 minutes of effort.

    I could run it at 2130 with about an hour of effort.

    If I needed to, I think I could get it down to 2080 within a few weeks.

    Granted I happen to be that 180lb driver they wrote the rules for, but the point is the weight is there to come out of these cars. For reference, the stock curb weight is 2350ish for the Golf 2, add the driver in and that is 2530.

    This is why I am not convinced that the Golf 4 cannot make weight. Stock curb weight is 2750ish. You need to get 580 out to hit weight. Tall order, but there is a lot more insulation, sound deadening, heavier window regulators, heavier windows, heavier door panels, heavier stereo system, full size spare tire, air bags, larger cooling fan, standard AC, yadda yadda yadda. It would take an all out - strip the undercoating - type effort, so there won't be many that get there, but I would rather shoot for that in B than ballast up for C myself.
    Chris Schaafsma
    Golf 2 HProd

    AMT Racing Engines - DIYAutoTune.com

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    Boy I am kind of diggin this thread.. keep in mind whatever goes for the MK1 GTI also goes for the MK1 Scirocco!!

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    Quote Originally Posted by JimW337 View Post
    How about moving the Rabbit to ''C'? Haven't I asked this before? Is it worth a letter?

    JimW
    Greensboro, NC
    At its current weight, the car is an overdog in C.

    Here I go advocating dual classifications again...
    Eddie
    ex RX3 and GTI driver
    "Don't RallyCross what you can't afford to Road Race" - swiped from YH and twisted for me
    "I have heard that any landing you can walk away from is a 'good' landing. I bet this applies to flying airplanes as well." - E.J.

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    Quote Originally Posted by shwah View Post
    Eddie,

    If you were allowed, you can get more weight out of the car.
    I actually know a MKI driver who had his car re-caged last year to get the car to 2080. It's that hard to get the car to 2080 with a 240lb driver.

    To get the car down to the 20.4lbs/stock HP that the MKIII and MKIV enjoy, the spec would be 1836.

    To get the car down to the 21.7lbs/stock HP the the MKII is at, the spec would be 1953.

    I don't see getting to either of those without resorting to removing the washer bottle
    Eddie
    ex RX3 and GTI driver
    "Don't RallyCross what you can't afford to Road Race" - swiped from YH and twisted for me
    "I have heard that any landing you can walk away from is a 'good' landing. I bet this applies to flying airplanes as well." - E.J.

  16. #16
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    Because we do the weight/power math based on post-IT-improvement power, the differences between generations of "theoretical" VWs are smaller than the values you illustrate, Eddie.

    Policies and practices don't really allow you to ask for less weight on the MkI or more weight on the MkII. You can ask that we "run it through the process," but that's about it. Problem is, the "can it reach minimum weight?" part of the process kind of presumes that "average" size driver, which you already recognize is problematic.

    We've had some spirited conversations (in the ITAC and more broadly) regarding philosophies about minimum weights but general practice seems to be to disregard how HARD it is to get to minimum weight, if it looks like it's doable. Some cars struggle to get to their process weight, some are right on without ballast, and some have to add weight. We get complaints from two of these three groups but as long as we have to hit the class guidelines we've got, this is how it will be.

    >> At its current weight, the car is an overdog in C.

    FWIW, the difference between an ITB MkI Golf and a theoretical ITC version of the same thing - with all pertinent assumptions being equal - is about 200#. Remember that if someone requests a review and their Borgward or whatever lands in a lower class, it's unlikely that it will be at the same weight as it ran the higher class.

    K

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    There's no way you'll get a Mk4 down to 2350 so its a moot point anyway.
    It's not a moot point or at least it certainly wasn't when discussing how the MR2 can't get down to the spec'd minimum weight.
    Dave Gran
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    Quote Originally Posted by Knestis View Post
    Because we do the weight/power math based on post-IT-improvement power, the differences between generations of "theoretical" VWs are smaller than the values you illustrate, Eddie.

    Policies and practices don't really allow you to ask for less weight on the MkI or more weight on the MkII. You can ask that we "run it through the process," but that's about it. Problem is, the "can it reach minimum weight?" part of the process kind of presumes that "average" size driver, which you already recognize is problematic.

    We've had some spirited conversations (in the ITAC and more broadly) regarding philosophies about minimum weights but general practice seems to be to disregard how HARD it is to get to minimum weight, if it looks like it's doable. Some cars struggle to get to their process weight, some are right on without ballast, and some have to add weight. We get complaints from two of these three groups but as long as we have to hit the class guidelines we've got, this is how it will be.

    >> At its current weight, the car is an overdog in C.

    FWIW, the difference between an ITB MkI Golf and a theoretical ITC version of the same thing - with all pertinent assumptions being equal - is about 200#. Remember that if someone requests a review and their Borgward or whatever lands in a lower class, it's unlikely that it will be at the same weight as it ran the higher class.

    K
    So here's the letter I'm thinking about writing:

    Please run all vehicles classed in IT through "the process". Because of the volume of work involved, I would suggest setting a completion date of Jan. 1, 2010.


    All in favor?
    Eddie
    ex RX3 and GTI driver
    "Don't RallyCross what you can't afford to Road Race" - swiped from YH and twisted for me
    "I have heard that any landing you can walk away from is a 'good' landing. I bet this applies to flying airplanes as well." - E.J.

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    Quote Originally Posted by BlueStreak View Post
    So here's the letter I'm thinking about writing:

    Please run all vehicles classed in IT through "the process". Because of the volume of work involved, I would suggest setting a completion date of Jan. 1, 2010.


    All in favor?
    Problem is, that was supposed to have been done 2-3 years ago. It's what's been referred to as "the great realignment". It's when some cars were moved and others had their weights adjusted. IIRC, anything that was w/in 100# of it's new 'process weight' was left unchanged. But, as Chris (chois) has pointed out, you've created the situation where you've now got a 200# 'envelope', centered around the 'true' process weight. In other words, you've got cars that can be 100# heavy, and others than can be 100# light.

    As far as writing the letter, why not? Others have done it. In light of the recent Protege classification, I don't know how a car w/ the same physical characteristics as a Rabbit GTI could be considered anything but a poster child ITC car.

    Quote Originally Posted by Knestis View Post
    Because we do the weight/power math based on post-IT-improvement power, the differences between generations of "theoretical" VWs are smaller than the values you illustrate, Eddie.
    Yes Kirk, but it doesn't matter if you use stock power or "IT power", you still have real differences (see my earlier analysis).


    We've had some spirited conversations (in the ITAC and more broadly) regarding philosophies about minimum weights but general practice seems to be to disregard how HARD it is to get to minimum weight, if it looks like it's doable. Some cars struggle to get to their process weight, some are right on without ballast, and some have to add weight. We get complaints from two of these three groups but as long as we have to hit the class guidelines we've got, this is how it will be.
    That's funny Kirk, from the thread about the Protege, that was put out as one of the main reasons why it went to C and not B, because it was felt that it couldn't make weight. That's probably the largest subjective factor in the whole thing. Without actually building a car, just how much can you get out of one. You couldn't get it out of the New Beetle, but you can get it out of the Mk IV Golf (when they have curb weights that are ~60# apart). You can get 700#+ out of one (Mk IV Golf), but can't get <400# out of another (Protege).

    >> At its current weight, the car is an overdog in C.

    FWIW, the difference between an ITB MkI Golf and a theoretical ITC version of the same thing - with all pertinent assumptions being equal - is about 200#. Remember that if someone requests a review and their Borgward or whatever lands in a lower class, it's unlikely that it will be at the same weight as it ran the higher class.

    K
    Except that's what happened w/ the Mk III Golf, and it then became the new standard.

    Couple of interesting things about the VWs, which I'm not sure exist anywhere else in IT.

    1) You have 4 generations of one car running in the same class.
    2) You have 2 models that are built on the same chassis, w/ the same engine/driveline running in different classes.

    Any other cars like this in IT?

  20. #20
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    Quote Originally Posted by Bill Miller View Post
    Problem is, that was supposed to have been done 2-3 years ago. It's what's been referred to as "the great realignment". It's when some cars were moved and others had their weights adjusted. IIRC, anything that was w/in 100# of it's new 'process weight' was left unchanged. But, as Chris (chois) has pointed out, you've created the situation where you've now got a 200# 'envelope', centered around the 'true' process weight. In other words, you've got cars that can be 100# heavy, and others than can be 100# light.
    You're kidding, right? You mean time and energy was taken to lay all these cars out in one process, but if a car was "close enough", it was left alone? Anyone in the know on this rationale, please respond. At first glance I find this disturbing.

    If we have a "process", and we intend to use it, I don't for the life of me understand why it's not applied across the board. It would seem to me that even if the "process" only suggested a 10lb weight change, we make the 10lb weight change. Why wouldn't you? What am I missing?

    Either we trust the "process" or we don't - which is it?

    It's a rulebook, not a marriage, you're not stuck with it forever. Trust the "process" and see what happens. If, after a season, the letters start rolling in that we have ruined IT, change the rules back and wait for the next great suggestion.
    Eddie
    ex RX3 and GTI driver
    "Don't RallyCross what you can't afford to Road Race" - swiped from YH and twisted for me
    "I have heard that any landing you can walk away from is a 'good' landing. I bet this applies to flying airplanes as well." - E.J.

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