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Thread: Engine selection: new advances V. tried and true

  1. #31
    From a team that has only been around for only a year (and has a limited size), I would recommend using an engine that is not only feasible, but will keep the interest of your team. That may not be the best way to win the competition, but in my opinion it is the best way to get there. I guess that I am with everyone else who says forget having the most power / lightest weight and just build a car that will make it back. Every engine selection has its ups and downs and is arguably the best. In the end it is how well / reliable you build the car, not the engine's weight or horsepower. Last year we used a YFZ-450 because of it's low weight, and we still ended up with a car that weighed 537lbs. Granted it was our first year, but a light engine does not = a light car. This year we are using a 2007 GSXR 600 because of it's tremendous ability to generate horsepower. However, we don't have a single person on the team who has any clue to tune it let alone set it up. In other words, it's about the total package not just the engine alone.

  2. #32
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by John Grego:
    "The engine is just a spacer. If it doesn't work get another one." -Terry Satchel during our debriefing in Detroit in 2006 </div></BLOCKQUOTE>

    I agree on so many levels, with a major one being this is a suspension race, not a horsepower race... and that goes for design competition as well.

    Also, I dont agree completely with the weight comment, i think once you are under 450 lbs or so, it is a case of diminishing returns... (depending on your setup) its all about your whole vehicle package.
    University of Cincinnati
    Bearcat Motorsports
    Graduate Student, Auto Design Advisor

  3. #33
    How bout this. Buy a good 02 system, decent ECM and sensors (and a dyno if you still have money) and then buy an engine with what money you have left over. If it's a Tecumseh, at least it will run real good. Next year you should be able to afford a better engine but you'll already have the stuff you need.
    'engine and turbo guy'
    Cornell 02-03

  4. #34
    Senior Member
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    Sorry jchurch, haven't had much chance to get back to respond to this one.

    Funny how one of the early posts states that the engine selection topic has been done to death - and then the thread goes on to score 30-odd responses and fill a couple of pages. It is like the big red button for FSAE junkies.

    The "competing to win" argument, (or trying to go from 100th to first in one year). Winning is certainly a goal we all aspire to - but more often than not the "every last bit counts" argument is used to justify some extra "design feature" that adds slabs into the development time, blows out the budget, and gives stuff-all points return. Compare the following:

    Team member A: "We are playing to win, and every last bit counts - that's why we need to have a carbon fibre reinforced magnesium intake runner"

    Team member B: "We are playing to win, and every last bit counts - thats why we need to have a kick-arse Cost Report"

    How often do we hear the latter? Hardly ever, (probably because the guys like "B" are usually the quiet ones actually going about getting stuff done). The "B"s are the guys who are carrying your team, they are the ones that deal with all that "boring" stuff that actually makes a difference, and they are the ones you want to keep. And the "A"s are the precious little petals most likely to stuff it all up for you.

    So I've got to say that if a team member doesn't want to hang around because they don't think your design decisions are "sexy" enough - they weren't worth keeping in the first place.

    Cheers to John Grego for chiming in, I hope people have a good long think about the Texas A&M example. The paranoid techno junkies will dream up some convoluted argument that this proves some sort of progression that a supercharged single supercedes a four, and that a twin supercedes them both, and therefore this all justifies that we have to radically change our design. (Believe me, this happens at our uni just like anyone else). But the wise ones will see the proof an A&M's results that it all just doesn't matter a jot. Build a bloody car, drive the damn thing. And make sure that you deal with all your cost reports and stuff on the way.

    I know all this project management talk gets repetitive - but look at the results year after year and you will see that the message just ain't sinking in.

    Cheers all, sorry if any of that seemed blunt.
    Geoff Pearson

    RMIT FSAE 02-04
    Monash FSAE 05
    RMIT FSAE 06-07

    Design it. Build it. Break it.

  5. #35
    FSAE has become a spec racer series.

    That should be a bold enough statement to keep this post going for a couple more pages.

    Here's why. The cars aren't EXACTLY the same, but they are getting pretty close. There are slight differences. Steel chassis versus carbon fiber. Inline 4 vs V-twin vs Single. 13" wheels vs 10" wheels. Yes, the suspension geometry is different, but almost every team runs unequal length upper and lower arms at each corner.

    They are very similar in that they all follow the same 100+ page rule book that has been refined for at least 10 years now. They are single seaters. They all have roughly the same wheelbase and track width. The winning cars all weight less than 500 lbs and make 60-80+ hp.

    New versus tried and true? I don't think it really matters. The key is IF you understand the design and can defend your choice versus other options AND provide both theoretical and physical testing evidence to reinforce your choice.

    If you've been to competition, the judges will likely care more about what you've done to the engine versus which one you have. Has the crank been polished? Kniftedged? Windage tray? Head shaved? Ported? Custom pistons? Lighter connecting rods? Custom camshafts? Slipper clutch? Stock transmission ratios? Electric water pump? Dry sump oiling? Intake design? Exhaust design? 4-1? Dual 2-1? 4-2-1? ECU management? How about selectable maps for dry or wet pavement like the new GSXR1000 which has 3 different power settings? Traction control? How was the engine optimized for use with the rest of the car?

    So, with a spec racing series, who wins? The team with the most knowledgable team members and fastest drivers.

    Who wins an FSAE competition? The team with the most knowledgeable team members and the fastest drivers.
    Dan De Clute-Melancon
    Iowa State FSAE alumni
    Project Manager 03-04
    Engine Team Leader 02-03

  6. #36
    Mechanicaldan, your post makes no sense. You claim this to be a spec series, and then go into several areas of diversity: powertrain, wheel size, tire size, suspension geometry, aero, etc.

    For example, kansas had a 68" wheelbase. Ours was 63". Yes, they both start with a 6, but they are not even close to the same! Would you prefer a team to have a 90 inch wheelbase, and be slow as sh*t, just to be different?

    do you consider Formula 1 a spec series? What about LMP1? I think you're confusing 'technically uninspiring' with 'spec series.'

    It seems that you're unhappy with teams finally beginning to understand how to make a fast car. There IS an optimum design for a given track, and some teams are fairly close to finding it. And we'd all find it a lot quicker if we knew what the endurance course looked like when we were designing our cars. Just because the series is going from 90 to 95% instead of 50 to 75% of optimum doesn't mean it's a spec series.

    The team with the most knowledgeable members and fastest drivers win EVERY series, not just FSAE and spec series.
    "Gute Fahrer haben die Fliegenreste auf den Seitenscheiben."
    --Walter Röhrl

  7. #37
    I second A&M's comment on needing reliability. Like they mentioned you can have the fastest car and not finish endurance and watch it go out the window. Thats what happened to us in California this year. Yes, we would have been able to prevent that tactless "acceptance speech" by the Aggies if we had just had an engine that didn't explode. But thats racing. We have a great design, a great team, and our focus has been on finishing the car early and getting lots of drive time. The drive time really makes the most difference as can be seen by this example. Our car is quite a bit different from the A&M car, but either one is capable of winning. Look at any of the teams that have been in design finals or semi's in that last few years and at any given competition, they could have a chance at winning. I know that a lot of you will bitch and moan about "just because you don't get to semi's doesn't mean you can't win." This is perfectly true, but then you would have to outright smoke everyone else in the dynamic events. Good luck on that.

  8. #38
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by VFR750R:
    How bout this. Buy a good 02 system, decent ECM and sensors (and a dyno if you still have money) and then buy an engine with what money you have left over. If it's a Tecumseh, at least it will run real good. Next year you should be able to afford a better engine but you'll already have the stuff you need. </div></BLOCKQUOTE>

    I think Tecumseh is going belly up, might want to put a Briggs, Kohler, or Honda in the 08 Cornell car instead......
    Mike Duwe
    UWP Alumni

    Former Drivetrain Leader and Team Captain

  9. #39
    First, I apologize for the speech in Califonia. That was pretty much useless. Didn't thank sponsors or SAE or the other teams for coming...sorry.

    moving on, in 2005 we did not make the design semis. We probably would have won the competition because our car was so fast. 1st in accell, 3rd in skidpad, 1st in auto-x, and we were up on Cornell by 25-30 seconds in enduro when we broke. It is definately possible to win without having the most innovative car. That car was very simple with a Yamaha 600, simple suspension, and steel tube chassis. But it was fast. It was ready in the middle of March and we had close to 2 months of drive time in it.

    Practice makes perfect. Wasting weeks of practice to lose a few pounds is not going to help. You will be slower in the long run because your driver doesn't know the car.
    John Grego
    2008 Suspension Lead
    Texas A&M University

  10. #40
    Your definition of 'spec series' means every racing series including demolition derby is a spec series.

    Apparently you don't understand the definition of a spec series. Spec means parts, ie chassis, engine, and/or tires are selected FOR you by the organizing body and built by a third party. This third party has a contract with the organizing body, not the teams, to provide identical parts that teams are not to modify for a resonable cost to those teams. Spec series purpose is to increase closeness of competition by defining the 'box' and restricting development and running cost.

    FSAE does not pick one part we must use, they don't even limit the tire size!!

    The reason we run a YZF600; it has the same frame mounts as a FZR600 which we ran since 95 or something when Nobody ran anything but a 4. That means lots of spare parts, any engine fits in any car, literally dozens of exhaust headers and intakes that are all interchangable on the dyno, testing done years ago still applies, ect ect...

    It could be the shittiest engine out there, but we know so much about it and have so much invested in it, why change. Especailly considering most people agree that engines don't win the competition. I'll agree that it weighs more, but not one time that we've lost the competition has it been because of motor choice.
    'engine and turbo guy'
    Cornell 02-03

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