+ Reply to Thread
Page 1 of 5 1 2 3 ... LastLast
Results 1 to 10 of 50

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

  1. #1
    Ok, I know some of the points I'm about to mention have been discussed in various threads in the forum, but I don't think anyone has taken this angle on it yet. I've been working with Oklahoma State's SAE team for about three years now (yes, we still have one...we just never seem to make competition.) We've always had a few members that stick with the team through each year, but this year we're incorporating it into OSU's Capstone design class. So, herein lies our problem:

    We've been debating a good deal on the various engine selections that FSAE teams now have at their disposal. The experienced team members want to run with something we'll be at least slightly familiar with, while the Capstone members that haven't yet touched the project support more drastic changes to the car as a whole. For the most part, our discussion has involved the Honda F4i, the Yamaha FZ6, and (surprise) the Aprilia SXV 550.

    By my judgement, our car is about due for a powerplant change since we've never deviated from the Honda powerplant. But, as always, our budget is extremely limited which by my reckoning (unless the stars align and a miracle occurs) rules out the Aprilia...So, I'm thinking the FZ6 powerplant would probably give us the most bang for our buck. We also know (vaguely) what we can expect from the FZ6 in terms of load bearing characteristics to the frame, since it's block appears similar to the layout of the F4i..

    Anyone who wants to weigh in on this would be much appreciated; I know Texas A&M has been successful with both of these engines. Do any of the A&M guys have a preference, and why? I know the FZ spec yamaha engine claims to stick the powerband right where we need it due to the modified cam profile, but does it live up to its claims? Thanks in advance, everyone.

  2. #2
    Ok, I know some of the points I'm about to mention have been discussed in various threads in the forum, but I don't think anyone has taken this angle on it yet. I've been working with Oklahoma State's SAE team for about three years now (yes, we still have one...we just never seem to make competition.) We've always had a few members that stick with the team through each year, but this year we're incorporating it into OSU's Capstone design class. So, herein lies our problem:

    We've been debating a good deal on the various engine selections that FSAE teams now have at their disposal. The experienced team members want to run with something we'll be at least slightly familiar with, while the Capstone members that haven't yet touched the project support more drastic changes to the car as a whole. For the most part, our discussion has involved the Honda F4i, the Yamaha FZ6, and (surprise) the Aprilia SXV 550.

    By my judgement, our car is about due for a powerplant change since we've never deviated from the Honda powerplant. But, as always, our budget is extremely limited which by my reckoning (unless the stars align and a miracle occurs) rules out the Aprilia...So, I'm thinking the FZ6 powerplant would probably give us the most bang for our buck. We also know (vaguely) what we can expect from the FZ6 in terms of load bearing characteristics to the frame, since it's block appears similar to the layout of the F4i..

    Anyone who wants to weigh in on this would be much appreciated; I know Texas A&M has been successful with both of these engines. Do any of the A&M guys have a preference, and why? I know the FZ spec yamaha engine claims to stick the powerband right where we need it due to the modified cam profile, but does it live up to its claims? Thanks in advance, everyone.

  3. #3
    Another engine debate thread? If you knew there were ones out there why did you bother to start another one?
    Mike Duwe
    UWP Alumni

    Former Drivetrain Leader and Team Captain

  4. #4
    Because the engine debate threads I've found and read don't really seem to focus on what I've mentioned here; they all have a lot of commentary and speculation on who thinks the SXV might be cool to run and why, but there's little real comparison going on...and the other threads are getting so long that they're getting off topic, so I figured a fresh start might be in order.

    Also, there's little discussion on the other qualities of the engines in question; looking at the specs on the SXV, it's easy to see why it's a great FSAE engine. It's half the weight of the I-4's, and produces a comparable yet much more consistent torque curve in its stock form. I haven't yet seen anyone address anything else about the engine, like its ability to be used as a structural member in the frame.
    I was just interested to see if anyone had anything to say on how the engine by itself affected the system as a whole.

  5. #5
    Senior Member
    Join Date
    Jun 2003
    Location
    Melbourne Australia
    Posts
    762
    Hi all,

    I've been known to rattle on about engine selction till the cows come home - but won't bore you with my usual rants. I am assuming you are running the F4i currently? I might have read between the lines there.

    My opinions:
    FZ6 vs. F4i
    To me that sounds like difference for the sake of difference. There is no real design revelation there, you are swapping one four cyl engine for another - the end results will differ so minimally it is not worthwhile. So you may be considering throwing out all your existing team knowledge in running the F4i, and starting a new development plan on an FZ6 that might one day, with time and money, get you the same results as you had with the F4i. Now I love my Yamahas, but unless you had some other motives (like having to pay for F4i's vs getting free FZ's), then I think you are just shuffling deckchairs.

    Aprilia: Sounds like a great motor on paper, and I think has a lot of potential. You need to weigh that up against potential reliability issues on an unproven engine. Honestly, FSAE is won and lost on good preparation and reliability, and if you look a the results you will see that most teams are have a reliability and management problem rather than a performance problem.

    If you haven't made it to comp yet, then focus on your management processes. There is no magic in the car itself - other than if you make a change of direction, it is going to distract you even more from getting the base systems in place. Any of the engines mentioned - Aprilia, an F4i, an FZ6, whatever, is capable of scoring 800 points easily and consistently. Once you have got there, that is when you can seriously start having good reasoned arguments about which one might suit your future development.

    Beware of new team members. They are invariably the ones who both make the most noise about wanting changes, and have the least understanding of why you shouldn't.

    Cheers all
    Geoff Pearson

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

    Design it. Build it. Break it.

  6. #6
    Those were exactly my sentiments on the Aprilia; but if that terrifying milky oil could be avoided by keeping an extra seal handy, then I'd definitely have a few seals on hand just in case. Waiting for parts while you're racing is never a pleasant experience.

    On the switch between the 4 cyl's, we've been considering the FZ6 as opposed to the F4i 1)Because it claims to bring in its maximum torque way before the F4i
    2)It's in our price range
    and, 3) This is our first year to actually have enough manpower to reasonably do a full redesign on our frame/suspension setup; we've been modifying the current model VERY lightly each year since 2004 (essentially fixing known reliability issues), and we'd really like to try to expand on our current design. The way I look at it, if our frame team wants to recalculate load paths in the first place, then we may as well at least try to run an engine that gave us a better powerband location right off the bat. That's why I was trying to get some details on the FZ6, to see if it lived up to the hype on the track.

  7. #7
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Big Bird:

    If you haven't made it to comp yet, then focus on your management processes. There is no magic in the car itself - other than if you make a change of direction, it is going to distract you even more from getting the base systems in place. Any of the engines mentioned - Aprilia, an F4i, an FZ6, whatever, is capable of scoring 800 points easily and consistently. Once you have got there, that is when you can seriously start having good reasoned arguments about which one might suit your future development.

    Beware of new team members. They are invariably the ones who both make the most noise about wanting changes, and have the least understanding of why you shouldn't.

    Cheers all </div></BLOCKQUOTE>

    You're exactly right in this respect, by the way. If it were left up to me, I'd love to run the F4i again simply based on the fact that it's been good to us in the past and its dirt cheap. But, in the past we've had team manager that pissed off the new guys so fast that we generally had about 3-4 that actually stuck around for the whole ride. I'm trying to make my best effort to look at every angle of an engine swap before telling them no, because I don't want it to look like my reasons are simply "cause I've been here longer and I know more than you"; that never goes over well for keeping people around...At the same time, I don't wanna compromise the project in order to keep people happy, so I'm just doing my homework as thoroughly as possible.

  8. #8
    My advice is go to comp first. I'm with big bird, your problem sounds management related. Last year you didn't end up with a car you could take to comp. This year you have more people, so you're going to be more ambitious... which might mean you're again not going to have a car you can take to comp. My point is, if you couldn't predict how much manpower it'd take you last year, why will this year be different?

    If i were you i'd think about "what will get us a running car as soon as possible?" Look at what you have, and unless there is a super important reason to go in another direction, lock it in. Getting the car finished in time for a couple of months of testing and driver training will make you far far more competitive than an extra couple of Nm of torque.

    If you don't believe me, look at the results and then look at what engine the teams were running. The results are so entirely jumbled up it's not funny. For example, the winners for last 3 years at FSAE Aus were: 2004 - Turbocharged CBR600F4, 2005 - NA CBR600F4i, 2006 - NA WR450 single. The other comps are similar. The engine you pick doesn't make as much difference as some people imagine (and i say this as an engine guy). What is important is that you do whatever package you decide upon well. Get it running right, get it reliable, get it comfortable to drive. And then just get it made very early. Once you're going to comp and reliably finishing the enduro, then maybe have another look at some of the basic decisions of your car.

    Summary for the bored: Many teams come to comp each year with a car totally different from the last in every respect except that neither finished the enduro. It's really not the formula to win.

  9. #9
    Seeing as your team is already familiar with the F4i, I would stick with it. Even if the FZ6 offers better torque down low, you could easily match that by doing some custom work on your F4i. Maybe get custom cams, better tune, better induction/exhaust etc.

  10. #10
    Being as how I've worked to make the Aprilia engines available to FSAE teams, let me speak to why or why not you should run the Aprilia.

    1. First reason is money. If you don't have it, buy any 4 cylinder off E-bay. Heck, buy 3-4 so that you have spares when you blow one up or melt a piston as you learn to tune an engine.

    2. Make sure you have a reliable car. If you've been to competition a few times and have a good base car that doesn't break components due to reliability problems, then go to the next step.

    3. Make sure you have people that can drive a FSAE car fast. This takes a lot of practice. You need to work to get 4 team members that each have 100 hours of seat time racing your old FSAE cars. That's a good start.

    4. Make sure your car isn't over 450 pounds. In my opinion, if your car doesn't weight less than 450 pounds, then you can't take advantage of the weight savings of the Aprilia engine.

    5. Only at this step should you consider the Aprilia engine. It's the next logical step to having a (arguably) lighter and faster car. BUT, you need to have all the above steps accomplished first.

    You can win FSAE competitons with 4 cylinder engines. You just have to know your shit and be able to drive really @#$%ing fast.
    Dan De Clute-Melancon
    Iowa State FSAE alumni
    Project Manager 03-04
    Engine Team Leader 02-03

+ Reply to Thread
Page 1 of 5 1 2 3 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts