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Thread: Engine

  1. #1
    UV03/4 Intake

    Colin, I gather from your email that you are going to design the intake for the new EFI. If that is so here are a couple of ideas that I have:<UL TYPE=SQUARE><LI>We can use the old guillotine (but the push pull cable needs to be adapted??)
    <LI>Incorporate adjustable length runners to tune power band.(slip joints?)
    <LI>backfire protection!
    <LI>Fiberglass for contours
    <LI>study injector angle/depth/spray
    <LI>use the old cone?[/list]Can you reply if you are for sure going to design it because the sooner we can get the P.E system going, the better. Also I think it will save us time if we simply(!) mount the PE system on UV03 rather than using the '97 engine. Wiring twice and making intake adapers takes time. Any other ideas anyone?

  2. #2
    UV03/4 Intake

    Colin, I gather from your email that you are going to design the intake for the new EFI. If that is so here are a couple of ideas that I have:<UL TYPE=SQUARE><LI>We can use the old guillotine (but the push pull cable needs to be adapted??)
    <LI>Incorporate adjustable length runners to tune power band.(slip joints?)
    <LI>backfire protection!
    <LI>Fiberglass for contours
    <LI>study injector angle/depth/spray
    <LI>use the old cone?[/list]Can you reply if you are for sure going to design it because the sooner we can get the P.E system going, the better. Also I think it will save us time if we simply(!) mount the PE system on UV03 rather than using the '97 engine. Wiring twice and making intake adapers takes time. Any other ideas anyone?

  3. #3
    Hayden,

    Yes, I'm working on the intake design. Regarding your points:

    I would like to try an off the shelf throttle body for its simplicity. I'm working with venturi/diffuser designs and throttle plate modifications to try and minimize the flow losses due to the plate and restrictor.

    I thought about adjustable length runners too, but I'm not sure how easy it would be adjustability would be considering the intake mounting and the chance of creating intake leaks (lead to backfires!).

    Backfire protection - eliminate leaks and tune the injection system.

    I've been thinking about fibreglass or carbon fibre. Open to suggestions as I'm not experienced with manufacturing with either of these materials.

    Injectors basically have to be pointed towards the intake valve(s). WE can use the ones from last year, so I haven't thought too much about injector spray pattern. I have to review my literature on location in the runners.

    Using the old cone will save us $40 - sure!

    I think the ecu should be a top priority right now - the more engine testing we get the better.

    We can decide on a test engine (97 or 02) when we get the ecu. IT would be good to get some test miles on UV03 and do some sponsor visits with the car before we pull it apart again.

    My plan with intake design is simplicity. I am trying to keep manufacturing ease a priority (mainly because I can't manufacture worth shite) and not try any radical designs. My goal is to develop an engine that runs consistantly and reliably, and not so much the winner at the dyno.

  4. #4
    UV03/04 Intake

    Sounds good Colin. Try and get in touch with Richard too, I'm sure he has some good ideas. Last year we thought the injectors weren't far enough into the runners, that was my only issue. I'm wondering if we might save some manufacturing time by using the old guillotine but it's not a huge deal. For the backfire protection I was thinkling of a check valve so we dont blow our intake but I guess we dont have to clamp the intake as tight as we did in Detroit. I you really want a composite intake, we can make it happen. As soon as we get some money, we will order the PE system.

    Hayden

  5. #5
    I have a (heavy) valve here that could be used for pressure relief. It threads into a 1" pipe thread. Otherwise, I'd suggest using a "grainger" valve, adjustable check-valve. McMaster Carr PN: 48935 K25 (you should be able to pull up a picture of it on their website with that PN) Its small and fairly light, adjustable, but it might not pass enough air to prevent damage to the intake.

    Seriously, the best way to avoid blowing up the intake is to have an ECU that works. I've had zero problems with other engine management systems backfiring through the intake as long as the basic timing and fuel maps are close.

    Colin, to answer some questions you emailed to me:

    I used 6061 mandrel bends to make the intake runners last year, from www.burnsstainless.com. Most likely you will have to do something similar again. Basically I took the prebent 180degree tubing and cut out the angle I needed.

    The restrictor was made from 0.020" 316 SS, and David Smith made it. Basically sheet metal wrapped around a core and then plasma welded.

    The "Runner Length Calculation" spreadsheet basically calculated the lengths necessary at each RPM in order to get the benefit of a positive wave. RV2 would mean the 2nd reversion, RV3 the third, RV4 the fourth, and so on. Each sucessive wave is of less magnitude than the previous wave, so RV2 is more important to tune for than RV3, and so on.

    I ended up choosing a runner length that would give the most reversions (RV2, RV3, RV4) over our desired operating range. (6000-12000rpm) I believe I ended up with about 12in. (don't forget, this includes the intake port length as well) I would say 11-13in including the port length is the range you don't want to step outside unless you are doing something extra tricky.

    I like the reversion technique better than using a Helholtz resonance model, (though it is useful as well) because it tunes for multiple reversions, unlike the Helmholtz model which just tunes for 1 or 2 reversions. (depending which model you use)

    The injectors were far enough into the runner, I had expected a more fan-like spray pattern, but as RC Engineering said, the small flow injectors tend to sqirt a pretty concentrated stream, and not the fan shape we all visualize.

    Don't fear the backfire, it isn't likely to repeat itself unless you've got another bum ECU, or some spark problems.

    If you need to get ahold of me, 250-701-1048 (cell) or 250-748-4086 (office) are most likely.

    -------------------------
    UVIC Formula SAE Team

    http://uvic.fsae.ca
    -------------------------
    UVIC Formula SAE Team
    http://members.shaw.ca/drax77/Formula%20UVic%20Sig.jpg
    http://uvic.fsae.ca

  6. #6
    Thanks for the info, Rich, it's very helpful. A couple questions: where did you find the reversion theory? Where in Smith & Morrison (Scientific Design....) did y ou find the info on plenum volume? I read so many different theories on plenum volume, it's difficult to know what's right. So far 70-75% of the engine displ. is the most popular, but I've read as high as 4x from a 2001 report from UTA.

    Lastly, that office number - is that a "home office" or are you working now?? Details!

    Cheers,
    Colin

  7. #7
    Scientific design... doesn't go much into plenums. It actually wasn't as useful a reference as I had hoped. Check the references list at the end of my 499 for the other books I used.

    You are going to have trouble keeping intake volume low, with the diffuser, runners, and plenum considered. We were about 2.5L last year, which is ~4x. Packaging is a more important design consideration than overall volume IMHO, just try not to make it too large or throttle response will suffer.

    -------------------------
    UVIC Formula SAE Team

    http://uvic.fsae.ca
    -------------------------
    UVIC Formula SAE Team
    http://members.shaw.ca/drax77/Formula%20UVic%20Sig.jpg
    http://uvic.fsae.ca

  8. #8
    What is the port length in the 2002 head? And did you use airhorns inside the plenum or just weld the ends of the runners directly?

    I remember there was a packaging problem with the car and intake design - I think it had to do with dimensions referenced from the '97 engine placed in the frame. As a result, you had to turn the intake upsidedown and pointed towards the rear of the car instead of up. Just to clarify, was this the problem? What were the packaging problems? I'd like to keep the intake pointing up so we get clean air into the filter.

    Colin

  9. #9
    The packaging problem that prevented us from having the intake pointing up was the main hoop being too low, at least that was one of the reasons. But since it was decided to keep the same frame next year, I guess we'll run into the same problem.
    Tifenn

  10. #10
    Can someone measure from the top of the roll hoop to the point on the head where the throttle bodies attach to? Vertical and horizontal measurements, thanks.

    Colin

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