Thoughts on the Aprilias

[Corey H]

So competition has come and passed and I want to know what the conclusion is on the Aprilia, from the teams who used it.

From what I can remember at West this year:

- The top 2 teams from 07 West, Texas A&M and Kansas were unable to compete because of engine trouble with the Aprilias
- EPM had the highest fuel consumption during endurance with 1.531 gallons with the SXV550

This is what I vaguely remember so correct me if I am wrong, but I am curious to see how the engine that was predicted to be the best thing for FSAE has worked out for the teams that have used it.

[Corey H]

So competition has come and passed and I want to know what the conclusion is on the Aprilia, from the teams who used it.

From what I can remember at West this year:

- The top 2 teams from 07 West, Texas A&M and Kansas were unable to compete because of engine trouble with the Aprilias
- EPM had the highest fuel consumption during endurance with 1.531 gallons with the SXV550

This is what I vaguely remember so correct me if I am wrong, but I am curious to see how the engine that was predicted to be the best thing for FSAE has worked out for the teams that have used it.

[Yellow Ranger]

UTA didn't attend West in 07 nor had any intention on attending it in 08. From talking to Montreal after the race, I heard that they had ecu issues that applied throttle enrichment for enduro, resulting in the fuel score.

Of the teams in Michigan, I believe that KU was the only team that didn't enter endurance because of the motor. UTA finished but was DQ'd for the wing thing. A&M was electrical, Auburn was drivetrain, not sure what happened with Georgia tech or UNC...

This is all hear say, I'm sure members from the actual teams can give you more exact answers...

[Corey H]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Yellow Ranger:
UTA didn't attend West in 07 nor had any intention on attending it in 08. From talking to Montreal after the race, I heard that they had ecu issues that applied throttle enrichment for enduro, resulting in the fuel score.

Of the teams in Michigan, I believe that KU was the only team that didn't enter endurance because of the motor. UTA finished but was DQ'd for the wing thing. A&M was electrical, Auburn was drivetrain, not sure what happened with Georgia tech or UNC...

This is all hear say, I'm sure members from the actual teams can give you more exact answers... </div></BLOCKQUOTE>

Texas A&M is what I had meant, thanks for the clarification

[Superfast Matt McCoy]

TA&M didn't show because they're switching to Formula Hybrid and didn't see the benefit.

My only experience with the Aprilia is sitting in line for endurance, watching TA&M's jaw dropping yaw acceleration. That sold it to me. I've seen too many teams cranking over their F4i, killing batteries and hopelessly punching numbers into the ECU to think that engine tuning problems are engine specific. Maybe it's harder with the Aprilia, but it obviously can be done and it's one of those things that needs diligence and patience that most teams don't give (including me when i was the engine guy). That doesn't mean it's not worth the time.

[PSUAlum06]

My experience is limited, but from what I understand, the motor is pretty compact and makes good power, but has some awful reliability issues. I hear they chew through starters and have trouble keeping the oil and coolant separate. The worst part is that those are problems with stock motors.

[Davidimurray]

Having spent some time researching and working with the Aprilia setting it up on a Motec and getting it run I thought I would add a few things -

Yes, a lot of people kill starters. This is often due to excessive cranking. We never managed to kill a starter through over 200 failed starts on the dyno, and probably another 100 succesful starts on the dyno and in the car. The biggest killer seems to be excessive cranking and in particular cranking at low voltages. The voltage has to be a minnimum of around 13V or the starter will just not throw it over fast enough. I have seen a lot of teams repeatedly cranking the engine over for 10+ seconds with voltages of 9V on the battery. It ain't gonna start. Wherever possible always start the engin off a backup supply. There are also decompressors fitted to each cylinder. Check that these are not worn and operate properly. IF you remove them, the engine won't even turn over on the starter - I've tried it!

Oil issues - yes, early engines did have this problem. Those engines had orange sealant, later being replaced with black sealant. Most old engines have been resealed or replaced. There are unlikely to be many orange sealant engines around, but stay away from them, or get it cheap and pay to have it resealed.

Getting it up and running on the Motec was very hard work. A lot have teams have tried adjusting the stock ECU using the Tuneboy, but so far all the cars I've seen using this setup have struggled. We worked closely with Auburn uni to get the Motec going. Once we got the engine starting reliably, we did most of the mapping in a single evening and the engine ran very well.

You have to remember that these are 'race tuned' engines running at near their limit. Not big heavy F4s running at 70% output. These engines need regular maintenance and looking after. Despite the bad things you hear, there are a lot of race teams out there running these bikes every weekend flat out and many strret bikes that have done 1000s of miles.

My biggest bit of advice would be to know what you are getting yourself into and do the research- there is a fantastic forum here -
http://www.apriliaforum.com/forums/forumdisplay.php?f=50
I spent months reading this site before we took the plunge, there is a lot of historical info on there and you can see how the problems have slowly been sorted over the past few years.

[Didier Beaudoin]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Yellow Ranger:
UTA didn't attend West in 07 nor had any intention on attending it in 08. From talking to Montreal after the race, I heard that they had ecu issues that applied throttle enrichment for enduro, resulting in the fuel score.

Of the teams in Michigan, I believe that KU was the only team that didn't enter endurance because of the motor. UTA finished but was DQ'd for the wing thing. A&M was electrical, Auburn was drivetrain, not sure what happened with Georgia tech or UNC...

This is all hear say, I'm sure members from the actual teams can give you more exact answers... </div></BLOCKQUOTE>

Yes, our fuel consumption at West was abnormal. It was caused by the fuel compensation potentiometer that we use for starting the engine that was not placed properly in the cockpit. Both our drivers in the endurance turned it to full rich accidentaly.

Our fuel consumption at East was better by a good margin.

I'm not the engine guy, but having driven the car a lot, and having driven 4 cars with a F4i before, I can see the benefits in the Aprilia. What impressed me the most was the throttle response we got from it, even if it was pretty badly tuned. You have to be lot more careful than with the F4i though, but I'm not sure I'd say it is unreliable in itself. Sure, we had our lot of problems (3 broken starters, but that was before we change the starter gearing. Broke the starter woodruff key 2 times also but once again it was probably caused by a badly torqued nut.) but I feel they were all avoidable with more care and experience.

In the end, we did finish both our endurances this year, something EPM had never done before in its 20-odd years history

[Erich Ohlde]

I'll post in here about KU's troubles.

1, yes we had trouble starting the engine and that is why we didn't make endurance. The reason for this is two fold. Our sprag clutch went the way of the dodo and one of our fuel injectors was intermittent.

2. We have not blown an engine, I heard rumors floating around at west about KU blowing several motors...that did not happen.

3. We did not attend West because we had no teammembers around to prep the car after east to get it ready for west.

4. The car is running very well now and we are going to have two drivers at nationals with it.

Hope i don't sound like a dick. peace

[Superfast Matt McCoy]

I would really like to see pictures of this winged KU car with the Aprilia. I suspect that would be the best platform for not only FSAE but SCCA as well. I expect KU will finally dethrone the UTA guys.

You dick. http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Kell]

I'll chime in for UNC Chalrotte.

We also ran an Aprilia last year and will be running it again. Our main issue at competition was a driveline failure. We had some cold starting issues with our motor and tunning issues related to the Tuneboy software, which I believe to be one of the poorest excuses for a tuning program I have come across. Besides the lack of real-time tuning, our Tuneboy had a nasty habit of Either failing to connect or failing to download maps and even stating "download complete" yet it had done nothing... We spoke with a few people who race SXV's and all had similar issues with Tuneboy. Garbage.

Anyways, We also had the same starting issues many of the other teams had, We managed to fry one starter on our engine dyno. The factory ecu has a 6-second starting limiter that Aprilia implemented because of the frail starting system. We also tore up a sprag clutch, yet that might have had somthing to do with a mysteriously missing needle bearing... Thanks Aprilia.

Once we got back and beat Tuneboy into submission, our motor ran perfectly fine, we were quite happy with it. If you do your research and figure out the quirks soon its a great motor, but it will bite if you dont stay on top of it. Maintinance is key in a motor this high strung.

[Brian Schien]

Kell outlined the issues that we had at UNC Charlotte but I'll add my comments


The have two issues with the motor it to loud it has a very low frequency at the rpm were they due sound, its hard to muffle so beware. The dry sump system is not really a dry sump from what I can tell it is basically a wet sump with an external reservoir and the tank just pushes oil out the vent which is usually just plumed into the air box on a stock configuration.

[Erich Ohlde]

how is it not a dry sump? the scavenge pumps oil from the case to the oil tank and the pressure pump pulls oil out of the tank and pressurizes it in the case..repeat. isn't that the definition of a dry sump?

[John Grego]

We didn't show up to California because our engine began having transmission issues and we didn't feel it was a good idea to travel all of the way to California on an iffy engine. We had blown our other one a few days before we left for Detroit.

Our electronic problem was in Detroit and was caused by one of the connectors on the MoTeC connection coming loose.

[Wesley]

The Aprilia does have a unique sound, the pitch change is 1/4th of that of the F4i, not to mention it's lower.

I've been doing a bunch of preliminary noise analysis of it, and I think it can be turned into something that sounds decent with a little tweaking.

It ought to be possible to make it sound driveable at least.

[Corey H]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wesley:
The Aprilia does have a unique sound, the pitch change is 1/4th of that of the F4i, not to mention it's lower.

I've been doing a bunch of preliminary noise analysis of it, and I think it can be turned into something that sounds decent with a little tweaking.

It ought to be possible to make it sound driveable at least. </div></BLOCKQUOTE>

What do you mean by "It ought to be possible to make it sound driveable at least." Does it sound like it shouldnt drive?

If you want to talk about a loud engine, the GSXR is a whore!

[Wesley]

Hah, no.

It just sounds like a tractor. I guess you can race a tractor... I mean, some teams run Briggs. http://fsae.com/groupee_common/emoticons/icon_razz.gif

[AlexS]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wesley:
The Aprilia does have a unique sound, the pitch change is 1/4th of that of the F4i, </div></BLOCKQUOTE>

what do you mean by pitch change?

My attempts to develop a analytical model for the aprilia muff provided unpractical results so i've reconfigured the OE muffler into a tunable format and just plan on altering the chambers until suitable noise suppression is achieved.

i have nothing about pitch change in my models, how critical is it in the analysis?

Cheers

[Wesley]

If you make a plot of exhaust note frequency vs. rpm, from idle to redline, the total overall change in pitch (the variation in frequency) is 1/4 as large with the Aprilia than with the F4i.

This has impacts in two areas - one, driver feedback. From those I've talked to who have driven an Aprilia car, it's almost impossible to tell where an Aprilia is in the power band by hearing it, like you can an F4i.

The other area is silencer design - as the range of operating frequencies is closer, any acoustic filter will have a broader range across vehicle speed.

In 2007 we developed a MATLAB script that predicted the attenuation of a two chamber (packed/unpacked) muffler that fit almost dead on. I believe it was based off of a sample found on wikibooks. The test muffler worked well, at 106dB on an F4i.

However, we found it easier to purchase a muffler, as it was lighter and better constructed than what we could make.

In terms of sound quality, I found a powerpoint illustrating that small changes in individual lengths can affect the noise output of an engine considerably with minimal impact on power. For instance, on an Aprilia, if you shift a pipe's length by a half wavelength from the other you can generate destructive interference at your tuned RPM, and so on. Again, with 2 cylinders, everything you do will have a lesser effect, and that's the Aprilias largest noise problem.

Plus, it vibrates a lot as a 77º engine.

[J.R.]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Wesley:
Hah, no.

It just sounds like a tractor. I guess you can race a tractor... I mean, some teams run Briggs. http://fsae.com/groupee_common/emoticons/icon_razz.gif </div></BLOCKQUOTE>

Most teams got beat by that tractor...

[Wesley]

True. And I'm mostly just giving you guys hell, you have a well-engineered vehicle, as you've proved in competition.

Besides, next year there'll be two tractors (or more) with our Aprilia.

I found this sweet undertray design though...
http://www.epoxyproducts.com/mower.jpg

[michaelwaltrip]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I found this sweet undertray design though... </div></BLOCKQUOTE>

oh no way. sucker cars have been outlawed since the early 90's.

http://fsae.com/groupee_common/emoticons/icon_wink.gif

[J.R.]

Haha, wouldn't that be something if we ended up cornering faster with a lawnmower deck?? Max Downforce! http://fsae.com/groupee_common/emoticons/icon_cool.gif Woot!

[JR @ CFS]

What about a ducati monster 600?

V-twin, air-cooled, so lower weight without the cooling system. Turn it east west and run a driveshaft straight off the output shaft. Less losses as you only go through one 90degree rather than two by running it north south.

Just an idea at least...

[Drew Price]

The Italian team from Firenze ran the Duc twin on a Magnetti-Marelli ECU at California and Italy in 2007, not sure if they still are. It's a 696 now (I think it might have been a 649 2 years ago) and they had to make their own custom crank and rods to de-stroke it to a 608 or something like that to meet our limit of 610cc. It was sweetly packaged, and sounded awesome, but was running badly when we saw it at West due to ECU issues.

The de-stroking process and the cost probably put it out of range for most teams, but Ducati was one of Firenze's major sponsors at the time and from talking with them I think they got engines supplied free, but I could be remembering a little wrong.

Best,
Drew