MoTeC sucks and other FSAE related thoughts

[Rogue9]

So this semester I finally jumped in on the Formula SAE team here at the U of Illinois. I got put on the engine team, but I've been around some of the other stuff too.

Engine is a CBR600 F4i, rules mandate a 20mm intake restrictor. Intake and exhaust are both custom built by us, along with just about everything else on the car. About the only thing that we buy that isn't touched is the guts of the engine, and of course the ECU.

Speaking of which....
MoTeC sucks.

To clarify, its not the ECU itself that sucks so much as the software interface. It's DOS based for christ's sake! It also has all kinds of nifty parameters you can change...but no explanation as to what they do, either in the software help or in the manual. The manual literally just says "use the software help".

So after many hours getting all the base parameters and shit set up we finally got around to trying to dyno tune our new intake/exhuast/fuel system. Its actually not bad to work with the fuel and spark tables once you get everything rolling, and it does give you a pretty good number or real-time sensor readings. We only had to set up our own air-fuel ratio plot using another program, the motec software told us everything else we needed.

So that was pretty much my 30 hours of crap this weekend, and we didn't actually get much tuning done due to stupid mechanical problems regarding the remote throttle actuator, the shitty dyno we have, the incomprehensible wiring associated with it, and also the electronics guys not wiring the fuel pump into the ecu (its kind of important).

There are some pics and info associated with the UI FSAE team at http://mechse.uiuc.edu/clubs/sae/formula/

If you guys are interested in this stuff I'd be happy to answer questions as long as they aren't part of our "secret" projects. We wanted to have a running car by the end of next week but the machining/splining/heat treating shops are slowing us down.

Chris

[Blown330]

I'm on our school's SAE Mini-Baja team...fun stuff. MoTeC is a bit much to get into...especially if you are new to EFI tuning. Can fill books on all the capabilities of the MoTeC systems...pretty much one of the most comprehensive systems on the market. Sadly we don't get to play around with all the EFI stuff in Mini-Baja. Building a 4WD hydraulic drive system has been a source of endless hours of fun though.

[Gregersonsalavage]

When you mean guts of the engine does that mean you can't do any porting? or Grooves?

[Blown330]

Depends on the engine and the teams budget usually. As far as I know (and the 2006 FSAE rules) the limitations on the engine is that it displaces no more than 610cc, be a 4-stroke, and run on pump gas. Many teams use hi-po B&S engines that they modify. Cost becomes an issue as the higher the power output of the engine the more it costs in the cost evaluation side of the competition. Part of these SAE competitions is that your are building these vehicles with the idea that you would produce them commercially so costs need to be controlled.

[Rogue9]

Yep, you can mod the engine if you want (And we do modify the oil system and pan), but especially on a sportbike engine, you're going to pay an awful lot for basically no gain. We could do just about anything we want and not get any power because the intake restrictor is the limiting factor. That's why racing series' like ALMS and other sports car racing use intake restrictors to control engine output even though the teams are all using different types of engines.

The cars have to be costed out under $25,000 dollars for the competition. We typically come in around 16k. This is not actual cost as everything is a one of a kind, but rather is the cost after the process has been perfected.

We also have to fight with the university on budget stuff. This year we have basically half the budget that we did last year. Largely in part because the university got into the Solar Decathalon project which is more high profile, so they dumped a lot of money that way. Their budget is in the half million range where ours is maybe 40k or less. Luckily we get a decent amount of sponsorship money.

And next year they're sticking us in the same shop as the Mini-Baja team, which will be fantastic....(nothing against baja).

Baja is pretty similar but they're a sealed engine competition and race off road whereas the formula stuff is autocross based. Baja would be a blast to drive, our baja team showed us a video of our car getting like 6+ ft of air. But then again our formula car will run 0-60 in like 4 seconds and pull 1.6g on the skidpad. Both are pretty cool.

Unfortunately i doubt I'll be getting to drive our car this year considering we have one guy who's been in the program for like 4 years, and another guy's been in for 2 and has been in kart racing and formula 500 since he was 8 years old. I still get a free trip to michigan and california (SAE West comp) though.

EDIT: What school you go to?
Chris

[brcSVO]

I was on the Mississippi State 2006 FSAE team. We also ran a Honda F4i motor. We ran a different ECU system. The thing that killed us at competition was of all things, passing the damn sound tech. We did manage to be one of the 40 something out of 120+ teams that actually finished endurance. But we used up so much time trying to pass tech that we didnt get to compete in the acceleration or skidpad tests.

Now I'm at a different college and the FSAE team here is having trouble (We have a rolling chasis, but the department won't give us shop access until they approve a design report for every part on the car... pretty much because the last team from this college got like a 10 or something on the design report).

Going to competition and being lucky enough to be one of the drivers (yay for being 1 of the 2 guys that actually had autocross experience) was one of the coolest things I've done in college. Good luck to you and your team.

[Gregersonsalavage]

A few things you may want to consider found on www.mpgresearch.com Singh Grooves( http://www.somender-singh.com/ ), powerlynz, ect.. Many of these same things not only increase gas mileage but they also let you run higher compression and more power without pinging. The Volvo guys have been doing the singh grooves along for a while finding that they can get another 10-15 degrees of advance timing without pinging on pump gas no less and oddly enough find that thier oil stays much much cleaner and lasts longer. So in your case you could bump up the compression, timing, and with increased power run faster times at the course without ever worrying about the restrictor plate issue and get better mileage.

Just some thoughts.

[lemming]

Originally Posted by Gregersonsalavage

words

Seriously, my eyes can't roll far enough.

Just to clarify, I seriously doubt that you're going to be able to run much (if any) more timing if you mutilate a freaking sportbike head like that. Furthermore, I'd imagine that such a ridiculous intake restriction is going to cause the engine to run at pretty low load anyway, and at low load, spark tolerance is the least of your worries.

[Gregersonsalavage]

Actually the main goal I was thinking of along with those ideas is to increase compression without retarding the timing which would get you more power out of the engine overall even with the restricted intake.

This is racing where every little HP counts when you are trying to win by feet or inches.

[lemming]

So, let's see, if they follow this idea, they're either going to have to switch to a rotating assembly that offers higher compression, or they're going to have to get the head milled, screwing with combustion even more than cutting fricking grooves in the damn chamber walls.

This is FSAE, where they probably don't have sufficient funds to cover buying a new engine after trying out your latest neural misfire.

[Gregersonsalavage]

Originally Posted by lemming

So, let's see, if they follow this idea, they're either going to have to switch to a rotating assembly that offers higher compression, or they're going to have to get the head milled, screwing with combustion even more than cutting fricking grooves in the damn chamber walls.

This is FSAE, where they probably don't have sufficient funds to cover buying a new engine after trying out your latest neural misfire.

On the assumption that it doesn't work. I simply pointed in the direction. I didn't say they had to do it. Even if not to peak curiousity. There are thousands of people around the world who've done it with no ill results heard of. Heck I dare you to find someone with bad results.

if you want more reading thier is an entire post over 20 pages long about it on turbobricks.org Having multple posters from volvo, toyota, bikes, racers, Etc.

http://www.turbobricks.org/forums/sh...ad.php?t=66779

[lemming]

I'm not going to wade through 20+ pages of posts to find such information, because I don't really care enough, but I'm not going to be satisfied that this does anything useful unless I see:

1. An OE-quality dyno run on a proper load-bearing dyno
2. Which demonstrates that either BMEP was increased or BSFC was decreased
3. On a cylinder head that actually has somewhat decent thermal efficiency in the first place, rather than some Ovlov head that was probably originally designed for a diesel generator or something.

If you can't meet all three conditions, as far as I'm concerned, you've just got rumors on the internets. You might a well tell them to buy a few magic fuel line magnets and a tornado fuel saver.

Yes, I know that this isn't a correct thing to do with an English sentence.

[lemming]

While I'm at it, I might as well invoke Greg Banish, (former?) OEM calibrator who has forgotten more about this stuff than most of us will ever know.

Everything I've learned in both the classroom and dyno cell would indicate that squish area is your friend. I can't for the life of me imagine why you'd punch a friend like this in the eye.

Of course I'm skeptical until I see data proving otherwise. These grooves appear to lower CR by all the historically wrong means; reducing squish area and creating crevice volumes. These crevice volumes often lead to storage of HC deposits that increase emissions and glow with a tendency to cause preignition. Further, sharp edges inside the combustion chamber are also historically undesirable since they are both a potential hotspot and stressor on the local material strength of the head casting.

Good charge motion can still be had (even near TDC) with proper port geometry and chamber design. This smells like a band aid approach for poor charge motion.

It's going to take a lot more research before I start cuttin the heads like this on my personal cars.

There seems to be a consensus that this might have some effect on engines that have poor charge motion characteristics and large piston-to-head clearances. I really doubt that either of these apply to a freaking sportbike head.

[Gregersonsalavage]

Grooves can also be done to the piston. Look around there are already a number of bikes using this design among other things like powrevalvz.

As for HC buildup.

http://somender-singh.com/content/view/82/49/

As for even a sportbike head. I think its worth researching and consulting about. I didn't say "do it." I just said "consider it" which includes research, consulting, seeing whats possible, ect. Wouldn't it be better to research the alternatives than simply saying no?

[lemming]

There's also such a thing as scope. They're required to run with an intake restrictor. The ability to run with a higher compression ratio and/or greater level of spark advance isn't even going to be necessary because the engine is running at low load. Unless you can address that problem, I'd imagine that any improvements would be minimal at best and probably not worth investigating when they've already got a lot of other stuff to worry about, like tuning the thing to actually work.

[brcSVO]

Originally Posted by Gregersonsalavage

This is racing where every little HP counts when you are trying to win by feet or inches.

Actually, its a design competition where having a design report ALONG with a cost report is more important than anything else. The second most important thing is having a simple car that starts up everytime you need it to. Competition can either be extremely fun... or hell. Just depending on how reliable your car is. Besides, other than the acceleration event, a good and predictable chassis and suspension is worth 100x's more than horsepower. These are 500lb and less cars, even with a restricted engine making around 40hp, you still have more than enough power to spin the tires at will.

[lemming]

I haven't looked at FSAE rules in a while; are you even allowed to make internal modifications to the engine?

[Blown330]

http://www.sae.org/students/fsaerules.pdf

3.5.1.1 Engine Limitations
The engine(s) used to power the car must be four-stroke piston engine(s)
with a displacement not exceeding 610 cc per cycle. The engine can be
modified within the restrictions of the rules. If more than one engine is
used, the total displacement can not exceed 610 cc and the air for all
engines must pass through a single air intake restrictor (see 3.5.4.3,
“Intake System Restrictor.”)

Hybrid powertrains utilizing on-board energy storage are not allowed.

Nothing that I've read says anything about internal modifications. Apparently as long as the engine(s) do not exceed 610 cc and of a 4-stroke piston design then you can do whatever. Even turbochargers and superchargers are mentioned. It does come out in the cost report, though, as a higher performance engine costs more per cc.

[lemming]

That 20mm restrictor has got to be a pretty huge limitation. I wonder how many teams go much beyond building the intake and exhaust systems; I've never been involved with anything like that (I was a CS major), but I've seen some FSAE cars, and it seems that a lot of effort probably went into developing custom EFI intake plenums.

[brcSVO]

You guys are exactly correct. The 20mm restrictor pretty much forces you to run stand alone EFI. Though some teams have been able to make tuner units such as the Power Commander work and in the past everyone used carbs. As far as turbos and what not, there's always atleast a handful of teams with turbo cars, mostly foriegn since their university teams are usually well funded. The major draw back is that the throttle body and restrictor MUST go before the turbo.

Infact the biggest trend right now is going towards single cylinder 450cc motors. If I remember correctly, atleast 2 of the top 5 teams from Michigan last year were running the 450's.