inferno94

iTrader: (2)

So my FSAE is building an 05 cbr 600rr based engine and is intending to go turbo (it's free from Garrett if you ask them) and from what I've seen other teams don't intercool or use WI.

We don't have a budget to build the engine / lower the compression properly.

Any special considerations pairing this engine with a gt 1241 (comes with a 8.8psi adjustable wg as per Garrett) aside from the normal stuff associated with turbocharging a NA engine?

I'm not on the "engine team" but they need all the help they can get so any suggestions are appreciated.

damir130

Curious question: why add the weight if you are not hp limited?

inferno94

iTrader: (2)

Teams must fit a 20mm restrictor, the bike's normal intake is 27mm. The turbo would be, more or less, an attempt to compensate for that. I'm not sure if you are aware, if you are disregard the above.

It's not my decision to turbo or not but the team feels it will benefit us as "Every team has a ~80hp car, more wouldn't hurt; besides that our drivers are light". I'm working on suspension myself.

damir130

The turbo still has to suck through the same 20mm restrictor. Unless it is seriously smoothing out intake pulses, all it can do is add heat. A well designed plenum does that just fine.
There cars out there running sub 50hp singles and winning. Just make sure that your powertrain guys deliver a reliable engine on time.

coastertrav

Don't waste your time (coming from the electronics/engine leader for the past four years). I know it sounds tempting, but the turbo would only be beneficial if you start getting into the cams/thicker head gasket.

You are still going to hit the restrictor limit at the same CFM level. Currently we are right at 80hp on the stock gsxr motor at the tires. Honestly, just get a motor to run through all events and you'll be doing better than 70% of other teams.

What school are you with BTW? I'm with the University of Central Florida.

inferno94

iTrader: (2)

I'm with the Conestoga College SOE (cambridge, ontario) it's the team's second year and first year of actually producing a car.

Personally I feel suspension and driver skill (assuming the car holds together) will win out as most important as far as winning races.

I see how we are massively limited by the restrictor and think my team mates see adding area under the curve as the goal of the turbo. I do agree it will add complexity and more failure points as well as require reworking aspects we could just leave as is, but that is one person's opinion on a team.

damir130

Reliability wins races. Just competing in all events guarantees you a place in the top half of the field. Going FI in your first year might be something that you will regret, I know we did ;-)
Also you'd better make sure to have a good story to tell the design judges when they ask you about the turbo. Something that includes a consideration between the tires torque capacity, the hp-curve, gearing and the rpm range you see on track. You might also consider throwing in a comparison between the weight added vs hp added and the number of sections of track where one helps vs the other.

Good luck!

Efini~FC3S

iTrader: (4)

Fuel Injected 450 single bored out to 500cc plus seems to be the new engine of choice.

Weight down, complexity down, reliability up... (win, win, win)

My FSAE team never ran turbos on our 600cc motors and we had some pretty good finishes, including one 7th overall in Michigan.

inferno94

iTrader: (2)

Thee team already bought a cbr 600 but I was thinking a liquid cooled two stroke might be a great choice. Some people cite reliability issues though my seadoo, with factory oil injection, has been solid as a rock for years (I know different application).

coastertrav

Excellent advice.

Reliability, I'm not so sure about that, maybe over a turbo four, but I doubt over a stock four. The four cylinders tend to restart easier, especially when hot (important for endurance), and I hate the idea that loosing an injector/coil/spark plug would end my day. At least with a four it would still make it to the finish line on three cylinders.

Any package can do well, you just need to have it work well with the overall package. Singles are nice, and I've loved the thought of going to an Ape'. A single would be pointless though if a team is unable to get their chassis under 70lbs, running 13" wheels. Now the sub 350lb full aero singles? Sexy.




And your SeaDoo is probably two stroke.

UCF runs a four, we're finally going to be under 400lbs this year (fully welded frame with all motor/suspension/misc mounts included is under 60lbs). We even have the dry sump system to haul around, which I must say is a surprisingly heavy bitch.

vehicular

iTrader: (3)

As a former Engine Team Leader, take the above advice as gospel. Simplicity is the name of the game. Well, simplicity and a tenured faculty adviser who knows when to step back and let the students work, and when to step in a drop wisdom. Being willing to go stand on teh department chair's desk and test that tenure out once in a while is a plus, too. A team leader that doesn't walk into the project lab with two Harley 1203s and instructions to pull a cylinder off of one and find a way to fit in the car at all costs doesn't hurt either.

If you don't over extend yourself, and document EVERYTHING, you'll learn a lot, and build a fast car. If you try to cram turbos and doo-dads into a car that's too early in it's/ the team's development (which it is if you're asking questions like this here and now), you'll never make it to competition. Or if you do, you'll go once, the team will melt down over the summer, and that will be the end of it.

cardriverx

iTrader: (12)

So, the problem is you must run all compression AFTER the restrictor. This means that the turbo must pull through it which causes many issues. You can reach the choke point of the restrictor easily with a turbo. This causes a vacuum on the compressor side. Turbochargers were not made for this, so it actually sucks oil out of the turbo.

That is the main problem with turbos and a FSAE car.

I highly suggest focusing your efforts else ware. The way this competition is going, high horsepower will not necessary win. It seems singles are the way to go, Oregon state won last year with a sleeved 650 single. Its all about light weight, which a turbo will not help with. It also adds many failure points which is a no-no.

Remember, this is really a design competition. Does your engine team have a really good argument as to why they want to turbo? Can they convince the judges that it was better to turbo the engine? They better have a really good reason, and the only thing I can think of is if you get it to spool real quick and improve torque down low.

We use the RR engine too (Pitt), and I have no idea how well it holds up. Keep in mind with a turbo you still won't be at stock horsepower, so it should be fine. I would HIGHLY recommend some type of intercooler tho. Hot intake air plus high compression is not good.



P.S Two strokes are banned, only 4 strokes are allowed.

damir130

You don't need a sleeved 650cc single either. The whole hp obsession is an American thing I guess. We did just fine with only ~450cc and 45-50hp (several wins and top 3 finishes over the years since 2003.
It does help to have a car weighing 300lbs..

Really try and keep things simple. Focus on competing and finishing. Nothing sucks like putting in 4 months of 7-day work weeks, filled with 20 hour days and then not even having a car to compete with. Designing, building and testing a simple, reliable car is a HUGE challenge in itself. Don't overcomplicate!

inferno94

iTrader: (2)

I directed some of the engine team folks over here and they ended up on the same page, one is looking for a single or twin engine for next year.

Thanks.

jacob300zx

can you swirl the air before the restrictor?

inferno94

iTrader: (2)

I'm not sure on that one but they are using the restrictor as a venturi, pretty standard.

Techsalvager

carbon seal

Techsalvager

What engine managment would they use with the turbo setup?

jacob300zx

I agree with the others. If you are mainly doing autox you would be well ahead for a lighter, simple, reliable car that finishes every time.

vehicular

iTrader: (3)

All swirling the air does is add useless velocity to it as it passes through the orifice, making it hit mach speeds/ choke flow faster. We picked up a tiny bit of flow by adding a linearizer (actually a piece of nomex honeycomb) between the throttle body and venturi section on our first GSXR powered car.