Why did your team go with a turbo/super charger?

[RBbugBITme]

I've started writing a feasibility analysis of going turbo with our F4i and I was just wondering what teams who have put a SERIOUS effort into weighing the pros and cons decided on in the end and why? What kind of arguments did you typically hear from those against the idea?

We're working on the idea of a 2 year design and testing period with an old car and if anyone says our fuel economy will suck... save it. Detroit 07 fuel economy point average was 9.6 out of 50 for those that finished so that is the least important thing on my mind.

Thanks

[RBbugBITme]

I've started writing a feasibility analysis of going turbo with our F4i and I was just wondering what teams who have put a SERIOUS effort into weighing the pros and cons decided on in the end and why? What kind of arguments did you typically hear from those against the idea?

We're working on the idea of a 2 year design and testing period with an old car and if anyone says our fuel economy will suck... save it. Detroit 07 fuel economy point average was 9.6 out of 50 for those that finished so that is the least important thing on my mind.

Thanks

[Pete M]

The turbo lets you make more area under the curve and to some extent more power. It adds weight and complexity. Drivability may suffer, although if you do it right, it won't. The big downside to a turbo is the amount of development time it consumes.

I wouldn't write off fuel economy. There's no reason why a turbocharged engine will be necessarily less fuel efficient. In fact, play your cards right and it could be more fuel efficient. Adding weight to a car will tend to increase the fuel used though. We used 3.4 L at our last comp (0.9 gallons), for what that's worth.

[RBbugBITme]

What I meant by the fuel economy thing was that if we end up being one of the few who complete the endurance, I won't care if we get <5 points. Based on the average vs total available for fuel vs. total available for the comp its very minor and could easily be made up in design points if the turbo system design is done well and presented well. I'm not saying I'm going into designing the system without a care toward designing for an efficient system.

I know everything that goes into this project, I'm just looking to bounce experiences off of teams who gone through the process of convincing everyone else that it is or isn't the way to go. So far from my guys I'm getting for the most part generic "we'll have turbo lag" excuses from people who have no turbo experience. Our alumni have had a turbo on the car almost a decade ago but most of what I hear from them is "its not worth it" with no real evidence as to why.

[Pete M]

Yeah, i know what you are saying. At West 06, we came 3rd by 0.441 of a point. Because of that, we have a bit of a different perspective on whether 5 points is worth it. If you want to win, you can't afford to sacrifice any event as unimportant.

If you're at the point where you're aiming to finish the enduro, hopefully mid pack, i wouldn't recommend a turbo. I believe the development time we put into it is worth it, but only because we have that development time to start with. If you're struggling already, a turbo is a whole other can of worms just begging to make your car late and unreliable.

[RBbugBITme]

haha aren't we all aiming to finish enduro every year? Jet nuts back off sometimes, damn gremlins.

We're heading in the right direction as a team, we'll be at VIR this year with DR07 and already began designing for DR09 so now is the time to take on long term projects like this.

[ad]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RBbugBITme:
haha aren't we all aiming to finish enduro every year? Jet nuts back off sometimes, damn gremlins.

We're heading in the right direction as a team, we'll be at VIR this year with DR07 and already began designing for DR09 so now is the time to take on long term projects like this. </div></BLOCKQUOTE>

I will agree with Pete here. It takes time, money, and a dyno at hand! Wollongong has put in 1000s of hours of development time (most of it on the dyno) to reach the current level of the system.

Although i have not been directly involved with a long term project (ie more than one year rotation) for fsae i have heard of terrible experiences mostly related to project management and member retainership. Make sure those undertaking the project are staying the two years!

Another approach may be to have it dedicated to a development project, for the first year, which could include incar testing, and until it is reliable then committ to placing it within the car.

my 2c.

[murpia]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RBbugBITme:
I've started writing a feasibility analysis of going turbo with our F4i and I was just wondering what teams who have put a SERIOUS effort into weighing the pros and cons decided on in the end and why? What kind of arguments did you typically hear from those against the idea? </div></BLOCKQUOTE>
My advice to you is to always use a top-down systems engineering approach to the problem. Set your targets for the vehicle performance / vehicle program, and if done correctly your analysis will decide for you if you NEED a turbo.

For example, your top level targets might be 900 points against the 2007 competition field, on a budget of $20,000 over a 2 year program. Note there is no mention at this stage of weight, tyres, engine etc. etc. As you assign the points, budget and time to each area of the programme (chassis, powertrain, aerodynamics etc.), you can make certain trade-offs. At this stage you will learn whether your powertrain requirements can be met without a turbo.

Regards, Ian

[RBbugBITme]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> My advice to you is to always use a top-down systems engineering approach to the problem. Set your targets for the vehicle performance / vehicle program, and if done correctly your analysis will decide for you if you NEED a turbo. </div></BLOCKQUOTE>

That is exactly what I'm doing.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> I will agree with Pete here. It takes time, money, and a dyno at hand! Wollongong has put in 1000s of hours of development time (most of it on the dyno) to reach the current level of the system. </div></BLOCKQUOTE>

We have our own engine dyno.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Although i have not been directly involved with a long term project (ie more than one year rotation) for fsae i have heard of terrible experiences mostly related to project management and member retainership. Make sure those undertaking the project are staying the two years! </div></BLOCKQUOTE>

Everyone interested in it will be around to see it through.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Another approach may be to have it dedicated to a development project, for the first year, which could include incar testing, and until it is reliable then committ to placing it within the car. </div></BLOCKQUOTE>

Thats the plan. We're going to use it on our 04 or 05 car IF we're ready to start building the system before VIR which I think we will be. Regardless we have a dyno and cars to test on.

[Pete M]

Well, it sounds like you're keen, which is a great start. The engine dyno will make a big difference, we use ours a *lot*. Mainly, my advice is to cut short development and get the thing running. Once its running you can develop more. We did our initial testing with a dodgy plenum that was made years earlier, etc. Don't fall into the trap of building an entire package and then hoping to get it tuned in a day or two a week before comp. The main other bit of advice, which you already seem to have covered, is to drive the hell out of it in a previous car.

[RBbugBITme]

Yeah I've been using the term "bare bones" a lot. I want a bare bones no frills first attempt done as soon as possible with a focus on just getting it running and proper turbo placement to avoid oiling issues while messing with the weight balance as little as possible.

From there at least we'll have real numbers as far as intake temperatures, pressures, actual flow and we can start working on optimization without working off of 100% theory and assumptions.

[moose]

Ryan, you should stop by our shop sometime soon, we can discuss the ups and downs of a turbo that we had a few years ago (mostly downs for us - currently chilling on our wall of shame). But I think that if you guys can justify it for design, cost, and making a better car, then go for it.

And for everyone else, you realize that Drexel's car a few years ago came in 21st (If I remember correctly) so it's not like they are a new program - they know the deal.

[RBbugBITme]

I'm definitely down for a discussion in person. When do you want to meet up?

[Malkovich]

This year, our team as decided to change the engine. We had a F4i and now we will go for a 500 cc. Because of that, we will go for the turbo. We made some model that we validated and for the moment we think that there is no reason why we couldn't have as much power as a F4i or any 600cc.

We are concious that there are some problem with the turbo seals but we already have some options to resolve them. Because we changed the engine, we already have to redesign the complete intake so we decided to go for a turbo right away.
We have the ressourve and a dyno at our disposition.

As an advice, I recommend you to see what the Melbourne University had done since a couple years on their engine. Their power curve for a 430cc engine is so high and so flat, this is almost like having a CVT. They are chocking really early, earlier than a NA 600cc...

Dominic O.-A
FSS Racing
Université de Sherbrooke