Turbos

[OPP]

Can anyone who has used a turbo in the past provide a description of any problems they encountered?

Thanks.

[OPP]

Can anyone who has used a turbo in the past provide a description of any problems they encountered?

Thanks.

[Big Bird]

Hi there OPP,

We ran a turbo last year at RMIT, I'm sure anyone who was at Carrum Downs could tell you what happened. Turbo failure on Saturday meant the car was a mobile smoke screen. Eventually we were put out of the comp, (gearbox funnily enough) but not until after the turbo had stuffed us around no end.

A few brief notes, and I'm not the engine guy so please excuse the generalities. We had a lot of troubles initially with seals sucking out of the turbo, and ended up replacing the seals with those tricko carbon ones that Garrett have. (There were also suggestions of building a bypass so that the seals wouldn't be subjected to vacuum). I think there were also oil feed problems to the turbo due to the pump not being strong enough. We blew two turbos on the dyno during tuning, fortunately not causing major engine damage. We also had a lot of problems building a strong enough intake system to cope with the boost, took three iterations to get it right. From all the above problems, I would estimate that turbo issues added at least five to six weeks into our build process, and even then we didn't get it right as the damn thing did a bearing at the comp.

I going to assume you are from Melbourne Uni? You guys are the only ones here in town that were considering going turbo this year.

I am sure you will realize from the above that I'm not particularly fond of turbos, at least in this comp. But I would STRONGLY suggest that you guys leave the turbo alone, for this year at least. The home-built twin that you are doing will be challenge enough, and until that is up and running and bug-free, then going turbo is only going to add more problems than it is worth. I don't imagine you have had your car running yet? Unless you have had the thing on track, and running well without hiccups and reliability problems, then you will be just making life harder for yourself.

You will get plenty of accolades by building your own engine if you achieve it, so no need to complicate matters too far. When it all boils down to it, a turbo is going to add even more into your development and build time. I personally believe that for most of us getting the car done early and getting the drivers used to it will do more to cut lap times than time spent chasing horsepower.

Sorry to be the pessimist, and I know that there are some teams around that have successfully done the turbo thing, (Cornell comes to mind - but they haven't had to develop their own engine block as well). But a lot of comments came our way last year about learning the hard way, and I think you will be a lot more successful and enjoy the event more if you let the turbo ride for the moment.

All the best,

Geoff Pearson
RMIT FSAE 2003

Design it. Build it. Break it.

[Sam]

I heard that you guys got some kind of prototype turbo that garret had not put into production = troubles.. is that correct?

Sam Graham
Engine Group Leader 2003
UQ Racing

[PatClarke]

Hi Geoff and all,
I remember the requests from your engine guys for permission to vent the seal to atmosphere to reduce the load on the seal.
The rule states that ALL air must pass through the restrictor, so venting to atmosphere was clearly not permitted, and there are many precedents. If any team have modified their turbo with a bleed hole (no matter how small) they better correct it before the comp.
In fact there is a request currently before the rules committee for permission to do something similar (not relating to the FSAE-A comp).
But, while the rules stay as they are (Intake...Throttle body....restrictor....turbo supercharger....engine) pressure drop across the turbo seals is going to be a major source of trouble.
Regards
PDR

Rudeness is a weak mans imitation of strength

[Big Bird]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Sam:
I heard that you guys got some kind of prototype turbo that garret had not put into production = troubles.. is that correct?

Sam Graham
Engine Group Leader 2003
UQ Racing <HR></BLOCKQUOTE>

Yep, the turbo we had was some pre-prod variable geometry thing. Having said that, I don't think the problem was so much with the turbo as the application - see Pat's note re seals.

Cheers,

Geoff Pearson
RMIT FSAE 2003

Design it. Build it. Break it.

[gug]

how have you guys gone with garrett in australia? ive seen the awesome deals they do the US teams, but when we approached them they didnt really want to know us.

- if it isnt coming, you need a bigger tool.

[OPP]

Thanks for your input Geoff.
I'm at Melbourne, but just an interested observer rather than a team member.
It seems to me that there is a strong push to run the turbo, but time constraints may prevent it.