GT-POWER help...

[Pedrot16]

Hi guys!

I´m from a new team, we are gonna for the class3 competition so we only have a wrecked engine right now to make some measurements and CAD.. (next year we are gonna get a new one http://fsae.com/groupee_common/emoticons/icon_smile.gif)

I´m doing some research into intake and exhaust optimization but GT-Power is gaving me some strange values: 104hp @11000rpm and power keeps above 80hp until 14000rom..
I think i´ve some parameters wrong, but i have no chance to get values right from the dyno since we have no dyno at all http://fsae.com/groupee_common/emoticons/icon_smile.gif, and we have a wrecked engine... I think the error comes from the cylinder friction parameters and the combustion parameters (optimum spark time @11000rpm using si-turb is 20º!.. does anybody have good values for the si-turb or data for the combustion vs rpm for the si-wiebe?).
I´ll apreciate some help with this parameters, thanks very much

Sorry about my english
Pedro Lima a30388@alunos.mec.ua.pt
"Drivetrain Guy"
Engenius UA Formula Student uart.proboards205.com www.engenius.pt.vu (http://www.engenius.pt.vu)

[Pete M]

Programs like GT-Power need a lot of empirical fudge factors if you care about the numbers being absolutely right. I doubt anyone is going to be able to give you all the data you need to get the model accurate. What it can be used for quite effectively is getting trends on changes. You can still tune your intake and exhaust somewhat, just ignore the absolute numbers and look at the shape of the curve. Make sure you've got all the flow-related data right though, such as cam profiles.

Normally, i'd say that you really need to back that up with dyno testing, but that's not an option for you, so i guess looking at other teams' curves is about the best you can do. I'd give you ours, but we're heavily turbocharged, so it's not exactly meaningful.

[Pedrot16]

Yes thanks, that´s a good point, thanks, thats what im gonna do, playing with the intake and exhaust, next year with a dyno maybe we have most of the work done with fluids.

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

But there´s anyone that wants to share at least the cylinder friction parameters?