I am looking for someone that is looking to help me out. I go to the University of MD and am in an engineering calss in which we are building a miniature indy car, in a competition called FSAE. We are to race the car in deoit in may. We are thinking aout using the YFZ motor over an R-6 sport bike motor. I know it sounds like no contest but either motor has to breath through a 20mm restrictor. I was wondering if there was anyone out there that would be willing to let us machine a restrictor, and have you put it on your YFZ and then you give it a test run just to let us know how much power you lost from it. If you can do this or know someone who can please contact me at my e-mail. cbarbour@umd.edu

 

College boy, you do understand how much airflow your gonna lose thru that much restriction, right???

A stock carbereator is like 40-42 mm, sucking thru a 20mm pipe....... do that math thing and the R1 is an expensive vacuum cleaner.

Maybe you ought to ask some of them NASCAR boys, cause you got yourself a college course on how not to build a NASCAR restrictor plate.

Better yet, how about installing a Turbocharger, anything in the rules against that.????? A tubo thru a 20mm intake pipe might work!

 

No turbo allowed, then maybe NOS injection into the 20mm pipe, yahooooo!

 

These engineering classes have super strict rules....

Hey Craig...I don't think the yfz will perform to its max...
is there a cc limit...
are you looking for hp or eficiency
can you run a 2 stroke
can you make/machine your own parts

to get that motor to run hard on that little air...you will most likely need to go with a smaller cam

This sounds like a heck of a project...why not the raptor motor? XR650r motor
CRF450r

 

Looks like some uneducated person hates higher education here.

I think you will need to change the cam, limit engine RPM, and possibly run a smaller carb to make the best out velocity and use of minimal airflow.

 

WE are not allowed to use a two stroke and we are looking into forced induction, we just don't know which one we are going to go with yet. We are in the process of doing the calculations of the amount of air flow we are going to be able to get through the restrictor. There is a 600cc limit on the engine. We need to come up with the power to weight ratio of the stock YFZ mtor and the stock R6 motor to see if the weight savings is enough to compensate for the power loss of a smaller engine.

 

BUDXXX i do realize that we will lose a lot of power going through a 20mm restrictor, most teams in the competition do use an R6 motor. We are trying somthing that hasn't been done in this competition before. Do you know anyone with a YFZ that will let us design a restrictor to put on? We know we need the airflow calculations, if we could just havea magic equation to do it we would, however it is A LOT more complicated thatn that.

 

If you want a motor that can take a beating and still has the potential of producing around 35hp,and wieghs about 25lb. You need to talk to any Jr. dragster racer. the can modify a 5hp Briggs & Stratton engine to run 74MPH in the 1/8 mile!! and the whole Dragster wieghs around 220lbs, and your Indy car will probably wiegh less.


Good luck!! sounds like a lot of fun!!





Bigger.

 

yeah those engines need air, if not they ant even gonna run

 

With the restrictor, I feel another engine designed too provide more low end power (TORQUE) would be a more wise option.