ESR exhaust flange

[zcarlson12]

Does anyone have any experience with the ESR "torque" exhaust flange? I'm ordering a bunch of stuff from them tomorrow and saw the option. ESR 310 on race gas if that helps. Thanks.

[ryanowarrior]

I just bought one and put it on....it's been rainin for a week straight so haven't got to try it out...hopin the o-ring design works better than the gasket too

[Bowtie316]

My buddies new 310 kit came with one, it has a smaller ID.  We didn't use it for that fact.  It might help low end torque, but I would  think it would give up high rpm power to do so.

[zcarlson12]

Thanks guys. I did see that the ID is smaller but I was interested to see if anyone had any seat time with one on. It's probably not a noticeable difference so maybe I'll just get one and see for myself.

[jamieg45]

I was taught to always open up the stock ones a little more to match the cylinder from a old pro rider engine builder. So I would be curious on how it works too zack.

[supernutt]

I had the smaller ID one on an unported cylinder with reeds, a bigger carb, and a pipe.  It ran ok but it is smaller than the outlet on the stock cylinder is so I didn't use it on any of my ported motors.  I think I measured it and I remember like 1.6" and the stockers and regular flanges were 1.71".

[zcarlson12]

Finally getting around to doing some work on the R today. Is there a specific torque for the exhaust flange bolts? Thanks.

[jcs003]

this is a good question for jerry hall.  he told me he has done testing with alot of different set-ups and combinations.

john

[etccb]

I remember seeing torque incerts that slid into the flange back in the day. I have also seen ex systems that had a sleeve welded to them that slid inside the flange when installed.

[Pumashine]

Aren't the 6mm bolts to be torqued to 6 ft-lbs just like 6mm clutch bolts?

[Jerry Hall]

this is a good question for jerry hall.  he told me he has done testing with alot of different set-ups and combinations.

john

I have not tested the ESR small diameter flange.

The exhaust flange inside diameter is part of the overall design of the whole cylinder and pipe combination. The Cr 250 cylinders traditionally have had a much smaller exhaust flange and head pipe diameter than the TRX cylinders, but their exhaust port designs are totally different.

My best results when developing pipes has been when the head pipe ID, exhaust flange ID and exhaust port ID are all about the same.  Like someone else mentioned, a lot of pipes use to have inserts that would fit inside of the stock flanges on some of the old Bills and FMF pipes. Sometimes the reducer sleeve would help.  I think the reducer sleeves were an attempt to fix a design problem on the rest of the pipe.

[udontknowme]

what diameter manifold does 250r typically use ?

[Jerry Hall]

what diameter manifold does 250r typically use ?

I am at home and do not have access to my parts or files.  I think that the ATC/TRX 250R exhaust flange ID is 45mm and the CR 250s are about 40 mm ID.

[udontknowme]

thats seems about right. ktm 250 is 40mm also. 45mm sounds like a more proper size though atleast when you start raising the rpm and power

[JasonB]

hadnt heard about these yet. i have the basic billet ex manifold they sold me with my 310 motor for race gas, has held up great for 30+ hours of abuse though. interested to get feedback on these