Turfrey Pipes

[ns86]

I was very fortunate to have a set of new Turfrey GP pipes offered to me last year. I was going to buy a used set of Lomas GP's and these were offered. I couldn't believe it. Does anyone know if there are differences in his pipe designs or if he made one standard type. These are narrow in the widest part I hope for high RPM. I bought them for a tuned engine thinking they should work better than the Jolly & JL designs without having to build a specifically designed set.

Appreciate any info about BT RZ500 Pipe Specs

[silverstrom]

Maybe ask BT himself? Better than the option you're sure to get shortly

[tacky1]

Lets go

[giron]

I spoke with BT today. He asked me to post this and I’m quoting BT. There is no need for BT to write specs on his pipes since there are multiple folks with the knowledge in the USA and Canada

[ns86]

Turns out that the Turfrey pipes are about 1cm smaller overall width (diameter not circumference) for the fattest segment compared to Jolly Motto. I assume they are for higher RPM, but what do I know? Approximate measurements.

Brian Turfey 9cm

Jolly moto 10cm

JL cm ?

Nikon cm?

Feel free to fill in the blanks.

[lost1750GTV]

did you type in the cm's backwards?

[MK]

If people discuss that diameter is related to rpm, then I guess this is the expertise that BT referred to...

[ns86]

Martin said:

If people discuss that diameter is related to rpm, then I guess this is the expertise that BT referred to...

I'm not a pipe designer but I have heard many times a fat pipe is for midrange, narrow pipe for High rpm, when compared in an equal situation, stock VS stock. Obviously a generalization and relative to porting and what rpm that porting is designed to rev to and how long they are since it's all proportional. Obviously you are knowledgeable, and build pipes as shown in your tutorial.

My NSR250 Nikon pipes are very Fat compared to the RZ500 ones. In itself that means nothing since these 250's have way more Port area than the Rz500 does for an equivalent 125cc cylinder, so it should be much larger logically.

If theres a Jolly Moto pipe for the same STOCK engine that is fatter than the Turfrey pipes, is it incorrect to assume then that the narrower one is for higher RPM tuning, all other things being equal?
I am curious about diameter as a function of ground clearance also. It is an issue with the stock swingarm and GP style pipes, Especially when converting to a 17" rear wheel.

[ns86]

lost1750gtv Said:

did you type in the cm's backwards?

Yes, It's corrected now, Thanx

[MK]

The most relevant dimension related to rpm is length.
Short pipe - high peak rpm, longer pipe = lower peak rpm plus usually more midrange torque.

When the "difference" is just 10mm I'd not really talk of a difference.
Generally spoken the "old" engines with a classic transfer layout don't need a big belly.
They're required for "modern" layouts that have big rounds, point to each other and "collapse" the flow over a flat domed piston.

All of the RD500 pipes suffer from the PV actuation at completely wrong rpms. I don't know what Yamaha was thinking, but ALL pipes included the stock ones benefit from different settings.
Generally spoken the aftermarket pipes require something like 6500-7500 start rpm and 10-11500 as end rpm. That cured a lot of ditches in torque curves like this one from BDK
https://www.bdkraceeng.co.uk/Images/RD5pv-ign.gif
or this TZR 250
http://3.bp.blogspot.com/_K5H5ZY-5C0g/T ... K+Race.jpg

Nowadays you have really nice simulation software like EngMod2T that helps a ton in pre-selecting suitable pipes for your setup.
I have run and successfully build 350 pipes that way.
For example I'm rebuilding my RD350 race bike and the sim pointed me to using the older 31K cylinders as they have up to 4hp more in the 5k region.

I completely understand BT not wanting to talk about that, because no matter what you say, there's always some keyboard warriors knowing better.

BTW: Jolly GP pipes reduced ground clearance so they were not suitable for racing in my case.

[ns86]

My Turfrey pipes are around 4-5 cm shorter and over 10% narrower than Jolly's so it seems they are for Higher RPM. They are tiny in comparison to my NSR250 Nikon's.

Thanks for your input Martin

[MK]

Can someone tell me why all pipe threads escalate that quickly into personal insults?
I mean we're all adults and should behave like that.

[BigGuy]

Can someone tell me why all pipe threads escalate that quickly into personal insults?
I mean we're all adults and should behave like that.

Your not wrong but if your on the outside lookin in it's pretty entertaining, lol

[steveho]

To bring this back on topic.......

Turns out that the Turfrey pipes are about 1cm smaller overall width (diameter not circumference) for the fattest segment compared to Jolly Motto. I assume they are for higher RPM, but what do I know? Approximate measurements.

Brian Turfey 9cm

Jolly moto 10cm

JL cm ?

Nikon 10cm

Feel free to fill in the blanks.

My Nikon's measure 10cm at the fattest segment.

[ns86]

Thanx steveho. Anyone with a set of JL's can measure them? I am guessing they are around 10cm Dia. as well. My RG500 JL pipes are around that. Most are close to the same length.

Seems the Turfrey pipes are Shorter/Narrower than the others and that they are a for a high RPM power curve. It will be running 34mm carbs.

The exception may be the Spec2 which are quite long, so tuned for midrange and maybe fatter less clearance?

I am asking for input, I am making generalizations based on the same engine. Apples to Apples . Thanx Guys'