201 replies to this topic

[stimps TT Bronze Member]

Well it's time to stop the opinions and roll out the facts (if that's possible). A dyno date has been booked for the 26th Feb to try to seperate fact from myth. Initial plan is something like below. This is all in the aid of seeing what these things really do. It's not cheap so appreciate any input on how we get the most out of this. Need to source a 19" rear road tire this week and get it all ready. If we don't melt it, it should be fun.:thumbsup:


Test Format.

1. Dep+Dep Silencer HPI Ignition on Power setting
2. Dep+Dep Silencer HPI Ignition on torque setting
3. Dep+Dep Silencer std Ignition
4. Dep+Dep long Enduro Silencer
5. Stock 05 pipe and stock silencer (96dB)
6. Stock 06 pipe and 05 silencer (US type96dB)
7. Stock 06 and 06 Euro Silencer (94dB)
8. Stock 06 and PC304 (Once touted as ultimate set-up).
9. PC Works pipe + PC304 Silencer
10. FMF Factory Fatty+Powercore 2 Silencer
11. FMF Factory Fatty+Shorty Silencer
12. 2C pipe + 2C Silencer
13. Rinaldi Pipe+Rianldi Silencer(YRRD)
14. Special Yamaha Works pipe+Dep Silencer
15. Unknown Cone pipe+Dep Silencer

[OW38B TT Bronze Member]

That's a major undertaking........I'll be very interested in the results.

Good Luck!

[brentn TT Addict]

yep I'll be watching this thread.

It would be great to build up a dyno database for the faq, hosting all kinds of dyno charts from different kinds of setups like above.

[shrubitup brap]

Wow, great effort! Wonder if you can find a way to throw in a krizzman style spark arrestor just for kicks. Maybe even a pipe spacer too? Sorry, you've already covered the range quite well! :thumbsup:

[CRF2eR TT Bronze Member]

stimps said:

Well it's time to stop the opinions and roll out the facts (if that's possible). A dyno date has been booked for the 26th Feb to try to seperate fact from myth. Initial plan is something like below. This is all in the aid of seeing what these things really do. It's not cheap so appreciate any input on how we get the most out of this. Need to source a 19" rear road tire this week and get it all ready. If we don't melt it, it should be fun.:thumbsup:

My brother Bob and I did this with our electric CRF a few months ago. We found a 19" tire that worked well. Can't remember offhand where we got it (I'll check and get back to you), but it was made to be a front tire for a streetbike of some kind.


Good luck with your project...
Randy

[KJ790]

CRF2eR said:

My brother Bob and I did this with our electric CRF a few months ago. We found a 19" tire that worked well. Can't remember offhand where we got it (I'll check and get back to you), but it was made to be a front tire for a streetbike of some kind.


Good luck with your project...
Randy

Looks like the same tire I use, mine was a 19x1.85 tire for the front of a Harley. I got it for free as a take off from a local bike shop that was throwing it out.

[SUnruh]

yes, go to any shop and get a used 19" front tire off a road bike. that's what i did. cost was zero.

if changing parts counts as dyno time (like it did on me) then having all of the tools ready and parts needed makes this go a LOT faster. also bring a long a spare waterpump seal as i blew one on the dyno and that shut it down quick. and a means to change it out (ie coolant catch bottle and funnel).

if possible leave the side panels off to help with changing the sparky. you have to leave the seat on as it is a factor for air flow into the airbox and not how you ride it.

dont oil the chain up as it will just make a mess also.

if you have never been on a dyno, your bike will get hot. the entire bike!!! even the tail end of the swingarm will be warm.

have them test in whatever gear gives 1:1 usually it is 4th.
make sure the tranny oil is fresh before hand.
bring along extra plugs and have them pre-gapped.
try to run the same tank of fuel for all the runs.

[Fever2Tel TT Bronze Member]

Thats very cool, but I think we all know that the FMF is going to come out worse than stock, and DEP on top. But will be nice to see by how much. Are you going to rejet the bike after each pipe swap?

How about a test with Vforce3 reeds? I would be very interested to see how much they differ from stock (eiter positive or negative).

And that RB designs carb mod, I have often wondered if its beneficial....

I cant wait to see your results!!!

[harrperf TT Addict]

Some words of testing wisdom.

Coolant temp is very important...you should keep it consistent at the start of each run.

Also, EGT is very important. If would not be fair to each product to not test it at the same EGT because it dictates how the pipe works (and thus how you engine produces power)

If you can measure it...do so! Then with each change of product try to get the EGT to the same number. One main jet is about 50F change EGT

And lastly...run each "run" as a couple runs....aka if your testing a pipe...do a spool up..let it come back down...rest a little to get coolant temps back..then spool up again..then back down...and usually a third is necessary. You will usually see the dyno curve shift to the right. It's due to heat soaking...but important for equal testing.

[brentn TT Addict]

Air temp and humidity would be important yea? Is there usually a way to control this in a dyno room?

First it needs to be jetted right for that air temp/humidity/elevation before any of the tests should be done?

Or are we getting too picky on the controls in this experiment :D

[RCannon]

harrperf said:

Some words of testing wisdom.

Coolant temp is very important...you should keep it consistent at the start of each run.

Also, EGT is very important. If would not be fair to each product to not test it at the same EGT because it dictates how the pipe works (and thus how you engine produces power)

If you can measure it...do so! Then with each change of product try to get the EGT to the same number. One main jet is about 50F change EGT

And lastly...run each "run" as a couple runs....aka if your testing a pipe...do a spool up..let it come back down...rest a little to get coolant temps back..then spool up again..then back down...and usually a third is necessary. You will usually see the dyno curve shift to the right. It's due to heat soaking...but important for equal testing.

I have no idea what "EGT" is. Is there a specific number you woudl tune "to" if that were an option?

The only internet search that turned up was for "ETG" which is a drug/alcohol test...oddly enough, I am familiar with that one!

[shrubitup brap]

Exhaust Gas Temperature.

[7thirtyseven TT Silver Member]

Exhaust Gas Temperature

[phil-coley TT Bronze Member]

well done stimps ,sounds like a long days work. great for us yz riders.phily cee

[RCannon]

7thirtyseven said:

Exhaust Gas Temperature

Oh.....Well, now that you put it THAT way.....LOL

I never made the connection.

How about a paypal account Stimps? I certainly would not mind buying the gas for the test or something....I mean Petrol. I THINK thats what you folks call it.

Dont let that hot exhaust pipe hit you in the fanny.

[7thirtyseven TT Silver Member]

Maybe harprf could dish up an egt temp that is ideal, or is consistancy more important?

[APBT TT Silver Member]

7thirtyseven said:

Maybe harprf could dish up an egt temp that is ideal,

They are frequently a thermocouple type probe that protrudes into the exhaust gas stream at a specified distance from the piston face. English translation: You drill/tap/thread a hole into each pipe to put the probe into.

[harrperf TT Addict]

7thirtyseven said:

Maybe harprf could dish up an egt temp that is ideal, or is consistancy more important?

It's the consistancy...for one to truly know and engine and what **their gauge** reads they usually have to burn it down once to find the limit with where their gauge is.

That said...most people tune around 1250 to 1300 F.

That is about the limit before piston melting occurs...some GP teams haver rumored to push it higher...but it's playing a fine line...and as stated where you gauge is...what guage etc...plays a role.

Most important for dyno testing is to stick to one EGT. So if the bike is jetted well on the race track...and first dyno test is at 1200, all remaining tests should be jetted to 1200 for fair results.

[BDubb106 TT Addict]

I noticed you have the PC silencer stock pipe combo but how about a fmf shorty with the stock pipe... I see ALOT of ppl using this combo in my area no matter what the make of the bike so I thought it must work fairly well?

Regaurdless Im def interested in your results! Your already taking on a huge task.

[4T_thumbs_down TT Bronze Member]

C'mon Stimps!!!! Make it so! :ride:

Thanks for feedbacks, complete with dyno readings haha! :thumbsup:

Suggest to sticky this on top, in a separate thread please! (my wishful thinking) :D