the DR650 thread

[Rex Nemo]

Originally Posted by motolab

There's something wrong with the data in the chart, as the O2 can't really be 20-22.5% (ambient is roughly 20.95%). CO2 is also way too low. A good running engine should have upwards of 10%.

Regards,

Derek

Yep, the dyno is old and crotchety, and the 02 and C02 numbers are highly suspect (in-pipe sensor may be at fault). Would that affect the hp or torque ratings? If so, back to the drawing board.

[rpet]

Thank you! I will do bars and wheel first, and decide on the seat based on whether I get knee pain. I'm more concerned about that than flat-footing (my legs are pretty long).

Originally Posted by kristofer

1. I am 6' and ride my DR650 with bar risers (1,5"?) and stock seat. I think that it suits me just fine that way. I have the 18" rear wheel and it is probably 1,5" taller in the forks and 2" in the rear. I can still get my feet down good enough, but I can't flat foot both at the same time.

2. I have the stock header and airfilter in an open airbox combined with a MXRob 39 mm FCR-MX (mated to a Lazer home-made slip-on). I have ground down the lug in the header a little, but have not gone crazy with it. So I would say no, there is no need. I'm 175 lbs and haul 30-40 lbs of gear with a 23 ltr fuel tank. The DR becomes pretty quick with that carb :)


All the best,
Kristofer

[Albie]

Originally Posted by Multisurface Rider

My new to me 01 DR650. Had a Corbin seat on it I don't like so I built my own.
Need some risers and then ride.

Looks good!!

[Feelers]

Originally Posted by motolab

There's something wrong with the data in the chart, as the O2 can't really be 20-22.5% (ambient is roughly 20.95%). CO2 is also way too low. A good running engine should have upwards of 10%.

Regards,

Derek

Shouldn't we be seeing around 40 or so ft-lbs for the torque as well?

[JagLite]

Originally Posted by Multisurface Rider

My new to me 01 DR650. Had a Corbin seat on it I don't like so I built my own.
Need some risers and then ride.

Excellent work sir!

[Rusty Rocket]

Originally Posted by acesandeights

For less than $1k, is there anything better than Racetech emulators and springs up front and Racetech shock shaft assembly and spring in the rear? This is for a Baja trip ~2k miles (mas o menos).

Depending on your weight whether you can still use the stock rear spring.

I sent my rear shock to Cogent and had the upgrade. (Cogent has a damper adjustment) I bought .47 Racetech springs and the Cartridge Emulators. Did the fork work my self. That all cost about $750. Great improvement. (really great) I was able to still use the stock rear spring. If you are over 190lbs, you will want to get a heavier rear spring. That included will put right about $1K.

It is the very next thing you should do after a skid plate, handguards and a DJ kit. Makes it a different bike! Maybe even do it before the DJ kit

[acesandeights]

Yep, I'll need a new rear spring. Doesn't Cogent just rebuild your shock using Racetech components (maybe I'm way off)? I wonder why people use him if they can buy the Racetech shock shaft assy, or do the Gold Valve for even less? Not knocking Cogent, but I just don't understand what he does that Racetech doesn't offer as an assembly, or as a Gold Valve kit? Why would sending it to Cogent be better than the shock shaft assembly? Maybe Cogent isn't using Racetech components/Gold Valve?

[Adv Grifter]

Originally Posted by rpet

I'm very close to owning a DR.

I have 2 questions:
At 6', and used to riding an XR250R (and DH mountain bike) and hoping to take this bike on either the TAT or CDT plus extra offroad touring credit next year, I am looking at RC High bars, Rox risers and high seat foam, plus an 18" rear wheel. Not looking to lower the pegs and reduce any ground clearance. Should that be an OK starting point for ergos?

Lots of guys run risers and Pro Taper bars. Good set up.

Most custom seat makers can build a "Tall" version, raising you up at least an inch, maybe two? Should help transitioning from seated to standing.

What is your thinking on the 18" wheel? It WILL raise the bike up quite a bit, depending on tire you use. Other than that, what is the advantage? Where will you source the wheel? Will the bearings (Hubb and wheel) hold up with an 18" wheel? Also, fewer 50/50 and street based dual sport tires available in 18". Your choice. If doing "all dirt" then the 18" makes more sense.

In the end, Ergos are quite subjective. Mess around, try different things, go riding, make adjustments as needed!

Originally Posted by rpet

2nd question: is a Q4 muffler fine or do I need to consider a header upgrade if the maximum performance mod I plan to do would be a carb, but probably sticking with just opening the airbox and replacing the filter. I'm generally skeptical on spending bones on headers if not overboring with cams, etc. I weigh 155lbs and pack light.

Great thread, but too much info to digest in a week (or a year).

thanks guys!

If you're a trail rider ... then your first concern should be suspension. But since you're only 155 lbs. (lucky bastard!! ) The stock DR spring rates are not too bad for you ... but still will be a bit "quishy" for aggressive riding. The DR's handling (both ON and OFF road) responds really nicely to suspension upgrades. Just for future thought and upgrades.
FMF
I'm not an FMF fan ... I know them well, have used their products on dirt bikes (and street) since the late 80's. My DR650 came with an FMF pipe ... the rivets started coming out at 4000 miles. I sold it. Also, it was TOO LOUD ... and needed constant repacking. FMF pipes fall apart. IMO? JUNK.

The current hot set up for the DR650 is the Titanium GSXR pipe. It's not as light as the FMF but is super high quality ... will last forever, NOT TOO LOUD. Flows pretty well too.

[Mongle]

Originally Posted by Feelers

Shouldn't we be seeing around 40 or so ft-lbs for the torque as well?

No

HP and Torque are mathmatical.

HP= Torque x rpm / 5252
Torque= 5252 x HP /rpm

A DR making 40 ft lbs of torque at say 6000 rpm would have almost 47 HP...which would be nice...but probably not possible in stock form.

edit: 5252 is a constant number in the math...if you look at a dyno chart HP and Torque ALWAYS cross at 5252 rpm...if it doesn't something is wrong.

[Rusty Rocket]

Originally Posted by acesandeights

Yep, I'll need a new rear spring. Doesn't Cogent just rebuild your shock using Racetech components (maybe I'm way off)? I wonder why people use him if they can buy the Racetech shock shaft assy, or do the Gold Valve for even less? Not knocking Cogent, but I just don't understand what he does that Racetech doesn't offer as an assembly, or as a Gold Valve kit? Why would sending it to Cogent be better than the shock shaft assembly? Maybe Cogent isn't using Racetech components/Gold Valve?

Cogent puts his own parts in the shock and you end up with a knob on the bottom of the shaft that has 30 clicks of rebound damping adjustment. Cogent also offers a hard anodize coating for a few bucks more that I believe is a good idea if the shock is of a certain age, if you know what I mean.

see the red knob in the photo: not there with a RaceTech mod. you live with the damping as it comes. Cogent is adjustable.

[ER70S-2]

205'd by Rusty

Originally Posted by acesandeights

Yep, I'll need a new rear spring. Doesn't Cogent just rebuild your shock using Racetech components (maybe I'm way off)? I wonder why people use him if they can buy the Racetech shock shaft assy, or do the Gold Valve for even less? Not knocking Cogent, but I just don't understand what he does that Racetech doesn't offer as an assembly, or as a Gold Valve kit? Why would sending it to Cogent be better than the shock shaft assembly? Maybe Cogent isn't using Racetech components/Gold Valve?

They add rebound damping.

Reusing our stock shock body keeps the remote oil resevoir, additional oil capacity adds to cooler running and longer service life. I have 27,xxx miles on my Cogent.

[Rusty Rocket]

Originally Posted by Mongle

No

HP and Torque are mathmatical.

HP= Torque x rpm / 5252
Torque= 5252 x HP /rpm

A DR making 40 ft lbs of torque at say 6000 rpm would have almost 47 HP...which would be nice...but probably not possible in stock form.

edit: 5252 is a constant number in the math...if you look at a dyno chart HP and Torque ALWAYS cross at 5252 rpm...if it doesn't something is wrong.

Horsepower can be misleading. 2 engines making equal foot-lbs of torque will have different horsepowers if they are acheiving them at different RPM's. The engine making the same torque at the higher RPM will have a higher horsepower. Say a 125 makes 40 ft-lbs torque @ 10,000 rpm and a 650 makes 40 ft-lbs at 6500, the 125 will have more HP> I'd rather have my torque from a lower revving engine so it lasts longer



The old saying (If I remember it correctly) Power, light-weight, reliability; choose any two.

[acesandeights]

Per Racetech and Procycle's site the Racetech has that same knob, with rebound adjustment.

[motolab]

Originally Posted by Rex Nemo

Yep, the dyno is old and crotchety, and the 02 and C02 numbers are highly suspect (in-pipe sensor may be at fault).

The failure mode of the type of O2 sensor used in the Andros gas bench is that it begins to read higher than normal. I suppose that if left uncorrected indefinitely, perhaps it could read as high as ambient. The software should throw a flag if the sensor is bad (unless it was spanned when it was no longer new). You can take the sensor out and check the voltage across the terminals. It should read 9-13mV, with much below 9mV meaning the sensor is bad.

HC is also quite low, perhaps unrealistically so. Unfortunately it is the infrared part of the bench that reads CO2, HC and CO. I therefore suspect that the CO readings are inaccurate as well.

A leak on the vacuum side of the pump would produce high O2 and low HC & CO2 (perhaps the drain valve in the first water trap is open). What doesn't seem to jive is that a leak on the vacuum side should also produce low CO, but the CO is in fact too high. That either shoots my theory to hell, or indicates that the CO is in fact much, much higher than the reading (!).

Would that affect the hp or torque ratings?

These readings do indirectly affect the HP and torque readings. If the CO is in fact inaccurate, and is in reality through the roof, then torque and HP would improve based on the jetting being corrected (it should improve a bit even if the CO was accurate).

If so, back to the drawing board.

To get a proper apples to apples sense of which of the parts work better, the combinations must be compared to one another when jetted correctly (I noticed that you don't have a CO trace for both runs, so you'd not be able to compare even if the data were not suspect). I would therefore fix whatever was wrong with the EGA and start over.

Regards,

Derek

[ER70S-2]

Originally Posted by acesandeights

Per Racetech and Procycle's site the Racetech has that same knob, with rebound adjustment.

I learn something new every day.