XT660 with stage 2 cam dyno results
 

Hi guys.

Got a XT660X on the dyno the other day.

Was equipped with a DNA stage 2 air cleaner, no snorkel, head was ported (so they claim) and air age slip-on pipes with a stage 2 raptor cam.

If you look at the dyno results, BLUE is a stock XTX-06 model. Red is the same 06 model XT with stage 2 DNA, powercommander, Leo Vince pipes and custom mapping.

the Green is an 07 XTX, with the mods above and the stage 2 cam.

Note, I also added the PCIII map I made for this bike.

http://i201.photobucket.com/albums/a...x/xtx-stg2.jpg

Quite interesting I thought the stage 2 would have produced more HP up top then it did. A poor result in my eyes for that mod. How well was the head ported Freez? To me it just looks as if a cam is fitted with no porting.

It seems the big bore & stage 1 cam produces more HP & torque then the stage 2 cam with a ported head. I am only look at the difference between the gains from the standard bike to the top reading at 6300RPM.

I have posted my dyno print out with the same rpm settings, only look at the difference between the reading as the dynos are at different altitudes.

Green line 686cc 11:1 piston stage 1 cam CCC cans PCIII both filters snorkel removed
Blue line center one 660cc CCC, both filters PCIII snorkel removed.
Blue lower line standard XT660

http://i201.photobucket.com/albums/aa202/kevxtx/1x.jpg

Hi Freez

Using Winpep can you post the runs for the 686cc, ported head, stage 1 cam, against this ported head stage 2 cam run, HP & Torque on the same page. I just want to see the gains & losses across the rev range between the two mods on the same Dyno.

Thanks Kev


686cc, ported head, stage 1 camshaft.

http://i201.photobucket.com/albums/a...portedhead.jpg

quindi � meglio il cam stage 1 ?
ci sono da fare modifiche per adattarlo ?

visto che sto mettendo il pistone da 102mm cosa mi consigliate
quello di off-the-road non va bene ?
oppure

http://cgi.ebay.com/ebaymotors/HOT-C...mZ280120262147

scusate le mille domande
e complimenti per le prove

Not to sure what you are asking, but that is the stage 1 cam shaft that is in our bikes & displayed on these dyno sheets.

I will wait for Fran to translate for me. My Google translator can't translate a few words.

Hi Kev.

Just remember that this Xt is a stock bore and stroker, so all the runs I have posted are from a 660cc motor with and without the cam. Also, I don't like the slip-on exhaust systems this bike was running. From testing on other bikes, I don't have much faith in them to be really good for performance. I am not sure what this bike would have done with a set of well made slip-ons, but anyway, I tested the bike with what was given to me.

I did not port this head and from what I have seen about other porting by the same person, it looks more like a cleanup job than a proper full on gasflow job. Also, this head uses stock valves and I don't even think they cut the seats again after the porting.

A bit of cleaning here and there is hardly going to make much of a difference.

I can still put the run on here that you requested, but there is no point in comparing a 686cc vs a 660. The 686cc will easily make more power.

It seems to me that the 660cc does not make much power with the stage 2 cam & looses the bottom end torque with not much top end gain.

My 686cc with standard XT cam produces more HP & Torque across the whole range then fitting a stage 2 cam to a 660cc motor.

Thanks for posting the results, all these findings will help to make the best all round build motor for our XT's, giving us the best torque & hp all over the rev range.

Freez how much do you sell your +1mm inlet valves for?

It is hard to say with the exchange rate changing all the time, but I sell a set of intake valves for around $50 to $55 US. In other words about $25 per valve. That's based on $1 US per 7.5 SA Rand.

I normally advise people to take the Manganese bronze guides with those valves. They only add about another $18 for two.

I make them in stock, +1 and +2 sizes

XT Heads
 

Pardon my ignorance if this is a stupid question, but are there any gains to be had by fitting the 5-valve head from an earlier XT or an MZ? Does that head even fit?

I do not think it would fit. :crowded: