Factory Pro Tuning - Jetting and Ignitech Optimization

[erock768]

Reposted from my thread over at North American Two Stokes- As this is very TZ focused I though you all would enjoy this report from my trip to Factory Pro to get my TZ dialed in for the upcoming season.

2/8/2018 – Factory Pro Tuning

I don’t know where to start this. Partially because I haven't yet gotten home from my epic 1600 mi round trip to Factory Pro Tuning in San Rafael. I'll get right into it. Based on my experience riding the bike on Jan 28 I had committed to bringing the bike to Marc to have it dialed in. (see previous test report). So last week I made the call and booked Thursday to spend with Marc dialing in the TZ. I left work at 2PM on Wednesday. Drove 745 mi to Cupertino to spend the night with friends. Arrived at 12:320p and was up at 6a to drive the last 60 mi across the Golden Gate to Factory Pro in San Rafael.

Why Factory Pro? Because Marc Salvisburg is the guy who has tuned Rich OliverÂ’s, Chuck Sorrensen’s and Roland Sands’ TZ (among many many others) on his EC977 eddy current dynamometer. The factory pro dyno and their software does things that no other dyno can do and with Marc's expertise the two are a great combination. The dyno is simply the tool to separate the bullshit from reality.

With the bike on the dyno and warmed up we started on the first test program. The dyno is an eddy current load control that enables stepping of the load to hold a predetermined RPM. The data acquisition also has a 5 gas analyzer to observe mixture in real time. The first run consisted of running idle and 100% throttle opening at 8000, 9000, 10000, 11000, and 12000 RPM steps. Repeated for the left and right cylinders to see WOT mixture. The procedure was repeated at each RPM step on each cylinder but at 100, 75, 50, 25 and 12% throttle opening to assess mixture at each RPM step and respective throttle position. Changes from the firsts session. Up the mains 1 step, lean the nozzle 1 step, richen the Power Jet and Pilot jet 1 step.

With the changes made we put the bike on the dyno for run 2. Repeated the entire test procedure as before and then moved onto ignition tuning. It was evident that the bike was making great power, but was falling off by over 50% at 12,000 RPM. Here's the beauty of the Ignitech – you can change the advance in real time while the bike is running. The bike was again run to each RPM break point (in the advance map) but then Marc would advance or retard the timing at that RPM until the most power was made. We worked through the RPM range up to 11,000 RPM where we gained 1-3hp across the entire range. Again at 12,000 the power fell of dramatically. Advancing the timing yielded no improvement, but sequential steps down resulted in increased power until the bike was putting down more power at 12k RPM and continuing to overrev without the power falling off. This was a revelation. The bike was a stonking monster pulling damn near off the clock. After the 40 minutes or so on the dyno for that run we looked at the data. Mid range and top end jetting was spot on. Slightly lean and unsmooth at very small throttle opening and high RPM. Changes: Richen both needles one clip position.

Changes made and back on the dyno for run three. This time were working on dialing in the power valve curve and assessing the partial throttle response at high rpm. Repeat same stepped procedure but only at 8K, 9K and 10k RPM steps at 25 and 12% throttle opening. Test sequence done we start to tweak power valve curve. Multiple iterations show that the bike is not sensitive to power valve opening. It's more like a light switch. Below X rpm PV close, above Y RPM PV open. We tweak the curve to be less like a curve than a step function. Bike pulls clean of bottom and comes on HARD. End the run and pull the data. Right hand cylinder partial throttle is spot on, left side is a bit lean. Recommended changes: Lean the left cylinder pilot 1 step, richen the needle 1 clip position.

With the changes made bike up on the dyno run4 and what would be the final run. Asses partial throttle again as performed previously, then some dyno pulls from down low to max RPM and in between. Power is butter smooth and making more power everywhere (from where we started). End session and look at data. Left and cylinder partial throttle is improved. Bike is a good as its going to get.

To recap, what did we learn? The dyno is a fantastic tool. I could spend another day just trying different combinations of parts, heads, pipes and silencers to see the effect. But given where we started the bike is fantastic with the ignition fully mapped and the jetting spot on– for the most part. You can always refine the partial throttle- high rpm by fiddling needles and slides etcÂ…but since I only have one needle and slide option it was just a matter of making my combination of parts work best. Marc passed on a tid-bit he learned from Rich Oliver about making the high RPM partial throttle as smooth as it can be– as that initial tough of throttle after entering the corner is key. Ill quote Marc when he says (tongue in cheek) that“2T tuning is just making it suck less”.

Also, I also learned that the only real way to know if you're going the right direction with respect to tuning is to have the right tool for the job. “Pretty spark plugs don’t tell you if you’re making the most power.” And learned at what temp most power is made.

I'm sure all of you would like to see some before and after graphs, and see some hard numbers. Well, I am going to withhold those as the numbers are only relevant when comparing bikes running on that dyno. Fortunately for me, Marc has run all the top AMA 250GP bikes on this exact dyno and I can see where mine stacks up. And I can tell you that it is among the best. You can see all his dyno numbers on his website www.factorypro.com

I had a great time and I learned a lot. Guys like Marc and Raul (partner at Factory Pro) are getting older and the market for tuning expertise is unfortunately shrinking. This post ends on a bittersweet note, at least as far as I'm concerned. Marc and Raul are getting older and the business isn't what it used to be. Think glory days of AMA in the 90s for reference. When these guys decide to no longer do what they do we will have lost a great deal of knowledge with no one left to carry the torch. I am lucky that I got to experience first hand what the top AMA 250GP guys were doing to get every last bit out of there machines, and for that I am grateful to Marc and Raul for everything. It was worth it.


Ready To Start


Gandalph at work


Super serious dyno room selfie


Wrapped and ready to head home.

[Super Dave]

Marc's a bright guy, and he's got a great dyno.

[andmak500]

Eric,

Excellent write up with lots of information. These guys seem extremely thorough. Wish they were closer so they could set my TZ up as they did yours.
Thanks for taking the time to share.

[galloway840]

Thanks for sharing. Great writeup.

[vince24x]

That pretty much sums up my experience w/ Marc, doing pretty much the exact same thing (Ignitech setup/optimization). I couldnt agree more w/ Eric that Marc is one of those incredible resources for us 2T guys that are getting more and more rare. Sad.

If anyone has the opportunity to get with him, it could quite literally be the best money you can spend to make your BIKE faster.

vince