Some fun testing - motec sidewinder

[Brent68]

Really nice setup. I see the knock levels are certainly pushing the limits of the fuel octane. Are you running straight 91 or with some Lucas additive as well.

Judging by your clutching parts and rpm you are making great power, well beyond what the stock turbo and any tune can support on pump for sure!

Looking at working towards a similar setup for my winder. Currently maxed out at 18psi with a cold air intake and header on straight 91 pump with stock turbo.

I do have the a small bottle of lucas in this tank, I'm guessing about 93 octane. It did exceed the knock threshold during tuning. I found during boost ramp up, it needed a good deal more fuel to avoid a knock event. Looking at the log file, I was thinking about going up another .5 psi .....

I was thinking of adding a header like you have but was concerned about heat issues on the trail. Do you think it would work for a trail set up?

 

[68gmc]

I do have the a small bottle of lucas in this tank, I'm guessing about 93 octane. It did exceed the knock threshold during tuning. I found during boost ramp up, it needed a good deal more fuel to avoid a knock event. Looking at the log file, I was thinking about going up another .5 psi .....

I was thinking of adding a header like you have but was concerned about heat issues on the trail. Do you think it would work for a trail set up?

I have the 321 Stainless headed from Precision and the factory heat shields fit with only a slight modification. No issue with cracking or heat after over 3000 trail miles. I think header would allow you to truely maximize your pump fuel trail setup but Precision headers are only available with a stage 4 kit. I know you can get Hurricane headers individually but I have not tried one so unsure if they are suitable for a trail setup.

Thanks for the quick reply. Appreciate the information!

 

[68gmc]

Here is a quick log of stock turbo with header on pump 91

 

[68gmc]

And here is a similar boost level as my Sidewinder on my 1200 Turbo Doo on 87 Octane. You can see how quiet the engine is with this particular timing and boost level. This is initial testing with Garrett GTX 2860 Gen 2 turbo. Moving on to a GTX 3071 Gen 2 and trying to maximize pump gas tune with torco/lucas. Shooting for 400 on 91 pump with a little additive help. Once finalized I will move on to the Winder and try to max out the pump tune on that after a turbo upgrade. Always interesting to see how far we can take these sleds on the trail with pump fuel.

 

[Fleecer]

I struggled with rpms to high at the start of a run, then dropping. Took me a while to figure it out. I had to add shimms to the spider on my stm clutch, I know that you cannot add shims to yamaha clutch, however you can use smaller diameter rollers which have the exact same effect. This is a big adjustment as it really allows your clutch wieght to be effective at lower shift ratios, you will then be able lower your arm weight to get your rpms where they need to be on top end.

Boostfever, can you shed some additional opinions on advantages/disadvantages of various roller size.

For example, if a guy runs a helix with too much initial/start angle and sucking rpms too low, would bigger rollers fix this?

Do rollers control first half of shift, or all of it?

What would be difference between 14.5 rollers vs 15 vs 16 etc in your opinion..
.....100 rpm gain per .5 up in size?

Thanks

 

[Brent68]

And here is a similar boost level as my Sidewinder on my 1200 Turbo Doo on 87 Octane. You can see how quiet the engine is with this particular timing and boost level. This is initial testing with Garrett GTX 2860 Gen 2 turbo. Moving on to a GTX 3071 Gen 2 and trying to maximize pump gas tune with torco/lucas. Shooting for 400 on 91 pump with a little additive help. Once finalized I will move on to the Winder and try to max out the pump tune on that after a turbo upgrade. Always interesting to see how far we can take these sleds on the trail with pump fuel.

Very clean clean knock readings! You could push that one harder for sure.

I used the 3071 gen 1 and made fantastic power with it on pump gas. It did have some lag on the trail. Changing the the compressor wheel to hta/htz made a noticeable improvement. With antilag it’s a brute. Next week I will compare it to the this setup.

 

[Brent68]

Here is a quick log of stock turbo with header on pump 91

I noticed your timing is at 33 degrees. I couldn’t ever get much past 24 with the stock turbo at your boost level. I’m very interested how you did this?

 

[68gmc]

I noticed your timing is at 33 degrees. I couldn’t ever get much past 24 with the stock turbo at your boost level. I’m very interested how you did this?

The 33 degrees timing is using the stock ECU. The Motec M1 setup on your sled uses a different crank index so a direct comparison of timing values from one to the other is not possible. The 33 degrees on the stock ECU is aggressive though and is only possible with fresh 91 fuel and utilizing the header and a richer lambda value to pretty much max out pump fuel tune with stock turbo.

 

[boostfever]

Boostfever, can you shed some additional opinions on advantages/disadvantages of various roller size.

For example, if I guy runs a helix with too much initial/start angle and sucking rpms too low, would bigger rollers fix this?

Do rollers control first half of shift, or all of it?

What would be difference between 14.5 rollers vs 15 vs 16 etc in your opinion..
.....100 rpm gain per .5 up in size?

Thanks

I believe brent got his setup to work without changing the rollers.
A smaller diameter roller essentially puts your cam arm in a higher starting position, the same as adding a shim behind a the spider of a clutch which allows for shims. This gives the weight more leverage at lower shift ratios, and continues throughout the shift range, I couldn’t tell you the exact amount of rpm gain or loss for a given roller size, and they shouldn’t be changed for that reason alone. This change will affect the shift pattern from start to finish. You will most certainly need to fine tune the clutch weights after a roller change. A smaller roller will allow you to run less weight at the same rpms, opposite is true for larger rollers. Im not 100% sure that you would want to go to a bigger roller if a steep helix was causing low rpms at the start, i would think you may want to try a shallower helix first, if the same characteristic persists, then try the bigger roller.
Its not something anyone talks about here, but I remember bender clutch kits that came with different rollers.
Also yamaha used to have really good clutch tuning manuals that talked about why and when you would change rollers, any yamaha dealer would have these old manuals, they even had a big poster that listed all the tuning parts that were available.

I am not trying to reinvent the wheel for anyone here, but as brent was explaining his clutching, it reminded me of what I was dealing with. The cure for me was adding a shim behind the spider.

 

[Brent68]

I believe brent got his setup to work without changing the rollers.
A smaller diameter roller essentially puts your cam arm in a higher starting position, the same as adding a shim behind a the spider of a clutch which allows for shims. This gives the weight more leverage at lower shift ratios, and continues throughout the shift range, I couldn’t tell you the exact amount of rpm gain or loss for a given roller size, and they shouldn’t be changed for that reason alone. This change will affect the shift pattern from start to finish. You will most certainly need to fine tune the clutch weights after a roller change. A smaller roller will allow you to run less weight at the same rpms, opposite is true for larger rollers. Im not 100% sure that you would want to go to a bigger roller if a steep helix was causing low rpms at the start, i would think you may want to try a shallower helix first, if the same characteristic persists, then try the bigger roller.
Its not something anyone talks about here, but I remember bender clutch kits that came with different rollers.
Also yamaha used to have really good clutch tuning manuals that talked about why and when you would change rollers, any yamaha dealer would have these old manuals, they even had a big poster that listed all the tuning parts that were available.

I am not trying to reinvent the wheel for anyone here, but as brent was explaining his clutching, it reminded me of what I was dealing with. The cure for me was adding a shim behind the spider.

Boostfever, I checked available roller sizes from Yamaha, four different sizes are available but the smallest is 14.5mm....stock size with the sidewinder. Was told roller material won’t hold up with a size below 14.5mm?

 

[boostfever]

That doesn’t give you any options does it

 

[Brent68]

That doesn’t give you any options does it

It’s a great idea. Fortunately the new helix corrected my issue. Thanks again!

 

[Fleecer]

I believe brent got his setup to work without changing the rollers.
A smaller diameter roller essentially puts your cam arm in a higher starting position, the same as adding a shim behind a the spider of a clutch which allows for shims. This gives the weight more leverage at lower shift ratios, and continues throughout the shift range, I couldn’t tell you the exact amount of rpm gain or loss for a given roller size, and they shouldn’t be changed for that reason alone. This change will affect the shift pattern from start to finish. You will most certainly need to fine tune the clutch weights after a roller change. A smaller roller will allow you to run less weight at the same rpms, opposite is true for larger rollers. Im not 100% sure that you would want to go to a bigger roller if a steep helix was causing low rpms at the start, i would think you may want to try a shallower helix first, if the same characteristic persists, then try the bigger roller.
Its not something anyone talks about here, but I remember bender clutch kits that came with different rollers.
Also yamaha used to have really good clutch tuning manuals that talked about why and when you would change rollers, any yamaha dealer would have these old manuals, they even had a big poster that listed all the tuning parts that were available.

I am not trying to reinvent the wheel for anyone here, but as brent was explaining his clutching, it reminded me of what I was dealing with. The cure for me was adding a shim behind the spider.

Well said, thanks.

 

[ClutchMaster]

Nice work! I love tuning and will probably get a standalone after the end of the this season. I currently get my fix tuning my Evo. Right now it’s running 850hp, 2.0l 4g63 but of course that’s not sufficient so I’m upgrading my turbo going for 1000hp next summer.
Be careful with high boost at lower rpm’s, that’s where your rods will start to have problems. On stock bottom ends you have to limit the boost down low so as not to damage the rods.

Have a Merry Christmas, Steveo

 

[Brent68]

Martin at Precision Sports helped me the past three days with dialing in the tune. It was impressive to see him bring the full potential out of this setup. I was amazed how much time and knowledge he was willing pass along....world class customer service!

The tune in this sled is set to maximize performance in short distances. We ran through many tests of timing, boost, and afr to arrive and the final result. From previous testing it picked up 200 rpm with the same clutching. One cool feature added is an "over-boost" function that is active for 4 seconds based on engine load. It ramps the boost from 18 psi to just under 21 psi at throttle positions above 90%. Again, boost is being measured after the throttle bodies. So these boost figures would equate to 19 psi ramping to 22 psi if you measured from the boost box like the stock setup. We ran the sled against two other sidewinders and a MoTec Doo with 3071....all on pump gas. Surprisingly, it was very close to the MoTec Doo. With to Doo getting and edge out of the hole with longer track (144X1.35) and better traction. From a roll they run side-by-side.

Happy New Year!